Twin scroll stock mount manifold

[turd burglar]

well either way if you cant afford a top mount or bottom mount then why get the bottom mount? lol top mount is ths only way to go if you have the option

[Realgib3]

Been looking around at turbos for some odd reason... idk.

Anyway, it looks like the Garrett's are about the "shortest" BT anyone will be running, so I am heavily in favor of moving the flange a little closer to the passenger side, like 1-2" if it wouldn't hurt anything.

As a reference, the PTE 5857 is about 1.5" longer than a 30/35R... and someone out there might be wanting to run a 5857 cuz it's sweet lol.

[MS3-a(sore)ASS-rex]

6262 or bust.
5557 and 5857 are too small lol.

[Realgib3]

Figure out how we can rev to 8k and 6262 it is lol.

[djuosnteisn]

^ Your almost there lol.

[Ziggo]

Originally Posted by steedspeed The manifolds will all be twin 38mm V-band or no gate for guys going with BW efr turbos.

Sure you don't want to try to do a single? As sexy as Twin 38s are, it is effectively 54mm of wastegating which is ALOT and makes me worried about boost oscillations when they crack open.

[PapaSmurf]

subbed, i will eventually be going twin scroll, just not sure which turbo yet, if this is able to fit an EFR turbo, then i will go that route, if not GT3076 it is... haha

[Dano]

Originally Posted by Ziggo Sure you don't want to try to do a single? As sexy as Twin 38s are, it is effectively 54mm of wastegating which is ALOT and makes me worried about boost oscillations when they crack open.

just throwing this out here cuz I don't know chit about twin EWG setup. Wouldn't there be driveability issues with twins as it relates to syncing the WG opening. I mean sometimes they might open at the same rate sometimes not, sometimes one before the other. All of this would lead to widely varying boost oscillation issues and control IMO.

now going WOT down the 1/4 isn't much of an issue but cruising around town might be quite a different story.

[djuosnteisn]

It depends on when your WG's are set to open. PT driving around town... your not likely to be hitting 15+ psi, at least not usually.


I've been wondering about this some too and talked with a few people. My manifold is true twin, and true twin gated. Here's the thought experiment i always think about.... lets say i have a 20psi spring in one, and a 19psi spring in the other. And i'm running straight spring pressure.

Once i get into boost... say it builds up to 19 psi. And WG 1 cracks open. Boost builds to 20, and WG 2 cracks, but WG 1 opens even more. Here's the big question.... if WG 1 can sufficiently flow enough exhaust to reduce boost.... will it simply continue to open all the way... maintaining 19psi and leaving WG 2 closed?

My best guess right now is: Nope. Both gates will open.


IMO... the electronic analogy is running 2 diodes in parallel. One diode will always conduct all the current. But diodes have a feed back thermal effect that increases their conduction... unlike WG's... lol. I know most people glazed over this... but it would be like saying the more WG 1 opens... the more it needs to open. Which isn't the case.

Another thing (pointed out to me by my boss, smart fucker) is that both cyl pairings are flowing into the same turbine. The fact that the turbine wheel speed is the same for both pairs helps maintain a balance of pressure in both manifolds (twin scroll is essentially twin manifolds feeding a common turbo).




On my infinite list of tests i want to do once my car is running again, is to put either EGT gauges on my dump tubes, and / or on 1 cyl of each pairing. Or rig up a flow meter somehow to show me how much each dump is flowing. I think it would be an interesting test.



Long story short... i think the WG flow difference boils down simply to the difference in spring tolerance. If WG 1 spring is X% softer than WG 2, it'll simply flow X% more exh gas.

I have no way to prove it yet other than thought experiments.

<---- not fluid dynamics major.

[Ziggo]

I was wondering how to feed the waste gates, I figure a single feed line from the solenoid teed off to each wg is important. The line length after the tee must be identical, connecting them in series is a big no-no I imagine.

