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Discussion Starter #1
Looking for some advice in the right direction.

Would a twin scroll manifold perform better than the Killer B ELH?


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Discussion Starter #3
Not an apples to apples comparison.


I understand but I heard Kikker B spools turbos really quick but is it as quick as a twin scroll manifold. That's my question really.
What you think Cake Eater?


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Twin scroll and Single scroll are two different turbine technologies so it's not an apples to apples comparison. They both effect turbocharger efficicncy in different ways.

First you need to understand how the turbines housings are different. Twin scroll has two seperate narrow volute openings to the turbine wheel, single scroll has one wide one. A closer look and you see the twin scroll openings are splitting the difference between the sweet spot on the turbine wheel, whereas the single scroll volute opening is centered perfectly on the turbine wheel's sweet spot.

There are obvious differences in manifold design, and I'm not going to write a dissretation here on the topic, the info is out there and has been covered many many times. I do recommend picking up a book on the subject if you really want to understand the tech behind it, as there is a lot of misinformation on the internet.

In short, a TS setup design has improved no-low load efficicncy and a SS version will provide optimized power generation. TS technology is becoming much more prevalent from the OEMs due to the need to meet fuel efficicncy standards which often come with smaller displacement.

OEMs can maintain decent response with smaller engine when going to TS technology, but what does it mean for the performance guys? Not a whole lot from our own testing. Keep in mind, turbocharger technology is not universal. In other words, we recommend single scroll technology for maximixing power potential for an EJ engine, but NOT for the FA engine. Bore, stroke, head flow, VE, etc. all play into which turbo technology is going to make best power where the engine naturally want to produce power. In other words, using a high RPM responding turbo is a bad idea on an engine that likes to make maximum power at low 5,000 RPMs.

So what we found on the EJ is that TS technology does improve fuel MPGs, low throttle input response, reduce lag 2-300 RPMs. You feel it in the seat of your pants more on a TS setup when you dip into the trottle say 6-8psi vs the same 6-8psi on a single scroll. This is exactly the point of TS. It also reduce peak power output, boost taper happens 4-500 RPMs sooner, and costs a lot more. Obvoiusly outlining the TS points out the benefits of SS. How much power increase did we see going to a SS? 40whp on a 500whp setup. To me that's a significant amount.

In a straight line the SS whoops the TS. In any power contest the SS beats the TS. If you want improved fuel efficiency or improved seat of the pants response, then TS is the option you want. Essentially it comes down to pick your poison.

There is no 'best of both worlds' and if anyone tells you otherwise, they are ill informed of how the technology works. You might hear 'with TS you need to run a bigger turbine housing' or the next size up turbo. The short of it is that both of those create more lag and you'd be at the same point you would be at using single scroll, but with a lot more added expense. Others will say turbo brand XYZ has TS tech that performs better than anyone else's. Again, you need to read between the lines here and do your homework. Looking at compressor and turbine maps will immediately show that's not the case. Not only that, no two different manufacturers make the same size turbocharger, so there can never be a true apples-to-apples comparison. It all comes down to what you're looking to get out of the setup, goals, etc. :)
 

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Discussion Starter #5
Twin scroll and Single scroll are two different turbine technologies so it's not an apples to apples comparison. They both effect turbocharger efficicncy in different ways.



First you need to understand how the turbines housings are different. Twin scroll has two seperate narrow volute openings to the turbine wheel, single scroll has one wide one. A closer look and you see the twin scroll openings are splitting the difference between the sweet spot on the turbine wheel, whereas the single scroll volute opening is centered perfectly on the turbine wheel's sweet spot.



There are obvious differences in manifold design, and I'm not going to write a dissretation here on the topic, the info is out there and has been covered many many times. I do recommend picking up a book on the subject if you really want to understand the tech behind it, as there is a lot of misinformation on the internet.



In short, a TS setup design has improved no-low load efficicncy and a SS version will provide optimized power generation. TS technology is becoming much more prevalent from the OEMs due to the need to meet fuel efficicncy standards which often come with smaller displacement.



OEMs can maintain decent response with smaller engine when going to TS technology, but what does it mean for the performance guys? Not a whole lot from our own testing. Keep in mind, turbocharger technology is not universal. In other words, we recommend single scroll technology for maximixing power potential for an EJ engine, but NOT for the FA engine. Bore, stroke, head flow, VE, etc. all play into which turbo technology is going to make best power where the engine naturally want to produce power. In other words, using a high RPM responding turbo is a bad idea on an engine that likes to make maximum power at low 5,000 RPMs.



So what we found on the EJ is that TS technology does improve fuel MPGs, low throttle input response, reduce lag 2-300 RPMs. You feel it in the seat of your pants more on a TS setup when you dip into the trottle say 6-8psi vs the same 6-8psi on a single scroll. This is exactly the point of TS. It also reduce peak power output, boost taper happens 4-500 RPMs sooner, and costs a lot more. Obvoiusly outlining the TS points out the benefits of SS. How much power increase did we see going to a SS? 40whp on a 500whp setup. To me that's a significant amount.



