Waste Gate mounting options - Whats your experience?

Given the same size different brands will flow different amounts based on design. I've seen many times stating the tial 60mm flows 330cfm at 1 psi differential pressure. I'm sure if you do some search you can find some flow numbers of smaller gates.
 
Hurley said:
For the sake if discussion, estimating your 'vented' flow rate is the key for sizing the wastegate and associated plumbing - I agree that you can compare cross sectional area to a percentage decrease, but.... does that really matter if you don't know whether you're venting 20 lb/min or 50 lb/min. (CFM are out the window when you compare drive pressure differences of a setup - i.e. dumping a 50mm gate at 30psi drive is different than dumping a 44mm gate at 100psi)



to me it goes back to packaging; you make a compromise to fit the situation, and optimize from there.
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I agree, compromises will be made. I just want to know the full effect of the compromises I make, if possible.

If we want to compare apples to apples, I think we need to modify you example a bit to match the conditions we are discussing, which is effectively comparing two different gate sizes on the same engine with the same setup with the only variable being the two different orifice sizes. Whether that orifice is our mount, or it's the gate itself.

IE: A 50 mm gate at 100 psi, vs a 38 mm gate at 100 psi.

Since the pressure is the same in both situations, it becomes irrelevant. The smaller one will have roughly 3x the velocity in order to flow the same volume of air.
 
I think what the OP will find with some testing and/or experience is that his theories are correct, it's just a matter of applying them as needed. I have a bunch of experience mounting gates on gasser stuff. Mounting the gate 90 degrees to the path of flow will not use the exhaust pressure to help open the gate as it would if the path of exhaust pushed directly on the head of the gate. Diesels are of much lower rpm and speed of exhaust flow, so my feeling is the manifold becomes more of a slow moving, pressurized chamber of drive pressure, and having a larger gate does get the job done. Also, you might be surprised how little the valve opens to achieve the desired pressure reduction. Therefore, having the inlet pipe crushed has less effect than the 90 degree mounting.

You wouldn't be the first to successfully weld the gate inlet pipe directly on the outside of the turbine housing. Laying it over so that it has the flow going directly into the gate will help it work tremendously. The trouble is keeping it from cracking. I have done a preheat and tig with 309l rod, on cast iron, and daily driven my truck about 2 years without any failures yet. I have not used this weld only to support the weight of a 50 mm gate against the vibration of my Cummins, though.

I would be more concerned about dumping the excess back pressure with the nitrous setup than using the gate to drop drive pressure between compounds. I think the back pressure of the atmosphere turbo on the outlet side of the gate slows the flow down a lot vs. dumping to atmosphere, and actual flow becomes much less, and you're really just balancing pressure in two chambers, so to speak. In this example, the 90 degree mounting works just fine, on my truck at least. I can tune the back pressure right out of the manifold, keeping it 1:1 up to around 70 lbs. of boost, then it starts climbing.

I have pics in my phone of the gates on a 6.4 Ford I'm doing for a guy, let me see if I can get them to show here....
 
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Pics of that 6.4 I'm doing...[ame="http://s34.photobucket.com/user/rfrank6goinbyyabig/media/DSC00423_zps2f689c0a.jpg.html"]DSC00423_zps2f689c0a.jpg Photo by rfrank6goinbyyabig | Photobucket[/ame]
 
Driver side up pipe
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Thank you for your input and your pictures. That is some beautiful work!
 
You're welcome, and thank you. See how all the gates are mounted on the outside of the bend, so the exhaust pushes against the valve head inside the gate? Makes it work much better. Best of luck to you.
 
Yes. I shouldn't have any trouble mounting the gate between the secondary turbine and the primary turbine, but getting one between the engine and secondary remains an issue with an oem style manifold. I'll post up some pictures when I start implementing a design.
 
In for the pics

Also I feel a tubular manifold opens up a lot of options and we both know they will flow much better than a "log" style manifold anyway and allow for a much more desired waste gate mount.
 
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Extended Power said:
This way doesn't work worth a sh!t....

IMAG1234.jpg
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You could have something there... Never had good luck with a gate that far away from the main stream.

smurfcomp05.jpg


This one works, its even divided to the bottom of the gate valve.
I've debated casting it but I've been too busy to get the model done.
:kick:
 
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