Controlling Boost with a Flash ECU?

[D.I.P.]

Ok so i have been out of the 3/S game for awhile and came back to find out we now have FLash ECU capabilities. I have been researching this but am a bit confused about how the Flash ECU controls Boost. I am going to be picking one of these setups but need to know the best way to go for Boost control. I don't have the stock BCS anymore what are my best options without having to use a standalone Boost Controller? Are there specific aftermarket Solenoids that can be used? Im going for maximum driveability with the car so the idea of have an OEM type application for tunning is very appealing to me.

[boosted3s]

Get a stock boost selenoid from someone parting a car.

[anyonebutme]

Contact one of the suppliers or Greg.....they'll get you squared away.

[Greg E]

Stock boost solenoid wont work with upgraded turbos. You need a 3-port.

Our boost controler works exactly like the EVO.

http://www.3sgto.org/tuning-engine-electronics-ecu-discussions/10777-chrome-v2-tech-manual.html#post211656

[NOMIEZVR4]

Have there been any further developments in this department? I would like to ditch my MBC and step up to ECU controlled boost. :) I read the link provided above, what is the hardware that's needed?

[Greg E]

http://i.imgur.com/XOKBeO1.jpg

Here is my setup installed. The harness has been modified to use the FPR solenoid as the boost solenoid. More info to come on this later.

[NOMIEZVR4]

oh nice! Please post details as soon as you can, I'd like to make the jump as soon as I can :)

Should I begin to source a factory FPR Solenoid? Were they available on all years? Only from TT's? thanks

[Greg E]

Only in TTs but they were available in all years. Get the harness for it too.

[NOMIEZVR4]

Another quick question...is there a limit to how much(or how little) boost can be run with this setup thus far? I'm not looking to run wg boost. I'm currently running 22lbs and want full control over the boost curve and would like to run as much as 25-27lbs...please advise.

[mb3000]

Subscribed for future use.

[LeRoyDL]

in for more info as i comes.

[CoopKill]

http://www.lolbrary.com/content/541/sneaking-into-the-house-after-staying-out-late-drinking-39541.gif

[NOMIEZVR4]

So I got my hands on a FPR Solenoid. What next? Should I send you a PM Greg or shall we discuss in this thread? I sold my Hallman MBC. :)

[Greg E]

Okay I'm gonna walk you thru this but its important that you realize this setup hasn't been fully tested to my satisfaction. I do not know the limitations or long term life expectancy of these solenoids! If you are willing to accept the risks then proceed!

What are the advantages to this?

The stock boost control solenoid is a simple bleeder valve which releases the air before it gets to the wastegates. It does this by opening a valve briefly to let air escape. The valve opens/closes in pulses. These pulses are defined as "duty cycle". Bleeding the air away keeps the wastegates shut longer thus giving you more boost. The problem is the stock solenoid is too small for the stock 6psi wastegate spring. Even 13Gs flow more air than the stock solenoid can bleed away.

As a result, a different solenoid is required. One that will block the airflow from the wastegates rather than try to bleed it. People have experimented with running different "pills" which aid the stock BCS by restricting airflow to the wastegates but the biggest problem with this is you also raise your "wastegate pressure". Meaning while the solenoid is shut off, your minimum boost is much higher than stock. It's also a PITA to make these pills and you have to experiment with different size ones to see what will work with your setup.

The problem with all the aftermarket solenoids out there is you can't plug them into our ECU. It'll fry the board. Luckily we have two 3-port solenoids on our cars already which will work without damaging the ECU!! Can't beat OEM equipment. ;)

First off, you can use either the FPR or the EGR solenoid. Both will work. I have no idea which one works better. Since I planned on keeping the EGR in my car, I opt to use the FPR solenoid. Both use the same style connector (which unfortunately are different than the BCS connector) and the only difference between the two are one has a cap over the upper port while the EGR has both ports facing the same direction. They both get setup in the same way.

For wiring the solenoid I hacked up the harness. All the solenoid share the same ground wire so that was easy. You just have to make sure the white wire for the BSC signal goes into your new solenoid otherwise the ECU won't be able to operate this piece. SODER YOUR CONNECTIONS!!!

This image will show you how to route the vac lines. Note that the port that goes to the y-pipe doesn't have a flared end. This isn't good for pressurized environment as it can blow off over time. I used a bit of glue on the nipple to help hold the vac line on.

http://i.imgur.com/N28XWZ4.jpg

After you get this setup it's important you test the solenoid operation. Open EVOScan, turn on your ignition (don't start the car) and connect EVOScan. Down in the custom request box at the bottom of the page, enter the request for the BCS, select repeat check box and hit enter.

http://i.imgur.com/TU5rWpx.jpg

If your setup was done correctly you should hear and feel the solenoid clicking on/off once every 6 seconds.

After testing the solenoid, its time to tune. Open up ECUFlash and immediately disable the CEL for the solenoids in periphery 2 (bit 15 and bit 9). Next you need to disable fuel cut by setting the Delay Timer to 10000ms (you'll find this in the Limits section).

Next go into the Turbo section and select Base WGDC table. Select all of the values and set them for something conservative. I usually start with 55%

Next, open the BCS Corrections table and select all the values and set them to 0. This will disable the Target Engine Load Error corrections feature so we can tune.

http://i.imgur.com/Hsdf5rj.jpg

Now, flash this to your ECU, start the motor and let it warm up completely.

Tuning is actually really simple. More WGDC means more boost/load. 0% WGDC is wastegate pressure. 100% is the most boost/airflow your setup will make. You'll need to raise/lower the base WGDC table to fine tune Load.

Tune using 3rd gear from 2500 RPMs FOOT ALL THE WAY TO THE FLOOR till redline. Datalog knock, RPM, WGDC and 2byte Load (you can log boost if you have it setup too but honesty boost pressure is a useless number now that you know the engines true airflow). The object of the game is to get those Load numbers as high as possible without knock. Remember Load = torque and moar is betta!

I typically add 5-10% incrementally during tuning. Having an RPM based duty setup like this is nice because you can regulate the turbos to operate in their best efficiency range thru-out the engine's power band. You'll keep upping the Duty Cycle and eventually start to see there will be a point that you keep raising the Duty Cycle but Load doesn't go any higher. This means you've maxed the turbo at that RPM. As a rule of thumb (especially when you're running pump gas) it's at this point you're just forcing hot air thru the motor and making it more knock prone. I usually back off the duty cycle about 5% when this point is reached (if you aren't already knocking).

I also never alter the Base WGDC (Low Octane) table. It's already set for zero which means wastegate pressure.



After you get WGDC tuned, you can then re-enable the ECU's Target Engine Load correction system if you so desire to use it (it's a nice feature). Simply re-enter the values you zeroed out in the Load Error Correction table. This table simply tells the code how much Duty Cycle to add or take away from the solenoid based on how far the actual Load is from the Target value.

Next you need to adjust the Target Engine Load tables to match the 2-byte load numbers you were logging. These values by default are set to match the HP curve of a stock VR4 so you'll need to adjust them for your new setup. Again, just worry about the High Octane Tables.

You'll notice there's an issue where you can't enter a value greater than 159 load into the tables. This is because of the 1 byte limitation. This is where the Boost Control Load Offset table comes in. It's another value which is added to the table look up to get around that limitation.

Let's say you got your turbos dialed in the way you like and this is your log for example:



*i will finish this post later

[NOMIEZVR4]

Thank You! :) I will stay tuned for the updates...Could you explain a bit more(maybe a diagram) for the wiring please?

[Greg E]

Thank You! :) I will stay tuned for the updates...Could you explain a bit more(maybe a diagram) for the wiring please?

Oh common... It's 2 wires. One black one white. The black one you don't even need to worry about. :p

Go look. If you seriously can't figure it out ill draw a cartoon for you in MS Paint. :lol:

[NOMIEZVR4]

NVM...I'm such an idiot...my car never came with the stock stuff, so please excuse my ignorance! :D haha

[CoopKill]

Advantages to this vs using lcdbc? Curious as I as most are looking to use the best solutions to date...

[TurboSinceBirth]

Has anyone ran those solenoids up to 35 psi or just 20-25? I'm looking for something with quite a bit of headroom if I replace my Hallman or Mac solenoid.

[mb3000]

Awesome, will have to give this a shot when I get the car up and running!

[Greg E]

Advantages to this vs using lcdbc? Curious as I as most are looking to use the best solutions to date...

The stock ECU will retard duty cycle based on TPS, knock and coolant temp. Being load based instead of psi based it'll adjust the airflow for temperature and Baro pressure as well as what gear you're in (if you setup the corrections properly).

Ill be honest I'm not familiar with how Anteros setup works though.

A major disadvantage is you have to flash the ECU for every change. You can't play it wit on the fly.


Has anyone ran those solenoids up to 35 psi or just 20-25? I'm looking for something with quite a bit of headroom if I replace my Hallman or Mac solenoid.

25 psi has been the max tested so far but the WGDC was still below 100%. Keep in mind you can run higher psi wastegates and thus back off the duty cycle of the solenoid.

[CoopKill]

So probably 3-5 flashes to set threshold, and no need to mess with till fuel, or parts change that would affect the tune.

[CoopKill]

One more question: Since switchable fuel maps are likely, could the boost setting be tied in to switch with the maps? I am guessing not due to needing a spare condition switch, or something of the kind, but PLEASE say yes!

[Greg E]

So probably 3-5 flashes to set threshold, and no need to mess with till fuel, or parts change that would affect the tune.

Yeah. After it's set, you can forget about it.


One more question: Since switchable fuel maps are likely, could the boost setting be tied in to switch with the maps? I am guessing not due to needing a spare condition switch, or something of the kind, but PLEASE say yes!

Yes, switchable base WGDC and target engine load maps are in the future! :)

[sergechronos]

All this information about things to come just makes your posts lately full of win Greg.

