My car isnt a ford lol ive own fords though and there seems to be alot of people on here with knowledge.I have converted my volvo 850 saloon from a 2.5 20 valve to a T5 now my down pipe from the turbo is 2 1/2 inch and at the minute ive just connected it to the std 2.5 exhaust cat back and the cat back exhaust is smaller possibly 2inch or 1 1/2 .Could having the smaller exhaust on the cat back restrict how much boost i run with running down a bigger pipe into a smaller one?