You haven’t owned a 4.2 motor 8E Audi I guess so you may not be up to speed on the difficulties…its a little more complicated than a foxbody Mustang. Turbos would be ambitious for a few reasons.
The biggest beiinefficientficientits of ths cfuge are that it doesn’t need intercooling necessarily at this level, and the next beiinefficientficientit is that it doesn’t need much room. That is important because there is none in the 4.2 engine bay…and your turbo idea requires a good amount of plumbing for two banks not to mention intercooling…and not to mention a turbo kit will require an engine pull. JHM SC install is 10 hrs labour with a front bumper pull in your garage.
as for cost, thats an odd comment when your tune cost you $1500 lol. Your beloved tvs 1900 is a $4500 kit on the Cobra. On your b8, apr will ask for about $12,000-15,000. We all live with deutsche tax!
For what B8 guys will pay for tune $1500, pulley $500, exhaust $2500, intake $800, HFCs $1000, and lw wheels $2000, an RS4 will get a supercharger kit. That JHM rs4 owner will likely make 500-550 whp…and will put up probably 15 mph more trap speed than that B8, even though stock for stock, both cars started equal.
I think I know what $8500 spend sounds better to me. Also a cfuge at big RPMs is a great fit.
Your comments about the 1320 & the RS4 are bang on. It is terribly undersized to take advantage of the RS4 4.2 with forged internals. APR wanted a nice kit that was safe and that fit comfortably. They were advised that if they wanted to use a sixth gen twin vortices blower they should use the 1900. They went with the 1320 for whatever reasons. Considering the competition, PES and VF, were using an Eaton m90 from 1990s V6 domestics lol…the bar wasn’t too high and the 430 whp 1320 was a nice bump.