Anyone running a mitsu with full 3" exhaust?

[1984Rampage]

I was wondering if anyone is running a mitsu with full 3" exhaust and doesnt have boost creep?

[Jay]

about 8 years back when i had my 1st of many t-vans, i thaught it would be cool to do straight 3" (un-educated then) needless to say i blew my 1st headgasket a week later from instant boost cut. i would say if you restricted it some how or ported the wastegate hole you'd be good

[tkelly27]

You didn't blow the HG because you were getting boost cut out, you blew it because the HG was old.

From what I've heard, you will go into cut out. I never did, even without running a down pipe, but my mitsu was kinda trashed.

If you've got a good running engine it can handle 14psi+ from the mitsu. If you get a 3bar cal, you'll have fuel and you can run that mitsu to it's 18-19psi limit. Or you can hog out the wastegate and port the turbine housing. All of which is a waste of time on a mitsu turbo IMO.

[bigswede]

I`m running a full 2.5 pipe from the mitsu all the way back to the rear bumper. No cat, no muffler. No noise tickets either. Hehe..

[aRTie]

I put a full 3 inch exhaust with a cat and muffler on my van with the stock turbo and I did get a lot of boost creep on my low boost setting. The low setting was the boost nipple from the turbo going directly to the wastegate. Stock exhaust showed about 5 psi, with the 3 inch exhaust it spooled to about 7psi and did the creep to about 10-11psi. Actually I did not mind a little extra boost or the bit of creep, the 5psi was a little too mild for my daily driving habits. On my high boost setting which was 17 psi through a grainger valve I did not see any boost creep. Although without a cat and muffler I really don't know what would happen.

[Kevin]

I had tons of boost creep with the mitsu turbo and 3" exhaust on my van.

[Ondonti]

You cant have boost creep on a mistu when the boost is cranked up high because it cant actually move enough air for boost pressure to increase lol.

Therefore 3" exhaust and 18ish psi should work great. What sucks is when you are trying to run 14psi and you keep hitting boost cutout because you havent fixed that problem and the mitsu creeps.

[detobias]

anyhoo, 3" exhaust is Way Overkill for a Mitsu

the inlet of that turbine housing is about 1.25" :tiny: and is the biggest bottleneck in a Mitsu-equipped motor BY FAR

unless you plan to later upgrade to a bigger turbo ...

[1984Rampage]

What about 2.5" side exit with just a striaght through muffler?

[pcrmike]

Okay, I went with a 3" exhaust and it would bump against cutout, and after disconnecting the battery and reconnecting, it hasn't done it again. How do you set it to a higher boost level? :-)PCRMike

[2.5TURBO]

i'm running the wastegate not connected and just the stock downpipe(no cat) and i get 20-24psi......it's so awesome

[pcrmike]

That would no way work for my daily driver. :-( PCRMike

[detobias]

Quote:

Originally Posted by 2.5TURBO i'm running the wastegate not connected and just the stock downpipe(no cat) and i get 20-24psi......it's so awesome

Huh ?

how is it you're computer isn't doing an overboost shutdown ?

how is it you're getting enough fuel at 20+ psi to not melt pistons ??

please provide more info ...

[tkelly27]

"Major modifications:
intercooled, computer"

Three ways to deal with boost creep. Restrictive exhaust (which is what the factory did), bigger wastegate, more fuel. On a TD more fuel above 15psi requires a chipped computer to handle a bigger map sensor.