Quick Diff question
Discussion
But that said, mine has 120k miles on it and if you jack up the back end and turn one wheel, the other will turn in the same direction. With an open diff they turn in opposite directions.
No idea if mine is as effective as it once was but at Brands I had no traction problems out of the hairpin so I suspect it still has some effect.
No idea if mine is as effective as it once was but at Brands I had no traction problems out of the hairpin so I suspect it still has some effect.
NeoVR said:
And if its a viscous diff, they tend to die after 60k miles and act just like a normal open diff.
Is this just something people regurgitate or is there any evidence, because my car has done over double that mileage on what is presumably the original diff and still locks up quite well, and I don't think I'm the only one.OllieWinchester said:
NeoVR said:
And if its a viscous diff, they tend to die after 60k miles and act just like a normal open diff.
Is this just something people regurgitate or is there any evidence, because my car has done over double that mileage on what is presumably the original diff and still locks up quite well, and I don't think I'm the only one.
ive got a 1.8... not discovered if it has an LSD or not yet.. back end does grip quite well though!
i would think it'd make it easier to spin it - you're limited with an open diff as you just spill the power away spinning up the inside wheel so slowing the car and regaining grip. With an aggressive lsd or welded one provided you have the power to keep the wheels spinning, you'll never regain grip - which could be a bad thing if you run out of talent + runoff :-p
Edited by dylan0451 on Monday 18th January 13:41
The subject of LSDs on forums always makes me laugh. It's one of those things everyone thinks they want but most have no idea why or what it will do for them.
An LSD will give better traction from a standing start but as Dylan said, once you start spinning the wheel you lose traction altogether if you don't have the skills to control it. This makes LSD better for those who want to go sideways and hold it there with the throttle but for 99.9% of drivers an open dif' will be the safer choice as while one wheel may spin the other will be going at road speed so should always have grip. As for track use, other than getting off the line (not a problem on track days) an open dif equipped car is likely to be quicker around most circuits as you can get on the power exiting a corner earlier without as much risk of power oversteer (that's assuming you want to get around quickly as opposed to just having a bit of fun).
LSD doesn't have any affect on understeer at all - it still slips allowing the outside wheel to turn faster than the inside wheel which is what a dif' is for.
An LSD will give better traction from a standing start but as Dylan said, once you start spinning the wheel you lose traction altogether if you don't have the skills to control it. This makes LSD better for those who want to go sideways and hold it there with the throttle but for 99.9% of drivers an open dif' will be the safer choice as while one wheel may spin the other will be going at road speed so should always have grip. As for track use, other than getting off the line (not a problem on track days) an open dif equipped car is likely to be quicker around most circuits as you can get on the power exiting a corner earlier without as much risk of power oversteer (that's assuming you want to get around quickly as opposed to just having a bit of fun).
LSD doesn't have any affect on understeer at all - it still slips allowing the outside wheel to turn faster than the inside wheel which is what a dif' is for.
MX-5 Lazza said:
The subject of LSDs on forums always makes me laugh. It's one of those things everyone thinks they want but most have no idea why or what it will do for them.
An LSD will give better traction from a standing start but as Dylan said, once you start spinning the wheel you lose traction altogether if you don't have the skills to control it. This makes LSD better for those who want to go sideways and hold it there with the throttle but for 99.9% of drivers an open dif' will be the safer choice as while one wheel may spin the other will be going at road speed so should always have grip. As for track use, other than getting off the line (not a problem on track days) an open dif equipped car is likely to be quicker around most circuits as you can get on the power exiting a corner earlier without as much risk of power oversteer (that's assuming you want to get around quickly as opposed to just having a bit of fun).
LSD doesn't have any affect on understeer at all - it still slips allowing the outside wheel to turn faster than the inside wheel which is what a dif' is for.
