I have an ati #8 kit on my 94 Z28 with 144,000 miles. I cant get #8 of boost out of it until I am right at 5500 rpm or so. I am also getting a knock signal and pulling 3-4 degrees of timing out. The o2's are around 880-910 mv when under boost. Fuel pressure is about 70-75 psi. I am using an FMU and a walbro 255 lph intank pump. I have the mufflex hard inlet tube. The exhaust is stock except for a flowmaster and gutted converter.
Last night I took a friend out for a ride. When I turned around to head back, I stood in it and spun it around. It smoked black like hell and backfired pretty good. Then exhaust leak. The converter actually split open at the seam.
I dont have any type of aftermarket ignition with boost timing control or lt1 edit or anything like that, so I dont know what to do to correct it.
Thanks for the imput guys
Stevie whitley