Hi Neil and welcome to the forum.
I'm making a jump here, but I think you are the chap I spoke to at GTI international regarding launch control aren't you?
My car was the ED30 on the JBS stand.
Good to see you finally made it onto the forum 
I'm also going for the Quaife diff through VW racing, so it'll be good to compare 
Hi Hurdy, I do remember speaking to you at Bruntingthorpe about the launch control as I use hand controls (motorbike + tree = wheelchair !) I couldnt brake and rev at the same time. Managed a 14.1 1/4 and 5.5 to 60mph by holding brake down with pole, had to grab the steering wheel a bit sharpish though.
How's things, was you clutch slipping? I've had the intercooler and KW suspension fitted since then, feels quicker. Could have used the Quaife diff before a track day at Silverstone in a couple of weeks, meeting two other mkv Gti blokes there, both prepared by VW racing for the VW cup. The 3 of us are in wheelchairs!! It may well end in tears (probably for me).