[TurboSinceBirth]

25 psi has been the max tested so far but the WGDC was still below 100%. Keep in mind you can run higher psi wastegates and thus back off the duty cycle of the solenoid.

Ok cool. I have 22 psi wastegates so it should definitely work. I wasn't sure if it was strong enough to handle it. I'll probably try it out after awhile but will be tuning the flashed ecu first after I get it installed.

[99 vr4]

I am probably the only one who has been running this setup with the STOCK boost control solenoid and has been since I started making the Clone ECU!

BUT - MILEAGE MAY VARY!

If you have 13Gs or lower and only want to run 15 PSI, then there is no need to change the solenoid!

This is not the optimum for anything over MHI 13Gs.

Let me stress this again. IF you have STOCK 9Bs or MHI 13Gs, with no other upgrades, and you still have the stock vacuum hoses with the stock Boost Control Solenoid (BCS), the ONLY thing you have to change is remove the restrictor from the nipple closest to the plug on the stock BCS (also known as the "free boost mod").

In order for this to work, the stock restrictor pill (brass pill) must be in the hose by the four way tee (this is how the system came from the factory). You also have to remove the restrictor from the stock BCS (some call this the “free” boost mod).

I run 15 PSI using 15Gs which bleeds down to 13 PSI at ~5000 RPM due to the 15Gs flowing too much air.

FYI, I am testing v2.5 of the ECU which will run the MAC, GM, or any BCS you can think of!

Brett

[striker2]

I wonder if anybody that doesnt need boost control (perhaps using an LCDBC or an N/A) would be willing to trade a VR4 ECU for my 99 SL ECU? Might have to post up in the classifieds.

[D.I.P.]

sweet write up! i'll have to run through EVERYTHING in my garage to see if i still have the FPR Solenoid. any easy way to distinguish it from the others?

[NOMIEZVR4]

http://www.3sx.com/store/catalog/stock-solenoid-pack-firewall-awd-09circle-600l.jpg

FYI...it seems the 99 harness is a slight bit different than previous years. I know for certain the 95's and below have the 6 pin harness plug(on far left), the newer cars have the 4 pin plug. The picture above is the older harness...Greg's pics have the newer harness. Don't mind the circled solenoid, its the stock BCS.

[Greg E]

http://www.3sx.com/store/catalog/stock-solenoid-pack-firewall-awd-09circle-600l.jpg

FYI...it seems the 99 harness is a slight bit different than previous years. I know for certain the 95's and below have the 6 pin harness plug(on far left), the newer cars have the 4 pin plug. The picture above is the older harness...Greg's pics have the newer harness. Don't mind the circled solenoid, its the stock BCS.

Correct. The 98/99 harness are a 4 pin plug and the 91-97 are a 6 pin.

....But the concept remains the same. They all share the same black wire and you must tap the white wire to your new solenoid.

[mjannusch]

3-port is the best way to do this and will provide the best control, so forget the old bleeder-style stock boost control setup.

[Greg E]

I'd be amazed if most people still even had their stock vac lines.

[Chris@Rvengeperformance]

on the stock restrictor pill setup the stock boost control didn't work at all on my dr750s with the drweldin springs. I checked them recently and with the pre-load matt set them up for and the heavy springs they didn't start to crack open until 15 PSI and that was the most I could run at 100% WGDC.

With the lighter springs it did have some effect, but couldn't exceed 15 PSI.

I'm sure you can fart with the stock bleeded setup, but I don't know why you wouldn't reconfigure it as greg stated if you want to run high boost with the lowest possible lag.

[99 vr4]

Well the stock system is only good for MHI 13Gs or lower. There is no issue with control or otherwise. Remember, that the stock system was designed by Mitsubishi for the stock MHI 9Bs and the Sport Upgrades aka MHI 13Gs.

This is a great way to run higher boost on an otherwise stock setup for those just starting out. There are no issues with control whatsoever if everything else is stock.

Obviously, DR750s, and my MHI 15Gs for some part, will outflow this system and you will be stuck at waste gate pressure at higher RPMs. Then of course you want a 3 port system. Whether or not you configure this as a bleeder or non-bleeder system should be determined on a case by case basis.

[Greg E]

The only thing you need to be aware of if you keep the stock solenoid/lines is that you're limited to how much max boost/airflow you can get from the turbo.

My completely stock 98 only peaked at 18psi at 100% duty cycle with the BCS rubber restricter pulled out. The turbos could have done more but the bleeder couldn't get enough air away from the wastegates to keep them closed any longer. This is probably fine for most BPU guys on pump gas, but its not gonna work for anyone looking to go beyond that.

Adding/modifying restricter pills basically does the same thing as installing stronger wastegates. You get more flow up top but also your minimum flow is increased. It's an annoying guess/check type setup that can only be catered to your individual setup.

Using a 3-port will allow you full control over the entire airflow range of the turbo from wastegate pressure all the way to max flow. The limitations to this setup aren't yet known.

[familyMAN]

You guys trying the $30 Mac solenoid? Works great on my car with AEM EMS.

[Greg E]

You guys trying the $30 Mac solenoid? Works great on my car with AEM EMS.

Yes. There is another thread about the right one that will work with our cars. I will add it to my post when I get time.

[mb3000]

Yes. There is another thread about the right one that will work with our cars. I will add it to my post when I get time.

Please do. I've got a MAC that I'm trying to sell from my EMS days and trying to source a FPR solanoid. I would love to simply use the MAC.

Edit: Here's the one I have: http://i928.photobucket.com/albums/ad128/mb3000gt_photos/Partsforsale005_zps9c2faa90.jpg

Double edit: Found the thread, appears that I have the same model that Jester was using, however still unclear about exactly what is required for use (resistor?).

[NOMIEZVR4]

Alrite...the picture on the 2nd page, where it says goes to INTAKE, are we talking about the Intake pipe? Will the nipple on the compressor housing also suffice?

[Greg E]

Alrite...the picture on the 2nd page, where it says goes to INTAKE, are we talking about the Intake pipe? Will the nipple on the compressor housing also suffice?

It has to be a vaccum only source. Anywhere before the turbos.

[CoopKill]

So the rear turbo intake pipe will do?

[CoopKill]

Also, any further info on using the MAC solenoid? I have both, but just curious.

[mb3000]

Also, any further info on using the MAC solenoid? I have both, but just curious.

It's loud as hell :lol: I had no idea what it was when I first bought my car with the AEM TRUBoost. Make sure to mount it with some rubber or something.

[99 vr4]

I have not had time to finish my testing this week on the different BCSs... So I will do that tomorrow.

[NOMIEZVR4]

So it seems with the adapter harness, the harness for the solenoid pack has no ground now. Looking at the schematics it seems I will have to switch pin 7 into 48 to make it work. I"l keep you guys posted.

[Ray]

Subscibing

[J-Groove]

It has to be a vaccum only source. Anywhere before the turbos.

And this is proving to be an important bit.

With my hard pipes I eliminated all of my vacuum ports. With no vacuum source and it running open it is unable to bleed off enough air fast enough to allow it to be as efficient as it should be. Caused me to have to swap out for heavy springs in my wategates to be able to get up to the boost I was wanting.

But I will be tapping a hole in my hard pipe to fix it, just will have to retune my boost once I do.

That said, ECU controlled boost works great, just make sure you set it up the way Greg has it pictured.

-John

[Chris@Rvengeperformance]

the other option is to get a 3/8" tee and hook it into the pcv valve thing that goes to the intake bubble.

[99 vr4]

I tested all weekend with the new beefed up hardware running a 1/2 amp GM 3 port BCS. Plenum pressure was fed to the normally closed port. The common port was connected to the waste-gates. And the normally open port was connected to the vacuum nipple near the rear turbo intake. BCS OFF, the waste-gates saw plenum pressure. BCS ON, the waste-gates were bled off by the vacuum very quickly. If you eliminated the vacuum nipple by the rear turbo, any where in that line.

There are a couple of places that draw vacuum BUT it is very easy to drill a small hole in the hard rubber of the bubble pipe and place a barbed brass fitting in there with a little rtv.

[Greg E]

You should tap into the pipe close to the turbo as possible.

[99 vr4]

Also, any further info on using the MAC solenoid? I have both, but just curious.

Coop . . . I started a thread here (http://www.3sgto.org/tuning-engine-electronics-ecu-discussions/13325-ecu-boost-control-clone2-ecu.html)to keep track of compatible solenoid.

Maps and directions coming soon!

[D.I.P.]

http://www.3sx.com/store/catalog/stock-solenoid-pack-firewall-awd-09circle-600l.jpg

FYI...it seems the 99 harness is a slight bit different than previous years. I know for certain the 95's and below have the 6 pin harness plug(on far left), the newer cars have the 4 pin plug. The picture above is the older harness...Greg's pics have the newer harness. Don't mind the circled solenoid, its the stock BCS.

Can anybody tell what color the wires i need to tap into are on the 6 wire plug? I don't have the extension that goes to the stock bcs or fpr that has the black/white wires so i need to that the wires at the 6 wire plug (although it only has 5 wires) on the vehicle harness side.

[NOMIEZVR4]

Red/Yellow and Red .

[NOMIEZVR4]

I would have posted results but by SL ecu needs to be modified to be able to do this...so its on hold temporarily..:(

[99 vr4]

On the 91 through 97 there should be 12v key on at position 2... This should be a solid red wire.

At position 5 is a red yellow wire. . This is the BCS control line.

Pos 2 and 5 are the middle pins..

Tap your BCS in to the red and red yellow line. It does not matter which is which as the BCS should not be polarity sensitive. . (If it is one of the tested BCSs it is not polarity sensitive)

Sent from my SPH-L720 using Tapatalk

[99 vr4]

Red/Yellow is the signal wire and the Red will be the ground.

Red is 12v . . . not ground... voltage comes from the MFI relay. The ECU acts as a ground switch using the control line . . . red-yellow

[Kx1984]

Came across this wondered if it was an option possibly better?

