It's the same cupra, was originally owned by Surfer_D (he posted on here the same time he posted on the vortex), Surfer_D sold it to Casper I think, Casper's active on here so he might post up.
Modded K04-23, running with MAP sensor mods. Cheap enough from L&S Cartec, but difficult to get specs out of them (I tried) because of the Language trouble.
Two other modded K04-23 you can get, one from "ImolaVirus" off audiworld.com, his name is Jacob Buehn (sp?) and he has a website
http://www.buehnengineering.com/forums/ he does lots of hybrids/modded turbos for Audi A4/S4/RS4 and he did a TT225 one. A guy on Audiworld.com had one for his S3, took AMD ages (Months?) to map it and I don't think it performed. Not sure if "Lee" with a Mk1 (?) GTi fitted one. Theres a thread on
www.audi-sport.net
Another one you can get is from
www.turbodynamics.co.uk. "Expensive" (£1200+vat) though, and their guy was of the opinion that you'd need a manifold as well. Might as well go proper big turbo.
Also, HGP do a different turbine housing to fit the K04-23 - I think it's the hot side that's weak on that turbo (opinion born out of nothing but guessing). That's classed as xpensive too - £600? Plus rebuilding, obviously. I'll see if I can find a link...
A&M and JBS are both talking about doing K03/K04-23 hybrids though - would be best for you surely? In fact, with a "better" manifold than the stock K04-23 manifold, these
might make more top end than a stock K04-23, with a theoretically high boost threshold.
Vern knows a lot about what other peeps are running, he might remember what BMX is running on his TT?
