Highest PSI on stock Evo 8 turbo
Feb 26, 2013 | 01:34 PM
#20
I've had mine 28lbs tapered to about 25-26 at redline. 93 octane, stock fmic, intake, mbc, exhaust. Made a modest 275whp with a conservative tune. Nothing to write home to mommy about.
Then I switched to the Green, running less boost, and more power. 24lbs all the way to redline.
It all depends on so many different factors. Tune, gas, spark, air, exhaust, vacuum, and even the turbo itself. Hell, my turbo could've been made on a Friday (Friday ****-Its) and only peaked 28lbs, when someone else's could have been made on a Wednesday and peaked 30lbs
Then I switched to the Green, running less boost, and more power. 24lbs all the way to redline.
It all depends on so many different factors. Tune, gas, spark, air, exhaust, vacuum, and even the turbo itself. Hell, my turbo could've been made on a Friday (Friday ****-Its) and only peaked 28lbs, when someone else's could have been made on a Wednesday and peaked 30lbs
Feb 27, 2013 | 12:29 AM
#22
I have had 4 evos, all of them running fast and quick, some of them on E-85 and some of them on methanol. I have a post back in 2005 or 2006 showing my car spiking to 31psi. Most of my cars running E-85 or methanol had no problems spiking to 31psi but in reality anywhere above 27ish PSI you are not making much power.
I made a post back in 2005 when I had a Evo 8 MR making 364lb-tq(bench mark back then on 91oct and methanol) and I made more power on 26psi than I did on 28psi.
Do a search in my name, I documented everything and I spent hundreds/thousands of dollars going to the dyno and having various set-ups and tunes. Tell your friend that he knows $ $ hit.
Carlos
I made a post back in 2005 when I had a Evo 8 MR making 364lb-tq(bench mark back then on 91oct and methanol) and I made more power on 26psi than I did on 28psi.
Do a search in my name, I documented everything and I spent hundreds/thousands of dollars going to the dyno and having various set-ups and tunes. Tell your friend that he knows $ $ hit.
Carlos
Mar 7, 2013 | 07:53 PM
#24
This. A long time ago I ran mine at 30 with a taper to 18. to get it to run that I had a pull a bunch of timing, run it a bit rich and the IATs on back to back dyno pulls with a relatively efficient IC would always get ridiculous. Switched to a 25->19 and it was a more consistent car on pulls and made the same power since I could add back timing and lean the car out. So yeah you can run whatever curve/psi you want but whether it makes good reliable power is the better question.
Totally concur with you and it also backs me up on what I mentioned, often running less boost results in a safer and more powerful output.
Carlos
Mar 8, 2013 | 02:30 PM
#27
Seriously though, there's many different reasons. From boost controller, to blow off valve, to the physics of the turbo itself, to the wastegate springs. I don't know enough to tell you a definite answer. I do know however, that the bigger the turbo you get, the more boost it can hold. Maybe it's just the profile of the turbo, and flows better, or maybe it's something else.
Hope I helped!
Mar 8, 2013 | 09:42 PM
#28
Get a bigger turbo. You could mess with the waste gate to get it to taper less but the stock turbo was not built to hold 25+ psi up top. Plus since you are outside its efficiency range it's IAT hell
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