lee101315

You guys should really have a peek at the DSM/EVO forums, a lot of their cars are running 30psi on pump gas

TRP951

Ive run up to 19 psi on pump gas. The key is getting a efficient turbo and tuning

V2Rocket

a turbo that is big enough to push that kind of air without heating it up too much? are you using the stock IC? and what kind of timing do you run?

lee101315

Its got a lot to do with the hotside you run too, not just the intercooler. The preturbo backpressure shouldnt go higher than 1.5 X the boost pressure.

TRP951

The turbo was rather large and it also had a #10 hotside on it along with a self designed intercooler. The timing I dont recall as I sold all the old management parts and now and putting a TEC3r on

TurboTommy

Something else to consider as well:
It's not that hard to run high boost, if tuning really rich and backing off the timing. Yeah, maybe you can get into the 20s psi boost without detonation, but if you have to run overly rich and/or retarded timing to do it, you're not going to get the most out of the boost you're asking the turbo to generate (which is also not free)

TurboTommy

+1
Absolutely
This is more important than being horny about getting high peak compressor efficiencies (as long as air flow isn't maxed out), or intercooler efficiencies.

alxdgr8

PSI is irrelevant without noting the turbo and many other variables. There is no absolute "PSI Limit" like some seem to believe.

951_RS

Yes, exactly.
With proper tuning over 15 psi is very easily done.
On the LR site they run 16 psi with 93/94 octane gas and achieve 305 whp on a stock turbo s with their 300 whp kit.
I'd imagine with a larger turbo and injectors that the power would only increase from there even running the same psi (as it would be able to hold until redline as mine does)
I'm curious what power I'm making now with my car running 16 to redline. I'll dyno it soon I suppose and then again once I've got new injectors and a maf.

TRP951

Of course many different variables to take into account. I was monitoring my backpressure so I could keep the boost to backpressure in check

gt37vgt

There realy is a psi limit but we are not likley to get there .
There Psi limit when you run way off the top of the map and you are heating the air to much to do much with it . But yeh most of the time the limit is some tuning issue of the fuel or ignition not being up to the task so we address that then add a couple more pounds and look for the next boost stepping stone generally

toddk911

Thanks for the before and after Cory. Glad to know the real story behind the downpipe and NO not worth the money knowing that. lol

toddk911

As others have said, a lot is dependent on the car and what you personally are looking to get out of your car.

To answer your question with my own trial and error of several set ups and the natural instinct to get to the root of an issue I feel that keeping the charge air as cool as possible will allow the most power based on the density of the cooler air and safety for not running higher octane, as I said most HG issues are blown due to heat/lean, not running too much timing.

That is how people run 30-50psi 2ith water/meth injection; COLD dense charge air can substitute for octane. Even as per Corkey Bell, every 15 or 20 degree drop of intake temps, you can run 1 additional psi of boost safely.

So that is done with very efficient turbo or bigger turbo and dead on a/f tuning. There is no need to turn up your boost without a better turbo or you are only creating heat and not hp and HEAT KILLS!

I am running 20psi on pump and now especially now into winter and having a bigger/newer MAF right at the panel ambient inlet hole where the snorkel was, my intake manifold is cold to the touch after WOT full boost runs and my post IC pipe is almost as cold as the outside sheetmetal and I see 1,475-1,500EGT max at 5K to redline. My pre IC pipe is warm, but I can easily hold my hand on it.

Of course, the experts in here are who you should ask; Vitesse and LR personally and John has already posted some feedback in here for you.

Mike Lindsey

We have ran 23 psi at 14:1 a/f without mishap. It's got a hole lot more to do with
exhaust pressure then anything else.

LS1Porch

V8 conversion