Nick-LT1

Would i benifit from using a 52mm tb? I have mac mids no cats loudmouth and 3.73.

96capricemgr

No
If you want to check first make sure that everyting in front of the TB is not a restriction(stock is) then use a vacuum gauge or datalogger to check WOT vacuum if there is more than 1.5" there is a restriction, as noted though if you haven't upgraded the intake tract yet that will be a restriction before the TB will. Generally you won't see much gain till at least heads or cam and with an A4 car reprogramming is needed unless you want to hurt the tranny. Reason being line pressure is referenced from throttle position and with a bigger TB it will make more power at lower throttle positions, the tranny needs the extra pressure to deal with that. There are ways to do it inside the tranny too.

besz28

yes anything that helps get air in is going to help. know will you see a lot of horsepower no maybe 3-5 with your mods,but as previously said with heads and cam definitely

Antz97ZNJ

no stock is just fine til you start producing big HP