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Old 01-13-2012, 04:05 PM   #41
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Quote:
Originally Posted by Boost Joose View Post
As far as firing order goes, I think that is more important on a N/A application and even then I have seen both configurations with negligible differences. I'm thinking of eventually making one like this but I'm trying to figure out why I've never seen one.
You have seen one, or at least a variation on the idea - you just don't realize it.

First, firing order is everything, whether it's NA or turbo. You will understand why firing order is critical after you finish reading this, and if you still don't, then I can't help you.

The reason that N/A guys do 4-2-1 is because it alters the RPM where the best scavenging happens. Each time the exhaust valves on a cylinder open, it lets a rush of hot air down that runner, which alters the pressure along the runner and at the collector. However, that rush of air will pull a vacuum on whichever runners are connected to it at the collector.

With a 4-1, that vacuum is spread across three other pipes, and it doesn't do much good. With a 4-2-1, though, you can transfer that vacuum into only one other pipe (at the 4-2 collectors), which means that the scavenging is much more effective. (Pairing is critical, though - if you pair them wrong, one cylinder will act on the other, but by the time the first cylinder is ready to release another charge, the vacuum effect of the second cylinder will be gone. You'll end up with varying VE per cylinder, and it's all bad from there.)

After a certain point, the pulses begin to blend and the effect goes away. Once that happens, you're blending the exhaust gases twice, which isn't as good as just blending them once, so you end up with a little power lost up top. In addition, if you have all four pipes running into the same collector, at a certain RPM (fairly high) you will end up with some of the same effect that the 4-2-1s enjoy in the midrange - as the exhaust pulses begin to pick up in speed, the pressure rises in the collector to the ideal point, and you end up with a little scavenging.

There's one small problem with all of this, though: It's all naturally aspirated theory. Virtually NONE of it translates into turbos. We are pumping all of our exhaust gases into the tiniest of orifices in order to build pressure in the manifold, which is something N/A guys strive to avoid.

What you HAVE seen before is twin-scroll - same kind of idea as a 4-2-1, but for different reasons. When you dump all 4 cylinders into the same turbo collector, the exhaust pulses begin to muddle themselves fairly early on, and you don't get the impact of each pulse acting as effectively on the turbine wheel. If you separate them into proper pairs, the pulses are more directed, and it transfers more of the energy into the turbo itself. The muddling still happens, but it happens at a much higher RPM, and by that point the turbo is wound up and ready to go. If you designed a twin-scroll housing that was the same A/R as a single-scroll housing, it would spool SIGNIFICANTLY faster. Or, you can size the turbo up and get a turbo that will make a lot more power, but still spool like a smaller unit. (The difficulty/cost of proper wastegate control on a twin-scroll setup is why it's not more popular than it is, especially on smaller/cheaper turbos. Supposedly the effect is also diminished on small turbos, but I'm not sure why that is.)

It has almost nothing to do with scavenging or exhaust velocities.

If you look at F1 cars from the 80s, you will see their turbos situated at the ends of a 3" long set of headers. Once you size the turbo to the point where you are actually seeing N/A levels of pressure pre-spool, you can lengthen the headers and get some of that scavenging effect back, or something like that. The complexities of that blend of the two is something that's a little beyond me so far.

One last thing - when I think of an idea that I haven't seen before (like you and your 4-2-1 turbo header idea), I don't immediately think that I am a "great mind" or that the idea is awesome or whatever. My modus operandi is to assume that the idea is stupid, because there are lots of smart people in the world, and if the idea was a good one, it's fairly likely that someone would have already done it. I will then do a little reading to decide whether it has any merit - sometimes it does, and sometimes I will even find the same idea executed in a different platform or at a different level of motorsport (i.e. our Inconel studs, which had never been seen in a Miata before we released them, but had been used in OEM applications, NASCAR, F1, etc. for a while). Usually, in the course of that research, I will either come to realize why the idea is stupid, or realize why it's been done differently.

It's not our job to convince you that your idea is stupid - you should be able to do that yourself. If you're posting it on here, it's your job to convince us that it's NOT stupid.

