Twin Scroll Revisted

[Canadian_CD9A]

D-Sport magazine just conducted an interesting test: http://dsportmag.com/the-tech/twin-scroll-vs-single-scroll-turbo-test-the-great-divide/

Same manifold, the only change was the turbine housing. It says they kept the same A/R which would obviously give the TS setup the advantage down low, but strangely, the SS didn't make more power up top.

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Discuss?

 

[bastarddsm]

Yeah, that test is junk. Even a junk worst possible designed manifold has a bigger effect than that. On my WH1c is was ~1000rpm going from a partially divded to divided on a 16cm housing.

On my S362 it was closer to 1500rpm. Car made dick for power in the T/S config both times.

 

[Canadian_CD9A]

Can Holsets be used for comparison? They aren't truly twin scroll I thought, merely a "divided" setup that still could mix.

 

[bastarddsm]

I also see the article mentioning full race doing computer simulations... I wonder who is doing it for them. The people who can actually set that up and perform a meaningful analysis are few and far between.

 

[bastarddsm]

oh jesus christ. Yes they are twin scroll. That whole "divided" vs "twinscroll" is just a fanboi shitshow. That goes back to ancient times with old tractor shit that had nozzles placed in different positions radial, not axially like we have. Sure some of the newer divded housings might be a bit more efficient than some of the old holset stuff, but that's no different than what we see with the open housings.

 

[jery1234]

Very interesting . I my self am running pte dbb 6466 ts 1.15 ar turbo & must say it's very street friendly . Before I have switched to ts I was on the same turbo with single scroll 0.82 ar housing & ts is much better in response . I also have tried 1.32 ar ts housing(lost only 160 rpm) so I have some data to compare . All was tested @40-42psi . Btw I'm 2.3 l

 

[ceedawg]

On my S362 it was closer to 1500rpm. Car made dick for power in the T/S config both times.

Don't know what was wrong or what setup you had on your car but I have the BW300sx 88-75'(s363) on my car full ETS TS t4 dual tial WG setup ,2.0l built motor and it makes some brutal power mid and top end . I have a .91ar housing and I will get it dynoed towards the end of this month. So we'll compare.

 

[CrackedDSM]

Don't know what was wrong or what setup you had on your car but I have the BW300sx 88-75'(s363) on my car full ETS TS t4 dual tial WG setup ,2.0l built motor and it makes some brutal power mid and top end . I have a .91ar housing and I will get it dynoed towards the end of this month. So we'll compare.

Ignore him. He has the habit of "it didn't work for me so its just shit". He's done this with Speed Density, TS Turbos, and a ton of other stuff that no one else seems to struggle with, but that don't work for him and suddenly they don't work for anyone ever.


Good article, OP.

 

[GST with PSI]

Yeah, that test is junk.

Your real world experience aside, what about this test specifically makes you think that?

Assuming the control variables we aren't aware of weren't dicked with (Dyno settings, dyno conditions, operator, etc.), it seems to me like this would be a pretty good comparison based on what information is written in the article? In your opinion, what could have skewed the results?

 

[bastarddsm]

Mostly just that everyone who has ever ran a t/s setup can tell you there is a bigger difference than what they are showing. There is no possible way that the data shown is real.

I mean on my first t/s setup it was an WH1C on a SFP divided manifold that had a common wg port, so it wasn't fully divided, and the runners were paired wrong.. 14cm housing. 5200RPM for 25psi in 3rd. I then built a real t/s header. It was similar looking to mrpeepers' manifold, but it was with larger tube, and it dropped 25psi down to about 4200RPM, on the same 14cm housing. I eventually got a 12cm housing and it was 25psi at 3700, but it took 30psi to get the car to trap 121, and it was only 24 on the sfp with 14cm.

I had similar result with my S362. I divided the WG passage on the sfp manifold. 30psi just before 5000 in a .84 garret t4 housing. This spring I cut the divider out of the sfp header to make it open, and it was 30psi at 6500, maybe higher. Had to launch the thing at like 7500. Sounded wild like that.

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Outside of that, it's pretty shitty that they don't tell much else of the setup. No pictures, ect. Furthermore it's not like magazines are peer reviewed or anything. They can print whatever they want.