I think the turbine wheel will maintain even pressure. It will maintain a specific pressure delta across it for a given turbine speed and since they both dump to the same pressure it should maintain the same upstream pressure. Ovbiously twin scroll setups with twin ewgs work we are not nearly the first to try it. I would be more worried about having a proper amount of waste gate area.

[Realgib3]

Yea I'm thinking... hoping really, that we're over thinking the flow differences between the gates. I would go along with the theory Dustin started on which is as long as you use a stiff enough spring in, you really shouldn't have issues normal driving since they probably won't crack until you're going close to WOT, where I'm sure they will bleed off the proper amount to keep boost steady at WOT.

So I would say as long as you run a 1 bar are more spring, you shouldn't have drive-ability issues. I could be totally wrong, but I hope not lol.

My concerns are more based on the cost and and space needed to route both dumps, but I have no problem picking up used wg's to save money and if I can't get the dumps back to the dp... than fuck it I'll be loud lol.

[Realgib3]

Originally Posted by MS3-a(sore)ASS-rex 6262 or bust. 5557 and 5857 are too small lol.

Awe man... fml... I've been looking for a twin scroll hotside from Precision, but they don't make em for the 57mm turbine wheels, so I was perfectly content going with the 5857 with an undivided hotside... BUT Precision just announced they will be offering a .84 A/R, twin scroll T4 hotside for the 5862 and 6262 turbos.

Please someone tell me that's too big of a turbo and tell me not to be the next guy running T4 divided turbo around here.

Dustin is corrupting us all with this giant turbo he's running!

[06Speed6]

The reason they havent felt the need to offer a divided t4 housing is because it spools at 2500rpm on even the smallest engines. That new housing would be good on a jet ski or something though.

[mason]

any updates?

[steedspeed]

I've moved the turbo flange toward the middle and have started on the prototype. I'll post pics when I have some parts finished.

[KRNAGE]

good stuff holding off on buying one of your mani's till this is out

[pearl_ms3]

i have a t3 gt3076 twin scroll and im using the original steedspeed mani with the changeable flanges. would this manifold really make any different or pretty much the same?

[djuosnteisn]

Originally Posted by pearl_ms3 i have a t3 gt3076 twin scroll and im using the original steedspeed mani with the changeable flanges. would this manifold really make any different or pretty much the same?

You really shouldn't run a twin scroll turbo on a non-twin scroll manifold. The divide between the ports on the turbo flange will simply create a flow restriction if used on a normal mani.


You can, however, run a normal turbo on a twinscroll mani without any harm. Just not the other way around.

[Realgib3]

Yea you'd actually be better of with an undivided hotside right now with that mani. The whole reason for twin scroll mani with divided turbo is keep the exhaust pulses separate all the way to the turbine wheel. This is what gives you the fast spool. Maximum velocity to the wheel because there's no turbulance.

However a TS mani to undivided turbo is somewhat beneficial and definitely acceptable because the turbine housing is just acting as a collector.

Just adding some to Dustin's point lol

[steedspeed]

Mani is real close to done guys.

[Ziggo]

Originally Posted by steedspeed Mani is real close to done guys.

Still dual EWG?

[steedspeed]

Originally Posted by Ziggo Still dual EWG?

Yes, twin gates. I will also make them with no EWG for the EFR turbos.

[Enki]

Is it possible to cap an EWG port in case you move away from an EFR?

[TRex]

Dustin you mentioned before that running a non twin scroll turbo on twin scroll on a twin scroll mani is ok

Would there be any benefit in running this new manifold over running one of steed's older manifolds? this new manifold is very tubular in design...does this offer a great benefit over the large single piece design (what is that kind really called?)?

[Ziggo]

Originally Posted by steedspeed Yes, twin gates. I will also make them with no EWG for the EFR turbos.

If I end up going 3071r TS that is going to be one hot mess behind my motor.

How far over did you move the turbo?

