Data on internal vs external WG
Mar 9, 2017, 08:10 AM
#31
Evolved Member
Your mistake? You specifically said the 2016 panamera, and I fould that you were wrong...LOL
None of the current Lamborghini's comes with factory turbo's...lol
No, we're discussing gasoline piston engines, that have an exhaust manifold not integrated with the head. You change to a rotary, and the needs of the system change. Same goes for diesel, and the newer cars that have the exhaust manifold integrated into the head. But even some of those cars, like the Focus RS, use a twin scroll turbo.
Great, the new type R uses a single scroll turbo, Honda also claims they used the Vtec system (variable valve timing/duration/lift) to overcome the lag associated with a single scroll. They LITERALLY admitted single scroll introduces more lag, but they used another design parameter to get around it...LOL
And most supercars come with twin scroll. The McLarens and Ferraris being most notable.
This is simply funny.
None of the current Lamborghini's comes with factory turbo's...lol
No, we're discussing gasoline piston engines, that have an exhaust manifold not integrated with the head. You change to a rotary, and the needs of the system change. Same goes for diesel, and the newer cars that have the exhaust manifold integrated into the head. But even some of those cars, like the Focus RS, use a twin scroll turbo.
Great, the new type R uses a single scroll turbo, Honda also claims they used the Vtec system (variable valve timing/duration/lift) to overcome the lag associated with a single scroll. They LITERALLY admitted single scroll introduces more lag, but they used another design parameter to get around it...LOL
And most supercars come with twin scroll. The McLarens and Ferraris being most notable.
This is simply funny.
The panamera model that I was referring to was the diesel 3.0 v6 engine and I was not wrong.
What the **** are you talking about. So, you believe all diesel engines have an exhaust manifold that integrates with the head, yes there are some models, much older ones that did, all newer do not. Even those type of engines that do, why should those applications not be included in the discussion? Do you think that we should all go by of what you want to discuss. Here we discuss turbos, and to me it is very relevant to discuss all turbo applications, wankel, diesel petrol, even hybrids.
Honda used a single scroll turbo because combined with the latest engine technology differs in no way than a twin scroll one. Otherwise if twin scroll was the only way forward and much more efficient than the single scroll setup they would have used a twin scroll one.
I do not know where you have heard/read and how reliable the source you use is, about Honda's claims. But the result is that the new type r is one kick *** package.
Most supercars do not use twin scroll turbo setups. Lambo being an excellent example.
The point you or anyone else needs to understand is if the single scroll turbocharger was made redundant and much less efficient than the twin scroll one, it would have been abandoned, but reality dictates otherwise.
I find nothing funny about your moronic attitute towards controlling the discussion, and if you do find something funny, along with the fact that you post certain mis-information, here it should be the fact that you are doing your best to do so.
Marios
Last edited by Evo8cy; Mar 9, 2017 at 08:29 AM. Reason: typo
Mar 9, 2017, 08:25 AM
#32
EvoM Guru
iTrader: (1)
I didn't say diesel's with an integrated mani, I said diesels, and the newer cars that have an integrated mani. If you can't see why turbo discussion doesn't crossover from gas to diesel, I'm not sure we can continue talking about this.
If you meant the diesel panamera, you should have specified. And while the diesel doesn't use twin scroll, it does use VGT technology as of 2017.
If you meant the diesel panamera, you should have specified. And while the diesel doesn't use twin scroll, it does use VGT technology as of 2017.
Mar 9, 2017, 08:38 AM
#33
Evolved Member
I didn't say diesel's with an integrated mani, I said diesels, and the newer cars that have an integrated mani. If you can't see why turbo discussion doesn't crossover from gas to diesel, I'm not sure we can continue talking about this.
If you meant the diesel panamera, you should have specified. And while the diesel doesn't use twin scroll, it does use VGT technology as of 2017.
If you meant the diesel panamera, you should have specified. And while the diesel doesn't use twin scroll, it does use VGT technology as of 2017.
You said we are discussing petrol engines that have not an integrated exhaust manifold to the head, meaning all the rest of the types of engines I mentioned, wankel and diesel, were considered as such.
