difference between f13 cr and wr

[jonn]

i have a f13 cw 3.94 gearbox on my nova than i use for autocross. i stay in 2nd gear 90% of the time small short track. the problem i have is i cant get enough speed out of second gear i just hit the limiter a lot. i don't use 3rd gear because i will lose to much time changing gear.

i have a f13 wr 4.18 cluster and i just want to find out will i get much more speed out of this in 2nd gear? any help would be great

[Stuart]

You will hit the limiter at a lower speed

[bazil]

Put the 3.7 diff into the wr box for a longer 2nd gear

[jonn]

ok so if i fit a lower final drive i should be ok then, the lower the better?

[bazil]

Use a ratio calculator to work out your speed-RPM also factor in your tyre size,

It really depends on what you want, what's your 3.94 diff from?

[Stuart]

To an extent... The rate of acceleration will be lower so you need to test/factor that in

[bazil]

To an extent... The rate of acceleration will be lower so you need to test/factor that in

This ^^^

My 1.6 GSI was slower and boring to drive with WR gears on a 3.74 diff, but when I fitted CR gears and 3.74 it was much better fun to drive.

[jonn]

ok thanks for the help

[garyc]

or fit larger tyres or up the limit of the rev limiter, what have you got it set at?

[jonn]

standard rev limit so about 6700rpm, i have a chiped ecu that revs to 8k so i might fit that, i was only .4 of a second from finishing in 1st place so every little helps! i cant really fit any bigger tyres because they rub off the inner arch and gearbox when i lock hard.