Do you under stand the physics of this system?

Because, yes, high speed compressible pulse flow dynamics are very sensitive to temperature and frequency, both of which are very different between a 3500 RPM diesel engine and a 8000 RPM gasoline engine...

Any other smart *** pseudo-questions you would like to ask?

 

I do not understand how high speed compressible flow dynamics change when going from a diesel to a gasoline car besides the fact that EGT's are a lot higher, and that rpms are much faster.

I do however know, that when I performed the twinscroll switch on my car it picked up a ton of low end and mid-range power, and now I have an exhaust manifold that can accept turbos that can produce 1200 whp if need be......

I just don't get how with the success of stock frame turbos and all the really fast cars running T4 twinscroll setups people still think this is some sort of voodoo magic. It's not. All these OEM's like Mitsubishi and Mitsubishi have way more money to put into the R&D then the likes of Tial or Precision turbo, and frankly I believe that they put it on the cars because it works, not because it looks nice.

Twin scroll works by doing a better job of managing the flow of exhaust from cylinders, which allows you to spin a bigger turbo with less exhaust pressure than a traditional single scroll unit. That is all.


Scorke

 

It's quite simple.

TS increases area under the curve to the left side of the torque peak at all throttle positions, simply due to the increase in VE afforded by the difference in turbine speed. What happens to the right of the torque peak is a function of several factors, all of which largely boil down to turbine housing sizing. I feel this much to be so self evident (as observed by the industry and individuals alike) at this point that it is beyond refute, and is of greatest value to those of us whose efforts are concentrated to real-world street behavior.

The only lingering question as far as I am concerned is what happens when the TS housing is sized such that the resulting power curve to the right of the torque peak is equal that of a particular open housing. Do the TS benefits to the left of the torque peak remain evident? My hunch is they do, albeit to a lesser extent. This is more important to a dedicated drag race application, so for me, it's mostly academic (but interesting nonetheless).

 

Scorke, you have to realize not a single post I have made has questioned IF it works. I am merely asking for somebody to put up factual data that proves it works on setups we are most interested in so that this argument can be put to rest.

Go search for posts from me from like 4 years ago, I was saying back then twin scroll is the better way for most setups.

I however don't have data to prove this point other then my opinion, so I try to stay out of the pissing match and am just asking for factual data.

I really don't care about the theory. We all know it by now and it's been beaten to death. I don't care about how the stock car has it either since we have no idea what the design intent that drove that decision was. I also don't care how it improved spool on a diesel engine with a 20 pound/min turbo revving to 3500 RPM since it's not even remotely similar to an EVO with a 35R revving to 8500 RPM.

I think it's hilarious because not only has nobody actually done a good fair and through dyno comparison to even give factual data, but all of you want to compare different setups all together and infer from those cars that it works every time, all the time and in equal proportion. Or even that it doesn't work in the case of the TS naysayers.

Then you get all this bull**** talk of how you have to feel it to understand. BULL****. If it's true, there is a test to put data on it start getting creative to come up with a good comparison or stop *****ing when people question YOUR OPINION.

 

Until or unless someone with a real financial incentive (?) decides to develop and publish testing does so, there are only real-world, third party observations.

 

MItsubishi is not going to test twinscroll setups for an evo from third party manufacturers to enlighten evom posters. SOooo. the next best thing is having indiviudals use single scroll on the same exact car, then swap to twin scroll same car and see the differences. A dyno pull or something perhaps. But why do it when it works better already. Dyno time is not cheap and that time can be used to tune someones car. A better discussion is can you warrant the cost of the manifolds? Ets twinscroll manifold is far more expensive than the non twin.

 

The issue is nobody on here is willing, able, or interested in doing the sort of research you are asking for.

It's not bull****, it's just the fact that there is nobody out there dynoing cars at 10 percent throttle at 3k rpm so you can't see and feel the huge difference that this makes to the cars at low RPMS.

I think the cheapest and most cost effective way to do a twin scroll test is to molest a stock manifold or an aftermarket one to make it effectively single scroll, and do the same to a stock hotside and see what you lose. Otherwise nobody is going to be happy with the third party tests because too many variables need to change to do have two optimized setups ( runner size/length/layout/wastegates).

