It has been suggested that I need higher octane to run this type of boost on my hot air and I was hoping someone knew how to calculate this to see where our compression is at this much boost or higher.
Thanks!!!
the calculation is in the archive somewhere, lol. I personally have run 22# of boost but on 94octane gas with 1 bottle of octane booster(outlaw I believe) no popping/detonation. 26# of boost would probly require AV fuel or a minimum cam II with 1/2 tank of sunoco 94.
Three steps to get the ROUGH effective compression ratio (ECR):
1: Boost + atmospheric pressure (AP)
2: "1" divided by AP
3: "2" multiplied by static compression ratio (SCR)
(Boost + AP)/AP)*SCR = ECR
Boost = 26
Assuming AP = 14.7
Assuming SCR = 8.0
(26 + 14.7)/14.7)*8.0 = 22.15
So your ECR is ~22. Remember, this is ROUGHLY. There are more precise ways of figuring this, but more info would be needed.
Also bear in mind how hot the air is getting at those pressures. There is a limit to the benefits of psi vs. air temps. I don't know much about hot-air cars, but 26 seems like alot. Might want to get some advice from other hot-air folks.
HTH
Dean
Thanks for the info.
I run straigt 110 all the time. We did find that the bolts in the turbo had worked their way out again, which could account for a lot of the knock issue. Didn't know the big one was gone until you could hear the sucking noise it was making. This is one of the flaws with the hot airs, the way the turbo is connected. We have reattached and the car seems to be running well. I will keep you posted.
Best to date is a 12.02 on my hot air.