RPM Motorsports
Member
This should get the air out the back pretty well 





I'm also wondering how much
This will not be a production peice, every car is different in slight ways and a peice welded up on a jig can come out slightly different every time. This is a custom one off exhaust specifically fabricated for our customers car.
A complete exhaust like this would run about $1000.
Yes as of right now, it's using the stock flex coupler, I'm waiting on some flanges and transistions to build the down pipe and were using a special flex pipe for the finished product.
As for the S and J pipe, There is no way to properly fabrcate a true 3" turbo back system. This down pipe will have to be 2.5".