Hi
I'm new round here and new to BEC's... however I have been conviced to get one.

To this aim I have purchased an R1 engine and I will need to purchase a diff to match.

So what is the best diff to use, I have a cossie one along with the drive shafts, but I understand there are better options as I don't need the strength (or extra weight).
apparently Dax use a ford donor diff were the shafts do not bolt up saving quite a bit of weight?

Any advice would be gratefully received.

Andy

OK I'm convinced, so are these easy to source and is the disc conversion cheap and easy?

push fit diffs are probably more common than the bolt on ones, but you wont find one with an LSD. On the bright side, you can add the LSD easily enough (if you want one), and the low ratio diffs are usually push fit anyway.

What ratios are suitable for racing on 13" wheels?

Do you need a box to make the ratio higher(?) ?

Andrew

with 13" wheels you'll need a 3.14 diff, no question. A 3.14 with 195/50/R13s will give these maximum speeds at 11750 RPM eng each gear on a 1998 R1 engined car. (not guaranteed to be completely accurate)

1st 54
2nd 76
3rd 94
4th 106
5th 118
6th 127

A 3.62 diff with 195/50/R15 tyres gives about 5% less speed in each gear and is perhaps a more common combination.

195/60/13 or 195/65/13 may be OK with a 3.38 diff but taller tyres may not give you as sharp handling as you may want

[Edited on 5-9-2005 by smart51]

...as already advised do your homework on the ratios. I built a live (escort) axle'd car with CBR thou' motor. Oops - you can only go to 3.54 with an escort axle!

I'm now building a 'narrow' deDion back end with a 3.14 Sierra diff (and they are getting hard to find and pricey - start looking now!). BTW my mate has a Fury R1 on 185-60x13" and he runs a 3.38 diff.