R&P Ratio for Auto-X???

[atomicjoe23]

Originally Posted by Rod P

AHHHH!!!!

Ring and Pinion...that depends on the final transmission ratio and tire diameter and engine max drive-able redline! on the current autocross tracks the larger SCCA tracks are predominantly 2nd gear tracks, the Goodguys tracks are quicker smaller 1st gear tracks....

what I shoot for is the ability to reach 70mph at edge of max redline(7000 rpm) in second gear

7000 RPM. . .WOW!!!

My pretty much stock Pontiac 400 is not gonna go anywhere near 7000 RPM!!!

When I drove my buddies EVO IX we stayed in second gear the entire time. . .same when he drove and when I rode passenger in a Solsitce and BRZ. . .

Originally Posted by 68Cuda

He means Ring and Pinion. For auto-x you want a combo if engine/trans/rear axle ratio/ and tire that allows you to spend most of the course in one gear. I have seen some people go faster leaving the car in 2nd even though it does not feel faster to them. So, it depends on the combo really.

Gotcha. . .so I need to do some math based on final drive ratio in first and second gear, tire diameter, and engine RPM. . .my goal was to stay in one gear. . .can't wait to ditch the automatic and get a T56 or TR6060!!!

Thanks for the info. . .both of these posts were helpful!!!