Racing Beat Arguement
IMO the fact that the center port does double-duty shared by both rotors is going to play havoc with the frequency scavenging as you propose it.
if you could keep center port gases separated rotor-rotor I could maybe see that, but I'm not sure it would play out to any achievable benefit over a properly converging 3-1 merge collector. Knight Sports attempted to do it with their header, except the just merged all four into a single collector. I don't get why you'd want to keep the center pipe longer though, it strikes me as counterproductive, both from a flow and frequency tuning standpoint. Especially given the double-duty flow sharing between the two rotors and the limited flow potential of the center port as compared to the outer one for a given rotor.
The reality is on a co-shared center pipe there is a pulse in it at the same time one of the outer pipes. However the pulse in the center pipe will have a lot of frequency noise from the overlapping pulses of the other rotor. The only thing that makes sense to me over a 3-pipe with 3-1 merge is a 4-2-1 arrangement where you keep the rotor flow separate in the center port with two pipes and a dam plate, bring the center pipe and outer pipe together for each rotor so that they are merging together and filling a pipe on the same pulse, then Y-merge those together to get a maximum rotor-rotor pulse scavenging effect.
Under the 4-2-1 scenario, if the flow differential is great enough between the split center port and outer port, you might be able to use the higher flow of the outer port to add some scavenging on the split center port for a net effective total flow gain at high rpm. Again, I'm not sure that the benefit, if any, would play out for such a complex design as compared to the simpler 3-1 merge.
Like you said, you'd really have to play it out on a dyno to know for sure, not to mention that I'm guessing as to your actual design and intentions.
if you could keep center port gases separated rotor-rotor I could maybe see that, but I'm not sure it would play out to any achievable benefit over a properly converging 3-1 merge collector. Knight Sports attempted to do it with their header, except the just merged all four into a single collector. I don't get why you'd want to keep the center pipe longer though, it strikes me as counterproductive, both from a flow and frequency tuning standpoint. Especially given the double-duty flow sharing between the two rotors and the limited flow potential of the center port as compared to the outer one for a given rotor.
The reality is on a co-shared center pipe there is a pulse in it at the same time one of the outer pipes. However the pulse in the center pipe will have a lot of frequency noise from the overlapping pulses of the other rotor. The only thing that makes sense to me over a 3-pipe with 3-1 merge is a 4-2-1 arrangement where you keep the rotor flow separate in the center port with two pipes and a dam plate, bring the center pipe and outer pipe together for each rotor so that they are merging together and filling a pipe on the same pulse, then Y-merge those together to get a maximum rotor-rotor pulse scavenging effect.
Under the 4-2-1 scenario, if the flow differential is great enough between the split center port and outer port, you might be able to use the higher flow of the outer port to add some scavenging on the split center port for a net effective total flow gain at high rpm. Again, I'm not sure that the benefit, if any, would play out for such a complex design as compared to the simpler 3-1 merge.
Like you said, you'd really have to play it out on a dyno to know for sure, not to mention that I'm guessing as to your actual design and intentions.
Originally Posted by rotarygod
At Sevenstock this year I shared my header design ideas with RB for the Renesis. It utilizes 2 seperate collectors instead of 1 with the center runner being longer than the outer 2. I first posted this idea here at least 2 years ago. They said that was a combination they had never tried and they tried alot of them. They were interested in it. I saw some of their experiments in header design and learned how they tested numerous others I didn't see and talked about what combinations they tried. I fully expect them to try my idea and if by some strange reason it works, I fully would expect them to build it and sell it. I have no legal claims to it so I stand to gain nothing if they did make it work other than personal satisfaction. I wouldn't say or claim they stole my idea and they aren't bound to give me any kickbacks from it if they do build it. If I didn't want an idea of mine potentially used by others, I wouldn't have told anyone about it. The idea doesn't include the exact parameters to build it. Just an idea to try many combinations on. I'll let someone else do the research into if it works or not and in what configuration it works best in, if at all.
Last edited by TeamRX8; Dec 23, 2005 at 09:46 PM.
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I would like to see someone try the dead-branch manifold design that some siamesed cylinder engines used. Resonance can be used to affect the pulsetrain inside the siamesed runner. The dead-branch frequencies can cause a phase shift in the interference in the center runner. I think this is ultimately more effective than the dual-Y.
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From: atlanta ga
I think there is nothing wrong with criticizing Racing Beat, their products or anyone else's for that matter, nor do I think there is anything wrong with a little heated discussion from time to time. Just be aware that if your argument is weak or if you are being ugly for the sake of it you stand a good chance of having a light shone on your "brilliant" opinions.
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From: Houston
Originally Posted by zoom44
i think i saw your arrangment in the collection last year
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From: Houston
Originally Posted by TeamRX8
IMO the fact that the center port does double-duty shared by both rotors is going to play havoc with the frequency scavenging as you propose it.
I did propose the deadleg manifold to them but I doubt we'll see that as it would be a space issue.
Originally Posted by CERAMICSEAL
I think there is nothing wrong with criticizing Racing Beat, their products or anyone else's for that matter, nor do I think there is anything wrong with a little heated discussion from time to time. Just be aware that if your argument is weak or if you are being ugly for the sake of it you stand a good chance of having a light shone on your "brilliant" opinions.
don't worry, there's enough scrutiny to go around for everybody ...
.
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From: Houston
Originally Posted by Richard Paul
Guys, if you want to talk about headers open a thread on it. It isn't fair to Racing Beat to have this heading with their name on it come up all the time.
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