" Okay, What I believe it is is the exhaust turbine and housing. Both need to be larger to produce the hp needed with that larger compressor wheel.
Terry, you need to check the back pressure of the turbo in the exhaust side. This similar situation happened to another guy when he went bigger turbo. He made the compressor size bigger but the turbine exhaust side the same and it wouldn't boost more than 14 psi.
His quote[QUOTE=KILLER-LS1;16606791]well I went out and drove it, still not making full boost, but its hard to tell driving it on the crowded streets without getting pulled over.
I hooked up the backpressure line to my analog boost gauge. I set the Eboost2 to read peak boost recall. Heres the results:
over 30+ psi of backpressure to 11.8psi boost pressure.
You guys were right. I talked to comp and they said that they think the turbo is being over-spun, creating the backpressure. "