mossy7 Posted October 7, 2017 Share Posted October 7, 2017 So... I've had one. It was noisy and the whine was dreadful over about 60 mph. It got me thinking. For the road, even spirited driving, do you really need one? Is the advantage outweighed by the noise? ( if I wanted to indulge in lurid power slides or doughnuts then yes but I don't.) To that end can anyone comment having driven cars both thus equipped and bereft on a road? Link to comment Share on other sites More sharing options...
Drumster Posted October 7, 2017 Share Posted October 7, 2017 Well, I'm no driving god but I drove round spiritedly in my 1700 x/f for 48,000 miles on an open diff and never had an problems. 'Upgraded' to a ZF LSD in 2009 and now managed another 40,000 miles and can't really say it's made a huge improvement on the road although a 2l Zetec was installed in 2010. So may be with 60bhp more power it has been 'beneficial'......I guess a lot of it will come down to your driving style..... Link to comment Share on other sites More sharing options...
Wrightpayne Posted October 7, 2017 Share Posted October 7, 2017 Mossy,I think the noise was the diff (CWP) rather than LSD per say. Certain types of LSDs are graunchy at low speed manoeuvring. I posed a question a while ago about whether they made the car safer to drive which had some interesting replies and viewpoints - I'll see if I can find it!Ian Link to comment Share on other sites More sharing options...
Wrightpayne Posted October 7, 2017 Share Posted October 7, 2017 Here it is https://www.lotus7.club/forum/chitchat/lsd-road-safer-yn Link to comment Share on other sites More sharing options...
gulf 1 Posted October 7, 2017 Share Posted October 7, 2017 I have 2.0l supersport R with an LSD but have not experienced the noise you complain of.For normal! road use I don't really notice much difference to an open diff but on a track it is beneficial. Link to comment Share on other sites More sharing options...
mossy7 Posted October 7, 2017 Author Share Posted October 7, 2017 Ian,thanks for the link to the thread.. Most interesting.Andy Link to comment Share on other sites More sharing options...
JNC Posted October 7, 2017 Share Posted October 7, 2017 Andy,I drive a 2ltr Duratec 220 bhp with a open diff all my driving is on the road and apart from wet or greasy roads I don't have a problem ! I even thought my diff was an LSD until I jacked it up and spun the wheels by hand Link to comment Share on other sites More sharing options...
mossy7 Posted October 7, 2017 Author Share Posted October 7, 2017 Hi JNC,what problem do you have on wet roads then? Andy Link to comment Share on other sites More sharing options...
JNC Posted October 7, 2017 Share Posted October 7, 2017 Loss of traction ! It can get a bit hairy but they are so predictable read the road any damp junction or bend it's time to back off the loud peddle even a car with a LSD will get exciting in the damp . Link to comment Share on other sites More sharing options...
dave_h34 Posted October 7, 2017 Share Posted October 7, 2017 Do you need it? Probably not. Do I regret fitting mine, no. If you have noise and whine in a straight line it's not the LSD as both wheels are rotating at the same rate. Clonking, grumbling at low speed in tight turns, that is the LSD (plate type anyway). The difference I found was in cases of loss of traction with the open diff, it would spin up a single side then on backing off would regain grip quite abruptly which wasn't very predictable. In the same circumstances with LSD the car simultaneously drives forward and tightens it's line, something I still can't understand as it doesn't feel like it's sliding at the rear. It's far better though, and more predictable. Link to comment Share on other sites More sharing options...
DJ. Posted October 7, 2017 Share Posted October 7, 2017 I would say you don't need an LSD for the road, but it is nice to have one. The thing is, how many Sevens are just driven on the road? My mainly road use Seven has done 3 Dunsfold handling days and a couple of Car limits days at North Weald. These were much more fun with an LSD, especially on wet days.I would also say that, although I don't deliberately slide the car on the road, there have been occasions in bad conditions when I have felt the LSD has helped me when I would have expected at least a spinning wheel with the open diff. Link to comment Share on other sites More sharing options...
Area Representative Richard Price Posted October 7, 2017 Area Representative Share Posted October 7, 2017 I even thought my diff was an LSD until I jacked it up and spun the wheels by hand JNC, Its quite possible you do have an LSD! - The Quaife ATM reacts like an open diff when tested as you state.I know of two early Duratec R400's that were supplied with ATB's rather than the titan now fitted (or the earlier ZF). Link to comment Share on other sites More sharing options...
