More HP by Cheaper Upgrades? (from Modik's reply)

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Originally posted by halfracedrift
lol ving... no.. its just we're all not up to his standards, therefore, we are dumb... not he is smart... :lol: j/k all not dissin
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I wish I knew a lot but cars are one of the few things I know a little bit about though...I'm still learning. Some of the guys on the supra forum make my head spin with all their lingo and mumbo jumbo concerning turbo and engine physics, fuel management etc. :eek:

But I appreciate the compliments!

-Daniel
-MidusGT
-Smarty Wombat Bum
 
I don't think octane will directly affect horsepower, will it? Perhaps I'm thinking of something else, but I wasn't aware that running race gas (104+ octane) would increase horsepower. Feel free to correct me if I'm wrong.

What I do know is that with a higher octane fuel, you can run higher compression in the cylinders. Since higher octane fuels are more resistant to detonation (when the temperatures inside the combustion chamber ignite the fuel before the spark plug fires).

For example, in my WRX: I could only run about 18 psi on the typical 91 octane premium gas around here before I started knocking. But, with race gas, I could probably run 22 psi with no troubles. That in itself equals more horsepower.
 
Well I know higher octane will yield acceptance of higher boost pressures but I also have read numerous accounts of higher octane yielding higher rwhp at the same boost. So I'm not sure actually...I'll search around for some dyno sheets of octane comparisons...I just read the other day that a supra owner first tried 94 octane and compared it to a mixture of 100octane yielding 97 and saw a 30hp gain running both at 20psi so I'll do some more searching.
 
You will get Higher HP with a higher octane, I'd highly doubt you'll get 30rwhp from just rising the octane boost though. When I dynoed my skyline with some octane additive, I did notice a power increase running the same boost, it was only about 5rwkw (10-15hp), but nothing extremely significant. The main reason for running a higher octane as AltF8 mentioned was to stop detonation, when rising the boost.

In japan regular pump fuel is approx 101RON, thats why they can run bigger HP, on daily drivers. Hey in Japan if your GTR is anything less than 700hp, then its slow :)

As with the larger exhaust's, in turbo cars they are necessary to allow the turbo to 'breathe' and spool more freely, i've seen massive gains in power from just a simple exhaust mod. Alot of WRX's and other turbo cars run without exhausts to get better spooling with less restriction. Of course.. thats saved for the track, and you couldnt really drive around every day without an exhaust, but with forced induction, the bigger the better.
 
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