sussex2 wrote:I've an MX5 (1.6 110bhp) with no LSD and I recently drove another with LSD. I think my, less powerful but unadulterated car, is much sharper and more pure.
The lack of such things as ABS/ESC etc keep you a bit more sharp as well, because you feel more vulnerable.
I'm not sure that's got much to do with the LSD though.
I have two front engine, rear-drive cars. Neither is particularly powerful, one is open diff and the other has a torque biasing LSD. My observation is that pulling out of tight junctions in low grip conditions, the open diff car will tend to spin a wheel up. The LSD equipped car will grip better initially, but then try and go sideways (until the electronics restricts it).
When I had an MR2 turbo, forum thought was that giving these cars an LSD contributed to more car/scenery interface problems than would have happened with an open diff.
My understanding is that in power-on limit conditions, cars equipped with LSDs tend to be more willing to continue going sideways (or spin), while open diff cars send the power to one wheel, "spinning" it away, so any sideways momentum is quickly lost. I guess where this may feel like twitchiness is over a short patch of low grip surface when the faster wheel then tries to grip again and send the car the other way.
For rear wheel drive cars, I suspect much of the "need" for the LSD comes from marketing, brought on by pictures of the Stig or Chris Harris going sideways on the lock-stops with smoke pouring off the tyres (which can only be achieved in a car with an LSD). Much like cars are being ruined by chasing nurburgring lap times. For FWD cars, with the quest for ever more power there's arguably more need to cope with sending too much power to the wrong wheels.
As for which on a road car - TBH, if you're driving within the law and to roadcraft, there should be naff all difference.