Originally Posted by maxxm
Now I'm confused. I thought the SC didn't even engage until higher rpm's -- about 2,900? 
Actually the PCM is progammed to engage it at RPM's below 3,000 and is dependent on all the funny little sensors. TPS and MAF / MAP are the principals... But you are partially correct... Averaging would be about 2,500 rpm...
And I think that's what my original answer to the question was... It will disengage prior to building-up back pressure... Thus, no need for a blow-off valve... Get it ? Back pressure from the SC spinning and the cylinders not...