I've been doing a lot of reading but I'm not confident enough to buy anything.

I need external WG's for this setup:

#ad


#ad


Now, what I'm trying to figure out is what is the proper way to go about sizing the gates. I understand how I can control the springs, ect, I'm talking about the 20mm, 30mm,38mm, 50mm, 60mm, ect.

I understand that if the gates are too small, they will not bleed off enough drive pressure, if they are too large they will bleed off too much, shut, re open, bleed off too much.. ect and that can cause flutter.

So how do I size these properly so that I have a smooth operation?

Also, if you cannot tell, I need a gate for each manifold. Installing them towards the rear of the manifolds on the bottom side will be preferable.

 

You provide detailes about your setup and any future setup you wish to also cover and let them advise you. If they tell you to go with the biggest gate possible you say thank you, ignore that advise and move to the next person.

 

alright.

Who is "they". As in, who would you recommend?

 

The people here. Post up your details.

 

Hard to say what size gate to run with out knowing more details about your setup.

 

ohh ok.

Well, what all is needed to know?

Its a 7 liter diesel. Currently the internal gate is locked up and I'm hitting 40psi. I need to gate it down to 35. The manifolds are 1.5" primaries, 2" main log.

Turbo is an S362. 62/74/14 twin T3-TwinScroll.

3.5" DP into a 4" straight pipe.

 

RPM?
Hp/Tq?


If it is not off the wall... a 38mm single gate would easily get you down to 35psi.

 

crank HP/TQ..... about 450hp/850tq. I don't rev over 3,000rpm.

Now, I need a gate on each manifold, I cant just run a gate off of one side.... so does 38mm still apply?

 

A single 38mm @ the merge was my thought.

 

I dont have a merge. Its twin scroll.

 

Yea, I failed to see that. One 38mm on each bank will be fine, even though many OE twin scroll turbos only gate one bank or half the cylinders. Hx35's on cummings motors, 16g's on Evo's ect.

 

If you are a good fabricator, you can do this with a single 38mm

#ad

 

I'm an exceptional fabricator actually, but doing that with a single 38 would cause a merge point between banks though, would it not? (I'm not sure if there is a common area shared when the valve is shut). I am against creating any sort of merge between banks, that's why I worked so hard designing this camshaft I'm running, and using the twin scroll setup.

That being said, even if it does not create a merge point, it would also turn out much cleaner/easier to just WG each manifold. I was specifically advised by my pump builder, who is a PSD builder to not WG a single bank, as the point of my WG's is to bleed off excess drive pressure.

Is there anything wrong with the $100-$150 Ebay style units? Or do I really need to use the $300+ "name brand" units?

 

Yes that would create a merge point between the two banks. The only way to do it with one gate is to have a cnc'd "seat" that the gate closed against to keep gases from mixing when the gate is closed, but when the gate was open you would have some cross flow. Sounds like 2 gates is what you should use.

 

Alright cool.

Now, are gates like these good?

http://www.ebay.com/itm/GODSPEED-GT...Parts_Accessories&vxp=mtr&hash=item4ab3de630d

http://www.ebay.com/itm/38mm-TURBO-...Parts_Accessories&vxp=mtr&hash=item3371947002

 

Once the wastegate opens,it shouldn't matter that the 2 banks are merged, as exhaust should only be flowing out. Also, the big advantage of twin scrolls in diesels is getting it to spool. If your gate is open, you are already spooled.

 

Agreed, however, when the WG is closed, there would be cross flow, which I worked hard to get rid of, and do not want. It is critical in my application.

Labor and fabrication wise it will be much easier to run dual gates. I just need to know if the gates I posted are good to use, I have no experience with external gates before now.

I just need to bleed off excess drive pressure.

I am curious though, even though I'm not doing it on this engine, but for future turbo kits that I build, since it would be much easier fabricating a single gate on a twin scroll when its on my engine stand. Is there a practical way, to keep the flow separated when the gate is closed?

Crappy night video but its clear, just to give you an idea on my spool.

http://youtu.be/IUbUv-Pq_Rs?t=38s

30psi boost gauge.

 

I just noticed that some of these WG's dont have heat ratings, but the ones that do are only rated for 480*C.... or approx 900*F. I will see exhaust temps higher than this, is there other options?