Limited slip diff?

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GroundZero

Original Poster:

2,085 posts

61 months

Monday 6th September 2021
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Question to Exige V6 owners, do you ever find that you would benefit from an LSD to get the power down out of corners?

I've come from a history of having a RWD 400+bhp GT car with a LSD and this made the car incredibly playful and capable on track. Something that I would definitely want in any future 'toy' or special occasion car that I bought.
As GT cars are now silly priced, and IMO at least, nowhere near value for money (especially if its something to be used on the road and not sat in the garage as an 'investment'), I've instead been looking more at the 'toy' aspect and to doing more trackdays.

I've only driven the V6 Exige on the road during a 'test drive', so nothing playful was explored within UK speed limits. (In terms of drifting or getting the car dancing around). However, on a couple of tight corner exits when I put the power down there was a noticeable spinning up of the inner-corner rear wheel.
The car salesman mentioned the V6 Exiges don't come with a LSD which I thought was quite odd given the power delivery and the nature of the car.

So do you guys find it an issue?
Are there options on the market to easily fit an LSD?

ecain63

10,590 posts

182 months

Monday 6th September 2021
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There are many that will tell you to fit one because "you'll just spin up the inside wheel when cornering", and there are many that will tell you that it's not needed at all. Some people spend money on stuff because it's something that the internet says to do.........

A few points:

Firstly, they're cheap to buy, but big money to fit. There's a whole lot of labour involved. Quotes of £3500 at an indy to £6000+ at a main dealer. Is it worth it for a second off your laptime? A good geo setup is a fraction of the cost and will make a big difference to cornering ability.

Secondly, the need for an LSD will depend on your driving style. If you are Mr Scandinavian Flick then you might well benefit...... but I'd suggest getting some tuition at the Lotus Driving Academy to iron out your style first. The V6 was never designed to be "chucked" as such. If you still feel the need after tuition then go for it.

Thirdly..... maybe seek the advice of some of the academy drivers (you can message the Academy via Facebook or email), or those on FB that do a lot of proper trackdays. There are a few on the Facebook V6 Owners Group and they'll offer sound advice where needed. A good percentage of the people who say to fit an LSD are unfortunately the same people who wouldn't dream of tracking the car and reckon they can experience a "one-tyre-fire" on their twice-yearly country road blast. That said, amongst the track addicts you'll also see reviews in favour of fitting.

Having done a good 14k miles now in my 410 and over 25 track days (over 2 years) I am yet to notice a single event where a diff would have made a difference..... more obvious to me now I'm going quicker. My car has a revised geo setup though. The grip levels are epic and even on the limit it feels progressive when it goes. However, having relearned the car at the Academy last Feb reckon this has more to do with my reworked driving style than anything else.

The worst you can do is fit one, it not make a difference and you've burned a few £k on labour. Best case, it turns you into a driving god and all us lot that say not to bother are made to look like fools smile

I've got my dealer on the case to supply a quote to fit one as a tester. If I notice the difference then I'll communicate the findings accordingly. If I don't...... same sketch.

Edited by ecain63 on Monday 6th September 21:11

Oilchange

8,763 posts

267 months

Monday 6th September 2021
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I haven't got an Exige or Elise type car, mine's an Esprit but I got the inside wheel spinning up all the time on track days coming out of tight hairpins and whatnot. Very frustrating. Decided to get a Quaife and haven't looked back, it's great. There are issues with seals though.

GroundZero

Original Poster:

2,085 posts

61 months

Tuesday 7th September 2021
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Thanks for the replies so far, two different angles which is interesting.

I guess you hit the nail on the head ecain63, in as much as it depends what the driver wants from the car.
I've done countless laps on tracks from my racing days and then when I used a number of my own cars over the years on the Nurburgring and Spa where I used to visit at least twice per year.
For me, if you are not racing, then lap times becomes a moot point. So outside of racing it is much more about "having a play" when it comes to track time. So that indeed becomes about making the car 'dance around', making it slide, having fun on corner exit, whilst all the time having a balanced solid platform which can deliver a surefooted progression around the track.

So yes there will be those who will focus on that next 10th of a second and will buy an Exige for that pursuit, but for the likes of myself (who surely won't be alone), will look for the "play factor".

