Just trying to figure out how much good the 4" exhaust does when it appears that there is a restictions in the down pipe from the turbo. I just re-read Joe Donnelly's article in issue 41 about air+fuel=power and it appears that you would have to change out the exhaust housing to a 16 sq. cm. and larger down pipe to get the most bennefit. Sorry for such a long post guys, but I am intersted in the 4" system & the downpipe seems to defeat the purpose. Am I better off changing out the housing & the downpipe & if so where can you buy these parts & pieces or who is the best person to point me in the right direction!
