I have a blob STI prodrive with a 3" decat turbo down pipe.Where the pipe marries the middle/rear section it goes to 2.5" then into prodrive back box.
I am wanting a remap but will it make much difference if I leave it as it is or am I better replacing it with 3" straight through,does it make any difference??

 

At the top end it probably will when mapping

 

Mines like this. It goes from 3", to 2.5", back up to 3" and was worried about this being my bottle neck....

It was on the car when I bought it, but know it was done at Scoobyclinic. So I emailed them, and they replied nice and fast saying a full 3" system is only need for about 450BHP. I am aiming for 420ish next month, so said this will be fine

 

It is a restriction but any decent mapper will work with the parts you have an extract the best performance possible out of them.

 

Cheers for that guys!!!

 

It won't make any difference at your level, not a restriction.

cheers

bob