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Matt Monson Matt Monson is online now
gearhead
 
Join Date: Nov 2007
Location: Loverland, CO
Posts: 23,650
Quote:
Originally Posted by 1colbrz View Post
With 7500 rpm, 25.6" rear tires, and an 8:31 RP that would give about:
14:31 for a 1st gear (66 mph)
25:26 for a 5th gear (153mph)

Sound about right?

Thanks,
Gerry

How powerful is your engine? That 5th might be a tick short depending on your powerplant.

What we will often do for the California tracks is use a 4th gear that is good for nearly 140 mph with an active 1st that tops out around 70mph. Then at most tracks you are driving it as a 4spd, and only really use 5th at Cal Speedway or for very short sections on a couple of the other tracks.

With your specs:

1st 2.125 70mph
2nd1.550 95mph
3rd1.260 117mph
4th1.080 137mph
5th0.941 157mph

Talk to Kevin Roush at GAS. He's a bit of a 915 guru and has a lot of experience building narrow body air cooled cars that can run with the water pumpers...
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Old 12-11-2012, 09:54 AM
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