In a straight line the SS whoops the TS. In any power contest the SS beats the TS. If you want improved fuel efficiency or improved seat of the pants response, then TS is the option you want. Essentially it comes down to pick your poison.



There is no 'best of both worlds' and if anyone tells you otherwise, they are ill informed of how the technology works. You might hear 'with TS you need to run a bigger turbine housing' or the next size up turbo. The short of it is that both of those create more lag and you'd be at the same point you would be at using single scroll, but with a lot more added expense. Others will say turbo brand XYZ has TS tech that performs better than anyone else's. Again, you need to read between the lines here and do your homework. Looking at compressor and turbine maps will immediately show that's not the case. Not only that, no two different manufacturers make the same size turbocharger, so there can never be a true apples-to-apples comparison. It all comes down to what you're looking to get out of the setup, goals, etc. :)


So what you're saying is, basically, on drag the SS is more of an advantage but on street dd the TS is a better advantage.


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Someone correct me if I'm wrong, the cost was alluded to but I don't think this was stated outright - there is also the consideration that going twin scroll requires replacement of almost all the exhaust plumbing (plus a twin scroll specific turbo) vs if you really wanted to you could replace the factory exhaust manifold with an ELH, may as well replace the downpipe at that point, but could run OEM turbo, uppipe, and catback.

Buying a car that comes twin scroll is one thing - as mentioned, it helps balance the power gains vs the common turn-offs that cause people to complain about factory turbo cars (fuel economy and laggy throttle response). However, when beginning with a single-scroll OEM setup, my understanding is there are more cost-effective gains to be had vs converting to twin scroll.
 

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welcome to the internal debate i have with myself every day. My version 8 EJ207 swap is twinscroll from the factory and should be running within a few months (C'mon weather!). Interested to see how it feels compared to the EJ25. Down the road i want to go bigger turbo and have yet to decide what route to go...
 

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Twin scroll and Single scroll are two different turbine technologies so it's not an apples to apples comparison. They both effect turbocharger efficicncy in different ways.

First you need to understand how the turbines housings are different. Twin scroll has two seperate narrow volute openings to the turbine wheel, single scroll has one wide one. A closer look and you see the twin scroll openings are splitting the difference between the sweet spot on the turbine wheel, whereas the single scroll volute opening is centered perfectly on the turbine wheel's sweet spot.

There are obvious differences in manifold design, and I'm not going to write a dissretation here on the topic, the info is out there and has been covered many many times. I do recommend picking up a book on the subject if you really want to understand the tech behind it, as there is a lot of misinformation on the internet.

In short, a TS setup design has improved no-low load efficicncy and a SS version will provide optimized power generation. TS technology is becoming much more prevalent from the OEMs due to the need to meet fuel efficicncy standards which often come with smaller displacement.

OEMs can maintain decent response with smaller engine when going to TS technology, but what does it mean for the performance guys? Not a whole lot from our own testing. Keep in mind, turbocharger technology is not universal. In other words, we recommend single scroll technology for maximixing power potential for an EJ engine, but NOT for the FA engine. Bore, stroke, head flow, VE, etc. all play into which turbo technology is going to make best power where the engine naturally want to produce power. In other words, using a high RPM responding turbo is a bad idea on an engine that likes to make maximum power at low 5,000 RPMs.

So what we found on the EJ is that TS technology does improve fuel MPGs, low throttle input response, reduce lag 2-300 RPMs. You feel it in the seat of your pants more on a TS setup when you dip into the trottle say 6-8psi vs the same 6-8psi on a single scroll. This is exactly the point of TS. It also reduce peak power output, boost taper happens 4-500 RPMs sooner, and costs a lot more. Obvoiusly outlining the TS points out the benefits of SS. How much power increase did we see going to a SS? 40whp on a 500whp setup. To me that's a significant amount.

In a straight line the SS whoops the TS. In any power contest the SS beats the TS. If you want improved fuel efficiency or improved seat of the pants response, then TS is the option you want. Essentially it comes down to pick your poison.

There is no 'best of both worlds' and if anyone tells you otherwise, they are ill informed of how the technology works. You might hear 'with TS you need to run a bigger turbine housing' or the next size up turbo. The short of it is that both of those create more lag and you'd be at the same point you would be at using single scroll, but with a lot more added expense. Others will say turbo brand XYZ has TS tech that performs better than anyone else's. Again, you need to read between the lines here and do your homework. Looking at compressor and turbine maps will immediately show that's not the case. Not only that, no two different manufacturers make the same size turbocharger, so there can never be a true apples-to-apples comparison. It all comes down to what you're looking to get out of the setup, goals, etc. :)


You just made me rethink my whole future build..dammit man!! I wanted ts for the quick response and from what I believe a rarity of the setup(haven't seen or heard of too many ts builds, stupid reason I know). But I want POWER plain and simple, so from what I'm understanding sacrifice quick spool for big power with a ss setup?