As I said when discussing two types of turbos as here, or turbos in general, all applications need to be included and discussed, as all and each application offers their own findings, info and different results.
I did specify, although there was no need as the only newest model that comes with single scroll turbo is the diesel one, VGT, or not VGT, it still is a single scroll. Anyone wanting to and is able to can use a single scroll with or without VGT.
You only focus on what suits your arguement and that's biased. Many other models out there use single scroll without VGT technology, but still manage better overall performance than their twin scroll equivalents, this is the point I want to stress.
You are free to leave the discussion anytime you wish.
Marios
Last edited by Evo8cy; Mar 9, 2017 at 08:57 AM. Reason: typo
Mar 9, 2017, 11:54 PM
#37
Evolved Member
Mar 10, 2017, 06:02 AM
#38
Evolved Member
I find it quite hard to find a OEM lambo turbo... I wonder why.. 
Mar 10, 2017, 06:13 AM
#39
Evolved Member
What hasn't been proven right? The fact that both twin and single scrolls setups can have same boost characteristics and working properties if you set them up right and there really isn't that much difference in between in them, or the fact that single scroll turbos make in general more power overall with equally functional powerband? Is it the fact that automotive companies still build and produce most of their everyday turbo cars with single scroll setups?
Do a search on the internet my friend, and ask around in the world, you'll find plenty of examples of proof of what I say.
I personally like both types of turbos, I like turbochargers and turbocharged engines in general more than aspirated ones, besides very few exceptions such as the ferrari california for instance, which if I'm not mistaken, the aspirated version, makes around 110hp per cylinder.
Marios
Last edited by Evo8cy; Mar 10, 2017 at 06:47 AM. Reason: added comment/typo
Mar 10, 2017, 07:50 AM
#40
So can we all agree here that this is the dumbest car related thing we've read this year so far?
Evo8cy, best of luck man. If it's true in your mind (but not In reality), just refer to them as "alternative facts" and move on. It works for our president, I'm sure it could work for you too.
As for anybody looking for factual data on twinscroll vs single scroll...go ahead and disregard the vast majority of this thread. Although, I mean...you can tell by reading who ACTUALLY has knowledge on this topic and...well...
Evo8cy, best of luck man. If it's true in your mind (but not In reality), just refer to them as "alternative facts" and move on. It works for our president, I'm sure it could work for you too.
As for anybody looking for factual data on twinscroll vs single scroll...go ahead and disregard the vast majority of this thread. Although, I mean...you can tell by reading who ACTUALLY has knowledge on this topic and...well...
Mar 10, 2017, 01:16 PM
#41
Who said that every thread on a car forum, has to be presented with hard evidence. I did not see you present anything of such, and I would not expect you do so on the specific matter. As I said if you want proof of what I say, search and you shall find, proof of this comparison is out there, there are numerous tests of various and different applications.
Marios
Marios
OP = Evo8cy = 94AWDCOUPE
Trolling hard in 2017.
Mar 10, 2017, 09:49 PM
#42
Wow.... okay... not sure why diesels were brought into this but it just shows that Evo8cy doesn't even know diesels.
Well, for the benefit of everyone else, pretty much any diesel you can buy and drive on the street comes with a single scroll turbo because they are also VNT/VGT (variable nozzle turbine/variable geometry turbo). So the vanes close when the turbo needs to spool up quickly and open when it hits the boost target. Around half the cars in Europe are diesel because fuel is like $8 a gallon.
So why is VNT common on diesels and not gasoline? Because of exhaust gas temperatures. Diesel exhaust gas temps in cars peak out around 760C or so. A moderate performance gasoline engine has exhaust gas temps of around 980C. Think Ecoboost Mustang. Top-end performance gasoline cars like a BMW M5 has temps topping out around 1050C. So needless to say, gasoline exhaust temps are way hotter than diesel exhaust temps. It turns out parts that have to move a lot relative to each other don’t like to operate in super hot exhaust gas temps because they would seize up. The one gasoline car on the market that has used VGT turbos is the Porsche 911 Turbo. That particular turbo uses very expensive/more exotic materials to handle the high heat of gasoline exhaust temps along with running a bit bigger clearances between the vanes and housing (big clearances between the vanes and housing are bad for turbine efficiency).
