Turbo Manifold Construction

[classicauto]

I think I understand what you're saying, and if I understand correctly, its not a great idea. Given that they'll diverge (from primaries into the wastegate runners) at a shallow angle, you'll *probably* have OK boost control - but placing them (the wastegate runners) that close to the start of the primaries is completely backwards with regards to boost control.

Tapping the runners in as close as possible to the turbine will get the best results. Ideally, on the outside of a bend.

Also personally, I wouldn't want that many merged/welded pipes directly at the entry of the manifold at that spot will get ALOT of heat. Not to mention if I'm envisioning this correctly, you're basically doing a >- right out of the engine on either port, yes? If so, the inside corner where those two pipes merge is going to get so hot from the exhaust pulses that it may not survive long - especially if its welded.

As an example of the above, on my dual exhaust system, the Y pipe shows massive colouration at the spot where the exhaust splits. And thats after its been out the engine, through the turbo, through a cat, and spat back towards the mufflers. Having a Y directly out the engine like that would amplify that heating wildly.

[vex]

Originally Posted by classicauto

I think I understand what you're saying, and if I understand correctly, its not a great idea. Given that they'll diverge (from primaries into the wastegate runners) at a shallow angle, you'll *probably* have OK boost control - but placing them (the wastegate runners) that close to the start of the primaries is completely backwards with regards to boost control.

Tapping the runners in as close as possible to the turbine will get the best results. Ideally, on the outside of a bend.

Also personally, I wouldn't want that many merged/welded pipes directly at the entry of the manifold at that spot will get ALOT of heat. Not to mention if I'm envisioning this correctly, you're basically doing a >- right out of the engine on either port, yes? If so, the inside corner where those two pipes merge is going to get so hot from the exhaust pulses that it may not survive long - especially if its welded.

As an example of the above, on my dual exhaust system, the Y pipe shows massive colouration at the spot where the exhaust splits. And thats after its been out the engine, through the turbo, through a cat, and spat back towards the mufflers. Having a Y directly out the engine like that would amplify that heating wildly.

I see your point. I'll have to think about that. So if I move it closer to the turbine inlet should I have a steep angle or a shallow angle? I imagine that the turbo is going to indeed get quite hot with higher boost levels (I'm currently aiming for 5psi) which would adversely affect the the life span of components.

I think no matter what angle I go at the welds are going to see some large temperatures. suggestions on minimizing the temperatures to the welds?