rear diffs

[hal 1]

What ratios are available for the jag diff as fitted to TVRs ? looking to go sprinting and now working on gear ratios
Thanks

[shpub]

2.88... 3.03... 3.33.... 3.54....

3.54 is normally the one to use. Having played around with ratios etc... unless you are prepared to change diffs for each circuit it is very difficult to get an ideal ratio to cover everything.

[jellison]

Jag diff - what TVR is this - Shpub - are they BTR ratios you are quoting?

Jag diff for my Griff200 is 3.55 - but presume loads of difference Crown wheel and pinions. You'd want shorter for Hill climb (maybe).

[Daftlad]

jellison said:

Jag diff - what TVR is this.

Most up to the new Griff and Chim had the salisbury unit. (Tr6 and GT6 diffs were used in Vixens and early Ms).

My Griff 400 (Real one) had a 3,54 salisbury 4HU - from a Jag, suspect yours will be the same?

[shpub]

Its for Wedges, M series.

[jellison]

Daftlad said:

jellison said:

Jag diff - what TVR is this.

Most up to the new Griff and Chim had the salisbury unit. (Tr6 and GT6 diffs were used in Vixens and early Ms).

My Griff 400 (Real one) had a 3,54 salisbury 4HU - from a Jag, suspect yours will be the same?

Yep but the are not the toughest. We have just put a Quaife ATB in own main LSD for next year, keep the Salibury as a spare with a different CWP (4.1) vs the new one (4.3!!).

Likely keep Griff200(Real One) as is for bit.

Didn't know you had a Griff!?

[hal 1]

Thanks guys, been offered a 3.54 and a 3.3 so i'll try both of those out
thanks

[heightswitch]

hal 1 said:

Thanks guys, been offered a 3.54 and a 3.3 so i'll try both of those out
thanks

Now I am always willing to be proven wrong guys but..

Griffith 200 / 400 were never fitted with a 3.54 Salisbury 4HU as standard. The salisbury 4HU in 3.07 was the original fitment in a griffith 400 and later 200's the early 200's had the MGB banjo Diff as per the grantura.

The Tuscan V6 was the first 4HU to have the 3.54. Even in this model the early cars had a 3.31 ratio.

I think the 3.54 came as standard on all salisbury equipped 3000M's

The 3.54 is generally the ratio of choice for UK short track's in a griff 400, I alos intend to keep a spare 3.7, for the very short track's.

Neil.

[jellison]

heightswitch said:

hal 1 said:

Thanks guys, been offered a 3.54 and a 3.3 so i'll try both of those out
thanks

Now I am always willing to be proven wrong guys but..

Griffith 200 / 400 were never fitted with a 3.54 Salisbury 4HU as standard. The salisbury 4HU in 3.07 was the original fitment in a griffith 400 and later 200's the early 200's had the MGB banjo Diff as per the grantura.

The Tuscan V6 was the first 4HU to have the 3.54. Even in this model the early cars had a 3.31 ratio.

I think the 3.54 came as standard on all salisbury equipped 3000M's

The 3.54 is generally the ratio of choice for UK short track's in a griff 400, I alos intend to keep a spare 3.7, for the very short track's.

Neil.

Cool - I am taking note Neil! All I know is that the think sitting on the garage floor is Jag diff with 3.54 on it God know what a 4HU is? 3.07 sound really long! I want massive acceleration! Spare 3.7 sounds good.

Neil - is it the 3.6 Jag XJS (or other too that have these in? All LSD Salisburys?). I'll get another when its built.

[heightswitch]

jellison said:

heightswitch said:

hal 1 said:

Thanks guys, been offered a 3.54 and a 3.3 so i'll try both of those out
thanks

Now I am always willing to be proven wrong guys but..

Griffith 200 / 400 were never fitted with a 3.54 Salisbury 4HU as standard. The salisbury 4HU in 3.07 was the original fitment in a griffith 400 and later 200's the early 200's had the MGB banjo Diff as per the grantura.

The Tuscan V6 was the first 4HU to have the 3.54. Even in this model the early cars had a 3.31 ratio.

I think the 3.54 came as standard on all salisbury equipped 3000M's

The 3.54 is generally the ratio of choice for UK short track's in a griff 400, I alos intend to keep a spare 3.7, for the very short track's.

Neil.

Cool - I am taking note Neil! All I know is that the think sitting on the garage floor is Jag diff with 3.54 on it God know what a 4HU is? 3.07 sound really long! I want massive acceleration! Spare 3.7 sounds good.

Neil - is it the 3.6 Jag XJS (or other too that have these in? All LSD Salisburys?). I'll get another when its built.

The Early XJS 3.6 cars have the 3.54 look for a powerlok tag or better still whip the inspection cover off the back to check for LSD. Also believe it or not, daimler hearses and Limos also had 3.54.
look for 4HU on the casing there were also 2 other types of jag diff, all not particularly good. The 4HU is the one that takes 2 people to lift. (I kid ye not)

The later 4.0ltr jags are also 3.54 but aren't 4HU's

Neil.

