38mm wastegate limitations?

[Liam2421]

Hello wondering if someone could tell me if a 38mm external wastegate would be adequate for a 25det running a psr 3076 .82 only looking for around the 300kw mark (or there abouts). My top mount has a 2bolt flange for the wastegate and as far as I can see anything over 38mm is v-band, if possible I’d like to not have to modify the manifold, thanks in advance 

sorry if this has been asked but I could not find any threads about it.

Edited January 31, 2024 by Liam2421

[hardsteppa]

It is likely to boost creep ' a little bit'...depending on the manifold and design. I have the same turbo setup and it often had an uncontrollable rise at the top of the rpm range, although the current g30-660 with .73 housing and same gate/manifold holds boost just fine.

 

[Liam2421]

2 hours ago, hardsteppa said:

It is likely to boost creep ' a little bit'...depending on the manifold and design. I have the same turbo setup and it often had an uncontrollable rise at the top of the rpm range, although the current g30-660 with .73 housing and same gate/manifold holds boost just fine.

 

I have a stainless ks racing top mount as it was cheap I assume the manifold design won’t be ideal? Okay is the g30-660 a smaller turbo or is it because of the smaller rear housing ? Pic for reference of manifold design 

Edited February 1, 2024 by Liam2421

[robbo_rb180]

Go a 45mm
Have tried smaller gates on cheap manifolds and they spike, even on 6boobs as wastegate flow is poor.
Stock manifold and internal gate will work fine or mod a stock one to external gate.