diff ratios

[mikel003003]

Has anyone fitted a 4.27 ratio diff, I have been sniffing around eBay for an LSD and just wondered if it was an option

[phillpot]

That's not going to help the fuel economy !!!!!

[mikel003003]

Mmmmm didn't think of that

[mikel003003]

There's also 4.44 but they seem to be megabucks

[S2Mike]

The guy I bought my S off had a cosworth LSD that he offered me for £400, at the time I didn't realise the benefits and declined, he put it on fleabay and got £600 for it, and I have seen them on there for close to £900.
Apparently a straight swop, with amazing improvements to handling, but obviously mpg will suffer as Mike points out.

[mikel003003]

I don't want to reopen an old subject what I think I need is a 7.5 inch 3.64 LSD with 100mm flange at a good price its a bit of a mine field I certanly can't justify
£600

[phillpot]

The "viscous" type are (or at least were?) available for a lot less but to get correct 100mm driveshaft flange sizes need to come from an early Scorpio Cosworth not a Sierra which are 108mm if I remember correctly

Later Scorpio's had traction control and so reverted to an open diff.

If you are looking for one the ID tag should have at least two A's in the middle of the code, last three numbers should be the ratio eg 364 would be a 3.64:1

[magpies]

I have a 4.27 LSD in my S

with the wheels/tyres I intend using will lower the top speed to 135mph (6500 rpm)

My car is not on the road yet so can't comment about road manners

[mikel003003]

magpies said:

I have a 4.27 LSD in my S

with the wheels/tyres I intend using will lower the top speed to 135mph (6500 rpm)

My car is not on the road yet so can't comment about road manners

Ah, so it will work ? Are you running original prop and driveshafts ?

[mikel003003]

What's an open diff ? Non LSD ?

[phillpot]

I've no doubt it will work but with standard ratio I'm always "looking for another gear" at about 70, lower ratio would be even worse (think Magpies is building a rally car?), guess it depends on what kind of use you want from the car?

And although TVR speedo's may not be the most accurate it will be even further out!


pulling 6500 revs in fifth might take a bit more than 170 horses ?

[phillpot]

mikel003003 said:

What's an open diff ? Non LSD ?

yep.

[magpies]

Original drive shafts and diff end of prop.....special prop made as I'm running an MT75 box (along with Cossy 24v engine = so about 220bhp). The crown wheel and pinion are from a 2.0ltr Scorpio, which uses the usual 7.5" diff.

Edited by magpies on Wednesday 17th April 20:56

[mikel003003]

phillpot said:

I've no doubt it will work but with standard ratio I'm always "looking for another gear" at about 70, lower ratio would be even worse (think Magpies is building a rally car?), guess it depends on what kind of use you want from the car?

And although TVR speedo's may not be the most accurate it will be even further out!


pulling 6500 revs in fifth might take a bit more than 170 horses ?

It ain't gonna work for me is it? Keep looking for that 3.64

[mikel003003]

magpies said:

Original drive shafts and diff end of prop.....special prop made as I'm running an MT75 box (along with Cossy 24v engine = so about 220bhp). The crown wheel and pinion are from a 2.0ltr Scorpio, which uses the usual 7.5" diff.

Edited by magpies on Wednesday 17th April 20:56

How's it comeing on Mick ?