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.

Originally Posted by DrBacon

A restriction I would figure would show up on the top end when you'd be making more boost than previously, you wouldn't be down on power throughout the whole pull when not pushing that much air. Obviously the new supercharger probably takes a bit more power to spin, but you are also building more boost throughout the whole RPM range too which I would imagine should be counteracting that.

I'm not sure if this has been asked but have you had a compression test done?

Originally Posted by redondoaveb

I talked to Seb about maybe doing a compression test and he will if I want but he and the shop that built my car both said the motor is acting healthy. There's nothing to indicate that the motor is hurt. I may have him do one and hopefully eliminate that equation.

Originally Posted by redondoaveb

I talked to Seb about maybe doing a compression test and he will if I want but he and the shop that built my car both said the motor is acting healthy. There's nothing to indicate that the motor is hurt. I may have him do one and hopefully eliminate that equation.

Originally Posted by DrBacon

Yeah with that stillen manifold in the way I know it's not a simple task to do but I think it might be worth trying just to see. I don't know what else would result in such a consistent loss of power across the entire rpm range even when you're making a fair bit more boost.

Keep us updated though, I am genuinely curious.