I currently run a J35A4 in My sand car and it is supercharged with about 5lbs boost "great motor never a problem" Looking for 50-75 more horse power. The j35a8 looks like a great swap out motor. is the Envelope the same with both motors or are they 2 completely different.

 

I'm by no means a J-series expert, but here's what i got- the A8 will be a "single port" exhaust head casting, "variable resonance" intake manifold, higher compression and bigger cams vs the A4. I'm not 100% sure that the blocks have the same bolt pattern for the transmission.

a head swap or cam upgrade may be options for picking up more power on your current engine. the intake manifold may be an upgrade option too.

what are the other details on the supercharger? are there upgrades available like a pulley swap or larger displacement blower? maybe a more efficient SC?

 

Thanks for responding. We have this figured out. The A8 would work if I did not want to apply 8lbs of boost. The compression is to high. Build the A4 out with larger pistons and better rods. Get 9lbs of compression and go up to 12lbs of boost with 110 fuel. Cant wait.!