HOA Imports | H.O.A. Imports, Inc. (http://www.hoa-imports.com/products/hoa-imports/)

tactrix sells the same thing for $40 more

[Jimvr4]

I'm eventually going to do this after I get my initial timing changes worked out.

One thing I didn't see mentioned is that if you use the factory FPR solenoid you actually may not have to tap any wires. What I will be doing is UNPLUGGING the stock BCS wire from my adapter harness at the FECU end and plugging inthe stock FPR wire in its place. Thus when the ECU controls boost it actually is controlling the FPR. No tapping or soldering and looks completely stock. I still have the hardline router on top of the TB so I will just add a loop around the outside nipples for the actual FPR.

[Greg E]

The plugs for the 2 solenoids are different. You have to swap one wire. If you're clever you can get the wire out of the harness plug without needing to cut/soder. As easy as it is to swap ECU pins, that is another viable option.

[Greg E]

Came across this wondered if it was an option possibly better?

HOA Imports | H.O.A. Imports, Inc. (http://www.hoa-imports.com/products/hoa-imports/)

tactrix sells the same thing for $40 more

I have that exact solenoid (got it years ago for my EVO). It works just as well as the factory FPR solenoid except you must cut and splice the wires.

[NOMIEZVR4]

The plugs for the 2 solenoids are different. You have to swap one wire. If you're clever you can get the wire out of the harness plug without needing to cut/soder. As easy as it is to swap ECU pins, that is another viable option.

Yeah thats what I did. But never got around to sending the ecu out..:(
Maybe this spring/summer...

[Jimvr4]

That's the benefit of using Brett's ECU and the adapter harness. You can make these changes on your own :)

[Kx1984]

Greg
Ok so that will not hurt the ecu?

[NOMIEZVR4]

That's the benefit of using Brett's ECU and the adapter harness. You can make these changes on your own :)

Yeah I jumped on the bandwagon and got my SL ecu before the prices jumped..

[twinspoolin94]

I am thinking about swapping over to the fuel pressure solenoid, with that setup would I need the factory H connecter with the restricter in the line or can I run new hoses?

[Greg E]

I ran new hose for my setup (because my car was missing the stock pieces). I imagine the restricter hose would just mean you need to run less duty cycle to get the same boost.

[twinspoolin94]

I ran new hose for my setup (because my car was missing the stock pieces). I imagine the restricter hose would just mean you need to run less duty cycle to get the same boost.

I had to use the stock line with red tap with the restrictor in it to build anything above wastegate pressure. Also dont run the stock tables with this setup. I started at 30% and was hitting 14 lbs.

[Greg E]

I had to use the stock line with red tap with the restrictor in it to build anything above wastegate pressure. Also dont run the stock tables with this setup. I started at 30% and was hitting 14 lbs.

Sounds about right. 55% got me about the same psi without the restrictive pill.

[Jimvr4]

Sounds like theoretically you can run higher boost if you use a restrictor line since you'll start at a lower duty cycle. Should also be influenced by the wastegate setting of the springs / adjuster.

My current AVC-R setup with 14 PSI wastegates doesn't seem to support closed loop boost control below about 18 PSI. The AVC-R unit has a minimum duty cycle of about 25%. I'm pretty sure I can run knock free at 18 PSI with 91 pump but if not then I will probably take out the wastegates and try setting them a couple of PSI lower. My trade will be what duty cycle I need to run to max out 101 octane with the switched maps. I'm guessing at least 24 PSI will be possible.

I have to read up on ECU boost again as I plan to switch soon.

[Greg E]

I prefer not to run with a restricter pill if I don't have to because it also raises your min boost pressure.

[Jimvr4]

Greg, would you mind finishing up Post #14 in this thread? It's been months since you said you would :lo5l:

[Greg E]

Greg, would you mind finishing up Post #14 in this thread? It's been months since you said you would :lo5l:

Still waiting for the tags for my car...

[twinspoolin94]

I prefer not to run with a restricter pill if I don't have to because it also raises your min boost pressure.

I would rather ditch the pill to, but what I am saying is that even at 100%, w/o that line I run wastegate pressure. I plan to test it out more this weekend while actually logging the boost.

[Greg E]

I would rather ditch the pill to, but what I am saying is that even at 100%, w/o that line I run wastegate pressure. I plan to test it out more this weekend while actually logging the boost.

Really! What ID hoses are you running? I run 1/8".

[Jimvr4]

Actually had to retract that first statement. The stock hookup is different than post #14 since the H connector always sees Y pipe pressure and the stock BCS vents pressure back to pre-turbo intake.

I'm very tempted to just try the stock BCS. A stock setup has 7 PSI wastegates and the stock BCS is able to hold 14 PSI boost which means it can bleed off at least 7 PSI and keep the wastegates closed up to 14 PSI.

With my 14 PSI wastegates if the stock BCS can still bleed off 7 PSI I would be able to hold 21 PSI. This assumes the limitation in the stock BCS is the delta between input and output PSI that it can hold. Could be a benefit of having higher wastegate spring settings

[Greg E]

I may not have worded it correctly but no, it doesn't bleed air away from the wastegates. It blocks it from going to them then dumps the excess air back into the intake.

If you have a couple of minutes try blowing into the perpendicular port, confirm air comes out the metal nipple (bottom). Then apply 12v low wattage power across (direction shouldn't matter, a small 12v battery should be fine) and blow into the perpendicular port again. Record which port air comes out (should be the top nipple now).

When I tested this a year or two ago i found no current, blowing through the perpendicular nipple, air comes out the metal/bottom nipple. With current (12v) it comes out the top one.

If you setup the FPR solenoid like stock, you are right, it won't bleed any more air away from stock. Setting it up like I did means the WG will only see pressure when the solenoid is NOT energized.

Without the little restricter pill, your stock BCS won't be able to do any more than 8ish psi. Ask me how I know. ;) The only way I was able to get away with the whole setup BCS setup is with upgrade wastegate springs.

[Greg E]

BTW I have tested this with the EGR solenoid and got the same results. Just that the 91-95 EGR solenoids don't seem to like to be "pulsed" in a duty cycle fasion like the 96+ EGR solenoids.

[Greg E]

With my 14 PSI wastegates if the stock BCS can still bleed off 7 PSI I would be able to hold 21 PSI. This assumes the limitation in the stock BCS is the delta between input and output PSI that it can hold. Could be a benefit of having higher wastegate spring settings

In testing the FPR solenoid, there was a car running some variation of 19Ts, stock wastegates and no vac restricter pill at 23psi dynoing something around 500-510 whp.

What happened was, up until 6000rpms boost would stay solid. As redline approached the boost would slowly creep up to 25-26psi. Lowing the WGDC 20% didn't bring down the boost in this range at all. Boost would still creep up.

I suspected maybe this was the result of some physical limitation to the FPR solenoid itself. Maybe the turbos were sucking in so much air that it caused a vaccum in the intake bleeder side of the solenoid which then continued to draw air away from the wastegate line. I was never able to get this car back onto that dyno as it ran into issues with the turbos, then the motor and... You know? Car makes power, car breaks...

This was the first order of business I planned on tackling with my DR750 build but I never finished that car nor have I found any volunteers to try and recreate this scenario.

That's where I'm sitting now with this FPR solenoid setup. Below 500whp and stock wastegates, it has worked great on a few test cars so far over the last year. There's no data for this setup on cars putting down more power than that yet.

BTW: R&D like this is where all your guys donation $$ goes! None of it goes into my pocket.

[twinspoolin94]

Really! What ID hoses are you running? I run 1/8".

Same as stock, i didnt measure but held it up to each other and its the same

[Greg E]

Same as stock, i didnt measure but held it up to each other and its the same

Then there's 3 possibilities.

*your FPR solenoid is broken
*your vac lines are routed incorrectly
*your wiring for the solenoid isn't right

[twinspoolin94]

Then there's 3 possibilities.

*your FPR solenoid is broken
*your vac lines are routed incorrectly
*your wiring for the solenoid isn't right

* cant be broken, now with the stock hose it works at 30%, 50%, or 100%. Boosting higher much higher than I am tuned for so turned down until I get dynotuned
* I have them routed exactly as you have pictured earlier in this thread, just with the stock line with pill
* Its only one wire....:offended:

When I get time this weekend I am going to test it agian w/o the stock line......when I tested it before I only went right up the street, saw I was running about 8 lbs with 30% duty cycle, then went home and put stock line on. I never turned up the duty cycle until after I put the stock line back on, so that may be my issue. Now that I think about it...30 % of 6 or 7 lbs is only an increase of 1 or 2 psi......maybe it was right.....also I have noticed alot more BOV flutter especially in the mornings when the air is cool since I switched over to this method.....Im starting to think I need to revisit this.

[Greg E]

Another thing to keep in mind is this setup isn't going to go beyond the limitation of your turbo itself. You'll probably never get high teens psi in only 1st gear.

Oh and also remember duty cycle is TPS interpolated too. Meaning you won't get full boost at part throttle. Foot must be planted firmly to the floor for the whole pull.

[Jimvr4]

In testing the FPR solenoid, there was a car running some variation of 19Ts, stock wastegates and no vac restricter pill at 23psi dynoing something around 500-510 whp.

OK so boosting 7 PSI wastegates up to 23 PSI so a delta of 16 PSI was reached.


What happened was, up until 6000rpms boost would stay solid. As redline approached the boost would slowly creep up to 25-26psi. Lowing the WGDC 20% didn't bring down the boost in this range at all. Boost would still creep up.

I suspected maybe this was the result of some physical limitation to the FPR solenoid itself. Maybe the turbos were sucking in so much air that it caused a vacuum in the intake bleeder side of the solenoid which then continued to draw air away from the wastegate line. I was never able to get this car back onto that dyno as it ran into issues with the turbos, then the motor and... You know? Car makes power, car breaks...

