Calculating FI Power?

[Massimo]

So I am trying to calculate the hp increse forced induction can have on an engine. Usually I calculate N/A engines using the hp/1000rpm/L method. I know a few common values this can give eg.

Average engine = 11hp/1000rpm/L

F1 engine = 15hp/1000rpm/L

BTCC Engine = 18hp/1000hp/L

I have come across a calculation for FI that was

hp = N/A hp x (1 + psi / 14.7)

Can I use the calculation above with my hp/1000rpm/L values to calculate peak hp values?

So the equation would look like this

HP = (N/A hp x (1 + psi / 14.7)) x (rpm / 1000) x Engine Displacement in L

Dose this look right?

Cheers Guys

[nando]

I would multiply your PSI value by about 75% to account for losses from things like intercooler efficiency. but, your proposed formula could get you close. A shortcut I'd take is use your existing N/A HP and simply multiply the peak by how many bars of pressure you're putting in it (1 bar for atmo + boost) mutliplied by a % to account for system efficiency (since nothing is 100% efficient). Not scientific but if you're doing something like sizing an injector it can be close enough.

On the other hand there are a number of highly advanced calculators out there that you can download for free. They take into account a large # of things, including compression ratio, cam timing, valve sizes, etc.