Compound waste gate

duramaxzak

Wanna be puller!
Nov 22, 2008
2,431
14
38
Minnesota
Wondering if this is the best way to gate compound's? I bought this kit used that was built by WCFAB, it has a Turbosmart Hypergate 38HP coming off the pedistal and dumping into exhaust pipe from the S472 turbine outlet to the S491 turbine inlet. Turbos are Forced Induction ETR S491/96 1.32 and Bullseye TCT S472/87 .90. Or would I be better off just blocking gate off? I'm new to compounds and would appreciate any info, thanks Zak

IMG_5518.jpg
 

Attachments

  • IMG_5518.jpg
    IMG_5518.jpg
    67 KB · Views: 56

Bdsankey

Vendor
Vendor/Sponsor
Feb 1, 2018
4,155
1,264
113
Larsen, Wisconsin
Run the gate with some type of manual adjustable controller. Watch back pressure and slowly increase the boost feed to the wastegate. What you're looking for is boost to stop rising with back pressure (point where back pressure keeps going up but boost doesn't).

This is how we did it on a friends compound truck and it runs damn good. I've also seen others run it to the point where the gate is closed under fuel only situations and opens when nitrous is added due to the increased pressures.
 

Bdsankey

Vendor
Vendor/Sponsor
Feb 1, 2018
4,155
1,264
113
Larsen, Wisconsin
Truck will not ever see nitrous...

So essentially what you need to control is the boos-to-drive ratio of the 472. Start with the gate somewhere in the middle (aim for say 60psi) and see what it does. Adjust from there. Ideally 1:1 is perfect from my understanding but I do know with spinning the 472 harder you may see better drivability/spool at 1.2-1.3 boost-to-drive.
 

Ne-max

I like turtles
Nov 15, 2011
3,361
64
48
Lincoln, Ne
I personally wouldnt. I'm doing a 88/72 twin set up. Wont gate it at all. Between trying gates and talking to many people I wouldnt. I even run nos. But this is a touchy subject.
 

Ne-max

I like turtles
Nov 15, 2011
3,361
64
48
Lincoln, Ne
Green. I personally think you should leave the gate in. I don't know if the 87 .90 housing will be too much of a restriction.

You can easily just feed it all the boost and keep it shut but I think the truck will need it when you start pushing those 150s.


150s are babies. He wont touch the limit of those turbos.
 

duramaxzak

Wanna be puller!
Nov 22, 2008
2,431
14
38
Minnesota
150s are babies. He wont touch the limit of those turbos.

Yeah, not looking to push these compounds to there limit, truck will be a street truck that may pull or 1/4 pass once in a while. This is also why I kept the .90 housing on the S472 for better drivability. 150's should get me to where I want to be 1,200-1,300 rwhp. My puller made more than that with 150's and ran great!
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,713
774
113
Texas!!!
On the 491/472 setup I built, we did not use a wastegate. I felt pretty comfortable not installing one, and now that the truck is running, I don't think we are missing out on anything. The turbos I used had a little more flow potential on the exhaust side, but he is also running bigger injectors.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,670
5,818
113
Phoenix Az
Green. I personally think you should leave the gate in. I don't know if the 87 .90 housing will be too much of a restriction.

You can easily just feed it all the boost and keep it shut but I think the truck will need it when you start pushing those 150s.

you need to sit back and learn a bit more. throwing 15 posts out each morning on different threads of half ass info does not work.
 
Last edited:

duramaxzak

Wanna be puller!
Nov 22, 2008
2,431
14
38
Minnesota
On the 491/472 setup I built, we did not use a wastegate. I felt pretty comfortable not installing one, and now that the truck is running, I don't think we are missing out on anything. The turbos I used had a little more flow potential on the exhaust side, but he is also running bigger injectors.

I did talk to him about the set-up you built.