f10 f13

[Morton]

between 4-5 speed isnt 1st 2nd 3rd the same ratio in these gearboxes??
if not which is better for acceleration ??
also would i see much difference with a 4:18 cwp ???:thumb:

[mowgli]

get an f13cr box.

the basic wr box has the same ratios 1st - 4th, with 5th as an overdive.

the 5th in a cr box is the same as 4th in a wr box.

a 4.18 diff would work great in a f13cr box for better acceleration, but lower top speed

[Stuart]

get an f13cr box.

a 4.18 diff would work great in a f13cr box for better acceleration, but lower top speed

note the lower top end is only a few % not like you lose 30-40mph lol

[Morton]

not speed doesn worry me its for rallying!! so ill be lookin for a F13 cr with a 4:18 cwp ... thanks

[mowgli]

for rallying, you should try to find a 4.53:1 from an astra 1200 mk1 or mk2

[Morton]

did 1.2s ever come standard with a F13cr???

[mowgli]

nope, just an f10. you could fit a whole cluster from an f13 into it..

look for 1.0 corsa b 12v gboxes, they are f13cr

[Stuart]

There is also a 4.29 (or 28) fd too if you stumble across one :)