Thread: Ta04r...
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Old 09-16-2003, 12:15 PM  
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Join Date: Jan 2003
Location: USA
Posts: 269

Originally posted by hawker
ok thanks for your help, i'll look at gearinf down, just what got me is that the rollout then means i'm very low compared to everyone else, but i'll see what happens, have u got a forulma to work out rolllout? I can't remember what it is
Multiply the diameter *PI
2.0 tire * 3.14 = 6.28 Circumference

Divide the pinion into the spur
15 pinion / 128 spur = 8.53 Ratio

Multiply Ratio * the Final Drive of any car (namely the 04)
8.53 ratio * 2.13 TA04 tranny = 18.17 Final Drive Ratio

Divide the final drive ratio into the circumference
18.17final drive / 6.28 Circ = .35 Rollout

This is about as simple I can make it to show you how to get the rollout. You can follow it with a calculator to see how the numbers get divided & multiplied. This is not metric but the principle is pretty much the same.

Some people usually use a spreadsheet like Excel or Lotus and plug and play. If you don't have those make a graph on a piece of paper.

Many times people focus on the Final Drive ratio rather than rollout. I know for me that usually is the case.

A big advantage, if you can afford it is getting the Orion LCS. It will help you see what kind of times your car is turning by the gear changes you make. If you cannot get that then ask a buddy to stop watch ya on the track.

You will find out that going blistering fast down the straights does not mean you are fast. Usually you will suffer on the 10 or so turns on the infield.

Hope this helps.


Last edited by gcooper; 09-16-2003 at 12:21 PM.
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