 

[bastarddsm]

Ignore him. He has the habit of "it didn't work for me so its just sh**". He's done this with Speed Density, TS Turbos, and a ton of other stuff that no one else seems to struggle with, but that don't work for him and suddenly they don't work for anyone ever.


Good article, OP.

Perhaps you should stick to building motors that don't actually fit your car, and leave the posting to those with first hand experience.

 

[bastarddsm]

Don't know what was wrong or what setup you had on your car but I have the BW300sx 88-75'(s363) on my car full ETS TS t4 dual tial WG setup ,2.0l built motor and it makes some brutal power mid and top end . I have a .91ar housing and I will get it dynoed towards the end of this month. So we'll compare.

It will be interesting to see. Mine was a tractor version. It was a 300 frame with a 62mm wheel and a 74mm S200 turbine. I ran it T/S in both a .7A/R T3 divided housing, and then I modified it to fit in a .84A/R Garret P Trim divided T4 housing. They both spooled better than my HE315, but didn't seem to make power. In their defense my car was sick at the time, and wouldn't make power. I'll post some real results from those days as soon as I prepare the plots.

 

[bastarddsm]

Here's some VD plots. I generated these with a dataq DU-109 pulling rpm right off the cas, I was actually logging boost and drive on 2 of these pulls. The green pull is from 2013 when the car was trapping 133-137 every pass, that was right around 35psi of boost, and ~20* of timing. The red pull is the HE351 with the wg line disconnected. It hit 50psi and fell to around 40. 15* of timing. The blue pull is the S362 in the .7A/R This was similar, this had an internal wg that was acting strange. It was cracking early, and then creeping to near 50psi. ~15* of timing too.

I might actually revist the .7A/R now that I have the car straightened out. It had a cracked crank, and smoked exhaust valve guides.

 

[bastarddsm]

All the literature I've seen has shown that a twin scroll turbine is about 3-4% less efficient than an open scroll.

 

[94awdcoupe]

my opinion of TS is it is indeed awesome when you want to maximize the power band on a street car. but pretty much useless on a drag car. should be the end of the discussion as that is it in a nut shell.

there is no such thing as a good back to back test that proves anything. the dsport test is flawed because they used a twin scroll manifold on a open scroll turbo so power on the open scroll was less than it should have been. there is also no such thing as saying turbine housings of the same size when talking TS and open scroll. you just cant do a good back to back. too many variables will change.

FP just started selling 2yrs ago bolt on turbos for evo 8/9 with their own design open scroll housing instead of the factory TS housing. there is enough dyno data on the hta green,red and black open scroll and TS to conclude quiet easily the TS powerband starts about 500-600rpm sooner for those size turbos. and the new open scroll makes 5- 10% more high rpm peak power for the same turbo size.

 

[ceedawg]

This thread here speaks volumes and the. OP'S results seemed massive.

http://www.dsmtuners.com/threads/built-not-bought-655awhp-487tq.498549/

 

[ceedawg]

rums>Dyno Talk>

Built not bought- 655awhp/487tq
Best Posts in Thread WatchIgnore Thread

1. You must be logged in to view this image or video.
   
   kickasskid2087 Proven Member
   Nov 4, 2015
   Finally got the build all together. Dyno is a dynojet.
   
   All work performed by myself.
   
   This is on a divided t4 billet 6265.
   
   Ended up at 38psi, 14 degrees of timing, 11.4-11.6 far, E-70 in the tank, revving out to 8750.
   
   The car was still making power but I didn't want to rev higher.
   
   Went to the track the following day, knocked out a 11.5 at 137mph with a 2.2 60". Already purchased a boost solenoid for boost by gear and no-lift-shift setup.
   
   
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   Dyno pull:
   
   
   Car in its current form.
   
   
   You must be logged in to view this image or video.
   
   
   
   Build thread:
   http://www.dsmtuners.com/threads/cornfed-97-awd-tsi.470638/
   
   Quick mods:
   2.0 6 bolt/ 10.0:1/ E85
   Manley I beams/ Wiesco hds
   Girdle/ L19s/ permatorque
   2g ported head/ kelford 280s
   Jmf race smim/ custom Ex manifold

 

[ceedawg]

These results say enough for me!! 137mph traps as well. Not good for drag racing you say? I disagree highly!

