Data on internal vs external WG
A huge V8 running a single turbo, T5 hotside, is quite a bit different than a ~2.0L 4 cylinder. Making a twin scroll work (with paired cylinders) on a single turbo setup on a V8 would be a nightmare to build the manifolds.
If all you 're interested in doing is 400 m it's easy, just stick a carby on it?
It'll work just the same.
Road cars have to do so much more.
Drag racing doesn't care about mid range anything.
It'll work just the same.
Road cars have to do so much more.
Drag racing doesn't care about mid range anything.
No it won't.
Extreme Tuners Evo is a road legal car. No twin scroll setup would make the power it is making , and neither would for any of the setups seen on the video.
I run a custom 6868 t4 open on mine , the car is fully road legal used on public roads. The car drives fantastic!
Marios
Extreme Tuners Evo is a road legal car. No twin scroll setup would make the power it is making , and neither would for any of the setups seen on the video.
I run a custom 6868 t4 open on mine , the car is fully road legal used on public roads. The car drives fantastic!
Marios
Back from your timeout eh. So can you explain why the Tilton Interiors team decided to go with a twin scroll setup for their 3-time winning time attack Evo?
http://www.motoiq.com/MagazineArticl...shi-Evo-9.aspx
http://www.motoiq.com/MagazineArticl...shi-Evo-9.aspx
Thread Starter
Joined: Sep 2006
Posts: 2,331
Likes: 39
From: Hermosa Beach, CA
Twin-scroll is used for spool-up and transient response. It typically will not make the same peak power as an open scroll housing? Why? Because the divider wall in the twin-scroll housing essentially doubles the surface in contact with the exhaust flow which increases flow loses.
So, where transient response is more important i.e. road racing, twin-scroll is often used. Or open scroll and anti-lag. Or in the case of more modern stuff like F1, e-turbos.
Drag cars use open scroll because they need maximum power and typically run anti-lag to spool up off the line.
So, where transient response is more important i.e. road racing, twin-scroll is often used. Or open scroll and anti-lag. Or in the case of more modern stuff like F1, e-turbos.
Drag cars use open scroll because they need maximum power and typically run anti-lag to spool up off the line.
That's the common understanding that most people here have. However Evo8cy seems to think otherwise. I'm still waiting on him to provide solid concrete evidence that backs up his claim but to date all he was able to produce was a drag racing video which proves nothing.
Originally Posted by spdracerut
Twin-scroll is used for spool-up and transient response. It typically will not make the same peak power as an open scroll housing? Why? Because the divider wall in the twin-scroll housing essentially doubles the surface in contact with the exhaust flow which increases flow loses.
So, where transient response is more important i.e. road racing, twin-scroll is often used. Or open scroll and anti-lag. Or in the case of more modern stuff like F1, e-turbos.
Drag cars use open scroll because they need maximum power and typically run anti-lag to spool up off the line.
So, where transient response is more important i.e. road racing, twin-scroll is often used. Or open scroll and anti-lag. Or in the case of more modern stuff like F1, e-turbos.
Drag cars use open scroll because they need maximum power and typically run anti-lag to spool up off the line.
Thread Starter
Joined: Sep 2006
Posts: 2,331
Likes: 39
From: Hermosa Beach, CA
Honestly, the EFR is the wrong turbo for drag racing. The TiAl turbine wheel compromises a bit on turbine efficiency (lower efficiency increases back pressure) for low inertia. The whole purpose for the TiAl turbine wheel is transient response. Same deal with the ball bearing in the EFR turbo. The EFR turbo as a whole is designed for maximum transient response, not maximum power.
If I were drag racing and using a BW turbo, I'd probably go with the S400SX series. Now, that turbo and many of the large Garretts only come with divided housings. Why? Because they are based on existing diesel product which use inline-6 engines, so 3 and 3 into each scroll of the turbine housing. Tooling for a turbine housing can be like $75k+, so there's not much business case for BW or Garrett to go make a new tool for an aftermarket performance application where they might sell maybe a hundred a year.
Every person is entitled to their own understanding of things, based on their own experiences and knowledge. I have been into motorsport, tuning and cars for more than 20 years, close to 25.
Many circuit setups in the time attack, btcc, european hillclimb championship and events, or any sort of time attack type championship use single scroll turbos, such as Greddy, JUN, Blitz, many european, english teams such as Norris Designs who uses a single scroll TO4Z on his evo 3 car, etc, international teams who compete in the Pikes Peak event. You ask for data but none of you have presented of anything as such apart from a dynograph ( which actually does not serve as any kind of scientific proof) and a youtube video, in which one example is used of a car that uses a twin scroll setup but there were other examples of previous years who got the title using a single scroll setup.