If your saying twinscroll is best for most setups which setups are you saying it is not the best option?

That is my question.

Scorke

 

here is my twinscroll HTA gt3582r on the stock 2.0 engine. Turbine housing is a t4 divided 1.06ar
20psi by 4krpm in 3rd gear

 

wow, you just slapped 3582 with no building. what about clutch? stock or twin disk? Keeping the torque below 400 I guess it's all good on stock block. Thanks for a good example.
Love the tangled snake style full race manifold

 

clutch is a ACT HDSS Which works great i might add

 

wow i love reading Evolutionm battles in the morning!

There WILL be factual evidence posted up once the new manifold has been built, after the exhaust housing has arrived. It will be based on the HKS 3037 (3076) on a SR22 engine with VVT.
yes i know blah blah blah the 3037 is a *crap* turbo, but the fact it puts down 380kwatw @ 26psi boost (340ish on 21psi), it doesn't seem that bad to me. (1kw = 1.34hp, and NZ dyno prob read lower).

The reason for this post was to find out which actual exhaust housing to use, and to see which is better. We'll be going for the T3 housing, so that the 3037, 3082R and 3582R turbos can be used on all the same manifolds. Carl (www.ehmotors.com www.driftcarl.com ) and his brother Hans are both running SR20 engines, so they can be swapped between them for drifting and circuit racing etc.

We know that Geoff from Full-Race has suggested/recommended to go T4 for future proofing, and there are exciting changes coming to the turbo mainstream market.
But the fact that the T3 options are available NOW, is the reason why the T3 option has been chosen.
Maybe when i'm sick of the FP Red (or i kill it lol) i'll jump on the T4 bandwagon

 

[QUOTE=riceball777;8397969]here is my twinscroll HTA gt3582r on the stock 2.0 engine. Turbine housing is a t4 divided 1.06ar
20psi by 4krpm in 3rd gear

I'm sorry Riceball, gear doesn't matter for Dynapack dynos when relating it to boost @ xxxx rpm.
Your ratio number is your final drive x your gear ratio. So your third gear is about a 1.4 ratio? and your final is about 4.6? (6.4 = 4.6x1.4)

The thing that shows how your boost ramps etc is the Run Time.
Here is a graph showing the difference between a 6sec run and a 12sec run. These were done back to back (20seconds apart).



This was with my external wastgate setup, it was horribly laggy. once i put the internal wastegate back on (so the pulse dividing worked correctly) it improved alot. 17psi in 2nd gear on the road (with logging) went from 5000rpm to 4400rpm just from putting on the internal wastegate.

 

Ok, so let me ask you this question. Should a company that is selling something be responsible for backing up their claims or should people just blindly purchase their product on blind faith it will work?

I don't care if "nobody" runs a dyno in a manner to show transient response. I want to see a vendor selling this stuff (or claiming it doesn't work for that matter) do it though.


I think the most cost effective and fool proof method would be a custom thin wall mild steel manifold built specifically for this test. The mild steel is cheap and easy to work with and will hold up fine for testing. Use a slip fit collector with wastegates built on to them for each setup that way the ONLY pieces changed would be the housing and collector/wastegates. Runners stay the same, downpipe the same, turbo placement the same. The only things changed would be the items of interest.


Full-Race did something similar back several years ago to prove how superior their low angle merge collector based manifold was over a log manifold.
http://www.honda-tech.com/showthread.php?t=925312

Something like that needs to be done on twinscroll vs. single scroll.



There are very few situations I see a single scroll would be better. In my opinion, it would only be when the weight and complexity penalty of the TS out weighs the power/response differences. Such a situation could be on a smaller turbo where the single scroll provided good response to the power range needed. Yes, a TS may improve spool, but it likely wouldn't make enough difference to truly be beneficial if the desired use never had the revs at a low enough range to make the spool differences matter.

 

Its a shame really that Mitsy didn't follow the larger heavier car needs a larger capacity engine like Superpoo did because we may have actually got larger TS Mitsy turbochargers in the same vein as the TD05 based ones .

The fact that the Evos go quite well in std trim and have gotten porkier and porkier and still we have a two liter four banger calling the shots says something .

