This may be a wierd question, but is there a formula to show how much power I'd gain by increasing the compression so many points compared to current compression. Just in case anyone misunderstands this, say I have a stock H.O. engine 225hp and 9:1 compression. Is there a mathematical equation that'll allow me to estimate my horsepower level if I were to increase it to 11:1?
compression formula
- Thread starter IntenseBlue
- Start date
65ShelbyClone
Founding Member
I think the rule of thumb is 12-15% per whole point of compression(like from 9:1 to 10:1). Its a percentage because the more power you make on low compression, the more you will make with high compression.
You'll have to get supporting parts, though. A stock 5.0 with 11:1 compression wont run on pump gas and will be badly choked by the induction.
You'll have to get supporting parts, though. A stock 5.0 with 11:1 compression wont run on pump gas and will be badly choked by the induction.
It depends on the total setup. More compression will usually make more power. With higher compression, exaust will be pushed out harder, and intake will be pulled in harder, resulting in more air in the combustion chamber. The compression will heat the mixture and make it more effecient, a hotter flame, making more power. This heat can also result in detonation. This is only static compression. With the stock heads, intake, and exaust, there would be some gain, but not a lot, while with a good H/C/I/E setup, it will make a lot more. You want all the compression you can get without detonation. The prevent detonation, you need higher octane fuel, or a colder air charge (intercooler, methanol) to keep the heat down. Cam specs can also have play in this. Compression is just one page of a book that determines engine performance.
Black1987Stang
Active Member
I forget how to figure that out, I only know the formula to find cubic inch displacement, compression ratio, and Liters.
