Limited slip?

[Pantera Dude]

I am under the impression that the Roadster does not have a limited slip differential/transaxle, is that correct? If so, why not?

 

[GSP]

I believe that the roadster has an open differential, and that it has been documented here on TMC.

Of course, I don't know why, but with all the trials and tribulations Tesla has just to get a working transaxle, first with Xtrac, then Magna, before Borg Warner stepped in and saved their bacon, I doubt there was any time to consider enhancements like limited slip or computer controlled diff lock.

I would be careful about retrofitting a limited slip as well, due to the tendency to induce oversteer.

GSP

 

[Doug_G]

Both the Roadster and Model S have an open differential (the Model S is just an enlarged version of essentially the same design).

 

[hcsharp]

I believe that the roadster has an open differential, and that it has been documented here on TMC.

Of course, I don't know why, but with all the trials and tribulations Tesla has just to get a working transaxle, first with Xtrac, then Magna, before Borg Warner stepped in and saved their bacon, I doubt there was any time to consider enhancements like limited slip or computer controlled diff lock.

I would be careful about retrofitting a limited slip as well, due to the tendency to induce oversteer.

GSP

In addition to the reasons mentioned (no time with pre-Borg Warner problems, worse understeer) it would also reduce range. Would really be nice to turn it on temporarily in certain snow/ice conditions.

 

[lolachampcar]

It seems MS is using one caliper to control single wheel spin. It is not elegant and it does dissipate power to a brake rotor but it stops the one wheel from lighting up and taking all the available torque.

 

[dhrivnak]

I think the goal is to have the most available traction, how that is obtained should be irrelevant. To that end I find the Roadster has the best traction of any car I have driven. There is no wheel spin with several runs at "Street Fights" (Open runs down Bristol's Thundervalley drag-strip NO-ONE has come close to the launch of the Roadster. If someone in a modified car beats me it is at the very end of the 1/4 mile. Why mess with perfection, or at least very, very good.

 

[Pantera Dude]

I think the goal is to have the most available traction, how that is obtained should be irrelevant. To that end I find the Roadster has the best traction of any car I have driven. There is no wheel spin with several runs at "Street Fights" (Open runs down Bristol's Thundervalley drag-strip NO-ONE has come close to the launch of the Roadster. If someone in a modified car beats me it is at the very end of the 1/4 mile. Why mess with perfection, or at least very, very good.

I agree that there doesn't seem to be much need for limited slip in the Roadster. The only time I get wheel spin in the dry is if I am really trying, on a sharp right turn from a standing/rolling start. I was surprised that a car that would do 0-60 in 3.9 seconds didn't spin the wheels. I guess with a manual trans and clutch that would have been a different story?

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Thank you guys for all the info!

 

[Doug_G]

The combination of smooth power delivery and somewhat-sticky tires is probably the reason. If you have to pause to switch gears then you need that much more instantaneous torque to achieve the same overall acceleration.