The new “what did you do to your Z today” (with off topic replies) XXXVIII

Originally Posted by redondoaveb

So we did a pulley swap and dropped my boost from 19.15 psi @62700 rpm to 15.81 psi @ 56400 rpm. Was hoping to pick up power by bring the blower back into the efficiency range. It lost a little more power and torque.

What's weird is that with my V3 blower, every pulley change I did spun the blower faster (out of it's efficiency range) but it picked up power and torque with every change. With the same pulley set up on the new V2 as I had on the V3, the V3 made more power.

Something isn't making any sense. I don't know if I want to change the intercooler and see what happens, although soho says their intercooler is good for 1000 hp, I researched difference IC cores and the same size core from Bell is rated at 425 hp and one from Vibrant is rated at 600 hp. The shop that built my car is suggesting spraying cold air (nitrogen or nitrous) into the the IC core while on the dyno and see if the hp dramatically rises. Then I would know that the IC is undersized. But the IAT's weren't high anyway.

Attached are 2 dyno sheets, one showing the 19.15 psi run and the 15.81 psi pulley change run. The other one shows my old V3 16.78 psi 679whp run and the V2 19.15 psi 634whp run utilizing the same pulley combo on both blowers.