Controlling Boost with a Flash ECU?

[Greg E]

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:

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?