| Diff Ratios | Tyre/Wheel dimensions | Engine Performance | ||||||||||
| DR1 | 3.38 | WD | 23.86 | Width | 225 | Weight | 650 | |||||
| DR2 | 3.38 | WC | 73.23 | Profile | 50 | Power | 280.8 | 5658 | ||||
| Size | 15 | Torque | 299.6 | 4195 | ||||||||
| Gear Ratios | MPH/T | 5800 | 6000 | |||||||||
| GR | FR1 | FR2 | 1 | 2 | MAX 1 | MAX 2 | ||||||
| R380 | 1st | 3.692 | 12.48 | 12.48 | 5.56 | 5.56 | 32.23 | 33.34 | ||||
| 2nd | 2.132 | 7.21 | 7.21 | 9.62 | 9.62 | 55.81 | 57.74 | |||||
| 3rd | 1.397 | 4.72 | 4.72 | 14.69 | 14.69 | 85.18 | 88.12 | |||||
| 4th | 1.000 | 3.38 | 3.38 | 20.52 | 20.52 | 118.99 | 123.10 | |||||
| 5th | 0.770 | 2.60 | 2.60 | 26.64 | 26.64 | 154.54 | 159.87 | |||||
| LT77 | 1st | 3.321 | 11.22 | 11.22 | 6.18 | 6.18 | 35.83 | 37.07 | ||||
| 2nd | 2.087 | 7.05 | 7.05 | 9.83 | 9.83 | 57.02 | 58.98 | |||||
| 3rd | 1.396 | 4.72 | 4.72 | 14.70 | 14.70 | 85.24 | 88.18 | |||||
| 4th | 1.000 | 3.38 | 3.38 | 20.52 | 20.52 | 118.99 | 123.10 | |||||
| 5th | 0.792 | 2.68 | 2.68 | 25.90 | 25.90 | 150.25 | 155.43 | |||||
| T5 | 1st | 2.950 | 9.97 | 9.97 | 6.95 | 6.95 | 40.34 | 41.73 | ||||
| 2nd | 1.940 | 6.56 | 6.56 | 10.58 | 10.58 | 61.34 | 63.45 | |||||
| 3rd | 1.340 | 4.53 | 4.53 | 15.31 | 15.31 | 88.80 | 91.86 | |||||
| 4th | 1.000 | 3.38 | 3.38 | 20.52 | 20.52 | 118.99 | 123.10 | |||||
| 5th | 0.630 | 2.13 | 2.13 | 32.57 | 32.57 | 188.88 | 195.39 | |||||
| FR1 | 1500 | 2000 | 2500 | 3000 | 3500 | 4000 | 4500 | 5000 | 5800 | 6000 | ||
| R380 | 1st | 8.34 | 11.11 | 13.89 | 16.67 | 19.45 | 22.23 | 25.01 | 27.78 | 32.23 | 33.34 | |
| 2nd | 14.43 | 19.25 | 24.06 | 28.87 | 33.68 | 38.49 | 43.30 | 48.12 | 55.81 | 57.74 | ||
| 3rd | 22.03 | 29.37 | 36.71 | 44.06 | 51.40 | 58.74 | 66.09 | 73.43 | 85.18 | 88.12 | ||
| 4th | 30.77 | 41.03 | 51.29 | 61.55 | 71.81 | 82.07 | 92.32 | 102.58 | 118.99 | 123.10 | ||
| 5th | 39.97 | 53.29 | 66.61 | 79.93 | 93.26 | 106.58 | 119.90 | 133.22 | 154.54 | 159.87 | ||
| LT77 | 1st | 9.27 | 12.36 | 15.44 | 18.53 | 21.62 | 24.71 | 27.80 | 30.89 | 35.83 | 37.07 | |
| 2nd | 14.75 | 19.66 | 24.58 | 29.49 | 34.41 | 39.32 | 44.24 | 49.15 | 57.02 | 58.98 | ||
| 3rd | 22.04 | 29.39 | 36.74 | 44.09 | 51.44 | 58.79 | 66.13 | 73.48 | 85.24 | 88.18 | ||
| 4th | 30.77 | 41.03 | 51.29 | 61.55 | 71.81 | 82.07 | 92.32 | 102.58 | 118.99 | 123.10 | ||
| 5th | 38.86 | 51.81 | 64.76 | 77.71 | 90.67 | 103.62 | 116.57 | 129.52 | 150.25 | 155.43 | ||
| T5 | 1st | 10.43 | 13.91 | 17.39 | 20.86 | 24.34 | 27.82 | 31.30 | 34.77 | 40.34 | 41.73 | |
| 2nd | 15.86 | 21.15 | 26.44 | 31.73 | 37.01 | 42.30 | 47.59 | 52.88 | 61.34 | 63.45 | ||
| 3rd | 22.97 | 30.62 | 38.28 | 45.93 | 53.59 | 61.24 | 68.90 | 76.55 | 88.80 | 91.86 | ||
| 4th | 30.77 | 41.03 | 51.29 | 61.55 | 71.81 | 82.07 | 92.32 | 102.58 | 118.99 | 123.10 | ||
| 5th | 48.85 | 65.13 | 81.41 | 97.70 | 113.98 | 130.26 | 146.55 | 162.83 | 188.88 | 195.39 | ||
| 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