I was searching through the forums and couldn't find any answers. I am going speed density in the next week or two. I was wondering, with my mods, what the max boost the stock 8 turbo can handle.

I have a BR IC, BR ICP, BR TBE w/out Cat, WeaponR Intake. As far as I know, the exhaust manifold and other internals are all stock along with the ecu. Thanks.

 

Would like to know the same thing... but for Evo9 stock turbo, mods: TBE no cat, 3inch front mount, injen pipes and injen intake

 

What fuel you use will be a determining factor. Only on pump gas I would say near 25psi. That's just from what I've read on here. You'll start to knock after that unless you up the game with some meth, higher octane, or e85.

 

I have seen the evo9 turbos in the rally cars spike 38psi and hold 32-34 but they only hold up for a few races. I have seen the 9 turbos at 28-29psi on pump gas for an on the edge street tune. As for the 8 turbo the most i have seen is 29-30 psi and for a pump gas tune 25-26 psi .

 

This is if you have all supporting mods. A good FMIC is a must for a stock turbo because they blow so much hot air. It also really all depends on where your car stops making power.

Pump - 25-27psi (depends on 91,92,93 etc... and Also if your tuner likes timing or boost)
pump+meth - 30psi
E85 - 30-32psi

I ran a pump+meth setup to 35-38psi but I stopped making power around 30psi. I was just pulling up my tq curve. I would not spin it over 32psi because you will blow the turbo sky high. That's what I did, but I didn't care because I went with a Red.

Here is my 30psi vs. 35psi. As you can see I didn't make 1hp more going to 35psi. Just a **** ton of tq.

 

ok, thnx for the feedback. I am running pump gas. My boost guage looks like it is at 22-23 psi. Once I am done with the SD conversion and all tuned up I will post up all the info.

 

Good luck, very interested in your gains

 

My buddy has an evo 9 with stock turbo runnin 35lbs boost but he has alcohol injection and head studs

 

I've found that after 27psi my waste gate was having a hard time keeping up (this is with a Evo 9 turbo). I only run it at 22Psi daily, and 25-26 when i want to turn up the wick.....hopefully i won't have to suffer with the stock turbo for much longer haha

 

On E85, I'm tuned at 30PSI on the stock VIII with 9.8cm2.

 

On pump and in Colorado that is about as good as you'll get....You start @ 1 mile above sea level right and then if you go into the canyons / mountains can go as high as 1.5miles above sea level (hard for the little turbo)?

 

get a high pressure W/G acuator.

 

I run 28psi daily on the stock IX turbo/pump gas.

 

Really?!?

With which supporting mods? please list all...

 

On 93 i was able to get 28 spike on pump without much knock. i have tbe plus 4in ets core with a cop.