Thinking back , the chain drive on early Clubsport cars seemed to work well , it took sometime to find a correct quality chain that would wear at an acceptable rate, but also these cars had relatively lower grip tyres and relatively little downforce, the cars would slide very controllable in corners , great fun, but the lack of grip would limit the load on the transmission components
When the Prosport 1300 was conceived , with F3 sized tyres and wings , the transmission load increased , and we had to work harder on chain life, especially when we were doing two hour races with refueling and driver changes, adjusting or lubing a chain mid race is not best idea
The chain drive is seen as very efficient, but, I would suggest folks should try to hold one in your hand when it is directly off the track, it’s another level of hot, amazing it continues to work, it gives you an idea of the energy it is coping with – it’s significant
Plus, it was 2001 and we should be thinking about moving on the level of serviceability from open, unprotected chain drive, worked well in 1901, but so did grey cast iron – until we discovered something better. And our customers were using in all locations, tracks in desert around a lot of sand, chain does not last long if it is not lubed regularly and exposed to grit.
As the SR3 was even bigger, more powerful, heavier, two seats etc, we looked at a simple way of taking drive from the output shaft to a differential.
The location and geometry designed the basic transmission layout really, a question of “joining the dots” drop straight back to rear axle with in line straight cut gears , and idler in the train to provide a better means of reverse
Mike Quaife was someone I had worked with for my ford based gearboxes in earlier life.
Quaife Engineering supplied our first 150 differentials for Clubsport and Prosport Cars.
Mike and Quaife Engineering was very supportive of new initiatives and attacked new ideas with the same energy that we all did , and was keen to show what they could do.
So together , back and forth with ideas , possibilities and costs , the “Gear Drive Unit” was concepted in double quick time.
Quaife paid for all casting design and tooling , with one proviso , that Mike and I still laugh about today , Mike insisted we must order and take “ at least 25 units “ last count was 2000 transmissions in 18 years ….. not a bad ‘bet’ by Mike!