It’s no secret that one of the E92 M3s tendencies is its sudden breaking of traction with both wheels at the rear. This is due to the factory ///M differential which is a clutch unit can suddenly lock, causing both wheels to move at the same speed often resulting in the rear end breaking traction completely. In contrast due to the differential being a clutch based unit it can wear, producing in poor lockup resulting in behaviour like an open diff. Both are not ideal situations for a road or track car.
The Wavetrac automatic torque biasing limited slip differential is a helical based unit with a big difference. A major drawback in helical units, up until Wavetrac produced its patent-protected design is that once axle load is low enough or lost an ATB like a Quaife will function like an open differential. Thanks to Wavetrac’s unique, patent-protected wave hub system it can create internal load in these situations, so the Wavetrac ATB LSD continues to work when others stop.
Scenarios, where this technology can benefit, is really in all. On track when cornering hard, unloading the suspension or hopping over curbs, lifting a wheel the Wavetrac ATB LSD continues to bias torque so drive is not lost and forward momentum is maintained.
On the road, when passing over the UK’s notoriously unsmooth tarmac, drop-curbs or simply low-grip conditions like dusty or wet roads the Wavetrac will outperform other helical diffs like the Quaife with ease.
Big benefits over a plate-style LSD is that the Wavetrac has very low noise vibration and harshness meaning your driving experience is not ruined with high NVH. The Wavetrac ATB LSD also never locks so you don’t have to compromise your chassis setup with having to overcome a locked axle, this is significantly useful when optimising the spring rates. It also requires zero maintenance and will have zero performance drop-off where a plate style diff will need to be periodically removed and serviced to maintain function.
All things considered, the Wavetrac ATB LSD is significant performance upgrade with zero maintenance costs.
As part of all of our Wavetrac ATB LSD installs we spec the backlash to within the OE specifications.
Whilst the Wavetrac will work fine with the factory oil, for axles like these which will experience a lot of track work we use the Motul 75w140 competition oil. Giving a little more protection for the OE components.
With the Wavetrac ATB LSD install complete on Ryan’s E92 M3 he is free to complete the bedding in the procedure below and enjoy the massive improvement in traction and grip