Drifto

iTrader: (6)

Jerry you really seemed bothered by the fact that some people are moving towards this. I don't understand why as you have nothing to gain by trying to disprove it. In fact you seem to want to disprove every new bit of info that comes to this forum. Why are you so angry?
.I used to build turbos for a living and I have swapped all kinds of turbine housings around so I have experience in that realm as well. I have seen some cars make drastic changes in spool and power with A/R changes and some not so much. I even have experience with swapping TS housings on an Evo so I know how that effects spool and power. Going from a .78 A/R to a 1.06 gained me roughly 60whp with only a 2-300rpm penalty. With the .78 A/R car went 122mph on pump gas, 23psi, and full weight (spare inncluded). You would be hard pressed to find another 3076 open scroll at the same boost and weight do that on pump gas.
As someone mentioned before cam selection appears to be a big factor in getting TS to produce. My first go with TS and small cams left me a bit underwhelmed but I switched cams and picked up 50whp in the mid and 35whp on top with same boost.
As far as your divided housing on an open header example that just further proves that the twin entry into the turbine housing has a positive effect on power and spool. Your claiming, along with all the other people trying to disprove TS, that the restriction is the divided housing itself. Doesn't appear to be that way in your example

Ted B

iTrader: (6)

Even if it did, the difference in street feel and transient response of the .78 A/R TS housing is far better than a typical .63 A/R open.


Except that observations and reports from several different participants here indicate the TS setups seem to be making a difference in spool/feel/transients without the power penalty of using a smaller open scroll housings. Again, this would appear to be a result of the TS divider making reversion physically unfavorable as compared to a regular open housing.

CaymanEvo3

i can see this guy has bad credit, lol.

mchuang

iTrader: (11)

It would not function the same, What twin scroll is doing is pretty much directing exhaust pulses to promote spool, based on firing order, that is why the runners are paired.

Im sure engineers developed twinscroll for a reason, but I feel that a twinscroll setup which requires use of a custom tubular manifold vs an open scroll setup using something as simple as a buschur cast or rev hard cast manifold, will yield similar spool up. In one setup the turbo takes away from the topend(Twinscroll turbo) in the other the manifold takes away from topend power capabilities(Cast Logstyle manifold), but the twinscroll seems to use its technology to promote better spool, while a cast manifold log style uses its short runners to exert all the exhaust gas energy to spool the turbo due to the velocity it comes out of the exhaust headports and not having to travel a long distance and lose speed as it would in a tubular manifold. So far personally I have only seen based on what Sean Ivey reported was the full race kit in operation and he says the spoolup is improved, but who is to say most of the improvement is not from the backdoor piping which elimates a ton of intercooler piping. This alone has yielded spoolup improvements even on open scroll setups. What I am also trying to figure out is why do twinscroll manifolds cost more than openscroll, given the price of material is the same. The reason I ask this is because I was shopping around for a manifold and saw on shearerfabrications.com there is a twinscroll manifold for the EVO and the cost is 1300.00, then you look in the dsm section on the same site you see a topmount twinscroll manifold, using tons more material(more material = more cost) but at 1299.00. Is it because the EVO cost more than a DSM although using the same motor platform if so, than that is not a very good reason to price gouge.

LT1runner

iTrader: (8)

^Well turbo placement is different in an EVO vs. a DSM. It's probably easier fabing up a header for a DSM due to more room.

94AWDcoupe

iTrader: (125)

I am not angry. Just dont want people to join the TS hype when its expensive and the gains it offers can be had much cheaper doing other mods.

I think its funny you report going to 1.06 and gaining 60whp. I gained 30whp going from 48 to 63 on the 57 trim. Internet and some other reliable sources said I would pick up another 50whp switched to the 82. The 82 lost 20whp midrange, lost 60tq, and spooled 400rpm slower. peak power was the same. The car was a horrible slug to drive with the 82. You cant just keep going bigger on exhaust housings and think you are going to gain power each time. Just doesnt work that way. My guess is your 60whp claim came after other tweaking of the setup, not the housing itself.

Even funnier is you think the back to back housing test on the VW proves the twin scroll works. You couldnt be further from wrong. The TS design is suppossed to keep pulses from interfering with eachother all the way to the turbine. If you have an open header the pulses are allowed to interact before they reach the turbo. Putting a TS housing on a open header is not a twin scroll setup. Your conclusion from the test is completely in error and based solely on TS hype. with statements like this I dont see the point of trying to discuss the TS scroll design.

And 123 on straight pump for that turbo is not all that impressive. It ceratinly doesnt prove the TS is working. There was on car buschurs low reading dyno that made 360whp on straight pump. that car would have gone that fast with that power. And that was with a 3071 and open scroll.

Ted B

iTrader: (6)

It is impressive considering how mild Drifto's setup truly was, aside of course from the turbo kit.

As for 'proving' that the TS is working, you'd have to actually drive the car to experience that. Unless or until you create opportunities to experience the difference from behind the wheel, you just won't be able to understand or appreciate the qualities to which we refer. There is just no replacement for first-hand observations where this issue is concerned.

94AWDcoupe

iTrader: (125)

Ted, I understand what you are saying. I have driven sooo many setups. Far more than the average poster. on the level with most shops. Some of the cars had the ulta lively responsiveness that you refer too and they were single scroll cars. The only TS turbo I have driven was on a S2000. It was nothing short of laggy as stink. it was not lively off boost. it was a gt40. Dont really count for purpose of this discussion here though.

