Flash tuning results: Billet DR650s

[Greg E]

Continuing from this thread:

Flash tuning results on a stock 99 VR4 - 3000GT/Stealth International Message Center

The car has undergone a lot of maintenance. Been slowly collecting these parts for years! Feels strange having an empty closet again... BUT it feels good to finally build the car of my dreams!

Pretty much everything attached to the engine has been replaced:

Timing belt & accessories
Water pump
Crank pulley
Timing belt + accessory tension & idler pulleys
Thermostat
Fuel filter
Alternator
AC compressor
Radiator & hoses
New coil pack, plugs and wires
Poly motor mounts
ABS delete with OEM parts
New brake and clutch master cylinders
New OEM Throttle body
Krank Vents (small style)
Megan coil overs with Maximal control arms (thank you Paul Dawson!)
Flow matched and remanned 560 EVO fuel injectors (thanks evotuner!)
Denso 310lph (NOT hotwired)
IPS downpipe with custom Billet muffler in place of a cat
IPS quad tip exhaust (coming soon)
Billet DR650s
Forge Wastegates
Forge BOV
EVO 8 MAF
EVO 10 Map sensor (installed before the build)
LC1 wideband

I'm still running the stock air box, intake tubes, innercoolers & pipes (even the plastic Y pipe). All emissions equipment are still intact and functioning. Aside from the wheels and suspension, this car looks completely stock.

Here's the car before the build at NG:


...and here it is now!




What a difference!

This is my exhaust currently. It's an IPS downpipe which I've modified to accompany a 3" Bullet muffler from Buschur Racing. BR makes these Bullet "cat" mufflers for the EVO and it slipped over the IPS downpipe almost perfectly. I had to notch the muffler to clamp onto the pipe better but that was easy with an air grinder. Then I had to cut 19" off the IPS pipe with a SS pipe cutter.



This muffler just BARELY fits under the car. I had to remove the stock underbody heatshield for it to bolt up, but if you're running stock motor mounts, it would hit the bottom of the car for sure. I wish I had the skills to modify the downpipe to sit 3/4in lower than it does to give more room for the "cat".

Had a nice surprise when tearing apart the car too. It always had some idle issues, even threw a CE light for "Idle System Fault". I cleared it up fairly well playing with the timing & fuel tables as well as adjust the BISS, but whenever the temperature outside was above 85ish degrees, it never wanted to idle while cold.

Found out why... Not sure how I never noticed this before:


Good thing I had an EVO 8 MAF to replace it....

Continued in next post!

[Greg E]

For a while now, I've been testing the EVO X map sensor in my car. The idea is to datalog boost pressure using EVOScan and the flashable ECU. This is the first baby step towards things like speed density, stock boost gauge mods, ECU based boost control...

The OBD2 cars have a 1 bar MAP sensor that can only measure up to 2.2 psi of boost and is located on top of the intake plenum. The ECU mainly uses this to operate the EGR. The EVO 10 uses a 3.25 bar MAP sensor that can measure up to 32 psi of boost. This sensor is nearly identical in appearance to the stock sensor, so it can be easily swapped in for some plug and play fun.

If you pop off the stock sensor, you'll see a space with a small hole. I believe this cavern is just an area to keep air turbulence away from the sensor so the readings are more accurate.



Here are the 2 sensors side by side. Note: the EVO 10 sensor is the one with the yellow cap on it.





No one would have a clue...


Part number for this sensor is 1865A052 and it's available for $145.16 plus shipping thru MitsubishiParts.net - Your #1 Source for OEM Parts and Accessories

Continued....

[Greg E]

I'm still using the stock BCS to control boost in my car. Setting WGDC to 100% on 9Bs with the stock wastegates only netted me a 16psi spike, falling to 11 at the redline.

Felt experimental and popped out the little restriction pill from the BCS solinoid like the 1G guys do for the free boost mod. Info on that is here:

Stealth 316 - Free Boost Mod for 1991-1993 3000GT/Steath

Much to my surprise, eliminating this pill allows a lot more that I anticipated. On my first pull, leaving everything at 100% WGDC, I saw 30psi before fuel cut!! I ended up with dropping it all the way down to about 64% to get 19psi with my Forge wastegates.

Spool-wise at 100% WGDC, the new Billet 650s see 27psi by 3750 rpms. Keep in mind I'm running the stock airbox and "stock style" MAF too! Gotta LOVE these turbos!!!



Kinda scary when the tires slip in 3rd gear while you're moving... Fuel cut spoiled that fun. Although my knock sensor didn't care for that kind of fun either.

I have spool tuned a bit more conservatively now where I see 19psi by about 3500. I will play with this more after I get my replacement wideband and a fresh tank of 93.

Horsepower-wise.... The results were quite a bit lower than I anticipated but not horrible. This is the previous tune on stock turbos with the new tune on the 650s.



How about that? Not even 100hp over stock turbos.... Don't get me wrong! The car still pulls great, but it's not what I was hoping.

To be honest I am VERY disappointed in the car. Come to find out my wideband sensor is dead so that made tuning a guess... The car also has become hyper sensitive to knock. Even at measly 19psi, I can't run anymore than 11 degrees of timing due to excessive knock. I'm hoping this is just a result of bad gas from the car sitting for so long or maybe my AFRs are too lean from a lack of a rewired pump.

For now the car will sit till I get my replacement sensor and catback from IPS.

Stay tuned!

[green-lantern]

Great info Greg, thanks for posting it here.

[mb3000]

Interesting read as always!

[VR-4 0wnz j00]

They are supposed to support ~550+ awhp but I've yet to see it. Would be nice to see someone with supporting mods dyno them on pump instead of just slapping them on a stock car with injectors and a piggy back.

[Greg E]

They are supposed to support ~550+ awhp but I've yet to see it. Would be nice to see someone with supporting mods dyno them on pump instead of just slapping them on a stock car with injectors and a piggy back.

No problem! Can I take a loan from you?

Matt M insists one of my biggest issues is restriction from the stock airbox. Ive got a Buschur Racing intake for the EVO MAF on the shelf which I'll slap on after the replacement wideband shows up. I'm also waiting on a rewire kit from Summit Racing which will allow me to keep the stock fuel pump resistor.

[Hans@GZP]

Are you running some colder plugs in there now?

[Greg E]

Are you running some colder plugs in there now?

Yeah. NGK coppers 1 range cooler gapped at .022-.024

[HilbillyHomeboy]

Phil (boostedzx) made like 440-450 on regular DR-650's with a stock airbox, several years ago. Lack of timing is killing your power, not that 390 is bad by any means.

Jeremy