Limited Slip Differential - Discuss

**Wobbly Dave** · Tuesday 25th April 2006, 16:15

I know enough to be dangerous on this particular subject. I also know that the 850R Manual had a LSD fitted in the M59 gearbox.

Reading through the Ty Croes thread - got me thinking - not particularly as a modification I would be looking to do but something that is not often discussed in here.

If any of you lot have an idea about the benefits and draw backs from having one fitted particularly to the T5 FWD scenario (but obviously other experiences and opinions on other cars are welcome) I would be grateful if you could share?

I have found some basic info here... http://auto.howstuffworks.com/differential.htm

Questions I have are - are they useful to road car situations or is it more of a track/race thing?
Would you need to be driving sufficiently daft/hard enough that the LSD would be of use on a T5?

**heyes** · Tuesday 25th April 2006, 16:40

I can only tell you my experiences when I used to have them on the saab 9000 aero's that I had. The last one was pushing out 295bhp and with the LSD it was so easy to drive with power especially around bends. You would position yourself just before the bend and the push it round the bend with ease. You do get a bit of torque steer but that's down to how you drive the car. I have always wondered why this wasn't a more popular mod given the power some of you guys get from your cars. QUAIFE do them for the M56 and M66 gearboxes at around £620. It should be interesting to hear from those who have one fitted.

**pault5** · Tuesday 25th April 2006, 16:49

Hi,
I made an enquiry to stuart at sw autos a couple of months ago.
The cost of an lsd with fitting is about £1250+vat, that is the lsd costing £750+vat and £500+vat for fitting.
Paul.

**Al115** · Tuesday 25th April 2006, 17:26

I can say that LSDs for our car are b*stard hard to get hold of! As I have been trying for some time myself

**Mrsmopp** · Tuesday 25th April 2006, 17:31

Wobbles speak with Ju as she already has one fitted she is probably one of the only ones that can give you "real world" experience of an aftermarket LSD

x

**BlackBeast** · Tuesday 25th April 2006, 18:08

Search on VolvoSpeed, there are quite a few good threads on there about the subject including prices and the best places to get them from.

**pzorb** · Tuesday 25th April 2006, 18:21

Just to throw some dirty oil into a muddy puddle:

swedespeed's EricF:
"There are to my knowledge two manual gearboxes for the FWD cars, the M56 and the M59. The M56 has an open differential, but is supposedly stronger than the M59. The M59 however, was used in Europe in the R's, and came with a high power-handling clutch and a limited slip differential."

swedespeed's Morley:
"The M59 does NOT have an LSD, it's more like a hydraulic coupling that transfers up to 190NM to the wheel that is spinning."

**siamblue** · Tuesday 25th April 2006, 18:41

Well i know a little about the LSD system, and to be totally honest, my newer car is so much easier to drive than my old FWD, as someone else stated you point it and power it,

Gary,

**Matt30462** · Tuesday 25th April 2006, 19:05

Heico do a LSD. No idea of the price though.

**Matt30462** · Tuesday 25th April 2006, 19:09

MMM! Well I don't know enough about this, is this Heico Diff Lock the same as a LSD or a different beastie?

http://www.heicosportiv.de/mainframe.asp?lang=en&e1=219

**Justin** · Tuesday 25th April 2006, 19:12

Having had 2 R's with LSD's i can say that they are easier to drive and easier to get round corners, although not alot. It just meant for me better grip off the mark really

Andrew · Tuesday 25th April 2006, 20:00

Originally Posted by heyes

I can only tell you my experiences when I used to have them on the saab 9000 aero's that I had. The last one was pushing out 295bhp and with the LSD it was so easy to drive with power especially around bends. You would position yourself just before the bend and the push it round the bend with ease. You do get a bit of torque steer but that's down to how you drive the car. I have always wondered why this wasn't a more popular mod given the power some of you guys get from your cars. QUAIFE do them for the M56 and M66 gearboxes at around £620. It should be interesting to hear from those who have one fitted.

