Electronic lsd?

[Alistair1537]

With the gadgetry available - is there any need for an LSD anymore? Surely an electronic version could be developed for the Seven that would be lighter and switchable - used as traction control?
I'm thinking of 2 wheel abs system with software written to prevent wheel-spin during hard acceleration. Has this been done?

[DCL]

Yes it could be done, and there are people out there, myself included, that have played about with traction control. But, IMHO, using an ABS type systems as a mechanism to control wheel spin would add to the complexity and weight of the car - both against the ethos of the Caterham.

[harry b]

VW uses this technology on their cars with syncro. (T4 syncro for example)
It isn't a diff lock. It just applies the brake to the wheel that spins. Don't know if I would want that on a light Caterham.

[Magic919]

Traction control, like Racelogic, works well at limiting power to keep wheel slip to a desired level. Controlling it on a per-wheel basis is probably too expensive for a retrofit. LSD and Racelogic, in reality, would achieve a good compromise.

[fergus]

DCL said:

Yes it could be done, and there are people out there, myself included, that have played about with traction control. But, IMHO, using an ABS type systems as a mechanism to control wheel spin would add to the complexity and weight of the car - both against the ethos of the Caterham.

The latest Bosch ABS "9" systems fitted to most sportsbikes, which have switchable modes to allow different levels of intervention weigh around 0.8kgs.
http://www.ashonbikes.com/content/bosch-abs-testin...

Using the ABS sensors to feback to an ABS based TC system, rather than the ABS feeding back the engine ECU is more expensive, as the TC ECU needs to interact with two discrete ECUs rather than one?

[Alistair1537]

My understanding of traction control is that the engine is detuned if there is excessive wheelspin? Is this the case? If so, then traction control is de-powering the car. LSD on the other hand, is providing more grip for available power?

So, having traction control is beneficial and having LSD is beneficial - but an electronic system could combine the two - full engine power and maximum grip?

[DCL]

Ideally you're looking for between 5% and 20% slip (depending on conditions)to generate maximum traction. It doesn't really matter if you reduce power or 'waste' power in the brakes, the net result would be the same as you can only use the grip available. The Racelogic system cuts the spark in a predetermined sequence and that reduces power and has a pretty instant response. Not saying your idea doesn't have any merit - it certainly being used, and developed, by some manufactures to provide electronic stability, but it's maybe not suited to a car where 'adding lightness' and raw diver experience are the selling points.

Edited by DCL on Saturday 2nd March 07:31

[Bobley]

Spark cut is a pretty crude way to control torque in this day. Given that new Caterhams use BMW differentials it would be interesting to see the effect you'd get using the lasting active M Diff?