There are a couple gasoline cars coming to market soon that do use VNT/VGT turbos without using crazy expensive materials. They do it by the engine running a Miller cycle which reduces the exhaust temps. Anyway, that’s the short on diesel cars on the street.
Well, for the benefit of everyone else, pretty much any diesel you can buy and drive on the street comes with a single scroll turbo because they are also VNT/VGT (variable nozzle turbine/variable geometry turbo). So the vanes close when the turbo needs to spool up quickly and open when it hits the boost target. Around half the cars in Europe are diesel because fuel is like $8 a gallon.
So why is VNT common on diesels and not gasoline? Because of exhaust gas temperatures. Diesel exhaust gas temps in cars peak out around 760C or so. A moderate performance gasoline engine has exhaust gas temps of around 980C. Think Ecoboost Mustang. Top-end performance gasoline cars like a BMW M5 has temps topping out around 1050C. So needless to say, gasoline exhaust temps are way hotter than diesel exhaust temps. It turns out parts that have to move a lot relative to each other don’t like to operate in super hot exhaust gas temps because they would seize up. The one gasoline car on the market that has used VGT turbos is the Porsche 911 Turbo. That particular turbo uses very expensive/more exotic materials to handle the high heat of gasoline exhaust temps along with running a bit bigger clearances between the vanes and housing (big clearances between the vanes and housing are bad for turbine efficiency).
There are a couple gasoline cars coming to market soon that do use VNT/VGT turbos without using crazy expensive materials. They do it by the engine running a Miller cycle which reduces the exhaust temps. Anyway, that’s the short on diesel cars on the street.
Mar 10, 2017, 10:28 PM
#43
Account Disabled
It's because diesels don't usually have a throttle (used for EGR) and even at low loads a diesel will flow lots of air. Unlike a throttled petrol engine.
EGT doesn't factor into it.
EGT peaks at lambda 1, petrol, diesel, the same.
A diesel at idle runs relatively cold due to the lean AFR/ excess of air.
The main advantage of a split scroll turbine housing is quicker spool for better mid range performance.
It's really about matching the turbo to the engine. A small turbo will give far better low RPM performance while maxing out early.
A bigger one will give better top end but takes longer to "turn on".
A split scroll gives the best of both.
EGT doesn't factor into it.
EGT peaks at lambda 1, petrol, diesel, the same.
A diesel at idle runs relatively cold due to the lean AFR/ excess of air.
The main advantage of a split scroll turbine housing is quicker spool for better mid range performance.
It's really about matching the turbo to the engine. A small turbo will give far better low RPM performance while maxing out early.
A bigger one will give better top end but takes longer to "turn on".
A split scroll gives the best of both.
Mar 11, 2017, 09:15 AM
#44
And diesels rarely ever run at lambda if at all. Only the high performance ones would get close. You start running to smoke issues too. Of course EGTs matter, try designing a VNT to survive typical gasoline EGT temperatures sometime 
A twin-scroll turbine housing is still often used on big diesel off-highway engines as it improves turbine efficiency. These are engines where they tend to operate at full-power all the time and don't need the transient response advantage of a VNT. While twin-scroll is a big improvement in spool-up and transient response, it can't compare to a VNT.
A twin-scroll turbine housing is still often used on big diesel off-highway engines as it improves turbine efficiency. These are engines where they tend to operate at full-power all the time and don't need the transient response advantage of a VNT. While twin-scroll is a big improvement in spool-up and transient response, it can't compare to a VNT.
Last edited by spdracerut; Mar 11, 2017 at 09:20 AM.
Mar 11, 2017, 11:07 AM
#45
Evolved Member
and I really do not care what underground racing does to their lambos as their typical use has nothing to do with wide powerband I like to see on a road going car
as for stock supercars, or any high performance car for that matter, all of them that have engines that CAN have twin scroll turbo (as twin scroll will not work on all engine configs) really do use them.