Last edited by Savington; 01-13-2012 at 04:15 PM.
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Old 01-13-2012, 04:07 PM   #42
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Til
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Old 01-13-2012, 04:11 PM   #43
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Originally Posted by Boost Joose View Post
Nitro-meth.....was hoping I didn't have to spell it out.

and it's no t3.....
Don't nitromethane cars typically fill the water passages on the engines, making that small radiator cap on the side/rear of the head in the picture unnecessary?
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Old 01-13-2012, 04:12 PM   #44
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Look at the bright side, we can combine this manifold with the squid intake manifold and we have our self a party in an ugly snake pit.
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Old 01-13-2012, 04:30 PM   #45
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Originally Posted by Boost Joose View Post
What were the results of this? problems? advantages? Great minds think alike .....thanks for posting this.
The manifold resonated more than the other shorter manifolds I've tried. I had to make a very stiff brace from the motor mount to the bellhousing flange to keep the IWG actuator canister from buzzing. It has very slow spool (on a 1.6/2560) but lots of top end.


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Must be a reason why he doesn't run that manifold on his track car. :P
I don't run it because I swapped in a 1.8, and I don't have a track car.
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Old 01-13-2012, 09:08 PM   #46
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Quote:
Originally Posted by Boost Joose View Post
Nitro-meth.....was hoping I didn't have to spell it out.

and it's no t3.....
l l LOLOLOLOL

Quote:
Originally Posted by hustler View Post
Don't nitromethane cars typically fill the water passages on the engines, making that small radiator cap on the side/rear of the head in the picture unnecessary?
Dude you dumb shi how do you think they filled the water passages? that is where they poured in the banana magnesium shake


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Originally Posted by triple88a View Post
Look at the bright side, we can combine this manifold with the squid intake manifold and we have our self a party in an ugly snake pit.
Thank you for commenting on my squid intake manifold. It deserves more attention. Tim refused to build it for me because it was too revolutionary. There probably would have been a rush on squid and the koreans and japanese would have run out of snacks.
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Old 01-13-2012, 09:22 PM   #47
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Squid intake FTW!!!
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Old 01-14-2012, 01:44 AM   #48
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Originally Posted by viperormiata View Post
I don't know why this kid hasn't been banned yet. He has no idea what he's doing or any any basic knowledge of turbo cars.
----------ING THIS
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Old 01-14-2012, 01:53 AM   #49
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Originally Posted by Savington View Post
You have seen one, or at least a variation on the idea - you just don't realize it.

First, firing order is everything, whether it's NA or turbo. You will understand why firing order is critical after you finish reading this, and if you still don't, then I can't help you.

The reason that N/A guys do 4-2-1 is because it alters the RPM where the best scavenging happens. Each time the exhaust valves on a cylinder open, it lets a rush of hot air down that runner, which alters the pressure along the runner and at the collector. However, that rush of air will pull a vacuum on whichever runners are connected to it at the collector.

With a 4-1, that vacuum is spread across three other pipes, and it doesn't do much good. With a 4-2-1, though, you can transfer that vacuum into only one other pipe (at the 4-2 collectors), which means that the scavenging is much more effective. (Pairing is critical, though - if you pair them wrong, one cylinder will act on the other, but by the time the first cylinder is ready to release another charge, the vacuum effect of the second cylinder will be gone. You'll end up with varying VE per cylinder, and it's all bad from there.)

After a certain point, the pulses begin to blend and the effect goes away. Once that happens, you're blending the exhaust gases twice, which isn't as good as just blending them once, so you end up with a little power lost up top. In addition, if you have all four pipes running into the same collector, at a certain RPM (fairly high) you will end up with some of the same effect that the 4-2-1s enjoy in the midrange - as the exhaust pulses begin to pick up in speed, the pressure rises in the collector to the ideal point, and you end up with a little scavenging.

There's one small problem with all of this, though: It's all naturally aspirated theory. Virtually NONE of it translates into turbos. We are pumping all of our exhaust gases into the tiniest of orifices in order to build pressure in the manifold, which is something N/A guys strive to avoid.

What you HAVE seen before is twin-scroll - same kind of idea as a 4-2-1, but for different reasons. When you dump all 4 cylinders into the same turbo collector, the exhaust pulses begin to muddle themselves fairly early on, and you don't get the impact of each pulse acting as effectively on the turbine wheel. If you separate them into proper pairs, the pulses are more directed, and it transfers more of the energy into the turbo itself. The muddling still happens, but it happens at a much higher RPM, and by that point the turbo is wound up and ready to go. If you designed a twin-scroll housing that was the same A/R as a single-scroll housing, it would spool SIGNIFICANTLY faster. Or, you can size the turbo up and get a turbo that will make a lot more power, but still spool like a smaller unit. (The difficulty/cost of proper wastegate control on a twin-scroll setup is why it's not more popular than it is, especially on smaller/cheaper turbos. Supposedly the effect is also diminished on small turbos, but I'm not sure why that is.)

