Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - View Single Post - Turbo Sizing Tips and Compressor Map How-To's

Kreator · 11-26-2002, 08:57 AM

Uhh, lemme bring this up back from the dead  <img src="#/f/iB_html/non-cgi/emoticons/crazy.gif" border="0" valign="absmiddle" alt=':crazy:'>

I guess this question will go all the way back to the CFM vs PSI part. How come the formula for calculating CFM (CFM = V*RPM*VE/3456) doesnt include boost? Does that mean that at 25psi i will need only as much flow as on a n/a engine? Or is it just cuz CFM is this imaginative figure which is used to calculate the compressor mappings, and if you raise boost u stay at the same CFM and just move up along the y axxis(pressure ratio)?

Basicly trying to figure what'll happen if i decide to run 8psi

11-26-2002, 08:57 AM	#25
Kreator Nissanaholic! Join Date: Mar 2002 Location: MD Age: 37 Posts: 1,975 Trader Rating: (0)	Uhh, lemme bring this up back from the dead  <img src="#/f/iB_html/non-cgi/emoticons/crazy.gif" border="0" valign="absmiddle" alt=':crazy:'> I guess this question will go all the way back to the CFM vs PSI part. How come the formula for calculating CFM (CFM = VRPMVE/3456) doesnt include boost? Does that mean that at 25psi i will need only as much flow as on a n/a engine? Or is it just cuz CFM is this imaginative figure which is used to calculate the compressor mappings, and if you raise boost u stay at the same CFM and just move up along the y axxis(pressure ratio)? Basicly trying to figure what'll happen if i decide to run 8psi __________________ кто болеет за Зенит, у того всегда стоит!