3" cold pipe for 12psi? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

neilsan · 02-26-2006, 04:03 PM

I know the turbo shaft is solid.

To better detail my concern:

These numbers will be inaccurate, but say if the turbo has to spin at 150,000rpm to generate 12psi with my sidemount, It's not going to hurt it if it has to spin 225,000rpm due to the extra volume of filling a 3" core and 3" cold piping to get the same psi?

Is compressor efficiency only based upon how much pressure the compressor can work against, as opposed to actual shaft RPM? Is there not a point in rpm's where the compressor just can't 'process' the amount of air that the turbine is making it spin to do?

Or more simply i think... is the lag is because the turbo has to spin faster, and is this extra turbine speed that harmful to a T-25.

by how much do you guess lag would increase by? currently with my 2.25" hotpipe, oem smic, tubular manifold and greddy dump boost comes on generously at about 2500rpm.

02-26-2006, 04:03 PM	#5
neilsan Zilvia Junkie Join Date: Sep 2004 Location: east coast Age: 44 Posts: 333 Trader Rating: (0) Feedback Score: 0 reviews	I know the turbo shaft is solid. To better detail my concern: These numbers will be inaccurate, but say if the turbo has to spin at 150,000rpm to generate 12psi with my sidemount, It's not going to hurt it if it has to spin 225,000rpm due to the extra volume of filling a 3" core and 3" cold piping to get the same psi? Is compressor efficiency only based upon how much pressure the compressor can work against, as opposed to actual shaft RPM? Is there not a point in rpm's where the compressor just can't 'process' the amount of air that the turbine is making it spin to do? Or more simply i think... is the lag is because the turbo has to spin faster, and is this extra turbine speed that harmful to a T-25. by how much do you guess lag would increase by? currently with my 2.25" hotpipe, oem smic, tubular manifold and greddy dump boost comes on generously at about 2500rpm.