Quote:
Originally Posted by Desert Rider
Darin,
My question about octane was based on my assumption that combustion cylinder pressures would be lower in an engine operating at high altitude, since less air (and so less fuel) entering the combustion chamber. Combustion temperatures should be lower, so internal pressures should be lower, so it seems there is less potential for detonation, hence less need for higher octane.
I will plan to visit with my dealer about octane and PCM (what is this?).
I've also ordered a cat-back exhaust, but wonder if it's needed, since less mass flow through the exhaust than normal.
Thanks,
DR
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I know your thinking is correct and I am almost 100% sure that 87 octane is what your going to be running but you need to clarify that first. When we raced in Denver every year the only thing we did was run a little more compression and a lot more timing due to the slower burn caused by decreased air density. Short of supercharging there is no way to make the same power as the sea level cars. You should really consider that. Its really the only option at that altitude.
As for modifications, any increase in volumetric efficiency is going to equate to more power. What works at sea level works at high altitude. Headers, cams, Cold air intakes, 160F thermostats and all the other things we do to increase engine air flow will have the same effect at high altitude. Some design perimeters change relative to alittude so when ordering headers or any other components make sure to tell them where you live. After you get headers, CAI and all the other mods you want a good tuner will step you up nicely!
If your out to make really good power a supercharge is really the best bet in your situation. Your not leaning on the engine or decreasing it lifespan at all with supercharging up there because your just getting back the power you lost! Well, you might want to make a little more. lol