Could it be exhaust pressure was causing the flappers to stay closed because of the weak 7 PSI springs?


BTW: R&D like this is where all your guys donation $$ goes! None of it goes into my pocket.

R&D is certainly appreciated! I might end up hitting >23 PSI on race gas so we'll see if I can help at all with determining the setup limitations

[Greg E]

Could it be exhaust pressure was causing the flappers to stay closed because of the weak 7 PSI springs?

Maybe... Usually you see wastegates blowing open under high pressures and weak springs.

What I wanted to try next was disconnecting the vac line that went into the intake to see what happened. In theory, the intake hose helps draw air out of the solenoid itself so it doesn't go to the wastegates. One of the things I wanted to experiment was just letting it vent into the engine bay to see if the boost changes under the same duty cycle. My $$ is on that it drops.

[twinspoolin94]

looks like I was mistaken. You dont need the stock line. boosts just fine with the duty cycle turned up.

[twinspoolin94]

Just wanted to give an update, ran the fuel pressure solinoid for a few weeks. It worked great until the other day.....It would be fine for the first half of my drive to work then i would notice that I couldnt build anything more than wastegate pressure. Could be the solenoid going out so I ended up going back to the stock setup.

[Greg E]

Just wanted to give an update, ran the fuel pressure solinoid for a few weeks. It worked great until the other day.....It would be fine for the first half of my drive to work then i would notice that I couldnt build anything more than wastegate pressure. Could be the solenoid going out so I ended up going back to the stock setup.

Doesn't surprise me. These things are 15-20 years old....

[Jimvr4]

Doesn't surprise me. These things are 15-20 years old....

Me either. I've already replaced a bad EGR solenoid a few years ago.

[Jimvr4]

I'm going to revert my WG springs to stock to see if that fixes my boost spike. Then I plan to proceed with the ECU boost setup.

[CoopKill]

Timeline on that Jim?

Sent from the Man Cave!

*\( ^o^ )/*

[Jimvr4]

Timeline on that Jim?

Sent from the Man Cave!

*\( ^o^ )/*

Thought I would get to it today but preempted by events. Hopefully tomorrow :lo5l:

[futurevr4man]

talked with gregory about this today. 2nd to last post is a bit disheartening. i may need to aim for an aftermarket solenoid.

for people that are blow thru, is it best to just grab a vacuum source from one of the turbo intake pipes? i cant think of anywhere else that has a good vacuum signal

[Chris@Rvengeperformance]

The vacuum hookup isn't necessary. I ran the vacuum line open when I was using ecu boost.

Sent from my RM-845_nam_vzw_100 using Tapatalk

[futurevr4man]

The vacuum hookup isn't necessary. I ran the vacuum line open when I was using ecu boost.

Sent from my RM-845_nam_vzw_100 using Tapatalk

:ORLY:

ill mess with it later. need to see if I threw out my BCS bracket and stuff. Might get a FPR solenoid and just make something

[Jimvr4]

I've made the switch to ECU boost today. Went with the FPR solenoid and used the restrictor hose in the wastegate path. Went with a wire swap at the ECU harness for the control. Set if for 25% duty since I have 14 psi wastegates and it pulled right at wastegate level (I'm still logging boost). I did a couple of 2nd gear pulls and turned it up to 40% then 55%. Then I went to the highway for some 3rd gear pulls. Highest load I saw was 207 at 4400 rpm and falling off after that. AFR at 10.6 and no knock. That's all I had time for. BTW the boost at that load was reading around 19 psi and the IDC was reading about 78%.

Boost and load are far from flat across the RPM range with a flat 55% duty cycle. Correct me if I'm wrong but I think the initial goal is to crank up the duty cycle at each rpm until knock is detected and then back off. So try to figure out the max load per rpm by adjusting the duty cycle. Correct? This looks like it will take quite a few runs and flashes to adjust.

So following post #14 the next step is to enter the target loads that I came up with (and using the offset to overcome the 1 byte load limitation). Then what ??

[Greg E]

Then you're done. Leave it alone and never worry about it again.

You will have a funky base WGDC map to get a flat boost curve. Some RPMs will be higher then others oscilating up and down 5% or so. This is normal.

[futurevr4man]

yeah, boost nor load should stay flat across the RPM range.

[CoopKill]

So to clarify Jim, You kept the Weldin springs in, and went ecu control which fixed the spiking?

[Greg E]

yeah, boost nor load should stay flat across the RPM range.

No. It'll flutter up and down a couple psi.

Jim, I just noticed you put the pill between the solenoid and the wastegates. You should put it between the y-pipe (or where ever your boost source is) and the solenoid.

[familyMAN]

Is anyone using a MAC bcs? They are only ~$30 and work really well with AEM.

[Greg E]

Is anyone using a MAC bcs? They are only ~$30 and work really well with AEM.

Need an EE guy to tell me if the resistance of the solenoid will damage the ECU or not. I used to remember the resistance for the stock solenoids but that was a long time ago now.

[mb3000]

^Didn't we have an entire thread about that? :lol:

[Greg E]

^Didn't we have an entire thread about that? :lol:

I don't believe the proper resistors setup was posted to make those solenoids work.

[CoopKill]

I thought that the newer hardware was equipped to use them?

Sent from the Man Cave!

*\( ^o^ )/*

[Jimvr4]

Then you're done. Leave it alone and never worry about it again.

You will have a funky base WGDC map to get a flat boost curve. Some RPMs will be higher then others oscillating up and down 5% or so. This is normal.

What makes the ECU start using the target loads and self correcting?


So to clarify Jim, You kept the Weldin springs in, and went ecu control which fixed the spiking?

Still have the Weldin springs at 14 psi. I think boost overshoot was because of downshifting into boost. I also fixed a leak at the EGR pipe.


No. It'll flutter up and down a couple psi.

Jim, I just noticed you put the pill between the solenoid and the wastegates. You should put it between the y-pipe (or where ever your boost source is) and the solenoid.

Yeah I got lazy because my other hose wouldn't reach the FPR solenoid output. Might need to get some vac line to fix it.

[Greg E]

The corrections table. The left side (the load error side) is the difference between the target and the actual load. The right side is how much it adds or takes away from the base WGDC table look up.

[99 vr4]

The ecus that I have built will work with the mac...

Yes I am alive. ..

Sent from my SPH-L720 using Tapatalk

[Greg E]

The ecus that I have built will work with the mac...

Yes I am alive. ..

Sent from my SPH-L720 using Tapatalk

Yes but the ones you didn't won't nor will any of your old ones.

[Jimvr4]

Jim, I just noticed you put the pill between the solenoid and the wastegates. You should put it between the y-pipe (or where ever your boost source is) and the solenoid.

Fixed it (stock FPR line would reach). WOW!! 55% duty and 14 psi WG and she pulls extremely hard :eek2:

Took her for a spin last night without the logger but my boost gauge said I hit 1.67 bar (around 24 psi). I never saw the knock cel but I felt the POWA!

I'm starting to think I'll hit 500WHP with the 101 octane. The car will be a total sleeper when I remove the AVC-R unit from the cabin. Even the engine bay has no signs of more than stock power. All you see is some stock pipes chromed and a K&N intake. The exhaust isn't too loud either if I close the cutout.

So almost there! Need to make a bunch of runs and dial in the duty cycle now.

[Greg E]

Sleeper cars FTW!!

[NOMIEZVR4]

Phuck...i want in...Brett..can you shoot me a PM back plz..:)

[Jimvr4]

Damnit ! Fun was cut short today. First pulls with 55% duty were breaking up so I dropped down to 50% and she ran clean but that was about 4 psi lower (22 vs 18 psi). 55% was knocking 10-15 counts at 4500-5500 rpm so I pulled the duty down to 50% in that range. Then she still knocked above 5500 so I went with 55% up to 4000 and 50% from 4000 on up. She pulled clean but my boost gauge inside the car said I only hit 0.89 bar. That's wastegate boost so something was broken.

Got back to the garage and tried the BCS actuator test and could not hear any clicking. Pulled off the solenoid and it has about 24k ohms resistance :(

Not sure if the FPR solenoid is up to the task of operating in a duty cycle mode since that is constantly switching the solenoid. I believe the solenoids have to be designed specifically to survive this type of use because of the contact wear, etc. A standard solenoid would be good for not more than several thousand cycles.

I believe the 99 model purge solenoid is designed for duty cycle operation so I think this is what I need to use.

[Greg E]

Damn. That's unfortunate.

Believe Adam is the longest running FPR solenoid user but he doesn't drive his car a whole lot these days.

...and all EGR solenoids are a duty cycle type setup. The top nipple is just turned 90 degrees vs the FPR solenoid which is capped.

If i remember they all take the same plug too. I ran them in my testing over a year ago now and it operates just the same. The reason I pushed the FPR solenoid over the EGR is its in every year car 91-99.

The purge solenoids in the 98/99 solenoids are very different than the older gen ones just FYI.

[Jimvr4]

Weird. Went back to the bench and the solenoid reads a stable 40 ohms. Put it on the car and went for coffee with copilot and boost was there again. WTF?! I wonder if temperature is a factor

[NOMIEZVR4]

This is great test data. Thanks

[CoopKill]

^^ Agreed!

[99 vr4]

Was the solenoid hot? Heat should not effect the resistance THAT much. .. But your original thought of a burned coil due to duty cycle seems more plausible. A burned coil could short out across the open. . And then act open again. I would keep an eye on this solenoid. .. It still might be bad but intermittently.

Sent from my SPH-L720 using Tapatalk

[Greg E]

Looks like my FPR solenoid is also dead. Going to dig out the EGR solenoid and swap it.

[familyMAN]

Mac ....

[Greg E]

Mac ....

What resistors do I need to keep it from frying the ECU?

[Jimvr4]

FPR was 40 ohm. Just add resistance as needed if MAC is less. Check wattage ratings though. My FPR failed again yesterday too :(

[Greg E]

My FPR failed again yesterday too :(

Seemed like mine was just dead the moment I drove out of the garage. Cool engine and everything.

