internal or external?

[TOMMYSDSM]

ok so i blew my old turbo and it had a tial 38mm wastegate setup on it and i think i was a 50 trim turbo now i upgraded to a 57 trim ### my old turbo blew and this has a internal gate on it should i switch it back?? it feels like a lost power!

 

[1gDSM4g63]

You'll have to do some tuning. For maximum gain and the 57 trim does have more spool lag than the 50 trim.

 

[TOMMYSDSM]

so i should keep the internal and tune?
or external and tune?

 

[LTUDSM]

external adds a bit more power,so its up to you... +it helps to get rid of the boost creep

 

[daarkness92]

external for sure...it holds boost all the way and doesnt trim off like an internal

 

[TOMMYSDSM]

ok so if i go back to external should i keep the spring thats in my wastegate its 11psi now?
also i have a fpr should i put that on to?

 

[LTUDSM]

if you have 550'cc injectors,the FPR isn't that necessary, and yeaah 11psi spring works with your setup

edit: Update your profile with all your GS-T's information

 

[turboglenn]

Go external with either a ball and spring or EBC. THe 57 trim lags like it's a 3 legged cow on the way to the slaughter house. The 50 trim is much happier to spool and not too far off from a 57 in terms of air flow. The 57 shows more on the map, but in real world apps, i haven't seen too much difference in numbers from a 50 to a 57.

Anyway, go external simply because it's a more solid setup that's easier to maintane and modify for more PSI if needed, not to mention more reliable control of boost.

I have a 57 trim as well and i love it in the top end but hate waiting on it to decide to spool, as i'm not a fan of retarding timing or running overly rich in the first few psi or the RPM range where initial spool is taking place. Simply because it creates an annoying flat spot in a street car, a track car is different since they run WOT 90% of their lives.

YOu wil be fine with an 11psi spring for now. I just put a 14.7 in mine (1 bar) and upgraded the cap to allow the use of multiple springs for higher boost days. If you've got a LSD you can get away with much more boost in the first 2 gears, at least compared to running an open diff. When i was peg legging my car i had to run 9 psi in first 14 in 2nd then what ever i wanted in third and up. Now that i've got an LSD i can run 15 in first 20-21 in 2nd and then 30 the rest of the time. OR you can jsut leave the boost cranked and learn how to feather the pedal through the first two gears. But some people need boost control to help as they get too excited and just mash the gas after they leave the line.