Wastegate Off Exhaust Housing

[joe blo]

hi guys. i have a china highmount manifold with a t04z on it. the 38mm gate was too small so i now have a 50mm to put on the setup. wondering if i should put it on the exhaust housing of the turbo or modify the manifold to suit?

[r33_racer]

It would probably be easier to just modify the manifold and fit it there. Being a china manifold, I doubt it would flow well to create the need for it to be mounted off the exhaust housing.

Welding to the manifold which I guess is stainless, would be far simpler then welding to the exhaust housing which is cast and requires pre heat and post heat and a slow cool down.

[R31Nismoid]

Make sure you get some bracing welded onto the manifold as well, it'll crack either way most likely but anything you can do to help stop it is beneficial

[ARTZ]

are you saying it will crack if its attached to the exhaust housing or the china manifold will crack ?

Im about to attmept welding one to the ex housing, the gate is heavier than I expected so it will have to be stuck on good n proper..any tips for welding onto the cast housing

[r33_racer]

Yeh the china manifolds always crack. They use too thin a walled tube for the runners.

Welding to the exhaust housing you will need to pre heat it to about 400 degrees, then tig it on and try to keep the heat in it for a while after welding. I usually chuck it in the oven and keep it at 400 degrees for an hour or so afterwards and then turn the oven off and let it cool down over night. Its normally still warm the next morning. If you dont have an oven, you can toss it in some sand to help it hold the heat in. But its important you pre heat it and that it cools down slowly.

[ARTZ]

[ARTZ]

ok..sounds easy enough..

Do you think it would be best to drill a hole in the housing big enough so you can insert the steampipe into it, then weld around ,or just weld it on top..is it sturdy enough do you think, have you had many problems with them cracking?

[r33_racer]

I drill a hole then die grind it out to size, usually the ID of the piece im going to weld on and then line it up so its resting on top, not slipped inside. So long as you do the pre heating and slow cool down it shouldnt crack. No problems with cracking so far mate.