Real world driving - LSD vs no LSD
Discussion
The reason 911's and most MR cars don't 'need' an LSD is purely down to the fact that they have a huge iron weight over the driven wheels! The handling is compromised by the downsides of LSD's whilst very rarely reaping the benefits, because traction is less of an issue. The lower polar inertia of MR cars exacerbates the problem, because the LSD's impact in inducing understeer (or power oversteer) is more keenly felt.
But in a powerful RWD car I would always prefer a limited slip diff or at least a digital attempt at one through good electronic control of the rear brakes. They just make the back end more controllable, and come into play in a number of real world driving siuations (low traction pulling out of junctions, roundabout exits, even just in snowy conditions).
In the OP's situation: Try and have a drive of a good example of both and decide what you prefer. It's so specific to the car and type of LSD employed that that's the only way to be sure. The right diff can make some cars, the wrong one can break others...
But in a powerful RWD car I would always prefer a limited slip diff or at least a digital attempt at one through good electronic control of the rear brakes. They just make the back end more controllable, and come into play in a number of real world driving siuations (low traction pulling out of junctions, roundabout exits, even just in snowy conditions).
In the OP's situation: Try and have a drive of a good example of both and decide what you prefer. It's so specific to the car and type of LSD employed that that's the only way to be sure. The right diff can make some cars, the wrong one can break others...
IMHO a LSD is a must for a fun car. It makes it more predictable and controllable and most importantly FUN !
Though in day to day driving it will make no difference, when your out for a fun drive you will notice it.
My day to day car is FWD with an open diff and is boring.
My weekend car is RWD with a LSD and would have trouble putting power down without it. I suspect the C63 would be even worse without one constantly spinning the inside rear.
Though in day to day driving it will make no difference, when your out for a fun drive you will notice it.
My day to day car is FWD with an open diff and is boring.
My weekend car is RWD with a LSD and would have trouble putting power down without it. I suspect the C63 would be even worse without one constantly spinning the inside rear.
Vladimir said:
An awful lot of people think they must have one but wouldn't actually notice in a (rather dangerous) blind test.
They are often the ones that think they can brake better with no ABS, don't need TCS and claim to heel and toe at all times.
It depends on the car and how you drive IMO. My TR7 V8 is screaming out for a LSD and it would be hugely evident difference.They are often the ones that think they can brake better with no ABS, don't need TCS and claim to heel and toe at all times.
I've three RWD cars with LSD's and no traction control (Alfa Spyder and 2 x 200SX s14's) and three cars without LSD's and with TC (a V8 E Class and 2 x C43's).
Hooning aside, electronics can only get you so far. If you are trying to exit a tight junction and one wheel has no traction a non-lsd car will either just spin the power away (without TC) or cut the power (with TC). Both are very poor outcomes.
In my book by far the best set up would be a mechanical LSD with switcheble TC.
It has never failed to surprise me how few powerful German RWD cars have had mechanical LSD's over the last 10-15 years.
For a C63 I'd certainly go for it myself. And I would imagine it would help resale (?).
Loads of C63 owners on mbclub.co.uk - why not ask some of them about their real world experiences?
Hooning aside, electronics can only get you so far. If you are trying to exit a tight junction and one wheel has no traction a non-lsd car will either just spin the power away (without TC) or cut the power (with TC). Both are very poor outcomes.
In my book by far the best set up would be a mechanical LSD with switcheble TC.
It has never failed to surprise me how few powerful German RWD cars have had mechanical LSD's over the last 10-15 years.
For a C63 I'd certainly go for it myself. And I would imagine it would help resale (?).
Loads of C63 owners on mbclub.co.uk - why not ask some of them about their real world experiences?
angusc43 said:
For a C63 I'd certainly go for it myself. And I would imagine it would help resale (?).
Loads of C63 owners on mbclub.co.uk - why not ask some of them about their real world experiences?
If it's a few grand option ( or more - I don't know? ), could you try a demo with and without?Loads of C63 owners on mbclub.co.uk - why not ask some of them about their real world experiences?
As above, it depends on how you drive and how the car is set up.
I've driven several models of RWD car both with and without, and only on those with traction problems (due to either a lot of power or a poorly set up chassis) could I really tell the difference on the road; but then I've never been the kind of person who drives sideways everywhere. It would never be a deciding factor for me on a RWD road car either way.