[familyMAN]

What resistors do I need to keep it from frying the ECU?
Not sure, but I'm giving you a an option to "keep from frying solenoids."

Brand: MAC
Part number: 35A-AAA-DDBA-1BA
Type: 3 port solenoid , this is the most common method to control Boost. 4 Port also available.
12 volts
5.4 watts ,25.4 ohm coil (measured), .45 Amps@12 volts
Full vacuum to 120 psi capable.
10-30 hz compatible, other ranges suitable depending on application.
PWM driven (Pulse width modulation)


Mac has so many valve options, you can probably find one that has the correct resistance to match what you need.
35 Series (http://macvalves.com/valves/3-way-valves/35-series/)

[familyMAN]

Greddy Solenoid & ECU control? - evolutionm.net (http://forums.evolutionm.net/ecuflash/368372-greddy-solenoid-ecu-control.html)

"Here is a picture of my MAC solenoid with a Weather-Pak Connector on it.
If you replace your stock boost solenoid with this you will need to install a 3 watt 10 Ohm resistor in line with the solenoid."


"You can measure the resistance across the solenoid to see how far it is from stock then you will know what kind of resistor you will need to add. I think the stock resistance is 35ohm, so if your solenoid is 25ohm, then you just need a 10ohm resistor with 3 or more watts."

[familyMAN]

BCS testing data - evolutionm.net (http://forums.evolutionm.net/ecuflash/379043-bcs-testing-data.html)
"Effect of Series Resistor Value

Its become the standard to use a 10 ohm resistor in series with the GM solenoid to bring the circuit resistance up to the resistance of the stock solenoid. However, adding a resistor slows the rate at which a solenoid can open as shown in the latency results earlier. Pressure at the "WGA" was measured with the GM and Prodrive solenoids tested with 1 ohm, 5 ohm, and 10 ohm series resistance value at 20 Hz (stock operating frequency). A near-stock size pill was used at the "compressor" for these tests. The effect of resistance on the pressure vs duty cycle was minimal with the higher resistance causing higher pressure in the mid-duty cycle range due to the higher latency. The results are shown in comparison to the stock solenoid. At 30 Hz, a similar result was obtained except that the Prodrive solenoid was too slow to operate at 30 Hz when a 10 ohm resistor was used. My feeling is that a 5 ohm resistor with the GM and Prodrive solenoids is a better choice than a 10 ohm. 5 ohm still brings the overall circuit resistance to within stock specification range while keeping the latency lower."

A ton more testing available on this link on pressure, duty cycle, etc.

[familyMAN]

So, do you know the resistance of the stock you are trying to make work? The mac is 25ohm.

[Greg E]

Not sure, but I'm giving you a an option to "keep from frying solenoids."

Thanks for the info. MrFred from the EVO community did a number of tests on several aftermarket solenoids one of them being speed and resistance. The GM solenoid was the fastest followed by the MAC. All the aftermarket solenoids can be made to work. (Edit: looks like you posted that while I was typing up this post)

The idea behind "frying solenoids" is to test if any of the stock solenoids that we all throw away will work. The major advantage to them is the cost (free) and the resistance is the same so they can be plugged directly into the BCS input and not fry the ECU.

That's not to say the cost is worth the $$ saved. Just that this isn't something that's ever been done before and I'm really curious. :)

[familyMAN]

Mac is $30. Works awesome. A bit loud though so mount it on something rubber so it doesn't sound like you have rod knock when it clicks through the chassis. If the FPR is 40ohm like stated before and mac is 25. Add 15 and good to go, if I am reading all of this correctly.

This took less than 10 mins to find. If you guys weren't so hung up on reusing stock this would've been solved months ago and Chrome would be that much better. Ecu boost control is the cats meow.

[familyMAN]

Bracket Only for Boost Solenoid Valve BCS Mac 35 Series Turbo PWM EMS ECU BCS | eBay (http://www.ebay.com/itm/like/231041810016?lpid=82)
http://i.ebayimg.com/00/s/MTM4N1gxNjAw/$T2eC16dHJGIE9nnWrc1rBP+OlpI)DQ~~60_57.JPG

Use this. Much cleaner than the one I hacked together because I didn't know this existed.

[Greg E]

Mac is $30. Works awesome. A bit loud though so mount it on something rubber so it doesn't sound like you have rod knock when it clicks through the chassis. If the FPR is 40ohm like stated before and mac is 25. Add 15 and good to go, if I am reading all of this correctly.

This took less than 10 mins to find. If you guys weren't so hung up on reusing stock this would've been solved months ago and Chrome would be that much better. Ecu boost control is the cats meow.

Yes I'm familiar with the noise. Ran one on my EVO back when the concepts were first introduced. You might even find a post or two from me in those threads back then. That same solenoid I used in my EVO back then is in my garage now waiting for its turn in line to be tested.

You'd think that someone who went thru all the effort of swapping in a DSM motor for the cost effectiveness and originality would have a certain understanding and appreciation for the efforts taken here. I'm sorry that Chrome isn't on a level to compete with the rest of the flash ECU setups yet. Sure you can blame me for that, but the code for controlling boost with the ECU has been available since Chrome V1 came out 3 years ago and that no one cared to use it. There's a pattern with this setup in this particular community where it seems if I don't do it first, no one will try it. Case in point, no one really used chrome till I took my 98 to the track and showed before/after results with it.

[NOMIEZVR4]

damn man...you're on a roll....

helping us 6g guys out...haha..;)

[Jimvr4]

From the MAC BCS thread:


Brett, Thanks for sending the datasheet for the MOSFET.

I don't have the circuit to look at so I'll make an assumption. The assumption is that the circuit controls the FET using a 0V / 5V switch from a register or similar. This voltage drives the Gate of the FET. The FET has its Source grounded thus the FET is turned on when VGS is at 5V and the FET is turned of when VGS is at 0 volts.

Now if this assumption is correct, the solenoid is connected between the Drain and Battery. When the FET is turned on (VGS=5V) the Drain voltage is forced close to the Source voltage. If the coil resistance is low enough then VDS will approach the minimum which is 0.7 volts. Now with the battery voltage running near 14.5V the solenoid will see 14.5-0.7 or 13.8 volts across it and it will be energized. When the VGS is switched back to 0V then the Drain voltage will float high near battery voltage and the solenoid will be off. Note the ON resistance for the FET is approximately 0.3 ohms when VDS is at 0.7 volts.

Now for power handling. In the energized case we have 13.8V across the solenoid. Let's assume the solenoid has 34.3 ohms resistance, then the current is 13.8/34.3 or 0.402 Amps. So, the coil itself has a power dissipation of 13.8*0.402 or 5.5 Watts. But, the MOSFET power is not nearly that high. It's power drain is I^2 * RON which is (.402)^2 * 0.3 or .05W in this case. The absolute max power handling is 2W on the datasheet and we have to derate it to 60% at 60 degrees C which is still 1.2W continuous. I haven't even considered this is a pulsed application which uses even less power.

Let's look at a solenoid of only 20 ohms. For this low resistance the current is 0.69 amps. Coil now draws 9.52 Watts but the FET only has 0.143 Watts. Bottom line is the FET's very low ON resistance is making sure that the FET is never stressed for delivering power to the coil.

We only need to worry about the solenoid power handling itself, not the ECU FET driver circuit.

BTW if anyone cares, the Apexi AVC-R solenoid has 35.1 ohms resistance. It is a perfect choice for the boost solenoid. It's probably a relabeled MAC solenoid.

I still claim the FET can handle the MAC solenoid safely without resistors. No charging / discharging delays then either :)

[Greg E]

damn man...you're on a roll....

helping us 6g guys out...haha..;)

http://www.3sgto.org/tuning-engine-electronics-ecu-discussions/11497-mac-bcs-revisited.html

This discussion is over a year old now. No one ever tried the MAC valve.

[Greg E]

From the MAC BCS thread:



I still claim the FET can handle the MAC solenoid safely without resistors. No charging / discharging delays then either :)

The ports on it are larger too than any of the stock solenoids.

[familyMAN]

Yes I'm familiar with the noise. Ran one on my EVO back when the concepts were first introduced. You might even find a post or two from me in those threads back then. That same solenoid I used in my EVO back then is in my garage now waiting for its turn in line to be tested.

You'd think that someone who went thru all the effort of swapping in a DSM motor for the cost effectiveness and originality would have a certain understanding and appreciation for the efforts taken here. I'm sorry that Chrome isn't on a level to compete with the rest of the flash ECU setups yet. Sure you can blame me for that, but the code for controlling boost with the ECU has been available since Chrome V1 came out 3 years ago and that no one cared to use it. There's a pattern with this setup in this particular community where it seems if I don't do it first, no one will try it. Case in point, no one really used chrome till I took my 98 to the track and showed before/after results with it.

I have no distaste for Chrome whatsoever. With the options in one package, once ecu boost is solved, not sure why anyone would go piggyback at this point unless it's just safc for some 13gs and 450's.

I couldn't even begin to comprehend putting together Chrome from scratch. I don't understand though how you could put it all together in a package, but couldn't take 5 mins to find the info about a simple solution to what some of Chrome's biggest advocates are asking for. Then every time I mention a cheap alternative to what you guys are trying to hack, you give attitude. And now you tell me you were even in those threads I posted. So why didn't you post them yourself? or is it one of those, "I have forgotten more then you will ever know" scenarios?

Chrome is awesome. So is standalone. In some situations, one will be clearly better than the other for a person's goals. In other situations, it will be a wash. Neither is the best for everyone. I can understand that. Can you?

[Greg E]

I have no distaste for Chrome whatsoever. With the options in one package, once ecu boost is solved, not sure why anyone would go piggyback at this point unless it's just safc for some 13gs and 450's.

