Hi All

I've done a search but can't seem to find a definitive answer!

I'm sorting out the bits for my build (a sort of morph from my single seater into my Westfield chassis).

I've got a Subaru diff (previous post) which looks good, is 22kg in weight and a lot longer than the Sierra / Freelander. It was also £60 complete with shafts / cvs etc.!

The chassis is an SEi (independent) so I Won't have the problems with the rear diff mounts fouling the de dion which I was originally planning.

It's a LSD and has a ratio of 3.55:1 which is in between the two ratios I was using on the single seater (54/16 and 54/15)

I was just wondering what others are using. This is a non road going sprint / hillclimb car by the way.

Regards

Wyn

[Edited on 15/10/08 by lsdweb]

I don't think there is a definitive answer Wyn, It also depends which engine and wheels you use.
I switched from a 3.62 to a 3.14 and although there is a difference, i wouldn't say either was better than the other, just different.
For that money i would give it a go, can't imagine it will be any problem, especially for the hills.

Al.




Originally posted by lsdweb
Hi All

I've done a search but can't seem to find a definitive answer!

I'm sorting out the bits for my build (a sort of morph from my single seater into my Westfield chassis).

I've got a Subaru diff (previous post) which looks good, is 22kg in weight and a lot longer than the Sierra / Freelander. It was also £60 complete with shafts / cvs etc.!

The chassis is an SEi (independent) so I Won't have the problems with the rear diff mounts fouling the de dion which I was originally planning.

It's a LSD and has a ratio of 3.55:1 which is in between the two ratios I was using on the single seater (54/16 and 54/15)

I was just wondering what others are using. This is a non road going sprint / hillclimb car by the way.

Regards

Wyn

[Edited on 15/10/08 by lsdweb]

Thanks Al

I guess you're right.

The 3.37 (54/16 tooth combination) was OK for the hills although I was only getting bursts of 2nd at Llys y Fran which is very twisty. Some of the guys were trying 54/14 (3.86) ratios but you can waste time changing up and down all the time!

I will try it although if I get it wrong it'll be costly to fit a Freelander unit afterwards!

Wyn

It's a Locost LSD, pretty difficult to ignore, in fact I'll....

OK, I've tried both the 3.2 Freeloader and 3.36 Sierra on my Westfield, using 205/60/13. Various Hairdrier units (R1's, Blades, GSXR's and a TL1000R). Basically, anything around this ratio is acceptable, I've got around 8-12mph/1K revs depending on engine. Some have the torque to pull right the way up, some not.

Simply adjust with wheel/tyre diameter

Are you sure the diff ratio is 3.55 ? , reason I ask is that Subaru quote final drive ratios in the handbooks ,a combination of diff ratio and final reduction in the gearbox , that is 1.1 : 1, so the diff could be 3.9 (3.55 x 1.1 = 3.9), suggest you count the teeth. Could you let us know the answer ? it would be nice find an alternative to the rare long ratio Sierra diffs !

RJ

I counted the teeth (I'm not at home so can't access the figures) - it's definitely 3.5454. I think it was 39/11 teeth (that works out right)

Unless there's some other method of altering the gearing in the nose of the diff I'd say this was just right!


Regards

Wyn

Brilliant, what car is the diff from , Impeza Turbo ?

quote:

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Brilliant, what car is the diff from , Impeza Turbo ?

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Photo
Rescued attachment diff1.jpg

And another
Rescued attachment diff2.jpg

Does anyone know the weight of a standard Sierra diff?

Have a look here.

Oh thanks!
So your new diff has about the same weight with the Sierra one, but yours is an LSD. Good find!

A touch heavier than the Sierra but it's a lot longer so I'll have a shorter propshaft. Plus it's a Subaru diff so should be unbreakable. And it cost me only £60, and I got the shafts in that price too!