I believe the future is with larger twin scroll twin waste gate turbine housings because they go a LONG way towards reducing the cost and complexity of a complete TS manifold and turbocharger system .
Not everyone is going running to FullRace for a competition spec manifold and a pair of external waste gates , they are real nice but not every has the brass to pay for them or wants a non std looking engine bay .
IF you have the split pulse manifold std and IF some manufacturer supplies a twin scroll twin integral gate turbocharger it is NO MORE COMPLEX to assemble that a single scroll turbo on a single collector exhaust manifold .
The properly designed TS/twin gate turbine housing takes a bit more effort to produce BUT it goes 90% of the way towards having a very OE looking engine that's capable of really serious torque output starting reasonably early and available over a quite wide engine speed range .

You can have all your high Hp/Kw numbers and to me it means jack **** , torque is everything and when you can have lots of it over a wide range in a freely spinning engine what else could you ask for ?
Someone mentioned why quote diesel engines in the TS mix , the reason why is because big ones have a very narrow rev range and so need to produce high torque across all of what they have . The fact that that they have lower exhaust gas temperature means they have less thermal expansion energy to work with so it's harder to get low restriction velocity energy to drive a turbine with .

I reckon that resistance to TS systems stems purely from cost and complexity , the Ralliart Lancer is a cost cutting exercise compared to the same era Evo and from memory it has a single scroll turbocharger .
Obviously not as good but the new purchase price of the vehicle is further within reach of a greater part of the car buying community .

TS is good and IMO always worth the effort if its an affordable reality .

Adrian in Oz .

 

1. No a company does not nor has to back up their claims when selling a product. I see and hear advertisements for all sorts of ridiculous stuff daily and know its B.S. because I have the common sense present to be able to distinguish between things that might possibly do what advertised and those that don't. You are not buying these twin-scroll manfiolds on blind faith, but you are buying them on the basis that the turbos that happen to be built in this type of configuration happen to work very very well on relatively small displacement 4 cylinder motors. Whether it be Formula 1, WRC, or OEM it seems all of the applications that are aimed at providing maximum power and or maximum response given other restrictions look to twin-scroll to achieve the end result they desire.

When you request to see a vendor selling twin scroll stuff or saying it doesn't work prove it, that is the exact opposite of what is ideal. The best candidate to describe what sort of performance advantages you gain from twin scroll are those that have nothing to gain or lose in disclosing their own results from trying both setups.

2. Unfortunately that candidate is not usually able or willing to do what you are asking. This requires building a manifold in two configurations with potentially 3 or 2 different wastegates, two flanges, two hotsides, etc etc etc. That is probably close to 2-3k of time, money, labor, and dyno time that people are not willing to spend.

As much as I would love to see the results of such a test, I don't think anything with that sort of relative closeness in setups will ever be ran simply because whatever the outcome the setup you determine to be best out of those two, is still not optimal because the header is the same between the two setups and the header needs to be significantly different to take advantage of either the single scroll housing or the twin scroll housing due to the different architecture of the housings. We know this because the people that manufacturer both single scroll and twin scroll manifolds run different runners on otherwise identical manifolds.

3. If you are saying weight and complexity are the only two downssides of twin scroll setups I don't even know what to say.... We could be running rear wheel drive cars to save weight and complexity, but the weight and complexity added to the car through the additional drivetrain and rotating weight to overcome is more than outweighed by the performance benefits it offers.

I believe the benefits of twin scroll are more than outweighed by the weight, complexity, and even COST downsides.

The only people that can say twin-scroll offerings didn't improve spool enough to outweigh the penalty of the weight and complexity are those that are only concerned with what the car does well past the boost threshold, at which point you are only concerned about 1 dimension of the cars performance, which happens to be at the very top of the rev range. Frankly any car that is driven on the street, road course, off road, or anywhere in between, is concerned with what happens between idle and maximum boost and for those people twin scroll offers a LARGE advantage over similarly sized single scroll turbocharged setups.

*I do not sell single scroll or twin scroll setups, I have nothing to be gained by saying one or the other doesn't work, I don't have any Full-Race products on my car.

Scorke