Wastegate location

[vtecds1]

Can anyone tell me the benefit of the wastegate being run off by the collector or where all the runners meet. These are pics of my current setup. I took the manifold off because the welds where poorly done and it started to crack. One of the runners actually had a weld stop about 1/2" before it made it all the way around. I`m asking because if this setup is a poor choice, I will be going another route in the near future. And please, any comment is welcome but give your take why or why not it's good. Thanks!!!







Before I forget, my wastegate dumps right on top of my cross member...bad idea? Should I extend it where it's open?

 

[Barnes]

Does it control your boost well enough? If yes, then it is probably fine. Save for the cracky manifold.

I would extend the dump tube just so you aren't covering things with soot.

 

[vtecds1]

It controls the boost fine whenever I get the damn Profec B working right. /ubbthreads/images/graemlins/smile.gif Also, did you mean save the manifold? As for the soot...There's really no soot where it dumps, but then again...I barely drive it.

 

[Whoodoo]

Going along the route of general airflow dynamics, its slightly beneficial to have the wastegate at a more acute angle to the direction of flow. Also, there is a small benefit to having it at the collector as opposed to on a single runner because it will keep backpressure more or less equal across all the cylinders. If its on a single runner, when the WG opens, it lowers backpressure on that cylinder more than the others.

As for the placement of the dump tube, having it pointing directly onto the cross member, you may see abnormal wear on the finish of the cross member due to the exhaust, but I'm sure it doesn't effect the operation of the WG at all.

Optimizing the location and direction of the WG probably won't give any noticeable performance gains. What it will do is increase efficiency, which could translate into better transient response, decreased heat generation, etc.

 

[turbowop]

Some guys have had wastegates that dump on the crossmember melt the wiring harness that runs along the bottom of the core support. That crossmember seems to do a good job of deflecting that heat right to the harness. I would point it a better direction.

In theory, having the wastegate mounted off the collector or off the o2 housing (which is roughly the exact same thing but on the turbo rather than the manifold) is the best choice. In practice, most people don't see much difference between that and having one mounted on one runner.

 

[vtecds1]

Thanks fellas!!! I guess the only down fall in keeping this setup is the access to taking everything apart. The dp took me roughly 2hrs to take off since the bolts/nuts wanted to play hide-n-seek, and to get the manifold out took me roughly over 1hr. BTW, what do you guys think of the heat wrap? Is it really worth having? I don't see too many people running it, but then again a lot of people are running a 2g or Evo3 mani with the heat shield on it.

 

[GreenGSX]

I would suggest extending the dump tube so it blows out under the pan. Your alternator is really sensitive to hot exhaust and blowing on the front cross member might put it at risk.

 

[prove_it]

^1 agreed, even if you barely drive it, it's better to have it set up right than driving around and risking burning your car down.

 

[vtecds1]

I`m going to try and find a way to extend it...The po set it up in away that there is barely any room to extend the dump. As soon as I get the mani back, I will try to find a way around the problem. Thanks fellas!!!