If i go with a 52mm TB what needs to be done with my tune? Im getting a dyno tune saturday and i may not have my 52mm TB by then. I can borrow one from a friend if i really need it.

How much does the TB affect the tune?

 

With an M6 probably nothing, the primary conccern with larger TBs is for the automatic trannies. They need more line pressure to compensate for the extra power at lower throttle inputs.

 

Yeh i'm wondering if i can put a 58 mm tb and was wondering what i need to do to make it fit

 

Well they are of little to no benifit till you do heads and cam, which honestly just from your asking how to make it fit I am going to guess you are not there yet. Once there though and prefferably while the intake is off for the cam swap you have to enlarge the intake opening for the TB because the stockers are something like 52-54mm. Some have done this on motor by packing the intake with rags and grease to catch the filings made while grinding. But like I said not worthwhile till after a cam swap so just port it while doing the cam swap.

 

you'll see that allot here on these post... but no one has yet to prove that theory. DYno 2 Dyno

 

Prove the larger ones are needed on stock motors or that stockers are good on modded motors? I can say for a fact that at higher rpms with a stock TB vacuum can begin to build and vacuum is a measurement of how much air is not getting into the motor. Yet the 502 crate motors use the same TB they have to be building a decent amount of vacuum doing so though. With a stock motor you might see slight gains somewhere over 5K for the cost involved there are MUCH better ways to spend money at that point.
I recently aquired a used 58mm which I plan to use after further modding of my already cammed car, I might try that vs. stock later in spring but that would be a couple months off at best. If it does happen I will post on the forums.

 

Im like you...just looking for hard data. there's plenty of Tb post on here with the same info... but no one has seemed to have hard tested it yet.