[jellison]

Cool - great info - Cheers Neil. Yep min is F'in heavy. Engine (fia iron heads and iron cased top loade and the jag diff make for huge weight low down on the this (downforce) - just as well the rest does not weigh much! What weight are you aiming for?

[heightswitch]

jellison said:

Cool - great info - Cheers Neil. Yep min is F'in heavy. Engine (fia iron heads and iron cased top loade and the jag diff make for huge weight low down on the this (downforce) - just as well the rest does not weigh much! What weight are you aiming for?

If i can get down to 14ST I will be pretty chuffed. Then I will start shaving from the car.
N.

[jellison]

HAHA.

I am 11stone and aiming for car to be under 900kg - but not really likely, but they change the rules in the TSCC championship last year after steve watton spanked allcomers and put weight to 1000kg!

[milko]

Hi people.

Sure the late M series had 4HU 3.54:1 diffs? I've heared they are 3.31.
Anyone have the facts?
I'm now tuning a 3000M. Want to keep the ford type5 4 speed gearbox as it is just exellent but I like the car to cruise on lower revs.
I can buy a 2.88 power loc unit from a '83 XJ-S and I calculated that if the standard diff is 3.31 it would have a top speed of 230 with the new dif. So I don't need a fifth gear with the 2.88 dif. The engine I'm building is a 3.4L version of the essex with a va63 cam and two double 38dgas webers.
I think the power will be around 215HP and as it is a 3.4 the torque will go up to about 330nm. I hope the 2.88 dif will still make the car fast in sprints with the added power. What do you guys think?

Cheers.

TVR 4ever!

[TVR_owner]

milko said:

Hi people.

Sure the late M series had 4HU 3.54:1 diffs? I've heared they are 3.31.
Anyone have the facts?
I'm now tuning a 3000M. Want to keep the ford type5 4 speed gearbox as it is just exellent but I like the car to cruise on lower revs.
I can buy a 2.88 power loc unit from a '83 XJ-S and I calculated that if the standard diff is 3.31 it would have a top speed of 230 with the new dif. So I don't need a fifth gear with the 2.88 dif. The engine I'm building is a 3.4L version of the essex with a va63 cam and two double 38dgas webers.
I think the power will be around 215HP and as it is a 3.4 the torque will go up to about 330nm. I hope the 2.88 dif will still make the car fast in sprints with the added power. What do you guys think?

Cheers.

TVR 4ever!

I think it will be a little over geared for sprinting. If you want the sprinting and the cruising, I would go 3.31 or 3.54 with a 5 speed box that has something like a 0,8 5th gear ratio (T5....)

We have a 3000S Turbo that has reasonable performance with the 3.31 diff (on 195/70*14 rubber). Cruising is fine.

Acceleration wise, its on a par with a standard Sagaris to about 110 mph.

Edited by TVR_owner on Monday 14th December 15:24

[Slow M]

Don't want to muddy the issue especially because my memory is not too clear regarding the 4HU but I believe the following will be of help.
http://www.pistonheads.com/xforums/search4.asp?h=0...
http://www.pistonheads.com/xforums/search4.asp?h=0...
http://www.coventrywest.com/Jaguar/tech_tips_archi...
B

[milko]

I mailed with David Gerald. All late M series with salisbury have 3.31:1 diffs he said. So no 3.54:1. the step from 3.31 to 2.88 is smaller than from 3.54 luckily for me so I think I'll try the 2.88 power lock in my 215hp 3400M.

Ive heared the TR6 rear wheel hub can brake. I had it happening to me allready with the standard engine but I thought it was a factory foult but now I ve read that more TR6's have the problem. Anyone have an Idear how to fix that problem?

Cheers.

Milko

[Slow M]

CV axles from Richard Good.
CV axles from Quaife.
Nissan 240 CV axles and a stupid amount of work.
Maybe call GKN.

[TVR_owner]

milko said:

I mailed with David Gerald. All late M series with salisbury have 3.31:1 diffs he said. So no 3.54:1. the step from 3.31 to 2.88 is smaller than from 3.54 luckily for me so I think I'll try the 2.88 power lock in my 215hp 3400M.

Ive heared the TR6 rear wheel hub can brake. I had it happening to me allready with the standard engine but I thought it was a factory foult but now I ve read that more TR6's have the problem. Anyone have an Idear how to fix that problem?

Cheers.

Milko

My race car ran with new standard hubs last year but will get the quaife units fitted over the winter. I think you've been unlucky to have a break on a road car - especially with that lazy diff ratio!

[foggyvolki]

Just caught this thread, Diff wise, if your after the ultimate LSD then your after a Drexler ramp & plate unit, it's slightly more pricey than a quaife but it really is the 'rolls royce' of the diff world. Drexler make stuff for F1 teams and loads of bespoke le-mans and touring car stuff where Quaife (as good as they are) tend to be more trackday oriented. the UK importers are bamboo engineering WTCC team, check out their site or e-mail [e-mail] to see how they can help you!