zerinS4

Uh, the Roadjet had a longitudinal 3.2 FSI engine.

Steffen Scheibler

Just for clarity, even on an ancient thread: You cannot put the Audi 4.2 V8 in an Audi TT. The 4.2 V8 needs to be mounted longitudally or it will starve for oil and fail within a very short time (minutes).
You cant physically fit the V8 longitudally in a MK1 (8N) or any other TT for that matter without fundamentally changing the chassis. The geometry of the front axle is completely incompatible OR you have to install the engine up high, which means your TT can only really be used as a dragster.
To make them work in a transverse install you need to make your own bottom end of the block. It makes no sense. It's insane.

If you want a V8 in your TT, you need to take the Yamaha V8 which is installed in the Volvos from the 00s and also the Noble. They will fit reasonably well and weigh 15kg less than the 3.2 V6 and around 35kg more than the 1.8T with 225/240 BHP, but you can eliminate all the turbo stuff, so even if you install the V8 in a 1.8T, the weight gain is marginal PLUS you move some weight to the back (battery) which helps with balance.