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Do you have links for 2.0 on 6466 T3 and T4 twin scroll with your appropriate A/R? It doesn't sound right logically that a T4 will spool better and make more up top over T3. I dont want to bore everyone with my logical inexperienced engineering thinking. Basically, twin scroll sacrifices top end for better spool up, but with this huge turbo, I don't see any benefit of using 1.0 liters to point flows to help with spool.
Twin scroll does not sacrifice top end. It spools faster and makes more power.
Here's a solid thread to read, if you start at the first page, but the link takes to the post the shows twin scroll is the master race. This is not new information, it's something that has long been established, and it's why OEM's use it. Twin scroll is simply more efficient due to cylinder pairing. Much likely appropriately pairing cylinders on an N/A exhaust manifold makes more power and torque.
Well, skimming through 1/3 of the thread, one thing is clear. You can't truely compare twin scroll against single scroll fairly.
Depending on a car's setup, it will favor one over the other. So I'll stick with what I know about the two. Single scroll is simple. It will be fairly consistent with "upgrades". Twin scroll will be tricky to net more power or better spool because a wrong mod can end up hurting power or spool. In theory, twin scroll will spool up faster at the trade off of top end. This is clear to me logically because that one scroll to help with spool is angled to transfer flow energy to turbine blades. The catch of having better transfer of energy is it will become a hindrance once turbine wheel spins faster then the 2 cylinders can produce and actually become a drag to the other 2 cylinder flows which is angled better to spin the turbine at higher speed.
Think of it this way. TS has a spool scroll and a efficient scroll to keep back pressure low. It's like short 1st gear vs tall first gear. Short gear will rev up fast and take off faster but will top out at lower top speed. The tall gear is the opposite where it accelerates slower but has a higher top speed. A TS is using both where short gear is dragging tall gear (better spool) and then the tall gear drags the short gear up top.
This works great if the wheels are sized for the engine exhaust flows but someone has to do the research to size everything right.
Also, realize that the spool scroll will have higher back pressure. That will cause those 2 cylinders to retain more exhaust gasses on each exhaust stroke, which means less intake (fresh oxygen) will enter for next cycle.
In short, TS has better spool at the trade off of top end. You can manipulate the tune to boost more or run more aggressive timing to make up for the power loss up top, but there will be a transitional trade off zone.
And since it is impossible to prove one way or the other, we can all choose what to believe.
Last edited by 2006EvoIXer; May 16, 2019 at 08:46 PM.
Well, skimming through 1/3 of the thread, one thing is clear. You can't truely compare twin scroll against single scroll fairly.
Depending on a car's setup, it will favor one over the other. So I'll stick with what I know about the two. Single scroll is simple. It will be fairly consistent with "upgrades". Twin scroll will be tricky to net more power or better spool because a wrong mod can end up hurting power or spool. In theory, twin scroll will spool up faster at the trade off of top end. This is clear to me logically because that one scroll to help with spool is angled to transfer flow energy to turbine blades. The catch of having better transfer of energy is it will become a hindrance once turbine wheel spins faster then the 2 cylinders can produce and actually become a drag to the other 2 cylinder flows which is angled better to spin the turbine at higher speed.
Think of it this way. TS has a spool scroll and a efficient scroll to keep back pressure low. It's like short 1st gear vs tall first gear. Short gear will rev up fast and take off faster but will top out at lower top speed. The tall gear is the opposite where it accelerates slower but has a higher top speed. A TS is using both where short gear is dragging tall gear (better spool) and then the tall gear drags the short gear up top.
This works great if the wheels are sized for the engine exhaust flows but someone has to do the research to size everything right.
Also, realize that the spool scroll will have higher back pressure. That will cause those 2 cylinders to retain more exhaust gasses on each exhaust stroke, which means less intake (fresh oxygen) will enter for next cycle.
In short, TS has better spool at the trade off of top end. You can manipulate the tune to boost more or run more aggressive timing to make up for the power loss up top, but there will be a transitional trade off zone.
And since it is impossible to prove one way or the other, we can all choose what to believe.
If twin scroll isn't making the same or more power up top, it's because you have the wrong A/R housing. When someone like JohnBradley says twinscroll is the way to go, you should probably listen.
The engine being able to handle more boost on octane limited fuel because of the better scavenging of twin scroll is not "manipulating" the tune. It's proof of higher efficiency and cylinder scavenging.
Both Full Race and DSport have good data proving the benefits of a properly built twinscroll system. Anyone who moves to a single scroll setup is taking a step backwards.
Both Full Race and DSport have good data proving the benefits of a properly built twinscroll system. Anyone who moves to a single scroll setup is taking a step backwards.
Both Full Race and DSport have good data proving the benefits of a properly built twinscroll system. Anyone who moves to a single scroll setup is taking a step backwards.
