Originally Posted by Thumper SRT6
After all those calculations, it looks like 10% under max S/C RPM may not be a good idea, See this thread:
talking about 192mm crank pulley
A 192mm Crank pulley gives:
192 Crank Pulley : 74mm Stock S/C - - Ratio = 2.594
Engine RPM @ 6000 - - S/C RPM = 15564
Engine RPM @ 6200 - - S/C RPM = 16083 - Rev Limiter W/Tune
Engine RPM @ 7000 - - S/C RPM = 18158
He was getting detonation at WOT with that pulley and no tune, so
15,564 S/C RPM is too much for the fuel system at WOT. This is REALLY close (64 RPM) to a 185mm pulley running at a tuned 6200 RPM (15500 S/C RPM)
Brian, you haven't had detonation at WOT with the 185mm crank pulley, have you? I don't remember reading anything saying that you had.
Assuming you haven't, that tells us that things start to go bad with a ratio somewhere greater than 2.5 (185mm crank pulley/74mm stock S/C pulley = 2.5) and less than 2.594 (192mm/74mm=2.594)
I was under the impression the 192mm pulley spun the s/c much closer to the s/c limit than what you calculated...if your calculations are correct its not even close, which is good.
As far as the fuel systems limits i thought it was determined that both the injectors and fuel pump were more than suffecient for turning up the boost near the s/c's max. I thought it was the tuning that was necessary at that point in time to eliminate detonation...? Maybe i need to re-search.