I've been using Quaiffe diffs for years.
My APR Stage 3 + Golf had one as did my MK2 16 valve with 200bhp+.
I found the diff was more efective in the MK2 than the MKIV as eventually running 350 + was too much for FWD.
Finding the limits in the MKIV on road use was difficult as the power came in later but on track the diff was helpful on road tyres until they heated up then it washed wide especially at Quarry Castle Combe....it still posted 1.20-1.22 last year on road rubber..GSD3 F1's.
I personally found it was far better utilised when I ran Intermediate tyre in particular I ran VW Cup Dunlop DO1j's.
The MK2 being lighter with better camber adjustment available was better suited to a diff.
I suspect that the MK5 running a WALK kit will be likewise. The earlier thump of power is ultimately better distributed and deployed with a good sticky rubber compound and running with a diff.
I suspect with my Ed 30 I will initially after speaking to Jim at Awesome and VWR will run Stage 1 a WALK kit some big brakes and some sticky rubber for track usage on stock suspension as I feel at this stage is pretty good. Later some KW's/ARB's and some polybushing 'may' follow budget dependant.
I reckon on the map and WALK kit and brakes and good rubber I will see about 1.20-1.22 a lap at Combe
My concern is that I wanted to keep it stock