JNC Posted October 8, 2017 Share Posted October 8, 2017 When I jacked the car up and span the wheels I also took a look at the diff it's a BMW and it had the numbers engraved on it ! Can't remember what else Link to comment Share on other sites More sharing options...
OliverSedlacek Posted October 9, 2017 Share Posted October 9, 2017 I can't say that in 100,000+ miles of road driving I ever felt the need for an LSD. I've got one now, but that's to handle more power. Link to comment Share on other sites More sharing options...
JNC Posted October 9, 2017 Share Posted October 9, 2017 Oliver how much power are you putting through to the wheels ? Link to comment Share on other sites More sharing options...
OliverSedlacek Posted October 9, 2017 Share Posted October 9, 2017 My XFlow is now producing 155 BHP which is definitely in the 'living on borrowed time' territory for my old Ital axle. I have plans for even more power..... Link to comment Share on other sites More sharing options...
Edzup Ezzer Posted October 9, 2017 Share Posted October 9, 2017 When I first built my Seven (1.6K Supersport) nearly 20 years ago(!?), it had an open diff. However, I wasn’t entirely happy with the way it handled in fast bends as it seemed nervous at speed. I also drove a similar spec 1.4K with an LSD which didn’t display the same nervousness at high speed. When the diff started leaking via the half-shafts, Caterham via Derek Moore’s Classic Carriage Company at Mallory Park decided to replace the diff. So I took the opportunity to swap to an LSD at this point as it only cost me the difference rather than the full cost of a new unit. This seemed to cure the nervousness but I don’t have a theory to explain why. Being able to do donuts and the like was a fortuitous additional benefit which I was more than happy to take advantage of. Noise levels were no different to the standard open diff so I considered it a win-win. I don’t claim to have categoric proof that the change of diff improved the handling but it was certainly an interesting and not unexpected beneficial coincidence.Ezzer Link to comment Share on other sites More sharing options...
JNC Posted October 9, 2017 Share Posted October 9, 2017 With both wheels driving how often say on greasy bends do LSD give the feeling of going straight on rather than round the corner ?. And do the front tyres of cars with LSD wear more than open diff's ? Link to comment Share on other sites More sharing options...
Mark Durrant Posted October 9, 2017 Share Posted October 9, 2017 do the front tyres of cars with LSD wear more than open diff's ? Not in my experience but the rears do Link to comment Share on other sites More sharing options...
JNC Posted October 9, 2017 Share Posted October 9, 2017 Mark I can understand the rears wearing but do the fronts scrub out ? Link to comment Share on other sites More sharing options...
OliverSedlacek Posted October 9, 2017 Share Posted October 9, 2017 In my experience with my old TVR, the problem with the LSD was that when one rear wheel loses grip the tyre that grips is trying to rotate the car is the drive force is now off center. This was very scary in the snow..... Link to comment Share on other sites More sharing options...
Mark Durrant Posted October 9, 2017 Share Posted October 9, 2017 The fronts will only scrub up if you induce understeer which will be caused by either a poor setup, driver error or both. I have never had this problem Link to comment Share on other sites More sharing options...
Edzup Ezzer Posted October 9, 2017 Share Posted October 9, 2017 I've not become aware of any downside to having an LSD fitted in my car. The noise 'issue' has not materialised in my car but I do accept that cars vary in this respect (& I've been lucky) and I've certainly not noticed any undesirable handling quirks, or increased tyre wear. So for me at least, the LSD has only added to the fun.Ezzer Link to comment Share on other sites More sharing options...
Ian B Posted October 9, 2017 Share Posted October 9, 2017 Since my post on the previous thread 11 months ago, I've become aware of at least 5 road incidents where the cars LSD has probably made an incident considerably worse. One resulted in a write-off, two other cars left the road and entered the scenery, and two spun on the carriageway.All but one reported encountering uneven road surfaces, and only 2 were in wet weather.I remain of the view that I expressed in the earlier post linked to above. If most of your driving is on a smooth track, and you're a driving god, then I suspect the case is different. Just be careful out there - especially this time of year on the road when grip levels decrease, tyres are colder, and potholes and ruts are more difficult to spot Link to comment Share on other sites More sharing options...
David Lynch Posted October 9, 2017 Share Posted October 9, 2017 Do not underestimate LSD set up and tyre combination in having something controllable in the wet. A021R with what I can only presume were well chosen ramp and preload made for a surefooted combination for such a light car. That became a Tillett eating 3500rpm limit on List 1A road tyres. As and when gets refurbished I hope present settings can be deciphered and duplicated. Link to comment Share on other sites More sharing options...
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