Data on internal vs external WG
there are NO stock lambo turbo engines..
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.
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.
This guy did a proper SS vs TS test on a 4G63, and shows quite clearly that the TS wins hands-down.
http://www.4gtuner.com/topic/27035-single-scroll-vs-twin-scroll-turbine-housing-dyno-comparison/
http://www.4gtuner.com/topic/27035-single-scroll-vs-twin-scroll-turbine-housing-dyno-comparison/
This guy did a proper SS vs TS test on a 4G63, and shows quite clearly that the TS wins hands-down.
http://www.4gtuner.com/topic/27035-s...no-comparison/
http://www.4gtuner.com/topic/27035-s...no-comparison/
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From: surpriseaz
None of the ss/ts tests I've seen were at choke flow making equal power. For example, take a 6266 making 800+ in an open t3, and compare it to a 6266 making 800+ in a t4 twin scroll.
Twin scroll is great for operating a turbo in the middle of its efficiency zone in a street car, or road race setup.
Twin scroll is great for operating a turbo in the middle of its efficiency zone in a street car, or road race setup.
None of the ss/ts tests I've seen were at choke flow making equal power. For example, take a 6266 making 800+ in an open t3, and compare it to a 6266 making 800+ in a t4 twin scroll.
Twin scroll is great for operating a turbo in the middle of its efficiency zone in a street car, or road race setup.
Twin scroll is great for operating a turbo in the middle of its efficiency zone in a street car, or road race setup.
Or pushing a turbo past it's rated power (7175 is rated for 985hp). Nbd.
https://www.evolutionm.net/forums/ev...084-744-a.html
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From: Cyprus
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.
I do not know how you came up with the egt numbers as they are not accurate, many turbo diesel engines operate in the 850-900c range and most performance gasoline engines also run in 800-900c egts, and why you have associated them in the way that you have, it's all wrong, apart from the fact that you are trying to build an arguement to support what? A false theory or way of thinking?
I used to own a turbo diesel it wasn't vnt/vgt. Now I own an aspirated diesel. All the turbo diesels we have over here none is of variable geometry, all use single scroll turbos. Most are jdm, either trucks or saloon type of cars.
A diesel engine does not need a variable geometry turbo to offer excellent results.
Variable geometry turbos are used in gasoline applications. Porsche is a fine example. Its turbos are not build of any exotic parts.
Marios
Last edited by Evo8cy; Mar 13, 2017 at 08:00 PM. Reason: typo/added comment
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From: Cyprus
there are NO stock lambo turbo engines..
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.
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.
I was not referring to stock. Everybody knows that Lambo is all about aspirated engines hence why all the turbo charged ones are built by tuning houses and are far superior than stock. I was referring to turbocharged lambo motors. Also Lambo themselves, Audi that is, has taken in certain requests by customers in co-operation with a third party tuning house to build some turbocharged versions of their engines on special requests through the years.
I find the Lambos build by the specific tuning house, very well build with a very functional and wide powerband.
I also disagree with you on the supercars matter, all engines can run either a twin scroll or a single scroll turbo. Most run single scroll units.
I have yet to see any turbo engine and not just, not being able to run either type of turbo.
Marios
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i.e. cant use twin scroll turbos on in line 5 cyl, and V8s with cross plane cranks (unless you connect both left and right banks in a mess of tubes)
twin scroll turbos are ideal in single turbo application in line 6 cyl, in line 4 cyl, and twin turbo setup on a single plane 8 cyl V8
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From: Croatia
Evolved Member
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From: Cyprus
you can not run, or better said, there is no effect running twin scroll turbos on engines where you can not pair cylinders so that you have equal firing between two scrolls..
i.e. cant use twin scroll turbos on in line 5 cyl, and V8s with cross plane cranks (unless you connect both left and right banks in a mess of tubes)
twin scroll turbos are ideal in single turbo application in line 6 cyl, in line 4 cyl, and twin turbo setup on a single plane 8 cyl V8
i.e. cant use twin scroll turbos on in line 5 cyl, and V8s with cross plane cranks (unless you connect both left and right banks in a mess of tubes)
twin scroll turbos are ideal in single turbo application in line 6 cyl, in line 4 cyl, and twin turbo setup on a single plane 8 cyl V8
All the above applications can run a twin scroll turbo/s, there is nothing stopping them from doing so.
Marios
Last edited by Evo8cy; Mar 13, 2017 at 06:34 PM. Reason: typo
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From: Cyprus
No he was not! I have seen numerous of times diesel engines running 850c+ of exhaust gas, i.e a seat ibiza tdi with a built engine and bigger turbo.
I have seen and built gasoline engine setups, including my personal car that run egts at 800-850c max
No it is not, the Koeniggsegg one is another, Extreme Tuners build lambo engines with vgt turbos, and a couple of italian and german tuning houses.
Also many other garages which are not known use these in their builds, across Europe.
A mass production 1.5L gasoline engine with vgt turbo, is VW's EA211 TSI Evo engine.
Marios
Last edited by Evo8cy; Mar 13, 2017 at 07:55 PM. Reason: added comment
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From: surpriseaz
Or pushing a turbo past it's rated power (7175 is rated for 985hp). Nbd.
https://www.evolutionm.net/forums/ev...084-744-a.html
https://www.evolutionm.net/forums/ev...084-744-a.html
Originally Posted by donniekak
I didn't read the whole thread. But where do they compare it against a large open housing?
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From: surpriseaz
I'm not saying the test would go either way, I just want to see a test to end speculation. There has to be a reason the fastest turbo cars at the strip run open housings. Maybe it's different now but all the promod drag cars I've seen were running open housings.