LSD Choice
Turbo Mini Forums

Hello,

I'm looking at getting a plate LSD differential for my project, and seen 2 on the market and just wanted to see peoples opinions on which is better.

The Tran-x Differential; available from Swiftune only
https://swiftune.com/parts-shop/transmissio...n-x-mk-6-2.html

NXG Differential; available from MED
https://www.med-engineering.co.uk/transmiss...sd-differential

I've seen on the MED site, they mention that the gearcase and diff housing requires modification. Will this also be the case for the Tran-x?
I've used Tran-x differentials when I used to work at a rally place, and know they're good, but they're quite a chunk more expensive. But they also say they require no pre-load to be dialed in, which useful, and easily serviced.

Opinions?


Dave.

David.

if this is for a road car then id suggest this instead of a all out LSD.
https://swiftune.com/parts-shop/atb-differe...sic-mini-2.html
Shane

As Shane has linked , if its for the road etc id go for the quaife atb. There a direct fit , they even take a standard crown wheel .
The tranx will need the casing modifying and you will need a new cwp

Not an issue getting things modified, just wanting to be aware before I buy it.
It'll be used on track, so will be wanting a real plated diff. Just wanting to see if anyone has experience of both?

David.

I’ve been using the Tran-x plate type LSD for about 15 years. No issues so far.

Phil.

WWW.TURBO-MINI.COM

I've driven with both but id sway more to the civility of the ATB, its personal preference but what's right for me may not be for you.
The added bonus with the ATB that has been mentioned is that they take a std crown wheel which easily opens up messing with final drive ratios for track use.

Shane

If the car is turbo'd and for track I would recommend an ATB. It is what I am using with a 3.1 diff and I do a lot of trackdays. You cannot get lower than a 3.4 with a plated LSD as far as i am aware, something that would make me never run a plated diff.

All mig guys run an quaife ATB. Admittedly they are limited to that by the regs, unsure they would change it out if unrestricted.

Jonny , I would definitely chose the plated diff over quaife in the mig if it was possible , and choose it for any out and out track car , but a good point you have made about final drive !
I run a 3.44 in the spaceframe and it’s ideally not long enough ! I’m going for a 3.1 / 3.2 when I get round to it !

I'd also choose a plate diff for a serious competition car.

Only point I can make is that Tran-X folded a few years ago and were bought out by Quaife. Are you definitely buying a Tran-x diff, and can you/will you be able to get plates and other service bits for it in the future? Worth finding out before you buy.

Could change the drop gear ratio to get a little more from the 3.44:1? Use a .958 Ratio? would that give you a half way house between a 3.44 and a 3.2, 3.29:1?

Edited by shane on 20th Dec, 2019.

Quaife are still producing what they refer to as a tran-x diff. A Mk6 version, not sure what mk they were on when they closed. Swifty don't list plate packs on their site for rebuilding, so that's a good point, I'd guess I'd get then direct from quaife.

I was also recommend a plate diff over ATB by my engine builder.
ATBs still act like an open diff should a wheel get lifted (curb jumping etc)

David.

If you opt for a plated diff and are restricted to the 3.44:1 CWP combo the achievable final drive ratios available from messing with the drops are;
1.136:1 drop gear ratio= 3.9:1 FD
1:1 ratio drop gear ratio= 3.44:1 FD
1.0416:1 drop gear ratio= 3.583:1 FD
1.0434:1 drop gear ratio= 3.589:1 FD
1.045:1 drop gear ratio= 3.59:1 FD
1.0869:1 drop gear ratio= 3.73:1 FD
1.09:1 drop gear ratio= 3.74: FD
.958:1 drop gear ratio= 3.29 FD

I run 3.2:1 ratio, on a track like Castle Coombe I found it ideal, but at my local track (Snetterton) the FD would be too short for some of the straights.
Id agree with Johnny's 3.1 to give the car some legs.
Personally (my opinion only) even if you opted for the 3.44:1 ratio with a .958:1 drop ratio you'd be revving the tits off of it with a loss of top end.
From memory (these figures are approximate) at 6500 rpm a 3.44:1 gave a top end of approx' 107mph but 120mph was achievable using a 3.1:1 FD
Depends what you want from the car, where its going to be driven, there will always be a compromise.

Shane.

Useful information. I've seen the guessworks calculator which'll map out revs, gear drop ratios etc and not played around with that too much yet. My last engine used a 3.7 ratio and was topping 110 over Avon rise at Combe. New engine is going to turn over a taller gear much easier.

David.

I recently built a SC box for a friend and we spent a fair amount of time procrastinating over ratios and final drives.
We ended up opting for a FD as a datum knowing/feeling it would have to be potentially revised after some use/miles.
Id suggest not making a rod for your own back and leaving your options as open as you can for future development.
There are more knowledgeable guys on here with more track experience than myself tho, they may be able to offer further pearls of wisdom.

Shane

Its a compromise, but I think a worth while one.
Especially when you factor in a decent suspension geometry set up and tailoring boost delivery to be linear as to promote minimal loss of traction.

Edited by shane on 23rd Dec, 2019.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Attachments:

214.15kb

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Strange, i must have messed up somewhere! I will check. Perhaps i am using a 3.2.

The speedo is GPS and rev limit is set at 7200 on the ecu. You can hear it nudge the limiter here at 3.18. https://youtu.be/p_Qtj-IR_H4?t=199

I have heard this before actually, though didnt piece it together till you mentioned 3J driveline.


And, thanks for everyones thoughts on this all. I'll also be using 13 inch wheels, so slightly larger rolling OD to assist in top end speed. The calculator I used said that at 6500rpm, it'll put me at 125mph... Not sure i want to do much more than that in a mini haha

Edited by mini93 on 26th Dec, 2019.

David.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

A bit late to the party but I have a Gripper plate type LSD and it requires no modifications to the gearbox. When i could not find any output shafts to fit they custom made me two new planet/sun gears (can never remember which sits where in diffs) for a veery affordable price so i could utilise the minispares units.

Own the day