iv got a BA xr6 turbo and still dont really know much bout them, im looking at doing a new exhaust system soon, and have my eyes on a fully system 3 1/2 inch from turbo back, now iv been told i may need to have the car tuned after, is this true? or what is the outcome of not tuning? i would like to hear from people that have tuned afterwards and people that haven't to be able to compare, i know that tuning would clearly be better but at the moment more thinking bout my pocket

thanks

If you dont get it tuned your boost will spike and motor will blow. Thats the short story. Just get it tuned,Your pocket will love you more when you dont have to fork out the cash for a rebuild.

The wastegate is the problem !!..
They tend NOT to flow enough exhaust to bypass turbine..
When better exhaust is fitted..
Porting the w/gate and fitting a bigger button helps sort issues..

would it make any difference if i didnt change the dump?