Besides this, there can be no actual correlation between the twin scroll setup and the title winning as there are many more, and far more crucial aspects and factors connected to winning the title in a time attack event such as the driver firstly and above, then comes suspension setup and tires, brake setup, gearing, and then comes the powerband. Any appropriate size either twin scroll, or single scroll turbo can do the job.
In comparison and in contradiction to a drag event where max power is of the utmost importance, and a driver has far less to do and no particular skills ,in relation to time attack, are needed apart from knowing his car and how to keep it on a straight line. Suspension setup is far simpler and there is only one type of tyres used, slicks.
If you want hard evidence with scientific data and parameters explained, ask such as the above teams to give it to you, but I do not think they will as every team has their own "recipe". I do not ask for such as I have done my own testing through the years and I know what actually is what.
Also in WRC and IIRC, most teams use single scroll turbos, such as Citroen, Hyundai , Toyota.
About the BW turbos, those housings mentioned are only the ones available to the U.S, I have a friend who is an official dealer over here of Borg Warner, and he can provide me with any housing for the s400sxe either single or twin scroll one, the same goes for any of the rest of the BW series.
Many other turbocharger manufacturers such as IHI, Holset, Garrett ,Turbonetics offer a wide range of housings for turbos of any application and purpose with the majority of them being single scroll. If single scroll was considered less efficient and inferior in any way than twin scroll then it would have become obsolete since the group B monster era where the single was still used by most teams. None of the OEM manufacturers whould create single scroll setups for their own everyday use automobiles.
This is said one last time in an effort to be understood this one. I considered single scroll and twin scroll types not so far apart in their functioning characteristics and the results they offer. The difference is that single scroll makes more max power than a twin scroll of the same size on the same engine setup. Also the single scroll lacks of nothing, boost threshold, spool time, full boost rpm point, powerband type, when setup right vs the twin scroll in any sort of racing event. What matters is the cm2 area of the housing not the type.
Marios
Many circuit setups in the time attack, btcc, european hillclimb championship and events, or any sort of time attack type championship use single scroll turbos, such as Greddy, JUN, Blitz, many european, english teams such as Norris Designs who uses a single scroll TO4Z on his evo 3 car, etc, international teams who compete in the Pikes Peak event. You ask for data but none of you have presented of anything as such apart from a dynograph ( which actually does not serve as any kind of scientific proof) and a youtube video, in which one example is used of a car that uses a twin scroll setup but there were other examples of previous years who got the title using a single scroll setup.
Besides this, there can be no actual correlation between the twin scroll setup and the title winning as there are many more, and far more crucial aspects and factors connected to winning the title in a time attack event such as the driver firstly and above, then comes suspension setup and tires, brake setup, gearing, and then comes the powerband. Any appropriate size either twin scroll, or single scroll turbo can do the job.
In comparison and in contradiction to a drag event where max power is of the utmost importance, and a driver has far less to do and no particular skills ,in relation to time attack, are needed apart from knowing his car and how to keep it on a straight line. Suspension setup is far simpler and there is only one type of tyres used, slicks.
If you want hard evidence with scientific data and parameters explained, ask such as the above teams to give it to you, but I do not think they will as every team has their own "recipe". I do not ask for such as I have done my own testing through the years and I know what actually is what.
Also in WRC and IIRC, most teams use single scroll turbos, such as Citroen, Hyundai , Toyota.
About the BW turbos, those housings mentioned are only the ones available to the U.S, I have a friend who is an official dealer over here of Borg Warner, and he can provide me with any housing for the s400sxe either single or twin scroll one, the same goes for any of the rest of the BW series.
Many other turbocharger manufacturers such as IHI, Holset, Garrett ,Turbonetics offer a wide range of housings for turbos of any application and purpose with the majority of them being single scroll. If single scroll was considered less efficient and inferior in any way than twin scroll then it would have become obsolete since the group B monster era where the single was still used by most teams. None of the OEM manufacturers whould create single scroll setups for their own everyday use automobiles.
This is said one last time in an effort to be understood this one. I considered single scroll and twin scroll types not so far apart in their functioning characteristics and the results they offer. The difference is that single scroll makes more max power than a twin scroll of the same size on the same engine setup. Also the single scroll lacks of nothing, boost threshold, spool time, full boost rpm point, powerband type, when setup right vs the twin scroll in any sort of racing event. What matters is the cm2 area of the housing not the type.
Marios
Last edited by Evo8cy; Mar 17, 2017 at 05:30 AM. Reason: typo