So going back to my test drive, the road was a mixture of dry and wet, but noticed the unloaded wheel spin quite easily in both conditions on slow corner exits. Which left me a bit "meh".

But the price mentioned above for fitment of an LSD sounds on the excessive side, but if that's what it is then I see why Lotus don't fit them as standard, as the retail price of the cars would place them up in to price bracket where buyers would be saying "well for the same money I could be getting x,y,z instead".

But what is apparent from the first reply is how happy you are with the car in stock form without an LSD which does say a lot about the stock handling and power delivery. I think I need to get one on track and explore in more detail, but I think if I did decide to buy one then I would look to be fitting an LSD all the same.

Please do update this thread ecain63 if you end up putting an LSD on yours and let me know how it turns out, I will be extremely interested in that!

ecain63

10,590 posts

182 months

Tuesday 7th September 2021
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@OP: what model are you looking at? Don't forget that the different models come with totally different suspension, wheel specs and tyre dimensions / brands. Let us know the model objective smile

GroundZero

Original Poster:

2,085 posts

61 months

Tuesday 7th September 2021
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It would likely be an early V6S for under £45k if possible.
Thats the sort of budget I have at the moment for a 'toy'. I can't really justify much above that.




mario328

148 posts

133 months

Tuesday 7th September 2021
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8 years, 17,000 miles in my V6S Exige all road miles and I can honestly say I’ve never craved for an LSD upgrade. There is so much grip in general you’d have to be in very poor weather or on a bad surface to feel the back end go or any wheel spin. My GT86 & old Mondial had/have them as standard but obviously totally different driving experience to a Lotus. IMHO the Exige is definitely not a drifting machine.

ecain63

10,590 posts

182 months

Tuesday 7th September 2021
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GroundZero said:
It would likely be an early V6S for under £45k if possible.
Thats the sort of budget I have at the moment for a 'toy'. I can't really justify much above that.
Ok, so it was probably on average tyres and stock suspension. That'll make a big difference over a 410/430 with wider forged wheels wearing Cup 2 tyres on Nitron 3 way suspension.

GroundZero

Original Poster:

2,085 posts

61 months

Tuesday 19th April 2022
quotequote all
ecain63 said:
T
I've got my dealer on the case to supply a quote to fit one as a tester. If I notice the difference then I'll communicate the findings accordingly. If I don't...... same sketch.
Did you get round to fitting an LSD ?


ecain63

10,590 posts

182 months

Tuesday 19th April 2022
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GroundZero said:
ecain63 said:
T
I've got my dealer on the case to supply a quote to fit one as a tester. If I notice the difference then I'll communicate the findings accordingly. If I don't...... same sketch.
Did you get round to fitting an LSD ?
No, the verdict was that it wasn't worth doing it until the car needed a clutch or other work where the box needed dropping. The labour cost was pretty heavy for what it is. As yet I'm still not feeling the need to fit one, but after seeing a V6 with a Quaife go round Silverstone GP I can now see where it may be marginally advantageous. We're talking a second or two a lap on the GP so it's not night and day unless you're racing.

Olivera

7,671 posts

246 months

Tuesday 19th April 2022
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IIRC GFWilliams on here stated that an LSD was by far and away one of the best modifications that he's made to an Exige. TBH every sports car should have one.

ecain63

10,590 posts

182 months

Tuesday 19th April 2022
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Olivera said:
IIRC GFWilliams on here stated that an LSD was by far and away one of the best modifications that he's made to an Exige. TBH every sports car should have one.
Well, if GF himself says that then it must be essential to ALL Lotus Exige smile

It really does depend on the car, the suspension setup, geo etc. Fitting one to a V6 / 350 with stock suspension is is going to have more positive effect on track work than fitting it to a 410/430 / Cup car on Nitrons. Adjusting aero and geo will give a decent and potentially more substantial improvement before the need for a diff. I changed my wing and vented the front clam and on my first trackday out knocked 2s off my Silverstone GP best. More importantly than the 2s off was the ability to match my previous PB consistently. 2.28 isn't as quick as I could / should be but it's not far off some of the other well-known and experienced owner laptimes. That was on old Cup2 tyres too.

After aero I'd say the addition of more track focussed tyres would open up 90% of the remaining potential in our cars. My old Cup2 tyres stick well enough to produce up to 1.5G in the corners, and they last forever. Stickier rubber will further reduce the need for that diff.

