Maximum boost.
11-08-2009, 02:00 PM
#1
Staging Lane
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Maximum boost. What is the maximum boost you can run for these compression ratios on a turbo
application. Motor is a forged LS7, Premium 91 octane gas and no meth.
CR: 10:1
CR: 9.7:1
application. Motor is a forged LS7, Premium 91 octane gas and no meth.
CR: 10:1
CR: 9.7:1
Last edited by ZO6 LandRocket; 11-08-2009 at 02:38 PM.
11-09-2009, 11:35 AM
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I'd expect to run 8-9psi. I've got a forged LS7 in my C6 and with 8.6:1 compression, I can only tolerate 10psi on the crappy 91 octane we get in Northern California.
11-09-2009, 01:43 PM
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Alright, my advice sucks... 
Damn internet....
Since my combination is similar, I'll just offer a REFERENCE with the understanding that engine combination and turbo system make maximum boost irrelevant and impossible to determine.
427ci LS7 forged
8.6:1 compression
91 California Octane shitty gas
GT2871r twin turbo
620rwhp / 700rwtq
~11.3 AFR
I see a few degrees of knock reduction when trying to exceed 10lbs of boost.
Free advice that is worth what you paid for it! haha
Damn internet....
Since my combination is similar, I'll just offer a REFERENCE with the understanding that engine combination and turbo system make maximum boost irrelevant and impossible to determine.
427ci LS7 forged
8.6:1 compression
91 California Octane shitty gas
GT2871r twin turbo
620rwhp / 700rwtq
~11.3 AFR
I see a few degrees of knock reduction when trying to exceed 10lbs of boost.
Free advice that is worth what you paid for it! haha
11-09-2009, 03:38 PM
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Staging Lane
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I don't want to run meth because I am shipping this car to Europe and don't want the hassles. I was just wanting to know if I can get by with 10lbs of boost and a 10:1 compression ratio. 91 octane is a worst case scenario over there.
11-09-2009, 05:14 PM
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Absolute worst case. They get some pretty good gas over there.
Methanol is available all over the word though
http://www.turbotuning.net/
Methanol is available all over the word though
http://www.turbotuning.net/
11-09-2009, 08:30 PM
#14
I'll one-up you:
Given the fact that HP is just a manipulation of Torque (i.e. - HP = {[T x RPM] / 5252}) at a given RPM, then I could accurately say that to suggest one should ask about HP when T is the only real measured value is bad advice as well.
Besides that, ultimately the guy simply wants to where he should set his wastegate, given his engine, and his fuel in the People's Republik of Kalifornia, so he doesn't melt / damage anything - you know that and I know that, so don't bring up that "boost is a bad measuring-stick" agruement unless you are really gonna help the guy out by explaining why you think this to be true; then (given your thoughts / explaination) he'll be able to decide whether your logic is sound or not.
OK - rant over.
Let the poorly constructed and illogical flames (from wannabe engineers, armchair technicians, and other KIAs) begin!
11-09-2009, 08:38 PM
#15
Not unless your tuner understands that your car needs a very rich mixture so the extra fuel will act as an additional source of combustion chamber cooling prior to the spark event. If the tuner does indeed know that fact, then maybe, but you'll still probably melt something over time given the BTUs produced.
11-09-2009, 08:50 PM
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11-09-2009, 08:52 PM
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Short answer - No.
Not unless your tuner understands that your car needs a very rich mixture so the extra fuel will act as an additional source of combustion chamber cooling prior to the spark event. If the tuner does indeed know that fact, then maybe, but you'll still probably melt something over time given the BTUs produced.
Not unless your tuner understands that your car needs a very rich mixture so the extra fuel will act as an additional source of combustion chamber cooling prior to the spark event. If the tuner does indeed know that fact, then maybe, but you'll still probably melt something over time given the BTUs produced.
Thanks