With all the power and torque available from my standard(ish) 1.6, I don't see getting off the line as an issue. More relevant is getting the power down out of tight, low speed corners, especially in the wet, where one wants to convert useless wheelspin from the inside back wheel into grip and acceleration. An LSD will help you do this, with the rider that if torque then overpowers friction for both back wheels, then you'll be going sideways. That gives you the option of enjoying the moment or coming off the throttle (or using a higher gear), as the mood takes you! Quickest, of course, is to avoid excess sideways travel but as you say, Lazza, sometimes it's all about fun!An LSD will give better traction from a standing start but as Dylan said, once you start spinning the wheel you lose traction altogether if you don't have the skills to control it. This makes LSD better for those who want to go sideways and hold it there with the throttle but for 99.9% of drivers an open dif' will be the safer choice as while one wheel may spin the other will be going at road speed so should always have grip. As for track use, other than getting off the line (not a problem on track days) an open dif equipped car is likely to be quicker around most circuits as you can get on the power exiting a corner earlier without as much risk of power oversteer (that's assuming you want to get around quickly as opposed to just having a bit of fun).
LSD doesn't have any affect on understeer at all - it still slips allowing the outside wheel to turn faster than the inside wheel which is what a dif' is for.
Cars with locked diffs - or very stiff LSDs - are notorious for their reluctance to change direction until they've been provoked into a big oversteer slide and I've read numerous magazine articles suggesting initial understeer as a result of having a LSD. I doubt this is a factor with MX5s, however. Of course, where it gets interesting is in front wheel drive cars with LSDs, currently all the rage in things like the Focus RS. Many years ago I rallied a Mini with an LSD which made it behave as if it was rwd. Powering through a bend sent the torque to the outside front wheel, making the car tighten its line. Great and very entertaining, until you broke traction with both front wheels, whereupon you abruptly went straight on. Kept the concentration up!
does anyone have any idea how much lockup a viscous unit is 'supposed' to give?
my car's on 120k and spent the last few years on track with super sticky yokos - 195/50/15 so i'd decided the lsd was all but dead, since it doesn't really have the power to spin the wheels from stationary but in the snow i was getting near as damn it 100% lockup, and with a heavy start with one wheel on snow & t'other on tarmac, managed some reasonable acceleration
until the oil (or viscous fluid?) got too hot and it started tramping
my car's on 120k and spent the last few years on track with super sticky yokos - 195/50/15 so i'd decided the lsd was all but dead, since it doesn't really have the power to spin the wheels from stationary but in the snow i was getting near as damn it 100% lockup, and with a heavy start with one wheel on snow & t'other on tarmac, managed some reasonable acceleration
until the oil (or viscous fluid?) got too hot and it started tramping
MX-5 Lazza said:
The subject of LSDs on forums always makes me laugh. It's one of those things everyone thinks they want but most have no idea why or what it will do for them.
An LSD will give better traction from a standing start but as Dylan said, once you start spinning the wheel you lose traction altogether if you don't have the skills to control it. This makes LSD better for those who want to go sideways and hold it there with the throttle but for 99.9% of drivers an open dif' will be the safer choice as while one wheel may spin the other will be going at road speed so should always have grip. As for track use, other than getting off the line (not a problem on track days) an open dif equipped car is likely to be quicker around most circuits as you can get on the power exiting a corner earlier without as much risk of power oversteer (that's assuming you want to get around quickly as opposed to just having a bit of fun).
LSD doesn't have any affect on understeer at all - it still slips allowing the outside wheel to turn faster than the inside wheel which is what a dif' is for.
Lazza, not often I'd completly disagree with you, but you are off the mark here china.An LSD will give better traction from a standing start but as Dylan said, once you start spinning the wheel you lose traction altogether if you don't have the skills to control it. This makes LSD better for those who want to go sideways and hold it there with the throttle but for 99.9% of drivers an open dif' will be the safer choice as while one wheel may spin the other will be going at road speed so should always have grip. As for track use, other than getting off the line (not a problem on track days) an open dif equipped car is likely to be quicker around most circuits as you can get on the power exiting a corner earlier without as much risk of power oversteer (that's assuming you want to get around quickly as opposed to just having a bit of fun).
LSD doesn't have any affect on understeer at all - it still slips allowing the outside wheel to turn faster than the inside wheel which is what a dif' is for.
Like for like & reasonably powerful cars with good drivers FWD & RWD 99.9% of the time lsd car will be faster on track, some cars don't need then so much- Elise/Exige often go without, & lower power rwd not really an issue & also with sticky tyres less of an issue.
