Stage .5

[Shel155]

I would like to know the cheapest easiest way to get 25 or so hp from my 91 940SE. I did stage 0 on it, don't want to get too involved but would like to pick up a few. I'm thinking for starters, since it has a brand new exhaust on it, just removing the cat and installing a free flowing muffler on it, and removing obstructions in the air box with possibly some sort of diy ram air. Then what? Would a high output coil help at all at this point? Also, can I increase boost a tad without adding a boost control valve ? It runs pretty good right now, I just want to perk it up as much as I can with cheap tweaks. I'ts been slightly lowered and all new Billstein touring on it. There's quite a debate on whether or not a cone filter will help or not, some saying its bunk others saying "hey, it worked for me" but their imaginations and wishful thinking might be more to blame... Jury's still out. Any tips appreciated.

[The Full Banana]

buy a MBC (manual boost controller) and turn up the boost to 12psi.

something like this should suit you and has been proven to be reliable. http://yoshifab.com/store/index.php?...d&productId=40


then get some chips. thelostartof on this forum sells them, and they are good. you will like them. i would PM him for details.

[Shel155]

Ha, even I can afford that and checking the chips now, thanks. Oh, what's wideband? nevermind...haha.

[91_740Turbo]

Lol could do what I did when I was 16, I screwed around with the length of the actuator rod....... Long story short spark plug go boom and as a result motor go kaput. Save up money and take all the proper steps to ensure that what you're doing is reliable, you already have a stage zero, don't let that go to waste

[The Full Banana]

also, diy "ram air" is a waste of time. gut the airbox and call it good as far as intake is concerned.

[Lando]

Originally Posted by The Full Banana

also, diy "ram air" is a waste of time. gut the airbox and call it good as far as intake is concerned.

^ This. Stock intake is pretty decent. The air filter is larger than many of V8 filters, just take out the foam and airbox thermostat and block off the hot air intake. Cone filters are a waste of time. If you set it up anywhere in the engine compartment it will increase intake temps substantially.

Start with MBC and boost gauge. Cat delete doesn't really help that much, and makes passing emisions tough.. Most of the restriction is in the mufflers and pipe. Go 3" or go home. Brown tops if 12 PSI isn't enough for you. Anything beyond that starts to get expensive.

[Shel155]

Originally Posted by The Full Banana

also, diy "ram air" is a waste of time. gut the airbox and call it good as far as intake is concerned.

Done, didn't want to do it anyway ("ram air"). Mm, so cat removal not appropriate at this stage, what about just the muffler (stock pipe)? I guess ur saying that a muffler change without 3" is moot. Do I need to go all the way to the downpipe with the 3"?

[Lando]

Originally Posted by Shel155

I guess ur saying that a muffler change without 3" is moot. Do I need to go all the way to the downpipe with the 3"?

No, I said mufflers and pipe are more of a restriction than the cat. A straight through muffler will help, but if you are going to spend the money on an entire turbo back exhaust, I would go 3". Stock exhaust is 2 1/4 so 2 1/2 is not that big of an increase.

Also, I the waste gate on the stock turbo is a big restriction. A similar sized turbo with a better turbine housing will help alot.

Also, read my above post about gutting the airbox that does help and takes like 20 or 30 minutes to do.

[Shel155]

Ok, have ordered the Yoshifab valve already, will do the airbox mods, probably will delete the cat plus a decent muffler, will wait on the 3" for the moment. Regarding the waste gate, that is something integral to the turbo and can't be changed except with different turbo? Btw, what is a BCV block off valve? Saw it on the Yoshi site.

[Shel155]

No emissions testing here!

[The Full Banana]

keep it simple. your stock CBV (which is the recirculator valve on the turbo) should be fine for 12 psi.

mbc set to 12 psi (and of course calibrated boost gauge so that you know how much boost you are running)
thelostartof chips
gutted airbox

after that, if you want to do a freeflowing muffler, fine. if it were me, i would do a full 3" exhaust right away, rather than fiddle with a different muffler only to end up ripping it out soon after.



start simple and dont get ahead of yourself. that's the most important part.

[Lando]

Originally Posted by Shel155

Ok, have ordered the Yoshifab valve already, will do the airbox mods, probably will delete the cat plus a decent muffler, will wait on the 3" for the moment. Regarding the waste gate, that is something integral to the turbo and can't be changed except with different turbo? Btw, what is a BCV block off valve? Saw it on the Yoshi site.

CBV (compressor bypass valve) block off is for people that want to run an external BOV (Blow off valve) or CBV. On the mitsubishi turbos, this valve is integrate. This plate just bolts over the old valve port and allows you to mount a CBV or BOV any where on the intake.

The waste gate is integral to the turbine housing. It is where the exhaust gases go before the turbo starts spooling. So intuitively, a larger waste gate will help with performance in your powerband when the waste gate is open (at idle and before the turbo creates positive pressure in the intake).

On garretts people often switch to a cosworth housing which has a much bigger waste gate. On the mitsu's you dont have that option.

http://en.wikipedia.org/wiki/Turbocharger

Read the wiki article. BOV/CBV's and waste gates all operate on the same principle, its a valve that opens with spring force and a pressure differential. The primary difference is the waste gate opens gradually, and the CBV/BOV opens suddenly when intake pressure spikes.

[7mgtesup]

I wouldn't bother with chips at this stage as they are for when you want to run alot more boost. Stock fuel map is plenty rich up to 1bar on a 15G.