gearbox

[mike r5 gtt]

i run a c1j lump and am looking at upgrading my gearbox!other than spending thousands with quaife was wondering is it poss / has any1 run a 172 / 225 box or similar????looking for longer gears and more strengh!

[Matt Cole]

i run a c1j lump and am looking at upgrading my gearbox!other than spending thousands with quaife was wondering is it poss / has any1 run a 172 / 225 box or similar????looking for longer gears and more strengh!

225 box completely different so no. 172 box will fit but questionable on wether its stronger. You will lose your speedo though.

[Andrew Cooke]

and the 172 has shorter gears, not longer.

[dave r5]

wat box would be better for quater miles the longer ratio or shorter 1.

or a mix up of the pair in 1 casing. (if thats possible)
bearing in mind i have the b18ft engine not a c1j.

[Andrew Cooke]

wat box would be better for quater miles the longer ratio or shorter 1.

or a mix up of the pair in 1 casing. (if thats possible)
bearing in mind i have the b18ft engine not a c1j.

at the end of the day there isn't a huge lot to be found in gear ratios, however, my choice is to gear it to rev just past peak power in 4th through the trap. The biggest problem is the rev drop 1-2, it's enough that a big turbo can drop out of spool. Most of the standard boxes have a bigger drop than the GTT one.

[dave r5]

so for simplicity, retain the standard box.

sounds easyer

[mike r5 gtt]

a 172 box has shorter gears than a gtt box????every gear??

[Scoff]

a 172 box has shorter gears than a gtt box????every gear??


Final drive is shorter, so speed is down at any fixed RPM compared to the GTT.

There is no one-for-all optimum, you have to decide what works best with the tyre height you are using, the shape of your torque curve and how much power (trap speed) you have.