I'm trying to game out how I'm going to run an external gate.

As for sizing, I'm thinking that WG size needs to be matched to the top turbo to establish some kind of "bypass ratio." I haven't worked out the details, but I suspect that the bigger the difference in size between top and bottom turbo, the bigger the WG needs to be.

Can a WG be too big? Part of thought about WG cycling, but the progressive nature of the WG spring would eliminate that as a concern.

I'm thinking a 40mm or bigger should be plenty.

Finally, how exactly is best to plumb it? I've seen spacers done on the manifold outlet. I've even seen them welded right to the turbine housing!

Can you weld a steel flange to a cast iron manifold? I don't know that much about welding. Ideally, I'd be able to do that, and have the WG perched on top of the manifold outlet and feed a bypass tube on the hot pipe.

Is there a "best" way to do an external WG? I was floored when I saw the external perched on top of the turbine housing, but I can see how it might even work!

I'd appreciate if any of you guys who run or have seen different external setups would "pipe" in

jh

 

I used a manifold adapter to mount my 38mm Tial. The wastegate can be tuned using either air, spring adjustment, or boost line valve. ks

 

I think I want to plumb mine so it only see's differential pressure, not total boost.

I other words, I want it to pop when the little turbo is making X amount of boost more than the little turbo.

Whaddaya think?

 

HERE!!!

There are some pics of my mounting...need to get some more of my control plumbing...it has all been changed since the pics were taken!

Chris

 

Yeah if you do a combination of spring pressure along with regulated boost pressure to help open the spring, but it'll take alot of playing around with to get it right, and a tial 38mm should be fine. And yeah you can have a WG thats too big