I'm runnin an '85 with a 351w bored .060 over. solid 9" rear end, 4.10 gears, edelbrock victor jr. manifold, holly 750cfm (slightly modified for boost), 9:1 compression with a 90mm turbo @ 15 psi, runnin' on alcohol. aeromotive A2000 pump @ 350gph pushin' 8 pounds through the regulator. fuel pressure increases pound for pound with boost. I'm not quite sure what is going on with my car though. I pull 2nd for the burnout around 5500 rpm, no problem. After the tree I tear through 1st and 2nd (traction is a whole other issue!!) but as soon as i shift to third POP!!! Backfire like a motha! flames coming all the way out the turbo exhaust, out from under the hood, keeps runnin' though and i just ease it down the rest of the track. Tried re-jetting, from one extreme to the other(70p & 81s all the way to 85p &99s). With the richer jetting there is more popping after that dreaded 2nd to 3rd shift. If I lean it out a bit, i only get one big pop. Checked plugs, nice and black, checked valves, all good. Anybody have any ideas on what I should do?!?
i forgot to mention I forgot to mention, I made a pass without the turbo hooked up and it made it down the track no problem (except for the lack of power). So this problem is only when i apply boost...
might be blowing the spark out .....gap the plugs down to 0.028" and try that....alcohol and boost+n20= hard to light!!!
