There's a photo in "maximum boost" of a toyota gtp engine with the external gate mounted on the turbine housing. Looks as though the housing was drilled, ported and then a flange welded up to mount the gate. I know it takes some skill to weld to cast iron, but what are the other disadvantages to this? Anything to do with thermal reactions to dissimilar metals? It seems like a simple solution, and Corky praised it's performance - and the toyota gtp 4 bangers kicked some *** in their day. - rob

Damn! I can't believe I found a photo of it.

 

That's probably pretty close to an optimum setup. Other than being the port roof of the turbine housing. Under full boost it's probably optimal, off boost sub-optimal.

Mark

 

yeah I wonder how much it distrupts the exhaust when traveling around the turbine and out the exhaust.

 

Ok. It's optimal for a "race car" that's basically focused on going as fast as possible all the time. That's a reference to the angle I'm assuming- and perhaps the location just past the turbine flange where the housing begins to close in? If it were at a 90* housing that should help with off boost gas flow- no?

Just considering something different from the #4 runner location. I'd do one of those sandwich adapters, but that would mean putting an extended section in the downpipe- and I don't have much in the way of vertical space with the top mount and the taller engine. Both from Innovative- I haven't seen the angled one before.

 

some EVO turbo upgrades have a cast turbine housing with an external gate flange cast right into the housing. maybe you can find one of those possibly?

 

cool - had no idea - thanks