Guess what broke on Project RH9? Another factory transmission. Old school Turbo readers might be seeing visions of another Project Talon in the works. To be honest, I’m picturing the same thing.

Text & Photos by Michael Ferrara


Back in the days, Project Talon chewed up every single available transmission in the Southern California area. All totaled, close to $10,000 was invested in factory transmissions that couldn’t last a full pass. Learning from our lessons of yesteryear, we decided to research our transmission options for our GT-R.

The Close-Ratio Aftermarket Gear Sets

A number of companies produce aftermarket gear sets for the factory gearbox. These gear sets feature improved ratios as well as a higher- strength material. From our research, we’ve heard of many applications making about 600 wheel horsepower that effectively used these gear sets.

The Straight-Cut Gear Sets

There are also a couple of manufacturers that offer straight-cut gear sets for the factory gearbox. These offer additional strength but are considerably noisier than the bevel cut gear sets.

RPM: 8000
Tire Diam. (mm): 640  25.2 inch
Diff Pinion: 9
Crown Wheel: 37
Diff Ratio: 4.111
Pinion Gear Total Teeth Gearbox Ratio Over All Ratio RPM Drop M.P.H.
C.M. 22 26 48 1.182
1st 14 34 48 2.870 11.799 50.82
2nd 17 31 48 2.155 8.860 1993 67.69
3rd 20 27 47 1.595 6.559 2077 91.43
4th 23 24 47 1.233 5.070 1816 118.29
5th 26 22 48 1.000 4.111 1513 145.87
6th 27 20 47 0.875 3.599 997 166.63


RPM to Speed chart (8000RPM)

RPM: 10000
Tire Diam. (mm): 640  25.2 inch
Diff Pinion: 9
Crown Wheel: 37
Diff Ratio: 4.111
Pinion Gear Total Teeth Gearbox Ratio Over All Ratio RPM Drop M.P.H.
C.M. 22 26 48 1.182
1st 14 34 48 2.870 11.799 63.53
2nd 17 31 48 2.155 8.860 2491 84.61
3rd 20 27 47 1.595 6.559 2597 114.29
4th 23 24 47 1.233 5.070 2271 147.86
5th 26 22 48 1.000 4.111 1891 182.34
6th 27 20 47 0.875 3.599 1246 208.28

 

RPM to Speed chart (10000RPM)

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