fd3 rear diff ratio gear..please look...

[rxv8]

does anyone know if i can change the rear diff ratio from the standard 4.1...to something between say a 3.1-3.5...and if so where can i get the gears and how cheap are they....help very much needed...thanks...

[MikeLMR]

the auto\'s have a taller diff, Garry had one for sale.

you can get hold of him through //www.rotarytarts.co.uk it may even be listed for sale on there.

[rxv8]

but the autos are 3.9 arent they...

[MikeLMR]

thats probably going to be the closest you can get, unless the 20B cosmo\'s came with somthing taller

P.S moved this thread and deleted the other ... one thread is enough.

[kev-yorks]

The 13b cosmo has a 4.1 ratio 20b has a ratio of 3.9

[clive]

3.9 is the highest gear your going to get.

An easier way is to up your rim size and your wall profile.

I just have with a set of 19\'s and 40 profile.

[20B_boy]

19s?! Shame on you Mr H!

Got any pics?

[rxv8]

i think i am going with a bmw 7 series rear diff as they are good for up to 600 torque....

[Glenn Butcher]

Why do you want such a tall ratio?

May be a little expensive to install a diff that would need a lot of modification to fit?

[rxv8]

i need the tall diff as with a 26"tyre i would be doing 6000rpm at 100mph with the th350 box,which is way to high...

[Glenn Butcher]

What is a th350 box?

[clive]

Hi Glen,

It\'s one of those slush boxes that goes up behind a V8

[Glenn Butcher]

Thought it may have been, but surely it would have a 1:1 somewhere in the box? (i.e. 3rd in the auto? or 4th with manual box?).

What are the ratio\'s then in the th350?

[rxv8]

Originally posted by clive
Hi Glen,

It\'s one of those slush boxes that goes up behind a V8

actually its an auto with a manual valve body which makes it virtually tiptronic...slush box,come on clive...