| Diff Ratios | Tyre/Wheel dimensions | Engine Performance | ||||||||
| DR1 | 3.14 | WD | 23.86 | Width | 225 | Weight | 650 | |||
| DR2 | 3.36 | WC | 74.98 | Profile | 50 | Power | 200 | 4750 | ||
| Size | 15 | Torque | 318.8 | 2600 | ||||||
| Gear Ratios | MPH/T | 5800 | 5800 | |||||||
| GR | FR1 | FR2 | 1 | 2 | MAX 1 | MAX 2 | ||||
| R380 | 1st | 3.692 | 11.59 | 12.41 | 6.13 | 5.72 | 35.53 | 33.20 | ||
| 2nd | 2.132 | 6.69 | 7.16 | 10.61 | 9.91 | 61.52 | 57.49 | |||
| 3rd | 1.397 | 4.39 | 4.69 | 16.19 | 15.13 | 93.89 | 87.74 | |||
| 4th | 1.000 | 3.14 | 3.36 | 22.61 | 21.13 | 131.16 | 122.57 | |||
| 5th | 0.770 | 2.42 | 2.59 | 29.37 | 27.45 | 170.34 | 159.18 | |||
| LT77 | 1st | 3.321 | 10.43 | 11.16 | 6.81 | 6.36 | 39.49 | 36.91 | ||
| 2nd | 2.087 | 6.55 | 7.01 | 10.84 | 10.13 | 62.85 | 58.73 | |||
| 3rd | 1.396 | 4.38 | 4.69 | 16.20 | 15.14 | 93.95 | 87.80 | |||
| 4th | 1.000 | 3.14 | 3.36 | 22.61 | 21.13 | 131.16 | 122.57 | |||
| 5th | 0.792 | 2.49 | 2.66 | 28.55 | 26.68 | 165.60 | 154.76 | |||
| T5 | 1st | 2.950 | 9.26 | 9.91 | 7.67 | 7.16 | 44.46 | 41.55 | ||
| 2nd | 1.940 | 6.09 | 6.52 | 11.66 | 10.89 | 67.61 | 63.18 | |||
| 3rd | 1.340 | 4.21 | 4.50 | 16.88 | 15.77 | 97.88 | 91.47 | |||
| 4th | 1.000 | 3.14 | 3.36 | 22.61 | 21.13 | 131.16 | 122.57 | |||
| 5th | 0.630 | 1.98 | 2.12 | 35.89 | 33.54 | 208.19 | 194.56 | |||
| FR1 | 1500 | 2000 | 2500 | 3000 | 3500 | 4000 | 4500 | 5000 | 5800 | |
| R380 | 1st | 9.19 | 12.25 | 15.31 | 18.38 | 21.44 | 24.50 | 27.56 | 30.63 | 35.53 |
| 2nd | 15.91 | 21.21 | 26.52 | 31.82 | 37.12 | 42.43 | 47.73 | 53.03 | 61.52 | |
| 3rd | 24.28 | 32.37 | 40.47 | 48.56 | 56.66 | 64.75 | 72.84 | 80.94 | 93.89 | |
| 4th | 33.92 | 45.23 | 56.53 | 67.84 | 79.15 | 90.45 | 101.76 | 113.07 | 131.16 | |
| 5th | 44.05 | 58.74 | 73.42 | 88.10 | 102.79 | 117.47 | 132.16 | 146.84 | 170.34 | |
| LT77 | 1st | 10.21 | 13.62 | 17.02 | 20.43 | 23.83 | 27.24 | 30.64 | 34.05 | 39.49 |
| 2nd | 16.25 | 21.67 | 27.09 | 32.51 | 37.92 | 43.34 | 48.76 | 54.18 | 62.85 | |
| 3rd | 24.30 | 32.40 | 40.50 | 48.60 | 56.70 | 64.80 | 72.89 | 80.99 | 93.95 | |
| 4th | 33.92 | 45.23 | 56.53 | 67.84 | 79.15 | 90.45 | 101.76 | 113.07 | 131.16 | |
| 5th | 42.83 | 57.11 | 71.38 | 85.66 | 99.93 | 114.21 | 128.49 | 142.76 | 165.60 | |
| T5 | 1st | 11.50 | 15.33 | 19.16 | 23.00 | 26.83 | 30.66 | 34.50 | 38.33 | 44.46 |
| 2nd | 17.48 | 23.31 | 29.14 | 34.97 | 40.80 | 46.63 | 52.45 | 58.28 | 67.61 | |
| 3rd | 25.31 | 33.75 | 42.19 | 50.63 | 59.07 | 67.50 | 75.94 | 84.38 | 97.88 | |
| 4th | 33.92 | 45.23 | 56.53 | 67.84 | 79.15 | 90.45 | 101.76 | 113.07 | 131.16 | |
| 5th | 53.84 | 71.79 | 89.74 | 107.68 | 125.63 | 143.58 | 161.53 | 179.47 | 208.19 | |
| Key | ||||||||||
| DR | Differential Ratio | |||||||||
| WD | Tyre Diameter as calculated | |||||||||
| WC | Tyre Circumference as calculated | |||||||||
| Width | Tyre Wdth | |||||||||
| Profile | Tyre profile | |||||||||
| Size | Tyre size in inches | |||||||||
| GR | Gear ratio | |||||||||
| FR | Final ratio as calculated | |||||||||
| MPH/T | Mile per hour per thousand revs as calculated | |||||||||
| MAX | Maximum Speed in Gear as calculated | |||||||||
Download the excel spreadsheet here
After I went to the extent of working all this out for myself I discovered that Quaife have produced a computer program which can do all the calculations, this can be obtained here