I'll start with my sheet and to say my tuner didn't think I should run more than ~12psi on just 93 pump gas. He said that after I told him I'd like to see mid 500's but wasn't sure if my pump or WG spring would get me there. He said he was more worried about running out of octane on anything over 12psi. He's recommending a switch to E85 or to move on from the stock cams.
So here's my sheet ...
My questions have to do with not gaining much power as we turned the boost up.
My tune from 2 years ago was 397/453 on 9psi.
My 1st pull yesterday was 406/45? on 10.39psi.
3rd pull was 429/45? on 11.44psi
My last was what you see on the sheet.
That's a net gain of 46whp going from 9psi to 13psi. Two years ago I went from 360 on 8psi to 397 on 9psi. This year I only gain 46 for going up 4psi ... what gives ??
I know that psi is only a measurement of restriction and seeing the psi increase but not the hp has me thinking I hit a serious restriction somewhere. I'm reading boost at the EGR plate on the Plenum so that's pointing me someplace past the TB/plenum. The stock PI intake should not be the issue and I thought the stock PI cams should make more then 450whp also.
On3 2nd gen FF turbo. 70mm turbo .68ar
MMR 600 shortblock ... 2 years and 10k miles. All with the turbo 10.39psi.
MMR stage II PI heads ... 4 years 13k miles
MHS stage II valve springs ... new this spring
Stock PI cams
Accufab 75mm TB/Plenum
So do my numbers look low or is it just me ??