Full Race article has a lot of good info. But realize, they didn't spend any time optimizating each system. The unequal length pipes were interfering with each other on SS. Out of curiosity, what do these pictures tell you?
Full Race article has a lot of good info. But realize, they didn't spend any time optimizating each system. The unequal length pipes were interfering with each other on SS. Out of curiosity, what do these pictures tell you?
You're arguing an already very long ago proven point, and you're wrong. It's really simple.
Also, the pic showing pressure in the manifold is showing the pressure at 15* crank angle, clearly one of those cylinders is on the exhaust stroke at that angle. UEL runners aren't the end of the world, and full races article very clearly demonstrated the superiority of twin scroll configurations.
Also, could you enlighten me on your 4cyl experience other than building an Evo engine and bolting on a stock frame 71hta? You seem to like to argue things that have long since been determined to be better way to do things.
As we know, red (higher back pressure) is the spool port/scroll. Can we all agree that up top, it ends up being a clog? The entry angle forces the exhaust gasses to turn around. This will drag on the other port. Thisvis why when we compare apples to apples, SS will outflow TS up top. This is simply a property of the TS design. Yes, a TS can spool faster and have higher up top, but that means the SS was not designed right (power band was higher in rpms and engine didn't rev high enough to see, which means turbo wasn't sized right -> apples to oranges comparison to me).
You're arguing an already very long ago proven point, and you're wrong. It's really simple.
Also, the pic showing pressure in the manifold is showing the pressure at 15* crank angle, clearly one of those cylinders is on the exhaust stroke at that angle. UEL runners aren't the end of the world, and full races article very clearly demonstrated the superiority of twin scroll configurations.
Also, could you enlighten me on your 4cyl experience other than building an Evo engine and bolting on a stock frame 71hta? You seem to like to argue things that have long since been determined to be better way to do things.
TBH, I doubt anyone can enlighten you unless their name is JohnBradley or FP. I have never seen you accept anything that makes sense.
Superiority of having a better usable street power band, yes. My argument is with your claim that TS has better spool and has same or better power up top. That is just not possible in the design unless you are comparing apples to oranges.
If you're gonna be buying a new manifold and everything I'd just go with a T4 TS as mentioned by others. I have an FP Zero and really like it but only because I bought my car with a tubular manifold and it was more cost effective for me to buy just the zero to replace my blown EF4 than buying a new T4 TS Kit. Honestly though I'm still gonna end up buying a T4 TS setup anyway. The Zero definitely makes good power with the right setup however. I made 671/558 on 38lbs on RRT Motorsports Mustang Dyno and have a good amount left in it in terms of boost and fuel so it should easily break 700. In short, both the Zero and 6466 will get you into the 10's and even 9's if you have the setup and can drive it there id just go with the 6466 or a 3586 so you have more options down the road should you decide to go bigger.
TBH, I doubt anyone can enlighten you unless their name is JohnBradley or FP. I have never seen you accept anything that makes sense.
Superiority of having a better usable street power band, yes. My argument is with your claim that TS has better spool and has same or better power up top. That is just not possible in the design unless you are comparing apples to oranges.
Empircal vidence has been presented to show that you are incorrect, from multiple sources. I have personal experience that shows you are incorrect. This is honestly laughable that you think you're right.
Kinda reminds me of when you were trying calculate piston speed and thinking you would/should only rev a 94mm stroker to like 7800 or something silly like that due to piston speed, only to eventually realize you were wrong because you didn't understand that the max accepted piston speed was expressed as an average, not a max number. After myself and some others repeatedly told you that you were wrong. It's like Deja Vu...
TBH, I doubt anyone can enlighten you unless their name is JohnBradley or FP. I have never seen you accept anything that makes sense.
Superiority of having a better usable street power band, yes. My argument is with your claim that TS has better spool and has same or better power up top. That is just not possible in the design unless you are comparing apples to oranges.
You will have better top end on a single scroll if the A/R on the turbine housing is the same for both setups. With that said you'd also be an idiot to not bump up to a larger A/R when moving to twinscroll. A larger A/R twinscroll will spool better and have similar or better top end vs a smaller single scroll A/R. It's been proven plenty of times in the real world.
I have a client with a 2.2 motor with buschur 272's and ported stock intake manifold that went from a Zero to the ETS twin scroll kit with a 6466, it went from 690whp @43 psi to 750whp at 41psi and less timing on an otherwise identical setup it also made more torque. It also spools a couple hundred rpm faster with the 6446, it makes 400wtq at ~4600rpm instead of closer to 5000. 100% go with the turbo kit.
what is your experience on the buschur 272's compared to other 272's.
May 16, 2019, 05:48 PM