Drifto

iTrader: (6)

I never said that I didn't have to tweak it to get the most out of it. That should be a given with any mod - to get the max you have to tweak it. Frankly describing exactly what I did to get those gains from the turbine housine after I worked my *** off to get them is not something I feel like openly discussing anyway. Point is that with the larger housing I'm able to do things I could not on the smaller one to gain more power with minimal loss in spool and I attribute this to the TS properties.

.

Thank you for clarifying that. I was starting to wonder if all of my hours of fab and months of tuning/testing/designing were wasted becuase you could just bolt a divided housing on a regular manifold and get the same results . It's statements like the above that let me know how valuable you are to this community.

.

Nothing I say is hype related. I drive a twin scroll setup on an Evo, and have been for over a year now,and as far as I know, I may have been the first to get this working with the T3 family of GT turbos. Hell, TedB was happy with his setup(GT35R, 4 into 1 header) and drove my car - which at the time was giving up 65-70whp to Ted yet he decided to sell his stuff off and go this route. There is more to it than hype I promise you.
As far as my conclusion, it's based off of people saying that the restriction is the divider in the turbine housing. Your friend picked up power and spool with a housing change - a divided one at that. I stated that divider may not be restrictive based on his results. Never for an instant insinuated that now it was a TS.

Maybe not, for that turbo, but with a stock head/block/intake manifold, and full weight it's impressive for that turbo on that car. What does "It certainly doesn't prove TS is working' mean? You keep saying that TS will kill top end. This is what I'm dissagreeing with. My Car picks up almost 30mph on the big end - with the small housing. I don't see where TS is a restriction based on my personal experience.

I applaud people making great power with less. When I ran 122mph I made 375whp on a DD with 0 correction in 85 deg.temps and exact set up listed above. The dyno I use reads very low like David's does, but would have gone that fast and did go that fast are two different things

Ted B

iTrader: (6)

Well that's just it. If you've driven enough good 3076R setups to know what to expect (and I know you have), a turn behind the wheel of an equally good 3076R car with TS will leave you with an impression. I'm not saying it's the best thing since sliced bread, just that so far, it seems to deliver more while giving up less. I have to say that Drifto's car has a factory feel to it - not at all like a hopped up performance project, but very refined.

There's more testing to be done, and it's in the works.

mchuang

iTrader: (11)

Not really considering the alternator is up front, It is about the same as far as difficulty. More material of the same kind is always more money period. Maybe its the wrong price who knows. Oh well, back on topic.

Dennis F

iTrader: (22)

I know he galant you speak of,

Tom N
91 Galant VR-4
11.4 @ 119 (evo316g)

Are you saying an Evo 8 or 9 has not gone that fast? Equally modded of course.

You must be nuts because there are plenty of evo's going that fast on stock turbo's and 272's.

And to boot, the evo is a much more fun car to drive because of it's ability to spool up faster and still make the same power.

And also throwing Curts name into the mix, no one has ever matched what he does or how he does it. But then again, how fast did Curt go in his evo 8 again?

Oh, thats right, 2003 EVO, 10.59@127.47 Stock turbo

TS for the loss right?

LilRico

iTrader: (21)

Well... Mitsu must have pair the EVO with a TS for a reason??? I know they could of made any design they wanted, but the TS was chosen for a reason... That's how I feel...

robertrinaustin

iTrader: (5)

How can anyone reasonably argue against twin scroll? There are probably 10 different OEMs running TS setups that have spent hundreds of millions of dollars researching this. No OEM would add the added cost and complexity of a TS setup if there were not substantial benefits.

With no disrespect to the OP, your post is a bit of a joke. You site one anecdotal story to disprove TS and then dismiss anyone else's anecdotal evidence as just better matching the AR.

Is the TS setup worth the additional cost? Those that have experienced it claim yes. OEMs obviously believe so. Ultimately, it's up to the individual to decide if the additional cost is worth it. However, denying that there are benefits to a TS system is like claiming the earth is flat.

03whitegsr

iTrader: (8)

So have you driven an S2000 with a GT40 on an undivided turbine side? (yes, I know Garrett doesn't make an undivided GT40 ***I wonder why???*** but maybe something close like a GT4088 from PTE with the undivided housing)

No? OH...

So how exactly do you find yourself as having a valid opinion when you've never really had any experience with it directly compared to others who have TESTED the twin scroll against the undivided setups?

Testing >> Speculation

I've got nothing to gain by saying this, as I don't sell parts and and have absolutely no affliation with any vendors nor do I buy from vendors in the first place. Twin scroll turbine setups offer better top end and mid range power, quicker spool, lower exhaust manifold backpressure, better engine volumetric efficiency, better turbine efficiency, lower EGTs etc. the list goes on and on.

This is purely my opinion, but twin scroll is NOT about getting a big turbo to spool faster. It's about getting more power out of a given turbo. If you can handle the lag of a GT40 with an undivided setup on a .85 A/R housing, then going to twin scroll you can bump up to a 1.05 A/R housing on the same turbo, getting as good/better boost threshold, better transient response, and loads more power across the RPM range.