Twin vs single wastgates.

[Shakeywakey]

I was always under the impression that twin scroll/ twin wastegates offers superior boost control, and therefore better.

But after speaking to people about turbo kits apparently Stu prefers a single wastegate setup. Looking for other opinions on this as the SAS mani I was looking at getting is a single 50mm wastegate and the Walton is a twin 40mm. This will be for a G35 1050 with a 4” downpipe on a Bridgeport engine.

 

[jack.am]

Twin gates are just a packaging and ease of fabrication thing.

Best thing for boost control is a gate(s) as close to the turbo flange as possible, even welded straight onto the turbine housing. A single gate is also just much less complicated for plumbing.

 

[Francob]

Go single, I have twin gates and they sound absolute aids, I’m moving back to Single irrespective of what’s better for control.

 

[Shakeywakey]

Twin gates are just a packaging and ease of fabrication thing.

Best thing for boost control is a gate(s) as close to the turbo flange as possible, even welded straight onto the turbine housing. A single gate is also just much less complicated for plumbing.

The SAS mani I was looking at uses a single, but it’s quite a way from the manifold. I asked the guy about this and he said it was to do with heat management and keeping the wastegate away from the engine.

 

[Shakeywakey]

Go single, I have twin gates and they sound absolute aids, I’m moving back to Single irrespective of what’s better for control.

Do you have screamers? I’m going to be plumbing the gate back in anyway so probably not that much of an issue

 

[Shakeywakey]

This is the SAS mani, the gate is quite a way from everything which I did think was quite unusual. All previous manifolds Iv had (for skylines) have basically had the gate attached to the collector, although space isn’t a major issue on them.

 

[Shakeywakey]

Vs the Walton

 

[jack.am]

This is the SAS mani, the gate is quite a way from everything which I did think was quite unusual. All previous manifolds Iv had (for skylines) have basically had the gate attached to the collector, although space isn’t a major issue on them.

Realistically, I doubt having longer wastegate runners will make much difference. Gate size is the big factor.

Coleman's manifold design is probably my favourite, but not sure if anyone has actually installed one yet:

 

[MILLION]

i have the SAS twin scroll / twin gate manifold and am very happy with all of it.

Steve knows his stuff

 

[Francob]

Do you have screamers? I’m going to be plumbing the gate back in anyway so probably not that much of an issue

Yes, 2 screamers, sounds god awful.

 

[D8nRx]

single 50mm recirced back sounds spot on

G35-900 v band and 3.5 inch dp on a streetport

 

[jack.am]

Tow hook engine lift point is genius

 

[Shakeywakey]

single 50mm recirced back sounds spot on

G35-900 v band and 3.5 inch dp on a streetport

View attachment 44774

That a SAS mani?

 

[Temujin]

Here to agree that twin waste gate screamers sound heinous.
If/when I can be arsed I’ll get it change to single but can’t even be arsed to open the garage atm so will see when that happens

 

[Shakeywakey]

So after seeing @Copyninja comment about the difference he saw when going from a divided T4 to a V-Band I did some reading and he is spot on.

Found a post from Rob dahm to after he did back to back testing with manifolds.

So I’m set on getting a T4 divided mani which basically means I’m going to go duel wastegates, hopefully they will sound okay when plumbed back in.

I did look if there was any good divided T4 mani’s that use a single gate, but there isn’t really and I guess that kinda defeats the point of the twin scroll.

I think I’m going to go with the WaltonMotorsport mani as tbh, they all kinda look the same and Walton have been in the game a long time. Happy to hear other opinions tho.

 

[Mir]

Design your own manifold mate. Its so much better and you will have the confidence in your set up. That is exactly what I did! However, I had my mapper on board when I was designing my manifold.

Cheers
Mir