Originally Posted by islandborn
replacing JUST the DP makes no sense. If you WERE to, then do the whole exhaust. Unless, someone can tune a stocker, then switch just the DP, then see if they can get more out... then how much they do, if they do, is it worth it. I would imagine no. but, I'm learning as I go along too!
Well, my numbers above show me the downpipe, with appropriate tuning, is worth about 5whp and 25wtq, with the stock catback OR aftermarket CBE behind it.
With the stock cat in place I cannot consistently push boost at peak beyond about 16.5psi without having to pull so much timing that it makes no sense. With a catless or high-flow catted downpipe on the cars I can run up to 19psi before det becomes an issue. In over 50 cars (I stopped counting) not once did an aftermarket CBE show gains above the average.
Well, whatever... it's your money!