LSDs can indeedy doodly create understeer, all depends on the type of dif & the lock up ratio, but in a few cars if you drive in exactly the same manner in the lsd verson as in the non, at slower speed bends you will just understeer off the road, I had a big momment on the 1st roundabout I came to in a porsche 964 doing just this & id driven many many of them before, (didnt realise the rare speedster had an RS dif)
Yes for novices is perhaps bect they dont have lSDs, I had 2 similar power modded 944 turbos & the non lsd one woudl happily spin its 300bhp away, the lsd one was a tad of a handfull on boost on bumpy b roads.
I was just talking about MX5s (which don't have locking dif's) and 99.9% of drivers in general, not just those keen drivers interested in taking their cars on the track. Remember the vast majority of MX5s never get nearer to the track than the car park and the vast majority of drivers are just interested in having a cute looking rag-top and aren't intesested in such things as the type of dif they have. We get spoiled on forums like this because the majority are very keen owners/drivers but we are very much a minority otherwise we would have over 800,000 people posting regularly
ETA: sorry, just reread my original post. I still stand by what I said - on an MX5 (which has rather limited power) on an average track with an average driver I don't think LSD would make them any faster around a track and indeed if the track was wet they would probably be quicker without LSD as they would feel safer exiting corners without having to control the oversteer as much.
ETA: sorry, just reread my original post. I still stand by what I said - on an MX5 (which has rather limited power) on an average track with an average driver I don't think LSD would make them any faster around a track and indeed if the track was wet they would probably be quicker without LSD as they would feel safer exiting corners without having to control the oversteer as much.
Edited by MX-5 Lazza on Tuesday 19th January 20:27
no way.
I have a 1.8 with LSD.
I get significantly more grip exiting corners than a non LSD car (which I can confirm from experience).
The Mx5 Torsen diff does not lock it is not a clutched diff, and is not aggressive like race car diffs discussed above, and I never feel it initiates understeer!
When it does go, it goes sideways, but I don't see this as a problem in a car as controllable as the 5. I think people of average ability upwards would be quicker with an LSD, If you are going to get scared by oversteer, then your going to get scared by wheelspin, the non LSD car will wheelspin (and probably oversteer also if less abruptly) way before the LSD car will oversteer.
But that is besides the point, track fun is not about laptimes, its about fun, and LSD's give plenty of that :-)
I have a 1.8 with LSD.
I get significantly more grip exiting corners than a non LSD car (which I can confirm from experience).
The Mx5 Torsen diff does not lock it is not a clutched diff, and is not aggressive like race car diffs discussed above, and I never feel it initiates understeer!
When it does go, it goes sideways, but I don't see this as a problem in a car as controllable as the 5. I think people of average ability upwards would be quicker with an LSD, If you are going to get scared by oversteer, then your going to get scared by wheelspin, the non LSD car will wheelspin (and probably oversteer also if less abruptly) way before the LSD car will oversteer.
But that is besides the point, track fun is not about laptimes, its about fun, and LSD's give plenty of that :-)
the kaaz clutch pack ones seem to come with a 1.5way option so full lock on acceleration and only 50% on overrun which is what, i presume you want for a good turn in to minimise understeer. i, once again presume it also makes a difference how aggressive the lsd is setup to how quickly it changes lock ratios i.e. from 50% under engine braking to 100% under acceleration - if it changes instantly i would have thought it'd be much harder to catch and drive than one that would allow momentary slip to build up the the full figure
i read everywhere that the viscous lsd's die after 60k, but since it's the fluid that goes 'off' i presume it would have a lot more to do with the average temps the car sees and how much abuse it receives - my eunos has done 120k and only came into the country in 2002~2005 so spent a long time in a warm climate presumably driven by a poser
it's had a few years track abuse before i got hold of it but the vlsd still seems to work, albeit not as hard, aggressive and instant as i'd like
i read everywhere that the viscous lsd's die after 60k, but since it's the fluid that goes 'off' i presume it would have a lot more to do with the average temps the car sees and how much abuse it receives - my eunos has done 120k and only came into the country in 2002~2005 so spent a long time in a warm climate presumably driven by a poser
it's had a few years track abuse before i got hold of it but the vlsd still seems to work, albeit not as hard, aggressive and instant as i'd like Gassing Station | Mazda MX5/Roadster/Miata | Top of Page | What's New | My Stuff