[Alpha]

Originally Posted by Realgib3 Awe man... fml... I've been looking for a twin scroll hotside from Precision, but they don't make em for the 57mm turbine wheels, so I was perfectly content going with the 5857 with an undivided hotside... BUT Precision just announced they will be offering a .84 A/R, twin scroll T4 hotside for the 5862 and 6262 turbos. Please someone tell me that's too big of a turbo and tell me not to be the next guy running T4 divided turbo around here. Dustin is corrupting us all with this giant turbo he's running!

No, EFR 7064 and 7076 runs a divided T4 setup, I'll be going that route for sure.

[Realgib3]

Yea if and when this car is totally figured out and can make the power the 6262 can produce. That divided t4 will be fucking naaaasty.

Will probably spool almost the same as the undivided 5857 I'll be running...

[djuosnteisn]

Originally Posted by TRex Dustin you mentioned before that running a non twin scroll turbo on twin scroll on a twin scroll mani is ok Would there be any benefit in running this new manifold over running one of steed's older manifolds? this new manifold is very tubular in design...does this offer a great benefit over the large single piece design (what is that kind really called?)?

Great question. I think the design of the new TS manifold is excellent, and would probably flow better than the standard, but there's no telling til people start using them.

As for benefits from running a TS mani with regular hotside.... a big part of me wants to say there will still be benefits.

Twin scroll improves spool by separating the exhaust pules from the various cylinders, so that they actually "punch" the turbine wheel. For arguments sake, imagine a manifold where all 4 runners merge instantly into one big pipe feeding the turbo. The big pipe will act like a plenum somewhat (similar to intake manifold) smoothing out the exhaust flow. The exhaust will simply flow into the turbine, eventually spinning it up.

Now envision the opposite, an exhaust manifold with 4 separate runners, each isolated all the way to the turbine. When the exhaust valve opens, and exhaust is pushed out, that pressure wave travels unimpeded all the way to the turbine and gives it a nice whack. Then the next cylinder in the firing order does the same, and the 3rd and 4th etc.... and you wind up with a situation where the turbine wheel is being repeatedly whacked, and it spools up much quicker.

Twin scroll is same concept, but simply pairing alternating cylinders.

[Realgib3]

I've been looking into this a lot, and from everything I've read Dustin's explanation is spot on. Basically in a normal, non-ts setup, the merging of air flow in the exhaust manifold causes the exhaust pulses to turn into one, constant, slow moving volume of air flow hitting the turbine wheel. The longer the exhaust pulse are kept separate, the more velocity and more, well timed, pulses you will get hitting the turbine wheel.

TS+Divided > TS+undivided > Non TS+Undivided > Non TS+divided

That's what the order of efficiency seems to be.

The Non TS to Divided is the worst because the turbine housing is separating air that has already merged in the manifold, which just causes more turbulence before the air hits the wheel. Couple that with the flow restriction of a divided housing and you have the worst flow out of all your possible options...

[TRex]

So even if your turbo is not setup to fully utilize the TS option (by being able to TS) you can still get the benefit of the pulsing on your single turbine yea?

anyone got a good link on the internal difference between TS and SS? i understand the concept but not sure how it is achieved.


so this goes back to the other question, will Steed make plugs to block off one or both of the EWG options after the fact?

[Realgib3]

I'll find a good link about TS stuff, as far as your other question though.

I would think you could block off both ports to run IWG if you really wanted to, without messing up flow toooooo much, but idk for sure.

As far as blocking one port and leaving one EWG. In a word... NO

[Ziggo]

Originally Posted by TRex So even if your turbo is not setup to fully utilize the TS option (by being able to TS) you can still get the benefit of the pulsing on your single turbine yea? anyone got a good link on the internal difference between TS and SS? i understand the concept but not sure how it is achieved. so this goes back to the other question, will Steed make plugs to block off one or both of the EWG options after the fact?

