just had 1 fitted and im still getting alot of wheelspin in the wet , is this to be expected ? i have inly driven cars with diffs in on dry roads/track
With your amount of torque it will always struggle to find ultimate traction especially in the wet but more importantly is the issue of early boost spike and/or power modulation with DBW cars.
The biggest gain using an ATB diff will be on a nice sunny day using track day rubber where when your increased heat in the rubber on intermediates or similar will transfer power nicely to the outer wheel and pull the front nicely through the apex. It is all about timing as crucially with the torque your engine or the Edition 30 produces will easily overwhelm the front if brutal.
I've had them on most of my previous cars and found it worked best on my 200bhp valver where the more sensitive and less torquey engine made it easier especially at Combe.
I found that I was lapping as quick if not slightly quicker than Bill Brockbank with his Jetta in my infamous valver at approx 1.21-1.22 around Combe. Amazingly I was lapping at 1.23 in the APR Stage 3 MKIV with 350bhp and a diff.
The Edition 30 on stage 1 no diff OE brakes but Yellowstuff pads and Motul fluid I peddled it at 1.23-1.24 on Intermediates and no diff. APR Stage 2 on road tyres made it slightly slower (To be expected). I never did try the full combo of Inters diff and big brakes.
I would look forward to warmer weather and Inter tyres and a good blast at Combe to see the real gains....1-2 sec per lap.