I couldn't even begin to comprehend putting together Chrome from scratch. I don't understand though how you could put it all together in a package, but couldn't take 5 mins to find the info about a simple solution to what some of Chrome's biggest advocates are asking for. Then every time I mention a cheap alternative to what you guys are trying to hack, you give attitude. And now you tell me you were even in those threads I posted. So why didn't you post them yourself? or is it one of those, "I have forgotten more then you will ever know" scenarios?

Chrome is awesome. So is standalone. In some situations, one will be clearly better than the other for a person's goals. In other situations, it will be a wash. Neither is the best for everyone. I can understand that. Can you?

Poor attitude begets you poor attitude in response. When you come in all "why are you wasting time with stock crap, just use this" and "if you would have just used this, your product would have been better" tends to rub me the wrong way. My question of "do you know the resistance" was to see if you have read up on it.

There's been a lot going on behind the scenes with alternative MAFs wired directly into the ECU. Been sharing a lot of that with Ray. During our last talk he asked me, "why are you wasting so much time trying everything under the sun to see if it works". The reason is I am doing my homework. When I'm finally ready to release the next version of Chrome (be it with my own custom MAF or just using what's available) you're going to read a novel of information about all the details into how and why the setup I used was the "best". All the gains and drawbacks of every setup so that the user can best choose what suits them.

You can't argue that this platform is cheap. There is an over whelming demand for things that are simple, plug and play and cheap! Yes, users will choose to use stock parts because $30 isn't worth for them to spend. Especially if they have to hack wires to use it when the free solution plugs in and works just as well.

It takes a certain kind of open mind thinking to do what I've done with chrome. Some people just don't understand why I do the things I do till the results are there. Hell, years ago Brett made fun of me for even "wasting my time" with ECU controlled boost. On the flip side, I'm sure you didn't appreciate the critisim in your 4G64 thread. Please don't be a hypocrite and bring that attitude into mine.

[familyMAN]

I actually don't care at all about the criticism in my thread and I think my posts on this forum on the subject reflected that. I did it because I want to. Couldn't care less if someone does or does not like it. Only time I was annoyed was on the other forum when someone kept asking the same questions that had been answered already and even directly to him.

You didn't answer my direct question to you. You don't have to answer, I'll leave your thread. Please stop following behind me in both forums when I have been answering questions about standalone benefits or that it isn't as hard as people make it out to be (especially with series2). If you want to compete head to head with standalone on options, it needs to be better. You cannot say it will do all things for everyone based on things you are going to implement. Only on what's available now. Please read my last paragraph you quoted again as I unsubscribe from this thread (I'm sure nomie will let me know when he finally fires up ecu boost). That paragraph succinctly summarizes exactly my opinion on the tuning options.

I've said it before and I'll say it again. Congrats on a great product. You should be charging for it.

[Jimvr4]

Appreciate what each of you is saying but let's get this back on topic. Went to the garage this morning and my FPRS reads 40 ohms again. I'll probably buy a new one and put it back to the FPR function as before. Yesterday I had a hot start problem and read that the FPRS function relates to preventing that issue.

[Greg E]

You didn't answer my direct question to you. You don't have to answer, I'll leave your thread. Please stop following behind me in both forums when I have been answering questions about standalone benefits or that it isn't as hard as people make it out to be (especially with series2). If you want to compete head to head with standalone on options, it needs to be better. You cannot say it will do all things for everyone based on things you are going to implement. Only on what's available now. Please read my last paragraph you quoted again as I unsubscribe from this thread (I'm sure nomie will let me know when he finally fires up ecu boost). That paragraph succinctly summarizes exactly my opinion on the tuning options.

I'm confused. Seems you have mistaken me for someone else or have completely misunderstood something I've posted somewhere. Can you please link me to said post about standalones (for that matter why this topic is getting dragged into here out of the blue). Seems you have some nagging issue with me on another topic that needs to be worked out. Maybe via PM is a better place to do that.

You asked me multiple questions in your last post but I think the one you're asking an answer for is "why did you ask me a question you already know the answer to?"

It's because the topic of the MAC has been discussed multiple times for a year and a half. It's almost been beat to death and always ends the same. No one has tried it yet (its #4 in line for me to try after the EGR valve. Stock BCS was #1, FPR was #2). The information is out there for someone to do it, just on one has for whatever reason. Since you decided to reintroduce the topic, I thought i would skip ahead to where it always gets left off.

My apologies if this has somehow rubbed you the wrong way. Such actions were not my intention. Hope this clears things up.

[familyMAN]

PM sent. Re-unsubscribing. Group chant.....Ecu boost. Ecu boost. Ecu boost. :D

[Greg E]

Appreciate what each of you is saying but let's get this back on topic. Went to the garage this morning and my FPRS reads 40 ohms again. I'll probably buy a new one and put it back to the FPR function as before. Yesterday I had a hot start problem and read that the FPRS function relates to preventing that issue.

There have been many many theories about this discussed over the years about why its there. I can't remember all of them but lets look at its function. The FPR solenoid is just a 12v on/off switch (which when energized) blocks off the vac source from the throttle body to raise the pressure. More pressure means more spray into the motor.

What's odd is, you can get more spray into the motor with more/less IPW during startup. The stock ROM has a coolant temperature based IPW lookup table. Seems kinda pointless to have both a hardware and a software setup for this....

I was curious to find out if the OBD1 3/S ECUs had this. Since I didn't have a 3/S ROM to look at, I turned to the OBD1 DSM disassembly. Found out, that ROM doesn't have a table look up for start up IPW. It's just a fixed IPW any time the starter switch is triggered. So assuming that logic bled over to the 1G 3/S (like most everything else does) the FPR solenoid made sense.

So why is it still on our cars after a software solution was developed? I believe that has to do with simple budgeting economics or (more than likely) the engineering team just didn't think to remove it. Classic example in large businesses where the left hand doesn't know what the right hand is doing.

There's examples of this every where in the car. Like FIAV in the throttle bodies for instance... Another is the Active Exhaust input/output pins on the 98/99 ECU. Yes it's still there and its even coded!! This is why you can take a flash ECU and plug it into a 91-94 car and the AE still works. In Chrome V2, I rewrote it to function like stock but take up less spare in memory and be easier to use. Even though you couldn't see or edit the tables in Chrome V1, it was still there and worked like stock.

Based on this information, I concluded that the FPR solenoid should be tested first as its function doesn't appear to be needed at all.

Some people theories it was there to aid in the delay to build pressure from the pump not activating till the engine is already cranking. To squash that theory, I added the Chrome mod - Fuel Pump on Clutch. This activates the pump when you press the clutch instead of waiting for the stater switch.

I never experienced any hot start issues with all 3 of my cars so I was never able to prove the mod did its job but there were many other useful features it could be used for (like easy testing fuel systems for leaks or even for a dead fuel pump) so it seemed like a great add-on.

In the case of your hot start hick up Jim, we can probably fix that with a simple tweak to the start up IPW tables. Are you still running stock values in that table?

[Jimvr4]

Good to know. Hot start issue was a one time thing but made me realize I might not be that smart running around without basic tools in the trunk.

FPRS tested out at 40 ohms again so went for a run and she boosted hard a couple times then nothing. Back in the garage she measures open circuit now whereas she was 10's of kohms before. So probably gone for good now. I do think a new FPRS will not handle the cycling and heat loads over time so do think we need alternative recommendations for the solenoid.

I measured the stock BCS at 48 ohms. My AVCR solenoid is 36 ohms and I don't really want to buy the MAC.

My AVCR solenoid was hooked up with the Common and NO ports and hosed between the Y pipe and H. The NC port vented to atmosphere which was fine. I don't think there is any need to route that back to the turbo intake hose. I really liked how the FPRS hosing looks so stock. Maybe the EGR type solenoid can be mounted in the FPRS position. If it can then I might buy a new one of those.

*EDIT*

I'm going back to post 76 and trying the stock BCS since I have upgraded WG springs. I only plan to run up to 24 PSI on 101 octane and the WG springs are at about 14 PSI already.

[Chris@Rvengeperformance]

I guess it is off topic, but I have a lot of weird hot start crap going on with my setup. Sometimes the car goes out to 17:1 for a bit while warming up after a hot start, sometimes it will chug rich for a bit and then idle 14.7:1 until I start letting out the clutch, then it idles 9.6:1! Sometimes its fine, you never know what its going to do really.

I have tried everything to tune it, but I'm wondering if this injectors just blow ass.... Should have gotten id1000s...

[futurevr4man]

Chris,

I have had hot start issues with my car since chrome (I think I had them before chrome too, but it was too long ago for me to remember). However, I can't blame chrome because my buddy with 16t's and 550's on a stock ECU with an SAFC2 has hot start issues too. I know of quite a few VR4's with hot start issues actually... most of which aren't running chrome. I have always wanted to questions Greg about it, but he has a lot of other things on his plate...

[Jimvr4]

Just checked all my 95 model solenoids. Only the FPR is a 3 port. The EGR is a 2 port with 40 ohm coil and the purge is a 2 port. I went to measure it and it is open circuit. Probably explains why I never heard the clicking when I first converted to the flash ECU. I know the 99 model uses a duty cycle purge and I think the 95 does not so again the cycling probably killed it as it has done the FPRS.

So if a stock solenoid is to be used it will have to be a 3 port duty cycle type. I believe those are only on the 98-99 models. Otherwise a MAC or equivalent is needed.

[Chris@Rvengeperformance]

I need to correct myself. It is *warm* starts. Cold starts are fine. If the car sits under an hour it is fine, but if it starts being multiple hours, but less than say 5-6 it has issues.

I suspect it has to do with the fact that the engine coolant temp is not a good tracker of what it is really like in the intake manifold. Either that or these injectors drip a bit while sitting off.

I'm sure the stock FPR doesn't help because the pressure at startup must be really high.

