3.5 inch should give you 14psi, there is a pulley chart somewhere. Pm Sideways he might be able to help you. I am also aiming for 14psi. Ordered my 3.3 inch pulley from asp last week can't wait... I will be running a front mount intercooler as well. So I will probably lose 2 psi of boost.

 

Yea, the pulley chart was what i went by when I ordered the pulley. It said a 4" pulley should make 12.5lbs of boost at 9Krpm. But it only made 10psi. Im really not upset though. I am super happy with the drivability of the new tune over the last one on 7lbs. Which I made 306whp with. But the car was a mess, the AC would kill it at idle, VTEC was set too low and the engagement criteria for VTEC was ridiculous. Now it drives like a stock S2000 with 130 more horsepower

 

Hmm yeah a 4" pulley on a VT should yeld more than 10 psi....either your engine is eating it all up to making it more efficiant (probably not) the belt is slipping....or the dyno is off in reading it. Could be the wrong size sent to you also. I know I had a 4.5 and made about 10 psi....I now make 18.2 psi on a 3.8 pulley. Don't get a 3.5 in my opinion unless you want to run a 8k redline not to blew the blower/motor.

I'm glad it's running better for you now though Joe!

 

i have 3.8 n making 10 psi my redline was set at 8200..

it depends on the size of header n exhaust also..
if i put a 3 inch exhaust it will net me to `12 psi .

 

it is a bit weird none the less making 400whp with 10psi and running also a 3.8 pulley on a Vortech, have you got the original map sensor?! maybe your probably at 14 psi and you are seeing only 10...

 

i have SOS map sensor...

 

Nope, I have the SOS map sensor, ID 725cc injectors, 4" pulley, VTSC SQV2 w/AC, ACT flrywheel and clutch, NGK 7113 or 7311 plugs (cant remember number), T1R 70mm Sparrow single exhaust from header back.

But maybe the tuner did not calibrate the new MAP sensor. Hmmm.

 

VTSC aftercooled, no map sensor, AP2 motor, greddy ultimate emanage, aem water/meth kit 50/50 mix, 11psi, 750cc injectors, 70mm dual exhaust, 63mm tp, 3.7 inch pulley. Mustang dyno (stock base run 167whp) after install and tune (295whp w/meth) after Mase tune (308whp) then it started throwing CEL...so went back to using shop map of 295whp.