Those bw efr's seem really nice btw. 8374 spools around 3800-4k rpm capable of 650+ on a built motor(if you build it power will come). I want to track the car and drag it

I have to read up and find out how much power a ts leaves on the table vs a ss..
 

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You just made me rethink my whole future build..dammit man!! I wanted ts for the quick response and from what I believe a rarity of the setup(haven't seen or heard of too many ts builds, stupid reason I know). But I want POWER plain and simple, so from what I'm understanding sacrifice quick spool for big power with a ss setup?

Those bw efr's seem really nice btw. 8374 spools around 3800-4k rpm capable of 650+ on a built motor(if you build it power will come). I want to track the car and drag it

I have to read up and find out how much power a ts leaves on the table vs a ss..
From my above post. This was the same exact setup with the only variables being the turbine housing and manifold.

So what we found on the EJ is that TS technology does improve fuel MPGs, low throttle input response, reduce lag 2-300 RPMs. You feel it in the seat of your pants more on a TS setup when you dip into the trottle say 6-8psi vs the same 6-8psi on a single scroll. This is exactly the point of TS. It also reduce peak power output, boost taper happens 4-500 RPMs sooner, and costs a lot more. Obvoiusly outlining the TS points out the benefits of SS. How much power increase did we see going to a SS? 40whp on a 500whp setup. To me that's a significant amount.

The GTX Gen IIs are an even more efficient product making more power with the same spool characteristics. If I were in your shoes, I would wait on the next G-series turbos to be released :)
 

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Discussion Starter #11
You just made me rethink my whole future build..dammit man!! I wanted ts for the quick response and from what I believe a rarity of the setup(haven't seen or heard of too many ts builds, stupid reason I know). But I want POWER plain and simple, so from what I'm understanding sacrifice quick spool for big power with a ss setup?



Those bw efr's seem really nice btw. 8374 spools around 3800-4k rpm capable of 650+ on a built motor(if you build it power will come). I want to track the car and drag it



I have to read up and find out how much power a ts leaves on the table vs a ss..


For the same reason I asked the question. My BMW track conrades all changes from SS to TS setup with EFR turbos and their drag times went lower.
I realise in the end it all comes down to what you want personally and just go with it.
If you are comparing the TS and SS running the same turbo the twin scroll will spool faster by couple hundred rpms where it's street or drag. You just have to decide on what you want and just go with it.
I'm going to switch to the TS setup as I wanted because I'm not too happy with the KillerB header. Many people are happy with the KillerB header but I'm just not one of them.


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So what you're saying is, basically, on drag the SS is more of an advantage but on street dd the TS is a better advantage.
Depends on whether you drive your car in it's efficiency range. If you insist on NOT doing that, it's at least partly your problem. The difference Chris related were a few hundred RPM, not thousands - IE you can't be complaining about a SS, switch to a TS and believe there was a engine swap with a big block.
 

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For the same reason I asked the question. My BMW track conrades all changes from SS to TS setup with EFR turbos and their drag times went lower.
I realise in the end it all comes down to what you want personally and just go with it.
If you are comparing the TS and SS running the same turbo the twin scroll will spool faster by couple hundred rpms where it's street or drag. You just have to decide on what you want and just go with it.
I'm going to switch to the TS setup as I wanted because I'm not too happy with the KillerB header. Many people are happy with the KillerB header but I'm just not one of them.


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Your right, it's your car and you do what makes you happy. No build will/should be the same imo. What don't you like about the kb headers?
 

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Discussion Starter #15
Your right, it's your car and you do what makes you happy. No build will/should be the same imo. What don't you like about the kb headers?


Mine warped and I wasn't too happy with it. That's it in a nutshell.


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KB wouldn't cover warping? Header's not the most difficult thing to replace . . .

There's a story here ?
 

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KB wouldn't cover warping? Header's not the most difficult thing to replace . . .



There's a story here ?


Chris from KillerB sent me a message about it but I've already decided to go TS. The only thing that surprised me was I didn't even do any track time. I know I didn't baby it though.


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Nothing is perfect. Thank em, give em props for covering it?




conrades all changes from SS to TS setup with EFR turbos and their drag times went lower.
So different turbos . . .


I realise in the end it all comes down to what you want personally and just go with it.
For your car? Sure. For what is actually better? Not so much - not that there aren't trade-offs to evaluate.

If you are comparing the TS and SS running the same turbo the twin scroll will spool faster by couple hundred rpms where it's street or drag.
Which would performance-wise be a good thing generally all else being equal. But it isn't.

From What Chris relates SS ought to fare better in drag . . .
 

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The GTX Gen IIs are an even more efficient product making more power with the same spool characteristics. If I were in your shoes, I would wait on the next G-series turbos to be released :)
This is my plan... Just waiting for their next size to be released... and for KillerB to mate one to a Spoolinator :) I think the GT25 - 660 is a bit small for my power goals.
 

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