Im am going to get my car tuned from jeff in about a month... however i will have a 3 inch downppipe going into a 60mm apexi cat back exhaust (and test pipe)

would it be best to tune the car with a full 3 inch now, or can i wait till later to buy one after the tune?

 

It would be best to tune it with the setup that you plan to run. Although it may not change enough to make it run bad, ideally you want to tune on the setup you are going to run so it is as close to perfect as possible.

 

I would say have everything you want to have on the car done, before you get it tuned.

 

damn.... more money to spend

 

thats how it always goes

 

It will lean out a little bit if you step up to a bigger downpipe/exhaust system, the boost might increase a little too due to the gas can now exit much quicker...