I dont have any numbers or times to prove my system yet, but Windsor exhaust at Richmond made me a custom 4" turbo back complete exhaust fitted for $1250. They have done all my cars over the last 20 years and have always done amazing custom work. Its mild steel mandrel bent and uses 2 straight through 4" muflers with no cat ... as I asked for a strip only exhaust and would not take this car on the street without a cat. It has the double 3 bolt flanges to install a cat for street use. Numbers will come soon just waiting on the stage 3 plazmaman cooler, 4" intake and bat reloc kit. They said they have skeleton crew over xmas but should be here soon. By the way a shout out to PJ at Plazmaman for a great package deal and amazing customer service. And just about to grab Joe's last GTX he has in stock and then off to C&V to let them do what they do best. I know they dont have the Nizpro name or Xforce, but every turbo car or bike ive ever had has made impressive numbers with there exhausts. Plus for $1250 fitted .... its hard to go wrong. Also il add, at 100 - 110kmh cruising you can only just hear it has an after market exhaust on it, it dosnt drone or do that terrible wave noise with ya windows down. The only thing you really hear which is loud is the whine from the turbo being its straight through. And the occsional large orange flame it throws during a limiter burn out is quite impressive and makes me laugh. Anyway guys just my 2 cents, no doubt Nizpro and Xforce have the times and numbers to prove themselfs, but just wanted to give these guys a shout out for price and quality work. have a merry xmas everyone.