Go look at the EFR turbo cross sections. The turbine housing contains 2 "scrolls" that feed the turbine directly.

The benefit of running a divided manifold is somewhat negated by having a single scroll housing on the turbo that acts somewhat like a plenum. How much of a benefit it would be would be an interesting experiment, but to pull it off you would need 2 identical manifolds, one divided and one not.

Part of the benefit of a divided manifold is that the pulses from each exhaust valve opening don't interfere with the opening of the next, increasing the VE of the motor at lower engine speeds. I would expect that's where\why you would see a benefit from running a divided manifold vs an undivided, but I don't think it would be better than an equal length tubular manifold where the flows are divided all the way to the plenum anyway.

I don't know that anybody has ever really looked at it, but runner length is very important for both undivided and divided. Too short and the extra VE is wasted early in the rev range, too long and the extra VE is wasted because the minimum exhaust manifold pressure is greater than the intake manifold pressure and extra valve overlap doesn't help you any. In theory, a 1-4/2-3 divided manifold with a TS turbo would have an optimum runner length of half that of an undivided mani with an identical SS turbo.

[Realgib3]

How does Twinscroll Work? with so much misunderstanding/misinformation and detractors of Twinscroll on this forum, i had some things i wanted to post and clear the air. These are ALL facts, and NOT opinion. I/Full-Race did not write any of this. A twin scroll turbine housing uses dual side by side passages into the housing. When coupled with a pulse converter manifold that separates exhaust pulses as many crank degrees in the firing order as possible, a twin scroll or divided housing works to reduce lag, decrease exhaust manifold backpressure on the top end, reduce the potential for reversion, and increase fuel economy The twin scroll is based off the same theory a tri-Y 4-> 2 ->1 header uses: keep spent exhaust gases out of an adjacent cylinder drawing in fresh air. At high rpm on a turbo car, exhaust backpressure is usually significantly higher than atmospheric pressure, and often higher than intake manifold pressure as well. A divider between each of the two volutes allows the cylinders to expel the exhaust gases without it interfering with the fresh air for combustion. Since there are two openings, each a smaller overall volume than a single scroll design, the exhaust velocity of each pulse can be maintained. This also spins the impeller more easily because lag is a function of the scroll area. A single turbine housing opening isn't as efficient in the larger turbo applications since cylinders on the exhaust stroke of the 4 stroke cycle contaminate the cylinders that are on overlap with exhaust gas, thus a conventional turbine housing is not as effective in using exhaust pulse energy to help spin the turbine up to speed since it does not exploit the energy contained in the pulses as well. there is a reason evo's came twinscroll dualwastegated from the factory some good reading:

This is pretty much everything Dustin and I said... just extended and put more technically lol. So if you still want more info... get it yourself.

In a nutshell though, TS is bad ass.

[Realgib3]

Originally Posted by TRex Dustin you mentioned before that running a non twin scroll turbo on twin scroll on a twin scroll mani is ok Would there be any benefit in running this new manifold over running one of steed's older manifolds? this new manifold is very tubular in design...does this offer a great benefit over the large single piece design (what is that kind really called?)?

I forgot to address this earlier, but the new manifold is being created using the same manufacturing process as before. Both old and new manifolds are tubular inside. I think you were confused by the earlier pictures Leen posted of the actual passages, not the finished manifold.

