I made a few passes this weekend with my LM1 hooked up. Im basically messing with jetting and outboard springs in my 416 sixpack.

It is a 1000' track.

I shifted at 6300 or so in first and the slope of the rpm line is pretty straight and looks like its still accelerating at the same rate- i.e., its not laying down up at 6300. Would that suggest i try going higher?

in second gear it does look like it lays down a little bit near 6100 - the rpms flatten out. so that would suggest I shift at 6100.

i cross the line at 5300 in 3rd. Can I get that up to 6100 by short shifting? I thought tha would work but it didnt. On the 2nd run I shifted at 5500 in 1st and 56 in second but I crossed the line at 4900 or so.

what do you think? Click on the attachment for the plot.

run 1 plot

The way I find my shift points is to go to a chassis dyno and figure out where the motor is making peak horsepower. I start out shifting there, and vary them in 100 rpm increments until it runs the fastest.

Short shifting will not raise your finish line rpm, as you found out. In order to raise it, you will either need steeper rear gears, or run a power adder. A 150 HP shot of nitrous will bring you through the traps at about 6000 rpm.

i'm already running 4.30's so the steeper gear idea is out.

I think I need to find a chassis dyno