No one with a 4 cyl yet, still trying to find testers etc. I can only speculate on the gains on one, but we'll just have to have someone try to see
Haven't thought of using a massive turbine housing, but if I had a dyno here and some time to test all the different options it would be great to get everything mapped.
It would be even easier if I had a FWD or RWD buddy that installed one as rwd dyno's are all over the place around here, but AWD are hard to come by.
Shoot me a PM with the details on your setup and when you're looking to build it, maybe we can work something out.