Wastegate 38mm or 44mm?
 

need to put an external wastegate but I do not know what to put between 38mm and 44mm. I have always had a wastegate actuator. what is the difference between the two? what wastegate you advise? I have a sr20det to 15 lbs of boost with a turbo GT2871R. with the external wastegate I'll get a 20psi.
Thanks!

38mm will be fine for what you need it for

Larger wastegate will help with boot creep but considering turbo size, I agree 38mm will do fine. This will all come down to preference.

Personally, I like larger wastegates.

well, larger wastegates take space and cost money. if you can do your job with a smaller one, do it. generally, you need a big wastegate when you wanna run low boost on a big cc engine. the more boost you run, the less open the wastegate is, so...

the really good thing about an external (when its got a screamer pipe) besides the sound, is that it effectively makes your exhaust bigger :) ...just by a bit.