Author Topic: Gear Ratios (Read 1452 times)

flat4 · « **on:** September 25, 2004, 04:18:24 PM »

Any suggestions as to what to do regarding gear ratios? I have no problems at the track with 1-3, but I seem to run out of power at the top end of 3rd before getting through the 1/4 mile, and shifting into 4th does me no good. I have a Rancho Pro Street tranny ( I have yet to verify R&P) and am stumped with this issue. Do I need to change both 3rd and 4th? Am I going about this issue the wrong way?

Bruce · « **Reply #1 on:** September 27, 2004, 12:53:44 AM »

You have to give more details.

What are your gear ratios now? 1-4 and R&P.
Tire dia?
What's your MPH at the end of the quarter?

flat4 · « **Reply #2 on:** September 27, 2004, 03:17:35 PM »

4.12 R&P 380 1st 2.06 sec 1.26 thrd .089 fourth. Currently, I'm running 205/75/15s on the back. End of the 1/4 is anywhere from 80-83 mph.

Bruce · « **Reply #3 on:** September 28, 2004, 01:39:15 AM »

Your rear tires are way toooooo tall. Your current gearing is even taller than stock.
Drop your tire size, you will see better acceleration in all gears. You shouldn't have to ever shift into 4th.
I'd suggest no taller than a 205/65/15. Even better would be a 205/60/15, or a 215/60/15.

Although your mph won't go up with a tire change, your ET will drop quite a bit. What's it now?

flat4 · « **Reply #4 on:** October 02, 2004, 10:00:05 PM »

I just ran a 15.4@84 mph