LSD - how common?

[Tierfreund]

An LSD tends to induce more understeer (unless you are breaking the traction at the rear). So unless you have a lot of power (actually torque at the wheel would be the relevant factor) to put down where you are overwhelming the traction of the rear axle, a LSD is not always an attractive proposition.

If you are a smooth driver on a dry road with the kind of power to tire ratio an E9 typically has: a car without LSD will be more pleasurable to drive.

If you drive on slippery roads and have more power at your disposal: A LSD may be usefull.

As usual: it depends...

Also: An original 25% LSD that´s never been overhauled will, through wear, today probably have less than 10% torque transfer left today. Hardly noticeable except maybe getting off the line with one wheel on ice and one on dry tarmac.
So, as with many performance mods: the knowledge of having a LSD may actually have more influence on the percieved benefits than the actual thing. Maybe writung an "S" on the diff would be sufficient (call it placebo tuning)

Of course, I have a LSD in my car. Wouldn´t want to drive without it...

 

[gwittman]

After 28 years of racing in SCCA and 33 years of driving my Coupe with a LSD, I have a different view of the LSD effects . I guess a very high torque bias ratio could induce some under steer in a normally neutral car. Under steer is a symptom of a diff with a locker. However, I doubt a typical LSD set up for the street induces any under steer. My 2800 CS with around a, 40% torque bias LSD, has never displayed anything close to under steer.

I find an open differential is safer in slippery conditions. When going around a corner while accelerating with a LSD, both tires can break loose and cause the rear to slip out quickly. A open diff in the same situation will break one tire loose while the other one will still hold lateral traction. This keeps the rear from slipping out.

In dry conditions a LSD will allow more acceleration when coming off a corner because both tires should be providing power to the ground. An open diff will spin the inside tire because it is unloaded due to the cornering forces. This reduces the power to the ground and limits acceleration.