Holset HX35 twin-scroll...two wastegates?

[Barnes]

Quoting onesickcrx:
cross talk>?



It was mentioned previously. If you have a fully divided manifold, and have two wastegate runners that merge into a single wastegate, the only way the true twin scroll design would be interrupted is if each 'half' of the manifold were able to 'crosstalk' through this merged pipe. I wonder if you would get actual gas flow going from one 'half' of the manifold to the other through the merged pipe. Or would it just be pressure pulses back and forth. Is this all it takes to negate the twin scroll scavenging effect that you explained. Which is as you said, another advantage other than just the design of the twin scroll turbine housing.

 

[BrandonEchols]

After some further research I'm not considering one of the VGT Holsets...currently trying to find as much info as possible on the HE341VE and the HE351VE...Thinking that this might be a better option than the twin scroll, or that restrictor valve. Not sure because it looks to be a very large unit...anyone have experience with either of these?

 

[Rausch]

Seems like you guys are on the right path. To run a true twin scroll set up, and still only use one WG, you would have to have total separation to the gate. Once the gate opens, the lower pressure behind the diaphragm should negate most all of that 'cross talk' noted above. Again, the WG tube would be completely divided all the way into the gate, with gasses staying compartmentalized (I just wanted to use that word) until such time as the gate opens.

Plumbing and fabrication costs to do this would negate any cost benefits over a dual WG setup. Unless the application only allows room for one gate- go two or go home. /ubbthreads/images/graemlins/smile.gif