Rover PG1 gearbox
The Rover PG1 gearbox fitted to the K series Elise, manufactured by PTP, 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;
C6BP.... Standard box for Elise Mk1 and MGF
C4BP.... MGF VVC box (as standard but final drive 4.2)
B4BP.... Lotus CR box, Elise Mk1 111s, Elise Mk1 Sport 135 + Elise Mk2 standard box
B4BPU... Exige S1 (uprated)
B4BPQ... Exige S1 with LSD
G6BP.... Elise S2 111S
Gearbox Application Table
| Car | PG1 | 1 | 2 | 3 | 4 | 5 | Final |
| S1 "standard" | C6BP | 3.167 | 1.842 | 1.307 | 1.033 | 0.765 | 3.938 |
| S1 111S & S2 "c/r" | B4BP | 2.923 | 1.750 | 1.307 | 1.033 | 0.848 | 4.200 |
| MGF vvc | C4BP | 3.167 | 1.842 | 1.307 | 1.033 | 0.765 | 4.200 |
| S2 111S "long" | G6BP | 3.250 | 1.895 | 1.308 | 1.033 | 0.848 | 3.937 |
| Eliseparts | 3.167 | 1.842 | 1.410 | 1.100 | 0.910 | 3.938 | |
| Suggested Ideal | *6BP | 2.923 | 1.750 | 1.307 | 1.033 | 0.765 | 3.938 |
| Exige S1 uprated | B4BPU | 2.923 | 1.750 | 1.307 | 1.033 | 0.848 | 4.200 |
| Exige S1 with LSD | B4BPQ | 2.923 | 1.750 | 1.307 | 1.033 | 0.848 | 4.200 |
Gearbox Codes
The first letter is the gearset
c / 3.166 / 1.842 / 1.308 / 1.033 / 0.765
s / 3.250 / 1.894 / 1.222 / 0.848 / 0.649
b / 2.923 / 1.750 / 1.308 / 1.033 / 0.848
k / 2.923 / 1.750 / 1.222 / 0.935 / 0.765
m / 3.166 / 1.842 / 1.222 / 0.848 / 0.649
v / 3.250 / 1.894 / 1.222 / 0.935 / 0.765
t / 3.250 / 1.894 / 1.222 / 0.935 / 0.714
r / 3.250 / 1.894 / 1.308 / 1.033 / 0.765
w / 3.166 / 1.842 / 1.308 / 1.033 / 0.714
l / 2.923 / 1.750 / 1.222 / 0.848 / 0.649
g / 3.250 / 1.894 / 1.308 / 1.033 / 0.849
The number that follows the gear set number is the Final drive ratio
4 = 4.200 (15/63)
5 = 4.062 (16/65)
6 = 3.937 (16/63)
7 = 3.647 (17/62)
The right hand letters are the diff
BP = Open
BPQ = LSD
Gearbox oil
- Texaco MT94
- Castrol TAF-X
- Castrol SMX-S
Other sources of information