Rover PG1 gearbox
The Rover PG1 gearbox fitted to the K series Elise, was manufactured by Powertrain Limited (who have now ceased trading), is a five-speed constant mesh gearbox, which employs helical gears for speed transmission and final drive. The transmission castings are full aluminium construction and all other components optimised for improved weight (36kg dry). The gearbox can be supplied with either a standard open differential or a Limited Slip Differential, presently Torsen.
Due to the modular design of the gearbox various final drive ratio and 1st to 5th gear ratio combinations have been used. Including both present and past an overall total of 21 ratio combinations, 5 speedometer gear ratios; and 7 clutch levers designs for both hydraulic and cable operation can be called on to ensure the customers requirements are met.
Gearbox type
Identification is via the serial number on the bell housing housing;
Gearbox Application Table
| Gearbox Code | 1 | 2 | 3 | 4 | 5 | Final Drive | Used In |
|---|---|---|---|---|---|---|---|
| G6BP | 3.250 | 1.895 | 1.308 | 1.033 | 0.848 | 3.938 | S2 111S (WR "long" box) |
| C4BP | 3.167 | 1.842 | 1.308 | 1.033 | 0.765 | 4.200 | MGF VVC (as standard but final drive 4.2) |
| C6BP | 3.167 | 1.842 | 1.308 | 1.033 | 0.765 | 3.938 | Elise S1 standard and MGF |
| B4BP | 2.923 | 1.750 | 1.308 | 1.033 | 0.848 | 4.200 | S1 111S & S1 Sports 135 & S2 135R & S2 standard (CR Box) |
| B4BPU | 2.923 | 1.750 | 1.308 | 1.033 | 0.848 | 4.200 | Exige S1 uprated (CR Box) |
| B4BPQ | 2.923 | 1.750 | 1.308 | 1.033 | 0.848 | 4.200 | Exige S1 with LSD (CR Box) |
| B6BST | 2.923 | 1.750 | 1.308 | 1.033 | 0.848 | 3.938 | Rover "BRM" 200 - CR box with std final drive & torsen LSD |
| 340R UCR | 3.0 | 1.937 | 1.556 | 1.273 | 1.043 | 3.92 | 340R LOTAC05255 Conversion |
| NA | 3.167 | 1.842 | 1.410 | 1.100 | 0.909 | 3.938 | Eliseparts |
Gearbox Codes
The first letter is the gearset
| Letter | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| b | 2.923 | 1.750 | 1.308 | 1.033 | 0.848 |
| c | 3.167 | 1.842 | 1.308 | 1.033 | 0.765 |
| g | 3.250 | 1.895 | 1.308 | 1.033 | 0.848 |
| k | 2.923 | 1.750 | 1.222 | 0.935 | 0.765 |
| l | 2.923 | 1.750 | 1.222 | 0.848 | 0.649 |
| m | 3.167 | 1.842 | 1.222 | 0.848 | 0.649 |
| r | 3.250 | 1.895 | 1.308 | 1.033 | 0.765 |
| s | 3.250 | 1.895 | 1.222 | 0.848 | 0.649 |
| t | 3.250 | 1.895 | 1.222 | 0.935 | 0.714 |
| v | 3.250 | 1.895 | 1.222 | 0.935 | 0.765 |
| w | 3.167 | 1.842 | 1.308 | 1.033 | 0.714 |
The number that follows the gear set number is the Final drive ratio
4 = 4.200 (15/63)
5 = 4.062 (16/65)
6 = 3.938 (16/63)
7 = 3.647 (17/62)
The right hand letters are the diff
BP = Open
BPQ = Quaife LSD
BST = Torsen
See also
- Gearbox Reversing Switch
- Gearbox oil
- http://forums.seloc.org/t/96372
- http://forums.seloc.org/t/110925
External links
- http://www.gearboxman.co.uk
- http://www.powertrainltd.com/brochure/pt_brochure_product.pdf
- WARNING - The Lotus line is wrong on the Powertrain brochure, as it has the B4 CR code but the G6 WR ratios
- http://www.quaife.co.uk/LOTUS
- http://forums.seloc.org/viewthread.php?tid=173780 Gearbox drive program