Why is a Twin scroll/Dual WG setup a benefit?

[SHEARER_TSI]

Twin scroll manifolds in conjunction with dual wastegates are great on really big turbos because it does allow for much better pressure relief and greater accuracy in boost control. Essentially is splits the exhaust from the turbo into two sections and you have a wastegate on each section, this allows for less gas to be controlled by each wastegate. I would think that if you were only using one wastegate on someting like a 42R at low (30 psi or less) boost than you would need something like a 60mm gate. Not to mention it just looks badass not a real reason to run that setup but it is sexy.

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[ViciousLord]

I see what you mean about the 42r... But on a 35r or smaller one should be fine running a single wastegate with a properly designed manifold.

I asked Cyber Engineering via Facebook about runners incorrectly paired for TS on a 4G63

their response: "There is no advantage of simultaneous ignition. It only attaches to the test."

 

[SlowChild3]

their response: "There is no advantage of simultaneous ignition. It only attaches to the test."

If this is true i wasted to much time on my manifold. Lol

 

[SHEARER_TSI]

I still think that some of these "35R" turbos should use dual gates. After all a divided housing is a T4 flange not a t3

 

[delta448]

Is it just me, or are these runners incorrectly paired for a TS set-up on a 4G63?

Conventional knowledge says you're right.
turbo manifold design | Equal Length Twin Scroll | Honda STI

A twin scroll manifold is designed for the most ideal exhaust flow a motor can offer. These manifolds are built so that runners that come together are paired to be 180 degrees apart from each other on their firing order. This is done so that there is little chance of exhaust flow interference from another cylinders exhaust gases. This not only helps the motor to better expel its exhaust, but also helps to keep the exhaust velocity as high as possible, aiding in the turbochargers spool and the motors torque output.

I'm not sure why they paired them the way they did, but I am sure there is a good reason for it. Possibly to maximize response from a large turbine by pairing exhaust pulses together to increase pressure differential across a single volute at a time? I'd think that would cause an imbalance in VE from cylinder to cylinder due to the difference in back pressure at the exhaust valve when the second cylinder on the same volute fired.

I for one am not buying that BS answer they gave on spacebook. I'd be very interested in the real answer to that if anyone actually knows.

      / \
    /     \  
2  1  3   4   2 
        \     /
          \ /

Conventional ^

Theirs:

      / \  
1   3    4    2    1
                \ /

 

[We're on Boost]

I for one am not buying that BS answer they gave on spacebook. I'd be very interested in the real answer to that if anyone actually knows.

I think whatever they were trying to say came out garbage because they probably wrote it in Japanese and used something like Google translator to make English out of it. Here's a choice "quote" from their Japanese web site, Google translated to English: "Personality was easy to thrust the field also let me soften."

 

[Steve93Talon]

Bringing back this from the dead. Why? To inform everyone that a proper twin scroll single wastegate configuration does actually work. If it works for the fastest Time Attack Evo in the world, it'll work for us too.

We ran a divided T3 manifold with a single Tial 44mm gate on a friend's car a couple years ago, this was the first tubular manifold JMF ever built. The turbo used was a BW S362 in the .85 divided hotside. Full boost of 38psi was around 4800 rpms, and peak power was 708whp, with no significant drop-off to 9k. The setup out-spooled and out-powered any other S362 setup I've ever seen using the open T3 .70 hotside, including a couple 2.3s.

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[ViciousLord]

^ very nice!

 

[fosforito95]

We ran a divided T3 manifold with a single Tial 44mm gate on a friend's car a couple years ago, this was the first tubular manifold JMF ever built. The turbo used was a BW S362 in the .85 divided hotside. Full boost of 38psi was around 4800 rpms, and peak power was 708whp, with no significant drop-off to 9k. The setup out-spooled and out-powered any other S362 setup I've ever seen using the open T3 .70 hotside, including a couple 2.3s.

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i dont think they make a divided .85 hotside anymore right? i think they only go as low as .91a/r

 

[ViciousLord]

My dream set up is a TS 30r variant in a T4 housing.

 

[SHEARER_TSI]

HTA86 in a twin scroll would be a nice setup.