[TRex]

Originally Posted by Ziggo Go look at the EFR turbo cross sections. The turbine housing contains 2 "scrolls" that feed the turbine directly. The benefit of running a divided manifold is somewhat negated by having a single scroll housing on the turbo that acts somewhat like a plenum. How much of a benefit it would be would be an interesting experiment, but to pull it off you would need 2 identical manifolds, one divided and one not. Part of the benefit of a divided manifold is that the pulses from each exhaust valve opening don't interfere with the opening of the next, increasing the VE of the motor at lower engine speeds. I would expect that's where\why you would see a benefit from running a divided manifold vs an undivided, but I don't think it would be better than an equal length tubular manifold where the flows are divided all the way to the plenum anyway. I don't know that anybody has ever really looked at it, but runner length is very important for both undivided and divided. Too short and the extra VE is wasted early in the rev range, too long and the extra VE is wasted because the minimum exhaust manifold pressure is greater than the intake manifold pressure and extra valve overlap doesn't help you any. In theory, a 1-4/2-3 divided manifold with a TS turbo would have an optimum runner length of half that of an undivided mani with an identical SS turbo.

so would you consider steed's other manifold Steed Speed - Mazdaspeed 3/6 MZR turbo manifolds as an equal length manifold? it looks like this manifold really has just two really big runners instead of four individual runners like you would see in a tubular manifold so that would make it not equal length?...also what would you call this type of manifold, just non-tubular?.....do you think it would be in steed's interest to make a SS tubular manifold? or would it not be that huge of a difference over his non tubular?

also i noitced in teh pictures that this manifold (in the link) appears to be divided...you were saying realgib3 that this is not ideal? but ziggo was saying you would maybe get increased VE.....so....what is the consensus?


sorry for all the questions guys...i was really interested in getting steed's other manifold...and i just want to understand them both

[Realgib3]

Originally Posted by TRex so would you consider steed's other manifold Steed Speed - Mazdaspeed 3/6 MZR turbo manifolds as an equal length manifold? it looks like this manifold really has just two really big runners instead of four individual runners like you would see in a tubular manifold so that would make it not equal length?...also what would you call this type of manifold, just non-tubular?.....do you think it would be in steed's interest to make a SS tubular manifold? or would it not be that huge of a difference over his non tubular? also i noitced in teh pictures that this manifold (in the link) appears to be divided...you were saying realgib3 that this is not ideal? but ziggo was saying you would maybe get increased VE.....so....what is the consensus? sorry for all the questions guys...i was really interested in getting steed's other manifold...and i just want to understand them both

No idea what the technical name for this type of manifold would be. The most common types that you see are either a log style (stock on most turbo cars) and a SS tubular style (most aftermarket mani's)

Though this looks similar to a log manifold from the outside, it is in fact tubular on the inside, with 4 separate semi-equal length runners.

As far as the subject of divided vs non divided. I was talking about a non-twinscroll (not divided) manifold paired with a divided turbine housing... This is the least ideal situation.

The rest of the talk was about the TS manifolds being better for a variety of reasons, and as far as the runner length, steedspeed seems to have a great length of runners for all their mani's so far, so I won't even question that side of things.

EDIT: The manifold in the link is not twin scroll (divided), pretty sure you are just being confused by the collector.

[TRex]

^yea yea i know that that one is not a TS

i got confused earlier when we were talking about your manifold comparison and taking it only from the view of a TS turbo

again i was just contemplating the benefits of possibly using a TS manifold with a SS housing....it appears the answer is in theory there could be some benefits but we dont really know

also how can you tell they are indeed 4 separate runners? from the picture it looks like they are separate for an extremely short run...then it basically ties 2 runners together and divides the two sets.....

Originally Posted by Realgib3 I forgot to address this earlier, but the new manifold is being created using the same manufacturing process as before. Both old and new manifolds are tubular inside. I think you were confused by the earlier pictures Leen posted of the actual passages, not the finished manifold.

edit: just saw this...makes total sense now

thanks all for your help...if i ever run into a major problem of having way to much cash on hand i may try and compare a TS and SS mani on a SS turbo...but until then it seems like the answer is just say fuck it an go TS haha

[steedspeed]

Some screenshots of the manifold before I work out the wastegate locations.

[Ziggo]

Originally Posted by TRex the answer is just say fuck it an go TS haha

QFT

[Realgib3]

Lookin fuckin bad ass. Can't wait to see the wg setup... so I can figure out where my piping will go