[futurevr4man]

I thought mine was the FPR too, but then when I put in my new fuel system, nothing changed. And it is the worst for me if it is hot starts... like drive a few hours away, turn it off to get gas, then when I go to start it up, it is all over the place unless I keep my foot slightly on the gas (1500 - 2000 rpm). It is annoying.

[Chris@Rvengeperformance]

I thought mine was the FPR too, but then when I put in my new fuel system, nothing changed. And it is the worst for me if it is hot starts... like drive a few hours away, turn it off to get gas, then when I go to start it up, it is all over the place unless I keep my foot slightly on the gas (1500 - 2000 rpm). It is annoying.

I had that with my old 1G, but my car fires up perfectly after sitting for just a little bit.

with the problem you have increasing the target idle and cranking ISC counts may help. I couldn't get mine to fire when sitting for an hour without using the gas pedal until I raised the cranking ISC A LOT. I know it is a kluge, but its better than the alternative.

[familyMAN]

Greg and I were just discussing this. Thanks for the call:D :cheers2:.

AEM does the same. I bump up my fuel enrichment at 122*F intake temp and up to compensate for the lean condition on a hot start when the engine is heat soaked. My intake temps when in boost stay below 110 anyway unless I am out of my turbo efficiency range. (Can't say this strategy would work for AZ where ground/ambient can be 120+) Somewhat counter-intuitive since you should remove fuel for less dense air. I know on the 6g my rear rail would boil fuel. I don't hear it boil on the 4g but the whole head, intake, rail, fuel is all heat soaked possibly making the fuel less dense.

edit: I don't have a hot/warm start problem. Just a lean idle condition when heat soaked which is managed by the fuel enrichment. (Just posted two vids on other forum of a cold and hot start with AEM, which seems to be the biggest complaint for standalone users.)

[Greg E]

Just checked all my 95 model solenoids. Only the FPR is a 3 port. The EGR is a 2 port with 40 ohm coil and the purge is a 2 port.

For some reason I thought 94-99 EGR solenoids were 3 ports. Looks like that's wrong.

This is a picture of the 3-port EGR off my car.

http://i.imgur.com/dKsJjtq.png

[Jimvr4]

I reverted back to stock BCS and hooked the FPRS back to stock hosing. It's not doing anything though until I get a new one. I went out and did several pulls, first few in second gear to see where the duty cycle was. I needed to raise it quite a bit over what I had with the FPRS. Currently I'm up to 70% duty and pushing about 16.5-17 psi. The wastegates crack open around 12 psi. With that I'm hitting a peak load of about 185 at 4000 rpm. Not yet at the loads I was able to hit when I last used my AVC-R boost. The power feels very smooth with the ECU boost though. Knock still zero but if I wind out 3rd and shift 4th into boost I'm hitting higher loads and getting some 8-10 counts.

I think the boost could be raised higher before 4000 to help spool and after 6000 to maintain the higher loads until redline. Seems like it doesn't make much sense to raise boost where timing drops down to 10 or so.

Anyway it looks to me that the stock BCS has enough duty left to get into the 22-24 psi range before it maxes out. I'm not sure I can get there with the 101 octane.

[Greg E]

The more restrictive of a pill you run, the more boost you can get with less duty cycle.

[Jimvr4]

I might have the restrictor line in the wrong spot again. Need to check

[Jimvr4]

Line is good. Did I mention I hit 422whp with the stock BCS :D

[Greg E]

Drive around today with the EGR solenoid controlling the boost. Didn't even need to retune and it works like a champ. :)

[familyMAN]

How low and how high of a duty cycle have you tried?

[Greg E]

0 is wastegate pressure. I'm at 76% tapering down to 50% at redline. This gives me 17psi peak down to 9 at redline. No knock. 93 octane.

No restricter pill either. :)

[Greg E]

The results are going to varry based on AITs and setup of course. My car is stock turbos, actuators and BPU mods (intake and exhaust)

[Greg E]

Jim, over the weekend I did a vac reduction on a 94 stealth and the guy let me keep all the parts I took out. One thing I found was the purge solenoid (the one right next to the stock BCS) takes the same connector, has the same shape and resistance as the BCS. Unlike the EGR and BCS solenoids though, the ports are 1/16" larger meaning it should be able to bleed away more air.

If you're feeling bored, I anticipate with your restricter pill that it will work better than the stock boost solenoid. For testing, you can just swap vac lines between the neighboring solenoids. This would still keep your purge system active. Don't forget you can pull out the rubber restricter in the lower nipple of the BCS too for additional airflow.

[Jimvr4]

If you're giving me your newly acquired purge solenoid then I accept lol. Mine is burned out probably from duty cycle use. Didn't check the BCS as I though that restrictor was only a first gen thing

[Greg E]

For some reason I thought the 94+ purge solenoids were duty cycle based. I could send it to you if you want it but if its just going to die like the FPR solenoid did then its probably not worth it.

After NG (hell maybe at NG) ill play with the MAC solenoid. You guys are absolutely sure a single 10ohm resister is all I will need? Guess I can sweet talk Adam into fixing my board if I fry it from I stalking the solenoid without the resistor.

[Jimvr4]

Yeah I think I'll need a 99 purge solenoid (duty cycle type) if I want that function to work and survive. No sense in getting the 94/95 purge solenoid and killing it. I did order a new FPR solenoid for about $50 from Cherry Hill. Only reason I did it was I read that it ensures you don't pull vac on the FPR during hot starts.

Regarding the MAC - I would be shocked if you hurt the ECM with it. Brett sent me the FET driver datasheet and honestly you couldn't hurt the FET unless you had a direct short across the solenoid coil. Same risk as with a stocker. IMO the 10 ohm resistor is completely unnecessary.

[Kx1984]

so the FPR solenoid doesnt hold up?

KX

[Jimvr4]

Got some more ECU boost runs in this morning. I've been using the stock BCS in conjunction with my 12 psi DrWeldin wastegates which has proven to be a good combo. I had started at 70% duty across the board and then looked at the stock tables which had 100% up to like 3500rpm so I went with 100 up to there and then 75%. I worked it up to 80% and got some 10 counts of knock above 6500 on one out of three runs. In four runs I had 425, 431, 448, and 449. The highest run was the one that had some knock above 6500 but the second highest run was made with 75%. There appears to be a 1-2 psi difference between them but almost the same power. So I conclude that I've found the limit for my setup on 101 octane which is right about 450whp. This is on the EVO399 and stock SMIC.

Looking at the logs I see that the airflow seems to be maxing out around 2200 Hz on the EVO399. It stops climbing and flattens out on most of my runs. I'm thinking I must be hitting the flow limits for the EVO as well as IAT limits from my SMIC. I have the MAFT+3.75 ready to go in but I may wait until Oohnoo has those upgraded SMIC ready.

Until then I plan to look through my data to figure out what the target loads should be and then setup the closed loop boost correction for the target loads. Then I have to put in some 91 and rinse and repeat since I'm taking the car on a 1000 mile trip in 2 weeks.

[CoopKill]

450 limit on the evo maf?

Sent from the Man Cave!

*\( ^o^ )/*

[Greg E]

You're getting close to the phantom knock HP border. ;)

[Greg E]

Update: so it turns out my FPR solenoid wasn't dead at all. It was my custom harness plug which must not have been making good connection. On my car, the solenoid is mounted on the intake plenum where the purge solenoid used to be. Rather than monkeying with the connector for the purge solenoid, I hacked up the harness for the solenoid pack that mounts on the firewall (for ease of swapping solenoids during testing).

After touching up this harness connector I decided to reinstall the FPR solenoid to really give it a stress test. We will see how it holds up. To my knowledge Adam is still running this solenoid too. Have to confirm that.

At the same time I finally took the car out for a real tuning session. Drained the couple gallons of bad (3 years old) 93 and filled up with a fresh tank. Mods on my car are nothing more than hard intake tubes, OEM EVO BOV, and a cat-less IPS exhaust.

100% WGDC gives me 21psi peak falling to 10psi at the redline. Basically maxing the turbos. After tuning, I've got it dialed back to a 19psi peak tapering to 7psi at the redline. Something like 215 LOAD tapering to 120 LOAD.

This is with stock wastegates, stock turbos, stock intercoolers/pipes and stock fuel (not hotwired). No restricter pill either. Just straight silicone hoses to the solenoid.

[Jimvr4]

My FPR was definitely dead. Still think it was killed by duty cycle. I absolutely kill the car every time I take it out :)

I have the ECU boost operating closed loop now. I'm using an offset of 50 and a target load range of 200 at 2500 down to 165 at 7000 (target loads are 150-115 in the table). This is giving me about 17 psi and about 430whp. I had some knock counts at 80% duty so backed it down to 75% and then entered the loads I was hitting. It looks like the tune went more conservative when I closed the loop. I can probably push the load numbers up by 5-10 but need to get some runs in to check it. I'm logging the target load, the WGDC, and the correction applied so I can see the closed loop behavior.

Also using only the tactrix standalone logging since it doesn't need any post processing and logs whenever TPS>75. I just leave it plugged in all the time and use my laptop to download the data from the Tactrix through a cable I have tucked in the center console. At home I'll plug in the CTEK to keep it charged but I really only need to if I don't drive for a couple weeks (haven't had that problem lol).

[mb3000]

Update: so it turns out my FPR solenoid wasn't dead at all. It was my custom harness plug which must not have been making good connection. On my car, the solenoid is mounted on the intake plenum where the purge solenoid used to be. Rather than monkeying with the connector for the purge solenoid, I hacked up the harness for the solenoid pack that mounts on the firewall (for ease of swapping solenoids during testing).

After touching up this harness connector I decided to reinstall the FPR solenoid to really give it a stress test. We will see how it holds up. To my knowledge Adam is still running this solenoid too. Have to confirm that.

At the same time I finally took the car out for a real tuning session. Drained the couple gallons of bad (3 years old) 93 and filled up with a fresh tank. Mods on my car are nothing more than hard intake tubes, OEM EVO BOV, and a cat-less IPS exhaust.