It has almost nothing to do with scavenging or exhaust velocities.

If you look at F1 cars from the 80s, you will see their turbos situated at the ends of a 3" long set of headers. Once you size the turbo to the point where you are actually seeing N/A levels of pressure pre-spool, you can lengthen the headers and get some of that scavenging effect back, or something like that. The complexities of that blend of the two is something that's a little beyond me so far.

One last thing - when I think of an idea that I haven't seen before (like you and your 4-2-1 turbo header idea), I don't immediately think that I am a "great mind" or that the idea is awesome or whatever. My modus operandi is to assume that the idea is stupid, because there are lots of smart people in the world, and if the idea was a good one, it's fairly likely that someone would have already done it. I will then do a little reading to decide whether it has any merit - sometimes it does, and sometimes I will even find the same idea executed in a different platform or at a different level of motorsport (i.e. our Inconel studs, which had never been seen in a Miata before we released them, but had been used in OEM applications, NASCAR, F1, etc. for a while). Usually, in the course of that research, I will either come to realize why the idea is stupid, or realize why it's been done differently.

It's not our job to convince you that your idea is stupid - you should be able to do that yourself. If you're posting it on here, it's your job to convince us that it's NOT stupid.
Great post Andrew
+1 on everything especially the bold part.

<3
-18psi

Last edited by 18psi; 01-15-2012 at 08:33 PM.
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Old 01-14-2012, 09:32 PM   #50
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Originally Posted by Faeflora View Post
Tim refused to build it for me because it was too revolutionary.
You are not talking about me are you?
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Old 01-15-2012, 04:58 PM   #51
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but I'm trying to figure out why I've never seen one.

Edit: Actually I have on a pro-drag SRT-4 making like 1400 hp, so maybe there's something to this.

Some of you guys need to learn to read. I know its not really written properly but its very simple to see that he said he has seen this setup not that he has one.
Why does everyone on this forum jump to bash peoples ideas if they do not include the tried and true? He didnt say the design was better he just asked why more people dont use this design. In my opinion the only reason to even consider this design is for a twin scroll turbo which im sure is used in your friends application.
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Old 01-15-2012, 08:32 PM   #52
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i made a much shorter version for my festiva when it was still 1.6 B6T. ran a 13.2 @112 in the 1/4 with a big 16g turbo attached to it. i blew up the 1.6 so i put a BP in my car and sold the manifold.


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Old 01-15-2012, 09:57 PM   #53
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Hahahahahaha.









Squid.
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Old 01-15-2012, 10:02 PM   #54
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Originally Posted by fastivab6tg25mr View Post
i made a much shorter version for my festiva when it was still 1.6 B6T. ran a 13.2 @112 in the 1/4 with a big 16g turbo attached to it. i blew up the 1.6 so i put a BP in my car and sold the manifold.
And there we have it. Solid, empirical evidence that improperly phased 4-2-1 manifolds cause engines to blow up.


Also, Boost Joose, if you're still around, welcome to Thunderdome.
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Old 01-15-2012, 10:04 PM   #55
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only *pussies* run nitrometh...

(---- dude Ive been waiting years to finally use that line and have it apply)
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Old 01-15-2012, 10:19 PM   #56
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And there we have it. Solid, empirical evidence that improperly phased 4-2-1 manifolds cause engines to blow up.


Also, Boost Joose, if you're still around, welcome to Thunderdome.
Two men enter, one man leaves.
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Old 01-15-2012, 10:30 PM   #57
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Having fought in thunderdtome, i can confirm this.
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Old 01-16-2012, 12:12 AM   #58
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it lasted 3 months...wish i could blame the manifold...
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Old 01-16-2012, 12:19 AM   #59
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Having fought in thunderdtome, i can confirm this.
Did you survive?
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Old 01-16-2012, 12:26 AM   #60
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Did you survive?
Obviously he did...
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