I'm looking into making a custom turbo setup for my car and I'm confused on wastegate selection amongst other things...

What is better an Internal or External wastegate?

From what I understand External has the wastegate separate from the turbo in the exhaust manifold and Internal has it in/on the turbo?

I am planning on running 10-15 psi, on a slightly built GM V6 engine 3.4L OHV. I am only going to use 9:1 forged pistons w/ p&p and install bigger valves (LS1) and harder valve springs. and maybe look into getting the cam reground since no aftermarket cam is available.

I am looking into making my own custom manifold/headers or just a simple exhaust crossover pipe w/ stock manifolds.

Thanks in advance for the suggestions

 

https://www.homemadeturbo.com/forum/...threadid=28135

and

https://www.homemadeturbo.com/forum/...;threadid=3921

 

i read the "Please read before posting section"


Anyone have an opinion on wastegates?

 

are you going single/twin turbo? I would use an external wg for several reasons: if you get a turbo with internal wg, it will be less expensive, but most internally wastegated turbos may not have large enough wastegates for your application, causing boost creep... a design using an external wg, properly sized, could allow you to keep more consistent boost levels.

 

thank you! that was exactly the type of answer i was looking for.
This will be a single turbo, I'm looking into the best turbo for my application, I figure this will probably be close to the last thing I buy for the setup. To me everyone says use a Garrett T-3/T-4 hybrid, but I'm exploring other possiblities. Looking mostly for something under $500 for a new or rebuilt unit. I havent heard of anyone using something besides the Garrett. I probably will use an internally wastegated turbo (since they are cheaper) and make the block off plate or something and weld an adapter for the external unit.

 

i am using a turbonetics t3/t04e 50 trim

 

steph,

i am using a Master Power t3/t4 hybrid on my setup.

57 trim, 50 ar cold side
84 ar hot side

boosts VERY nicely.

just pulled a 14.0 @ 106 on saturday. with a NICE exhaust leak on the xover before the turbo. so i guess i found my low end loss problem.

once i get that welded up a mid 13 sec pass is obtainable.

and DONT go over 12 psi on stock/felpro gaskets, they dont last. i had one blow out on me on my last run of the day on saturday, and i had it running 10 psi, but some ****** messed with the boost controller and turned it up to 15psi so i did one run at 15 psi, 2 10psi runs later she was down for the count and puffin white smoke everywhere.

i was pretty happy that we were able to swap out the rear head gasket in less than 4 hours!