 

[bastarddsm]

I'm not sure those results say much for the T/S. I trapped 137 in my full weight 1g on a much smaller single scroll turbo at around 35psi. I was on dks272's, and an 8.5:1 2L. It's tough to see from kickasskids dyno chart, but it doesn't look like he's making a ton more at a lower rpm. Also remember I was running $125 truck turbo on a $99 cast exhaust manifold with the factory internal gate.

I'm certain you could have put kickasskids turbo in a .63 t3 housing, and produced similar results with a lot less complexity. A billet 62mm compressor turbo should be making 750 at that kind of boost, especially with k280 cams and 10:1.

It really seems like the t/s is a crutch for running a bigger turbo than you need. I'll give it that it helps a turbo be a "little more quick on its toes" but it's not some magic bullet that gives you 40R power with 16g spool.

I'm playing with something a bit more high tech these days, someday I'll revisit the t/s stuff.

 

[ceedawg]

I think you feel the difference in just driving the car TS vs single scroll, my car does not feel like I have to sit there and wait for the turbo to spool up especially between shifts or on initial throttle. There is also no light switch feel.I don't think a dyno would tell the whole story but I posted this anyway. I still think 137mph in the 1/4 with this setup is impressive . Boostdriven(Alex) came from Washington State to NYC to tune my car and he was surprised he told me at the violent immediate response of the car. For me the experience was quite frightening. There is no waiting g and my car makes tons of power thank God I had the transmission built.

I'm not sure those results say much for the T/S. I trapped 137 in my full weight 1g on a much smaller single scroll turbo at around 35psi. I was on dks272's, and an 8.5:1 2L. It's tough to see from kickasskids dyno chart, but it doesn't look like he's making a ton more at a lower rpm. Also remember I was running $125 truck turbo on a $99 cast exhaust manifold with the factory internal gate.

I'm certain you could have put kickasskids turbo in a .63 t3 housing, and produced similar results with a lot less complexity. A billet 62mm compressor turbo should be making 750 at that kind of boost, especially with k280 cams and 10:1.

It really seems like the t/s is a crutch for running a bigger turbo than you need. I'll give it that it helps a turbo be a "little more quick on its toes" but it's not some magic bullet that gives you 40R power with 16g spool.

I'm playing with something a bit more high tech these days, someday I'll revisit the t/s stuff.

 

[bastarddsm]

If you sized the turbo to the to the power you wanted to make, you wouldn't be waiting.

This is exactly was every t/s guy says when presented with info contrary to T/S hype:

1. You can measure the gains on a dyno.
2. Well that's not an apples to apples comparison.
3. Auto cars suck up more power so you can't compare it.

It's all bs and hype. If t/s was really the magic bullet the hype leads you you believe there'd be more than a few people doing big things with them.
There are 3 in the dsm world peepers, beansblacktsi, and the guy with the black 1g. I think anyone of them could do the same with an open setup.

And for every 1 guy that is doing well there are several with nothing but disappointment.

 

[ceedawg]

If you sized the turbo to the to the power you wanted to make, you wouldn't be waiting.

This is exactly was every t/s guy says when presented with info contrary to T/S hype:

1. You can measure the gains on a dyno.
2. Well that's not an apples to apples comparison.
3. Auto cars suck up more power so you can't compare it.

It's all bs and hype. If t/s was really the magic bullet the hype leads you you believe there'd be more than a few people doing big things with them.
There are 3 in the dsm world peepers, beansblacktsi, and the guy with the black 1g. I think anyone of them could do the same with an open setup.

And for every 1 guy that is doing well there are several with nothing but disappointment.

Tons of Evo guys are using the TS setup making big numbers! Why are you saying it's hype? Because only 3 or 5 guys you kow with dsms are using a ts setup? I'll admit it is an expensive setup so I know that expensive and Dsmers dont mix! Lol

 

[ceedawg]

I'm not dissapointed and as you know there is something to having all the right parts complement each other to make power.

 

[bastarddsm]

I've seen lots of disappointment on the evo front too. Lots of guys claiming things, but no one making the numbers or the slips.

How much power are you thinking yours is going to make? If it's not 7-800 you have way to much turbo, and a smaller ss turbo would have done you better.

 

[DeadlyAKrunna47]

I love seeing these tests! Thanks for sharing!