What involved changing English axle open diff to lsd?

[Qwertyseiw]

Hi

Ive been looking at a fairly recently built 180bhp Westfield track car,  that has an English axle, but with an open diff.  I have 2 questions,  why would someone build a dedicated track car with an open diff?  What is involved in changing the car to LSD?

Thanks

[B.RAD]

Don't know why someone would do that (could be cost, knowledge, or a combination of the two) but it's a pretty straightforward task.

Unbolt the prop, remove the wheels, pull out the half shafts, drain the diff, unbolt the diff carrier, remove. Then you decide whether you want to fit a new LSD to the original carrier or have a second carrier built up with an LSD so you can just bolt the new one in. A good time to replace the carrier for an alloy version if weight saving is your game and a good time to change the ratio depending on your intended use too.

[Marto303]

If it’s a wide, I might have an axle already built up with Lsd 4:4 CWP and disc brake conversion I could be talked into selling 

[Qwertyseiw]

Hi Marto/all,

Would a 4.4 ratio suit a track car?  2l Zetec, 170, T9 with std ratios?

[AdamR]

Yep, ideal 

[Onliest Smeg David]

21 minutes ago, AdamR said:

Yep, ideal 

What do I know!  Was just going to say opposite as I had thought standard type 9 ratios would be too short for a 4.4 diff unless engine very high revving!

[B.RAD]

2 hours ago, Qwertyseiw said:

Hi Marto/all,

Would a 4.4 ratio suit a track car?  2l Zetec, 170, T9 with std ratios?

It'd be spot on. You may lose out slightly on top end but it'll be a ripper in the corners and corner exit. You can always fit 15" rims to bring some top speed back.

[AdamR]

1 hour ago, Dave (OnliestSmeg) - Manchester AO said:

What do I know!  Was just going to say opposite as I had thought standard type 9 ratios would be too short for a 4.4 diff unless engine very high revving!

Hmm. Got me worried! I'll explain... I never hit top of 5th in mine, with soft limiter at 6400 and a 4.1 diff and similar power, so a 4.4 should give optimal gearing I think!

[B.RAD]

26 minutes ago, AdamR said:

Hmm. Got me worried! I'll explain... I never hit top of 5th in mine, with soft limiter at 6400 and a 4.1 diff and similar power, so a 4.4 should give optimal gearing I think!

Same, I never got near top of 5th in mine on a 4.1 and that was with a fair bit more power, so 4.4 would be ideal IMO

[Onliest Smeg David]

Ah! That makes sense- as 4th is always 1:1 ratio?

A longer ratio of 1st gear makes it a more 'usable' gear?

So a 4.4 on standard ratio gearing good in higher gears, but maybe not be so for 1st/2nd?

[AdamR]

Yeah, makes use of the 5th gear (and puts all the rest closer), otherwise you're just carrying it around doing nowt.

Fast starts from stationary, just use 2nd, that'll be pretty much the same as a long 1st in a posh box.

[Qwertyseiw]

I’m following this with interest.

[Marto303]

You could work all this out for yourself and compare what you have now with what you’d have with a new diff ratio using any of the online gear ratio calculators available, like this one on Tiggers site http://westfield-world.com/gtc.html

[AdamR]

And you only need 120mph (ish, depending on headlight size, windscreen type, etc) at the limiter in 5th gear 

[John Loudon - Sponsorship Liaison]

I've always run 4.44 in my car. However, too shorter first gear combination will spin the rears from a standing start very easily. I would be aiming for 125-130mph top end

Martos diff / axle offering is a bargain