External wastegate help/info

[talon187]

ok im going to running a tial exernal wastegate with a 2g ported into manifold my question is where should i have the flange for the gate welded on the manifold? Also whats the best way to weld it to the manifold? I have a guy who can weld almost anything and he said that with cast iron its kind of a hit or miss thing i just dont want to ruin the manifold whats the flange made out of anyway? thanks for all the help guys

 

[synthetek]

A flange meant to be welded to a cast manifold is usually made of mild steel. Welding steel to a cast manifold can be kind of tricky for someone that dosent know what there doing. The cast part has to be heated first and kept hot while the steel is welded on then it needs to be cooled slowly or the welds will crack it should be stress relieved too. Other options might be a tubular or cast manifold like the SBR one with a flange already on it, or an o2 housing with an external flange.

 

[talon187]

whats better have it on the manifold or the 02 hosuing?

 

[c711]

it is not good to have it only on one runner from the manifold. only 25% of the exhaustgas going through that runner! so ideal would be on the collector of the Exhaustmanifold.
In your case i would go for a o2housing solution. Dont forgett to port out the wastegatehole in the turbo, stock should be 31mm, i gues your tial is 38mm or bigger.

If you plan to build your own o2 hoasing, it is better to reroute the wastegate further down in the downpipe. so there be less turbolences.

Regards
c711

 

[GSX Ben]

I've had an external wastegate welded on to my manifold and the weld blew up on high boost 3 times finaly i just got a new manifold with a wastegate port so it just bolts on and its a whole lot less trouble trust me... if your gonna weld it get an awesome welder or just dont bother at all heh.