I can vouch for this - I utilise my LSD to scare people often when powering around bends

Saffron_C70 will confirm

**Engineer** · Tuesday 25th April 2006, 20:07

Hi Dave interesting subject (talking in general and not just about the types fitted to T5’s) as you know there are many types of LSD units and all have been used at one time or another for different vehicle applications.

One important thing to remember is that most can be set up to deliver different strengths of application depending on speed or torque differences between the driving wheels, which normally ends in maximum lock up. Most road cars are set soft so as not to send the car into the scenery (no pun intended mate).

If you’re on the track then one type or another is a must, and normally set a lot harder depending on conditions and type fitted, some suit certain vehicles better than others and some drivers prefer some types over others etc. Ask Hamish.

One things for sure IMHO whatever type you fit to a FWD vehicle (4WD is a slightly different story) it will increase the torque steer in proportion to its design and settings when you ask it to deliver.

One I liked for road use was the VC type fitted to the Cosworth Sierra provided it was set right it always delivered. On the other hand the just current RS Focus Quaife type is a bit of a bitch on the road but does the business on track.

Link below gives some details on different types you can use.

It’s the one thing I wished my R had instead of the Tracs system if it ever snows Ill use the W setting anyway lol.

www.houseofthud.com/differentials.htm#EDL%20why

Andrew · Tuesday 25th April 2006, 20:13

When i was getting my turbo fitted SW commented on how my LSD was set fairly stiff - tempted to put her on the track now to see if she delivers as per your comments

**Engineer** · Tuesday 25th April 2006, 20:30

Originally Posted by Andrew

When i was getting my turbo fitted SW commented on how my LSD was set fairly stiff - tempted to put her on the track now to see if she delivers as per your comments

You going on a diet then lol.

Only joking mate August it is then the big B meet.

**Wobbly Dave** · Wednesday 26th April 2006, 09:09

I think some of you have got me wrong - I dont want an LSD - never did. I just thought it would be something interesting to discuss as it has not been a topic much covered in VPC.

I had heard that the M59 box was weaker with the LSD and tended to break. Did the phase 1 70 series R's have them?

Ultimately the question is - does the T5 need a LSD?

**Mrsmopp** · Wednesday 26th April 2006, 10:28

Originally Posted by Wobbly Dave

Ultimately the question is - does the T5 need a LSD?

Well Volvo didn't seem to think so so I would say no!! After all they are the the ones that know what they are doing. lol

x

**lance** · Wednesday 26th April 2006, 10:46

Yeah you cant beat a bit of torgue steer and wheel spin, thats all part of the fun,
RWD drive owners go on about flicking the back end out!

I enjoy lighting up my tyres existing a large corner and just keeping my foot to the floor waiting for the car to gain composure and catapault me away.

However Im sure lsd (even the halucnogenic stuff) is more usefull than tracs but lets face it that woundnt be difficult anyway, If I drive any car these days I turn the fun button on i. e tracs off!

**Wobbly Dave** · Wednesday 26th April 2006, 10:53

I am sorry Moppy, but I think that Volvo have made mistakes and as a club we should question the manufacturer. E.g turning the fairly decent coupe into a very average convertible. Mind you - No-one really knows what the driving force behind the decisions were.

Maybe the Volvo "powers that be" thought that it was too difficult or too expensive to develop a good LSD? Instead they seem to be battling away with the development of AWD systems. Given that there are both drive train solutions out there - which would you (as in all) would recommend eg. to a new person looking for advice on which drivetrain to have.
Just FWD? FWD with LSD? AWD (viscous coupling)? AWD (haldex)?

**BlackBeast** · Wednesday 26th April 2006, 12:00

Originally Posted by Wobbly Dave

which would you (as in all) would recommend eg. to a new person looking for advice on which drivetrain to have.
Just FWD? FWD with LSD? AWD (viscous coupling)? AWD (haldex)?

Another question to add into the mix, which type of LSD would be best for our FWD cars?