Thread: Wastegate size?

Thanks to Thomasf36 and the manifold I bought from him, I'll be tossing the td04 for a t04e this weekend.

Now, my question is about the size of external wastegate that would be best. I remember reading somewhere that with larger turbos, you should use a smaller wastegate? Like a 38mm for larger turbos, and something like a 44mm for smaller?

I have a t04e with a .76 turbine. So I'm not sure if that actually qualifies as a large turbo when compared to say, a t66 or t70 or something that uses a .82 or higher trim turbine.

use what you have you will be fine i think it goes the higher the boost the smaller the wastegate you need i could be wrong in that statement though

Don't have one right now. I had an internal gate on my td04. My friend however, fried his turbo and is switching to something a bit smaller /w internal wg, and ditching his external setup. He said I could have his ext. wg. It's 38mm I believe. Not sure.

I'm thinking the smaller gate helps keep a larger turbo spooled? Or helps with response or maintaining the higher psi? But then how would a smaller turbo benefit from a larger wg? Or does it have to do with balancing the turbine flow with the wg when open?

yes you are correct , that came from miller and T1. and if you want precise boost with no creap run the lowest pressure spring you can with co2 to the top of the gate with an electronic boost controller.

And me.

Co2 as in a tank of it connected to a electronic boost controller? How exactly would that affect things?

CO2. it keeps the gate closed longer.

Remember a larger turbo means more intake flow, which means more exhaust flow, which means you will need a larger gate to keep from creeping.

The only way running a "too-small" gate is not going to creep is when the turbo is maxxed to the point it just can't supply any more boost.

A larger gate is always the best solution. run as big as you can fit. There really is no gate that is too big, unless you fail to hit the desired boost level lol.

Even when running a low psi spring, you are running less boost, less airflow, and less exhaust gas. This does not require a large gate, because you aren't flowing that much through it. Just like your turbo won't be flowing much through it.

But I guess it is a perception issue. Think about it, let me know if my rambling makes any sense and you will have your answer.

Tial 44mm FTW!!!

Thanks guys. I know I may ask a lot of questions, tend to ramble, and sometimes over-think things. But I'm glad to be able to ask someone who knows from experience.

I just like to try know almost every aspect of something before I attempt it.

At the end of the day the most important thing is to decide how little boost you want to run compared to how big your turbo is. If you want to run low boost (ever) you'll want a larger wastegate. If you don't mind making tons of boost (and never being able to make less) then a tiny wastegate is fine (or no wastegate at all).

I'd go with around a 44mm wastegate on that turbo because I'd want to tune low boost settings and maybe work with a valet mode sometimes. It's maybe overkill but I'd rather be safe than sorry. A 38mm or so sized gate could probably get the job done but I'd rather not chance it unless I knew I never wanted to keep boost lower than say 10 psi.