What size wastegate?

91shelbydaytona

91shelbydaytona

New member
On my 12v with a 62/68 over s475 or possibly s478, Which size gate do you recommend for feeding the primary? Should I be looking at the 40mm or 50mm?
 
This is only my opinion...but if I had to do mine over, I would rather error on the bigger side of gates. That leaves room to grow, if you ever add more fuel and air.
Going too small is just useless...

You can open the bigger gate "less" than 100%...but you can't open the smaller gate "more" than 100%.

....see what Lance has to say.
 
I think on fuel only, the 40mm will control that secondary very well.
I'd only recommend the 50 if you had plans for big nitrous.
We need to size the gate for charger its controlling (with respect to desired PR). And our 40mm easily handles a 68mm turbine.
 
I do have a nitrous kit, but if i ever decided to install it i would rather install a second gate to have total control over boost.
 
Sorry to high jack here...

Lance, my secondary is a 68mm, and my primary is a the S480/96/1.32

I had one 38mm JGS gate, but no matter what, drive pressure remained at over 100 psi.

Just picked up a second 38mm gate, so I can run one on each bank.

Was this a good idea, or should of I went with a single 50mm?
 
If the waste gate isn't getting good direct flow from both banks you will get poor gate performance.
We see this in turbo gas V8s all the time, installation on a inline motor is more straight forward and predictable.

BTW- We don't build a 38mm wastegate, never have.
 
Backhoe man said:
It's a single gated into the exhaust system, s400 charger with a 74/83 turbine
Click to expand...

Single setups like this do have problems using a 50mm correctly, the large pressure drop across the gate makes a 50mm gate flow a metric ton more than if it was breathing back into a 20-40psi hot pipe.
 
jgsturbo said:
BTW- We don't build a 38mm wastegate, never have.
Click to expand...

Well, then they are 40mm.

Here's the one I used last summer....needs some new o-rings.:hehe:

image-52.jpg



And the one I picked up today from Colin.

image-55.jpg



I'm not trying to start anything...I love the JGS wastegates and BOVs.
 
Last edited:
Dirty! Its all good, just a reminder :)
The second one is a much older diaphragm model so be careful with it.

The V-band 40mm does seem to flow better than the old 2 bolt model.
 
We ditched the diaphragm quite a few years ago. They were expensive and people wanted to use pressure to close the gate.
We had to buy $8K of them at a time as well.

We do offer an upgrade service to install piston hardware for $100.
 
jgsturbo said:
We ditched the diaphragm quite a few years ago. They were expensive and people wanted to use pressure to close the gate.
We had to buy $8K of them at a time as well.

We do offer an upgrade service to install piston hardware for $100.
Click to expand...

Augh...:bang

Can you PM me a price for 2 new 40mm gates that have the Vband connections please?

To all: I am selling both of my 40mm JGS gates that are flange mount.
The one I own will have new O-rings installed.
The one I bought from Collin will come just the way he posted it in the for sale section.
 
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