Originally Posted by '10Anamoly

The stock curve was similar but the Weldina gave about 4-6hp and 4-6tq from 3000-4500 and 5000-6500. Peak horsepower was still about 275hp and 230tq. Basically a midrange boost. The problem with the Weldina is that going into the Y-section it necks down to a single 2.5" pipe and then comes back out into two 2" pipes. The exhaust stays at 2" all the way through the resonators and then jumps back up to 2.5" through the rear exits. I used a 304 stainless 2010 Mustang X-pipe and some Vibrant 2-1/2" stainless resonators to make a full 2.5" system with the Weldina muffler in the back. Much smoother after dropping out that midsection and replacing with a proper 2-1/2" full x-pipe.