There are negatives to an LSD being fitted to the Exige platform as well. Increased tendancy to understeer is the big one, which can nullify the gains made in exit grip. Driving style is also a major factor.

In short, a diff might well be a big improvement to a car, but only in a situation where other improvements have not yet been made.





GroundZero

Original Poster:

2,085 posts

61 months

Wednesday 20th April 2022
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Agree with some of what you say about LSD but also it can be a subjective thing based up on your own driving style and expectations.
From my racing days however it was clear that an LSD made a 'huge' difference to lap times ('huge' in quotes because although were always talking of margins, it makes a big difference in comparison to the competition). Made more of a difference with drivers who were able to dial in to the potential gains it offered and dial in a good car set up to match.

You mention increased understeer, but this can be sorted with other tweaks on adjustable suspension set ups.
But for me the instant improvement for a track car was later braking due to better stability, more trail-braking, earlier power application on corner exit, all of which gives more confidence in the car and ability to be more consistent lap after lap. But also importantly for racing, you could protect your position better in braking and acceleration zones.

If I were to pick up on the noticeable negative effect of an LSD on the cars that I raced, this was usually with the mid-corner balance with throttle application, whereby on the limit of grip you could induce unwanted understeer, but this only usually occurred on long sweeping corners and can be dialed out with more front end camber if you wished. But then as you'll know more camber has its own effects, so as always it was a question of overall lap balance, subjective appeal from the driver, driver style/capability and of course lap time.

Any way, many thanks for the update, much appreciated for your feedback on your car, and hope you continue to enjoy it, as you do sound like you know your car and what you want to gain from its potential pleasures.




Rocketreid

655 posts

79 months

Wednesday 20th April 2022
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I looked into this a while back although I have the Cup430 which has adjustable slip which to some degree helps with not having a LSD.

I had some lessons with a Lotus/Caterham Pro driver who took me around Silverstone on a BRDC day with no noise restrictions.

He did not see any reason for a LSD with the extra weight and costs involved as he felt the benefits would be very marginal and far better to get a set of track wheels and tyres for the money etc.

Incidentally he did a 2,20 with me on board and did a lap on his own a second or so quicker

GroundZero

Original Poster:

2,085 posts

61 months

Wednesday 20th April 2022
quotequote all
Rocketreid said:
I looked into this a while back although I have the Cup430 which has adjustable slip which to some degree helps with not having a LSD.

I had some lessons with a Lotus/Caterham Pro driver who took me around Silverstone on a BRDC day with no noise restrictions.

He did not see any reason for a LSD with the extra weight and costs involved as he felt the benefits would be very marginal and far better to get a set of track wheels and tyres for the money etc.

Incidentally he did a 2,20 with me on board and did a lap on his own a second or so quicker
Yeah, when you compare tyres vs LSD, then totally agree that grippier tyres will always be a winner in terms of lap times.
Going back to what I mentioned earlier, I presume Lotus don't fit a mechanical LSD as standard equipment mainly because of the cost, and therefore price market competition.


Still trying to familiarize myself with the Exige, could I ask what sort of adjustable slip you have? Is it the traction control, ie. an e-diff setup that works through the rear brakes? And to what extent can it limit the slip difference?

ecain63

10,590 posts

182 months

Wednesday 20th April 2022
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GroundZero said:
Yeah, when you compare tyres vs LSD, then totally agree that grippier tyres will always be a winner in terms of lap times.
Going back to what I mentioned earlier, I presume Lotus don't fit a mechanical LSD as standard equipment mainly because of the cost, and therefore price market competition.


Still trying to familiarize myself with the Exige, could I ask what sort of adjustable slip you have? Is it the traction control, ie. an e-diff setup that works through the rear brakes? And to what extent can it limit the slip difference?
The diff itself is £500. When seats cost £3k each it's not a cost decision in my opinion. They fit an LSD in the Evora 410/430 so it's something they must have considered. I still stand by the epic standard grip provided by your stock 410/430 Exige platform.

I've fitted quaife diffs to cars before, both rwd and fwd, so I'm not totally blind to the benefits. I just don't see where it's going to justify £3.5k+ when other cost effective adjustments can do 90% of the legwork. We're not racing at the end of the day.