True Twin Scroll Turbo & Manifold Design Discussion

[sneakey pete]

Gate setup when it was off of the manifold might have been the issue?
 

[iruvyouskyrine]

Looks like you were using an old school Jap gate on a decent sized precision housing. Was the gate kept divided or was it just open to both scrolls?

My issue is I'm looking at doing it on a tiny turbo housing so getting good flow to the gate and keeping it divided will be difficult

[czy18e]

Yep exhaust manifold design was not as good as it could of been for a big precision. (Was sweet with Garrett)
It's a progate 48mm wastegate.
Yeah would be difficult on a small exhaust housing.

[MJTru]

I believe the problem was the direction of the gas flow. I have a book on turbo design and setup. It's always best to have the gate plumb in a angle that best for gas flow. So the best would be off the turbine housing, as to get that same angle off the manifold would require lots of space which most setups don't have. It's the best way to control boost. But from what I gather here it's all about the way the pulse hits the turbine wheel. And just adding the gate on the turbine housing is just like having a fake twin scroll manifold, hense it will control boost better as it's easier to release the exhaust gas/pressure. But I would say if it's not separated all the way to the gate valve like most have mentioned. It's not a true twin scroll. It's about faster boost not to much the control of it. I do agree that the control is important.

[MJTru]

[MJTru]

Anywhere in the collector would work well only if it can be angled in the direction of the gas flow from what I understand will control boost the best. And the gas/flow doesn't have to change direction in such a hard angle. But the plus is a different story and like GTSBoy said if there is a merge anywhere before/or an opportunity to do so will reduce the response of boost coming in faster. Just my 2 cents

[MJTru]

Whats funny is as old as this book may be. Haltech was still in it. Lol.

[Lithium]

On 10/03/2017 at 10:10 PM, r32-25t said:

I've always been skeptical of these single gate twin scroll manifolds 

I had at one point too - but the more I thought about it, the more I figured actually so long as the manifold was built like the one pictured above... the less it's really a thing at all, probably at worst it'd be much of a muchness with a full twin gate setup, and possibly have it's advantages.  I certainly have been impressed with the Sinco single gate divided entry setups I've experienced

[burn4005]

I've jumped on the divided single gate bandwagon because of plumbing headache of twin gates. my only concern is boost creep due to 90 degree turn the flow needs to do to get out, but with high enough exhaust manifold pressure I'm hoping that shouldn't be too much of an issue.

the divider is very well constructed to the contours of the wastegate valve face, and the seat ring JUST fits over the ends. for all intents and purposes they are insolated until the gate opens.

 

Edited March 13, 2017 by burn4005

[MJTru]

I've jumped on the divided single gate bandwagon because of plumbing headache of twin gates. my only concern is boost creep due to 90 degree turn the flow needs to do to get out, but with high enough exhaust manifold pressure I'm hoping that shouldn't be too much of an issue.
the divider is very well constructed to the contours of the wastegate valve face, and the seat ring JUST fits over the ends. for all intents and purposes they are insolated until the gate opens.

 

I'm is exactly the same way mate. I see you have a EGT on every runner? I take it that's it's for individual cylinder tuning.?
It's very nice. Do you cap them all off after the tune.?? Sorry for all the questions mate.

I think if the runner for the gate was just angled abit when it was welded to the collector it would be way better at controlling boost at lower pressure. Keeping it angle as much as it can in the direction of the gas flow.

[LaurelPWR]

I'm is exactly the same way mate. I see you have a EGT on every runner? I take it that's it's for individual cylinder tuning.?
It's very nice. Do you cap them all off after the tune.?? Sorry for all the questions mate.

I think if the runner for the gate was just angled abit when it was welded to the collector it would be way better at controlling boost at lower pressure. Keeping it angle as much as it can in the direction of the gas flow.

I was always under the impression that those ports on each runner where for anti lag hahhah please correct me if I'm wrong

[iruvyouskyrine]

For anti lag what exactly? You were very very wrong haha

[LaurelPWR]

For anti lag what exactly? You were very very wrong haha

No mate hahhaa.....I'm definitely not wrong.
Do a Google search and you'll find a myriad of info on what I'm talking about...
Below are a couple of pictures of examples of antilag systems...

Here's a link to an aftermarket kit I'll be using - https://brewedmotors.com/blog/rally-style-anti-lag-system-tuning.html

[LaurelPWR]

So the site seems to have crashed and now restored but many recent posts have been lost.....?

Anyways my last post was something like "I might just start an antilag thread to get more detailed info from other who have had hands on experience with it, unless there is already a decent thread out in SAU"

[etang789]

So nothing off the shelf is perfect in this sense if you want a plumbed back twin scroll

[TriniGT]

Has anyone done a GTX3585 v band twin scroll manifold with twin gates?  I am looking at the GCG merge collectors to fabricate a manifold for my GTX3582 turbo.  Any pics will be helpful as getting a proper merge collector for twin scroll is proving to be a big problem.

[sneakey pete]

As far as im aware its impossible or impractical at least to do a twin scroll manifold with anything but a divided T3 or T4 flange?