Limited Slip Differential???

[r10crw]

Drivers cause understeer, not LSD's . . .

Quote of the week, gotta be.

One point I think worth mentioning is that the car is more difficult to drive properly with a LSD. It will grip longer and snap quicker, maybe its not techinically correct but definatly what Ive found,
Cheers Craig

[tut]

I have not driven without LSD for five years now as N1 and N3 with JDM engines both have it. As a result I can not tell whether I would prefer to have it or not, as I have always gone along the lines of preferring no driving aids, electronic or otherwise.

I appreciate that it is different when racing, Scotty praised the ABS in the wet, and traction control would make a big difference as well, but when you are following a quick driver on a Trackday with T/C, ie Craig, it looks unnatural and jerky as it kicks in and out.

tut

[Mikie711]

Drivers cause understeer, not LSD's . . .

Quote of the week, gotta be.

One point I think worth mentioning is that the car is more difficult to drive properly with a LSD. It will grip longer and snap quicker, maybe its not techinically correct but definatly what Ive found,
Cheers Craig

I find that with my car, also it can give you understeer as the rear has more grip and tends to push the front IYSWIM.

[Victor Meldrew]

I dont know for sure, so dont shoot me down in flames, but I found Mikes car a little reluctant to turn in when I came off the brakes compared to mine. The car didnt want to rotate into the corner. I was talking about this with some of the other drivers at Boyndie and when I mentioned that mine still had a std diff they said it is possible that I was feeling the effect of the locking diff under engine braking...

Basically, if an LSD is fitted to the car it can make it slow to turn in..

Discuss..?

[Mikie711]

I can't see how, as the car is still in a straight line under brakes the diff won't be doing anything, it only starts working in the corner. Transferring drive between the rear wheels. Car's fitted with a quaiffe ATB which is a torque sensing diff. Will post up a pic from the data logs and you can see it working.

[fd]

Wasn't a flippant comment . . .

I spent many hours playing with my (LSD equipped) caterham at KH, it understeered terribly sometimes, it oversteered sometimes but it rarely worked brilliantly then one day it just went round Macintyres as if my magic, no oversteer, no understeer but much faster than before, uncanny, another hour went by before I managed to do it again and started working out what I was doing . . . the car never changed, same tyres, same everything . . . but all of a sudden it became vastly easier to drive . . .

I would expect someone not used to that car to think what I used to - it understeers like a pig or snaps into huge (but controllable) oversteer . . . however that's not how it works if you know the car well enough . . .

Point is, no matter the car (within reason) the driver has a massive influence on how it appears to handle . . .

Fd

[Mikie711]

Wasn't a flippant comment . . .

I spent many hours playing with my (LSD equipped) caterham at KH, it understeered terribly sometimes, it oversteered sometimes but it rarely worked brilliantly then one day it just went round Macintyres as if my magic, no oversteer, no understeer but much faster than before, uncanny, another hour went by before I managed to do it again and started working out what I was doing . . . the car never changed, same tyres, same everything . . . but all of a sudden it became vastly easier to drive . . .

I would expect someone not used to that car to think what I used to - it understeers like a pig or snaps into huge (but controllable) oversteer . . . however that's not how it works if you know the car well enough . . .

Point is, no matter the car (within reason) the driver has a massive influence on how it appears to handle . . .

Fd

There is no substitute for seat time, I know what you mean as I have experienced the same thing with mine. It's a question of changing the way you drive to suit the LSD.


You can see the diff working on this log, just look at the changing wheel speeds for the two rears wheels.

[alicrozier]

I can't see how, as the car is still in a straight line under brakes the diff won't be doing anything, it only starts working in the corner. Transferring drive between the rear wheels. Car's fitted with a quaiffe ATB which is a torque sensing diff. Will post up a pic from the data logs and you can see it working.

If you're still on the brakes into the corner (as you should be in an Elise) as Victor says it's possible a differential can hinder turn in. Depends how aggressive it is on overrun of course...

I mentioned my car has a Torsen diff (again torque sensing), one thing I've found is it's more throttle adjustable on corner exit. Where an open diff can just continue to push the nose wide if you apply too much throttle too early mine will more easily nose in and take on a little power oversteer.

[Victor Meldrew]

I can't see how, as the car is still in a straight line under brakes the diff won't be doing anything, it only starts working in the corner. Transferring drive between the rear wheels. Car's fitted with a quaiffe ATB which is a torque sensing diff. Will post up a pic from the data logs and you can see it working.

If you're still on the brakes into the corner (as you should be in an Elise) as Victor says it's possible a differential can hinder turn in. Depends how aggressive it is on overrun of course...

I mentioned my car has a Torsen diff (again torque sensing), one thing I've found is it's more throttle adjustable on corner exit. Where an open diff can just continue to push the nose wide if you apply too much throttle too early mine will more easily nose in and take on a little power oversteer.

I think Mike has the data trace from our runs.. Might be able to see from the trace if there was any difference between brakes on turn in.

[Mikie711]

It's hard to see braking with just the accelerometers. Will have a look and see if it shows any sort of difference. That's why I've got a brake pressure sensor to fit, be able to see when and how much braking is being done.