I probably wouldn't buy a sporty FWD car without an LSD, but then to be honest I probably wouldn't buy a sporty FWD car at all.
I'd want one on a track car, whichever wheels were driven.
I've driven several models of RWD car both with and without, and only on those with traction problems (due to either a lot of power or a poorly set up chassis) could I really tell the difference on the road; but then I've never been the kind of person who drives sideways everywhere. It would never be a deciding factor for me on a RWD road car either way.
I probably wouldn't buy a sporty FWD car without an LSD, but then to be honest I probably wouldn't buy a sporty FWD car at all.
I'd want one on a track car, whichever wheels were driven.
I find the LSD in my Eunos (A VC type) to be excellent for skidding about and general hooning but it does cause more understeer in the low speed stuff, especially when grip is reduced due to dampness etc.
The Mrs has a MKII MX5 with a Torson LSD and that is a big improvement over the VC one for reducing understeer in the low speed stuff.
nick
The Mrs has a MKII MX5 with a Torson LSD and that is a big improvement over the VC one for reducing understeer in the low speed stuff.
nick
My Boxster S never had one and my M3 did.
Depending which one I was in each day I can say the M3 pulled out of the slippery road end at my work far better than the boxster which just flashed traction control lights/ cut power and slipped a bit.
If its an option its always worth having, dont accept sales talk that it has an electronic traction control which is just as good. It isnt.
Depending which one I was in each day I can say the M3 pulled out of the slippery road end at my work far better than the boxster which just flashed traction control lights/ cut power and slipped a bit.
If its an option its always worth having, dont accept sales talk that it has an electronic traction control which is just as good. It isnt.
louiebaby said:
Alfanatic said:
The one with the LSD would be more stable under an emergency start and the tradeoff was more understeer in tight corners because, of course, the slip across the driven axle is being limited.
I have nothing to add to the discussion, other than loving the above phrase.
nottyash said:
If its an option its always worth having, dont accept sales talk that it has an electronic traction control which is just as good. It isnt.
I'm not sure how true that is any more - as soon as a car can brake the driven wheels independently (and most modern traction control/ESP systems can), it can essentially do exactly the same thing as a mechanical LSD but without the downsides. kambites said:
nottyash said:
If its an option its always worth having, dont accept sales talk that it has an electronic traction control which is just as good. It isnt.
I'm not sure how true that is any more - as soon as a car can brake the driven wheels independently (and most modern traction control/ESP systems can), it can essentially do exactly the same thing as a mechanical LSD but without the downsides. My only caveat would be that such systems can mimic viscous type LSD's very closely, because they rely on actual wheelspin and differential wheels speeds to activate the diff lock up, whereas very clever mechanical torsen diffs actually move torque about before any wheel has actually lost traction.
kambites said:
nottyash said:
If its an option its always worth having, dont accept sales talk that it has an electronic traction control which is just as good. It isnt.
I'm not sure how true that is any more - as soon as a car can brake the driven wheels independently (and most modern traction control/ESP systems can), it can essentially do exactly the same thing as a mechanical LSD but without the downsides. kambites said:
nottyash said:
If its an option its always worth having, dont accept sales talk that it has an electronic traction control which is just as good. It isnt.
I'm not sure how true that is any more - as soon as a car can brake the driven wheels independently (and most modern traction control/ESP systems can), it can essentially do exactly the same thing as a mechanical LSD but without the downsides. 300bhp/ton said:
I'd want to refine the claim a little further, a purpose built e-diff can simulate an LSD very well and offer enhance capabilities and adjustability. Regular ESP and TCS is not capable of this.
But the difference is only in the intelligence of the electronics, is it not? kambites said:
nottyash said:
If its an option its always worth having, dont accept sales talk that it has an electronic traction control which is just as good. It isnt.
I'm not sure how true that is any more - as soon as a car can brake the driven wheels independently (and most modern traction control/ESP systems can), it can essentially do exactly the same thing as a mechanical LSD but without the downsides. TCS will cut power once a driven wheel looses traction. ESP will brake individual wheels if it looses grip for instance when cornering, so its actually a really safe thing tpo have IMO, certainly worth the £400 option when I specced my VRS.
Edited by nottyash on Thursday 16th February 14:43
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