Okay, I have a used RNR 50 trim turbo kit with out a wastegate. The manifold was flanged for a 46mm wastegate. That seems like overkill.

My options are

find a 46mm wastegate

or

reflange for something more appropriate like 38mm.

How would a large wastegate affect drivability if at all? It seems either spend extra on the big wastegate or spend money on reflanging the manifold.

Suggestions?

 

i would suggest getting a tial if you can.
it comes with a flange, so you would have to reweld it.
i hear the 44mm is really good, but tial is on backorder from what i was told

 

Are you sure its flanged for a 46mm? Their is no problems in using a bigger wastegate. It won't effect driveability or boost control.

 

I would agree....the wastegate is gonna open/close to maintain the desired boost levels anyways. The larger wastegate should flow more if you ever need it.

 

i have a tial 44 mm WG with my fullrace kit. It was a bit pricy, but worth it. I got the 1.1 bar spring and can/hold hit 30psi on my gt-3037r no problem. It holds like a champ.

 

44mm is a great wastegate, with a 50 trim a bigger wastegate is a good idea becuase you will vent more exhaust pressure than a bigger turbo and you don't want boost creap. A 38mm can do the job but a 44 will do it better. Just my .02

 

I appreciate the help. The prior owner of this manifold had modified it to fit a 46mm wastegate. I expect to receive it any day now.

 

44mm seems to be what everyone uses. that what i have. i have had two friends who has te tial 38mm get stuck in the open position.

 

i agree.. 44mm seems to be the popular wg. from experience, i would recommend the 44mm over the 38mm since it's larger and with a 50 trim, it can deal with and handle the exhaust pressure flow a bit easier than the 38mm. however the 38mm can perform the job as well even though i know a few also who used the 38mm wg on their evos where their's got stuck in the open position too. on my other car, i replaced my wg cuz i noticed it kept bleeding off boost pressure as i accelerated into higher rpms... so i got a tial 46mm and couldn't be happier.

anyway, tial makes superb wastegates overall. go tial .

 

I got the manifold and the shop I bought it from deflanged it prior to shipping it out. That must be his way of insisting I get a 44mm Tial...

Oh, this is one of the nicest manifolds I have seen.

 

the bigger the wastegate, the better the boost response!

 

This is what my subaru buddies told me:

Big turbo/ low boost - big wastegate needed
Big turbo/ high boost - small wastegate needed
Small turbo/ high boost - small wastegate needed
Small turbo/ low boost - big wastegate needed