100% WGDC gives me 21psi peak falling to 10psi at the redline. Basically maxing the turbos. After tuning, I've got it dialed back to a 19psi peak tapering to 7psi at the redline. Something like 215 LOAD tapering to 120 LOAD.

This is with stock wastegates, stock turbos, stock intercoolers/pipes and stock fuel (not hotwired). No restricter pill either. Just straight silicone hoses to the solenoid.

How do you have enough fuel to sustain that?

[Greg E]

How do you have enough fuel to sustain that?

21psi at only 4000 something RPMs out of 9Bs isn't a lot of air. The thing that amazes me is how it can run that at stock timing without knock.

[familyMAN]

I used to run my 91 with 9bs for everything they were worth on pump. Sounds about the same as you. 20ish spike with a hard drop. Stock 360cc injectors can supply anything the little pea shooters can on gas and then some. Cast crank and 18spline survived it all.

[99 vr4]

For some reason I thought the 94+ purge solenoids were duty cycle based. I could send it to you if you want it but if its just going to die like the FPR solenoid did then its probably not worth it.

After NG (hell maybe at NG) ill play with the MAC solenoid. You guys are absolutely sure a single 10ohm resister is all I will need? Guess I can sweet talk Adam into fixing my board if I fry it from I stalking the solenoid without the resistor.
greg... The 99 ecu can handle the mac without failing. ...

Sent from my SPH-L720 using Tapatalk

[CoopKill]

I will be doing this once I get the engine broke in, and off waste gate.

[CoopKill]

If it fries, I will need to ship it to you for repair! :p

[Jimvr4]

For some reason I thought the 94+ purge solenoids were duty cycle based. I could send it to you if you want it but if its just going to die like the FPR solenoid did then its probably not worth it.

After NG (hell maybe at NG) ill play with the MAC solenoid. You guys are absolutely sure a single 10ohm resister is all I will need? Guess I can sweet talk Adam into fixing my board if I fry it from I stalking the solenoid without the resistor.

Wait, wut?? Are you stalking your ECU now :suspect::suspect:

[Unlogic]

I'm about to start upping the boost in my car so I took at the stock values. Am I missing something or are the stock values set so that it tries maintain a load of only 100 for all RPM's above 3500 when your going faster than 30 mph?

http://pics.unlogic.se/3000gt/projekt/stock-ecu-boost.png

Load table A is on the left and load table B on the right on the picture above. It feels almost like the loads tables are switched, why would they restrict the loads above 30 mph?

[Greg E]

It doesn't restrict the load based on speed. It restricts based on octane. Basically if there's too much knock it brings down the boost to wastegate pressure.

[Unlogic]

Okay but what's purpose of the "Target Engine Load Table Set Switch Speed" table?

[Greg E]

That will switch between set A and B based on speed if you enable it in the chrome mods.

Edit: I see what you're getting at now. The purpose of this chrome mod was to help reduce the boost over shoot spikes when accelerating in a high gear.

[Unlogic]

Thanks for the explanation Greg, I had failed to notice that it was a Chrome addition and not a standard feature of the stock rom.

[Greg E]

Yeah there were 2 sets of high and low octane tables in a stock rom, I just set it up to switch between the two based on speed. Next version will switch between the two sets based on the AE dash switch or ethanol sensor. :)

[Unlogic]

I started playing around with the ECU boost features tonight, made a separate thread about my findings here:

http://www.3sgto.org/tuning-engine-electronics-ecu-discussions/14570-unlogics-chrome-ecu-tuning-thread.html

[Unlogic]

A quick question Greg, is the value set in the Boost Control Load Offset table added to both the low and high octance target load tables or only the high octance table?

[Greg E]

Both low and high.

[Unlogic]

Thanks Greg!

I bet some people will miss that since it's very easy to forget to about the low octane table due to it being locked when using the default user level in EcuFlash.

[Unlogic]

Is anyone else here using the stock solenoid and stock restrictor pill?

I'm still having problem with boost spikes both when shifting during wot pulls and also when I'm building boost at part throttle and then floor it.

I've gone through my old logs and the problem is there even when I'm running the stock values regarding boost/target load. However since the stock values targets a lower boost at high RPM the spike after shifting is smaller but still there. The part throttle, the floor problem is also there but also to a lesser extent.

I've been playing with the load correction table and it works but the problem is that it seems be a delay and I suspect that the tiny hole in the restrictor pill could be culprit. Given how small the hole is it probably delays the air pressure slightly when going from low boost (or no boost) to high boost which in turn cause a delays the opening of the wastegates.

When I turn up the load error correction I still get the spike and then I get a big dip instead which seems to indicate a delay of some sort.

Maybe getting rid of the restrictor pill and installing a bigger solenoid is the way to go?

[Greg E]

No. The restrictive pill is the only reason you're getting more than wastegate pressure at all.

You have to cut back WGDC a lot earlier to keep the spikes at bay. In a sense, you need to make the turbos slightly "laggier" by having the wastegates open sooner than you want.

On my white 99 with the DR650s and 12psi wastegates with the stock solenoid and pill I was only running 55% WGDC across the whole RPM range to keep the pressure below 19psi in all gears. The corrections would add or take away a few % here and there but if I set the base tables to anything higher, I would get spikes.

[Unlogic]

By cutting back WGDC a lot earlier do you mean that I should run a lower base WGDC and rely more on the load error correction to increase the WGDC if necessary?

I'm still on stock wategate springs and 11b turbos so I'm having to push the WGDC quite high in order to get 14+ psi all the way to redline.

[Greg E]

By cutting back WGDC a lot earlier do you mean that I should run a lower base WGDC and rely more on the load error correction increase the WGDC if necessary?

Yes.56

[Unlogic]

That worked great Greg. I lowered my WGDC to 70% and increased the load error compensation significantly. I drove over 2000 km this weekend (to the annual Swedish 3000GT meet) and I didn't encounter a single boost spike of more than a psi or two.

The behavior is now inverted, the boost starts low and works it way up which feels much safer than the other way around.

[Jimvr4]

Robert, Sorry for not getting back to your question. I still had some boost overshoot the last time I checked. Can you post your tables so I can see how you are setup at this point?

[Unlogic]

Here you go Jim:

http://pics.unlogic.se/3000gt/chrometune/wgdc.png

The values above give a very smooth boost curve on my small 11b turbos. I adjust the boost using the target load table. A target load of 185 gives me about 13-15 psi of boost depending on RPM.

[Jimvr4]

Those are similar to mine except I have no more than 5.0 WGDC change for -10 to -20 load error. How do your larger values (up to 30.0) improve boost overshoot? What do your target load table and offset look like? Do they add up only to 155 and then you use the correction to add 30 more to get to the 185?

[Unlogic]

I understand that those values must look funky to you since our setups are quite different in this area. I'm running small 11b turbos on stock wastegates so i have to run around 90-100% duty cycle in order to get the boost/load I'm after.

The philosophy behind values is to run a much lower than required base WGDC and then have the ECU increase the boost to the desired level using the load error correction table. The way this work is that the ECU starts with the base WGDC value and then with a slight delay starts applying the correction. This small delay is the key to overcome the boost spikes. One could almost say that the boost spike and the delay before the load error correction is applied cancel each other out.

However I suspect that with stiffer wastegate springs and bigger turbos you may need to use a much lower base WGDC than I'm using.

[Jimvr4]

I understand that those values must look funky to you since our setups are quite different in this area. I'm running small 11b turbos on stock wastegates so i have to run around 90-100% duty cycle in order to get the boost/load I'm after.

The philosophy behind values is to run a much lower than required base WGDC and then have the ECU increase the boost to the desired level using the load error correction table. The way this work is that the ECU starts with the base WGDC value and then with a slight delay starts applying the correction. This small delay is the key to overcome the boost spikes. One could almost say that the boost spike and the delay before the load error correction is applied cancel each other out.

However I suspect that with stiffer wastegate springs and bigger turbos you may need to use a much lower base WGDC than I'm using.

Robert, I see what you did there. My issue at present is the minimum boost I can run with the stiffer WG springs is around 15 psi. On 91 octane with crappy stock SMIC I really can't go above that level of boost either so I don't have any dynamic range to work with. On 101 octane I should be able to try your strategy though. Once I upgrade the SMIC I expect to be able to push to higher boost levels. If the dynamics aren't there I may have to go back to lower WG springs (that will force me into a MAC or equivalent boost solenoid as well).

[Unlogic]

I little heads up, if you live in a region of this planet with a cold climate and plan to use the ECU to control the boost then don't forget to check that your car reaches the temperature set in the WGDC vs Coolant table.

I've been chasing my tail due to that for a few days now before I finally realized my car wasn't reaching the 180°F required for full boost.

[Jimvr4]

Thanks for the update. Reminds me of what I need to do when I finally install Oohnoos SMIC I have sitting here along with the MAFT and Z06 maf. No issues with cold weather here though.

[knights19]

Old thread revival alert - Sorry, I'll likely get a special hat or something but then again this is my first attempt at using the flash ECU so apologies for the revival. Before I even get to the flashing though, can I ask if the BCS boost connection that goes to the Y pipe, could go to the plenum take off instead? Most of the original pipework on my kit car has been misplaced or replaced and I have no take off point on the boost side before the throttle body. If I use a spare plenum take off, will that effect off-throttle boost levels?

[Unlogic]

The reason you have the connection to the y-pipe instead of the plenum is to avoid vacuum being pulled through the boost solenoid.

[knights19]

Which would result in?

[knights19]

Are any of the three connections on the throttle body boost pressure rather than vac?

[Unlogic]

Yeah there were 2 sets of high and low octane tables in a stock rom, I just set it up to switch between the two based on speed. Next version will switch between the two sets based on the AE dash switch or ethanol sensor. :)

Did this feature make it into any version of Chrome?

[Greg E]

Never publicly