Shift Points??
 

Ok I'm just curious as to what I should be shifting at with my current combo. I'm running a custom upper intake, F cam, 351W heads, long tubes, 3.73 gears. I have a girdle for the rocker arms, but not the bottom end, I am also running on the stock 89 bottom end. Also have custom chip with no rev limit.

I've been shifting at 5700RPM, but wondering if I should be going higher?? And on that how much higher could I go and not have the stock bottom end start throwing parts out the block?? Engine has 'bout 60K miles on it.

To do that right you need a dyno curve so you know your TQ and HP charatarsitics and do some calculations. Got one?

Vary your shift points at the track to see how it performs, but 5600-5800 should be pretty close.


-Josh, aka the tireburner

I do have a dyno sheet, but they only took the car up to 5500.

Peak TQ was 280 @ 3000
Peak HP was 238 @ 5300

Those numbers were before I had the car tuned with a chip as well so they could be slightly different now.

I put your dyno data in a spreadsheet I have to help see where to best shift. Attached is the resulting sheet. You have a very flat torque curve which is good. Generally I like to keep my car between peak torque and peak HP on the track. Using that as a guide, I would shift 1-2 @ 6,000 rpm, 2-3 @ 5,400 rpm and 3-4 @ 4,600-5,000 - experiment with the 3-4 shift to see what gives best ET.

Wow, thats awesome. Thanks a ton. I need to get me one of those programs.