Back to topic -

Just talking theory here, but if the exhaust manifolds/headers just dumped to the open atmosphere(not considering sound regulations or emissions issues), how would the efficiency of such a system compare an exhaust with full tubing?

Would the short distance to travel overcome the rapid cool-down effects, and the positive effects of the tubing?

 

OK, so here are my diagrams of how I think the different pipe setups operate.



The first is a Y pipe. The flow through this type of piping would have the each pulse line up right behind the other. A problem to this could be the volume of each pulse in relation to the volume between each pulse, which we dont currently have any info on.

The second diagram is an X pipe running with ideal flow. Each pulse would go through the X and would weave perfectly between the opposite flow.

The third... if this type of flow is possible, then we have a problem. If the pulses were to enter the cross section at the same time, they would collide. This could result in diagram 5, or some mixture of flow #2 and #5. If the flow does not weave perfectly, it would create a mess in this section of the exhaust and possible impede flow.

The 4th diagram is an H pipe. The design is simple... as the exhaust flows through both sides, the air in the middle section could travel left or right to balance the pressure as each pulse goes by.

The 5th diagram would be when exhaust pulses from each side dont weave correctly. The pulses would instead push on eachother and go straight down. The problem with this is that instead of a balance of pressure, you are getting pulses that are fighting for space.

To think that a Y pipe cannot line pulses up, means that diagrams #3 and #5 are also possible. Given this, how does an X perform better than a Y?

Comments and further elaboration on this is welcome.

 

I think that dumping the exhaust after the headers would be ideal for peak power. For peak power, dumping after the headers should minimize restriction to the header tubing and would still preserve the vacuum effect.
However, I have no idea how this would perform in the lower RPM range. Would it perform the same as if we were to use full piping? I would imagine that it would still be better because we are still cutting out all of the pulse mismatching and negative waves/resonance that is present with a full high flow system.

Which vacuum effect is greater? the vacuum caused my other pulses through a tube, or if the vacuum was the atmosphere ? (each chamber would have its own small exhaust tube straight into the atmosphere.)
Worded differently... could we get lower than atmospheric pressure inside an exhaust tube?

 

Such a short exhuast would ruin the power band for anything but full on wot at high rpm. One has to understand that's exhaust gas velocity. And it's this velocity that helps "pull" the gasses and helps it out of the engine. When you have a long train of pulses going down a tube, they all help push/pull the others along. Sorta like NASCAR drafting. A line of cars can actually travel faster than just a single car. And the cars behind the lead car, can go faster or travel the same speed with less energy. When you dump the exhaust into the air right after the header, they just stop. And the rest will just stop. Sorta like when you stand in a long line that moving slowly. Then one person stops. Everyone behind that person bumps into the person in front of them.

 

^true... and good example... but that would only be the case if we can confirm that the vacuum caused by the pulsating behavior of the exhaust is greater than the vacuum created when an explosion/exhaust pulse is directed to open atmosphere through a single pipe independent of any of the other exhaust pulses.
Otherwise, it could be like a bunch of people running in a line alongside 30mph winds. Individually they could run faster, but in a line they are limited to the speed of the person in from of them. Sorry, I couldnt think of an example as good as yours...

 

Could it just be as simple as space under the car, cost of one pipe/muffler vs two and style?
I don't know about gas flowing thru a pipe but I do know that 500gpm of water can be flowed through 1 - 3in or 2 - 2 1/2in firehoses

 

Buddy... over and over again, you kept dodging the question, and you started bashing him when he asked if you can stop dodging the question and just give him a straight answer. Implying that he was stupid and couldnt understand you... when actually, we all understood you perfectly well. And we also understood that you werent addressing the question.

The problem? The problem is that I'm also a salesman, and a business man... and being so, I can sniff out bullsh*t a mile away. My intentions werent to make him look good. My intentions was to show how much of a jerk you were being. Its sad to say, but I have to agree with trey.hutcheson... I also used to respect you. I believed that you knew your stuff, and were a respectable forum member. Unfortunately, as Clean G 4D said... believing is one thing, and knowing is another. Now I know better.

Please save whatever thread of respect you have left, address the technical question in a technical manner, and leave all condescending and childish behavior out. Asside from that, ISMSOLUTIONS, thank you for the knowledgeable input you have provided.

 

I can clarify my statements easily. Ever experience a bad exhaust leak near the headers? Low end performance suffers greatly. If my theory wasn't sound, one would not experience a loss of low end performance at all. But it happens. It happened on my maxima. The Y pipe comes together into a flex section. This section broke and was leaking. Performance suffered noticably.

 

Mandrel bent tubing in many sizes up to 4". Not difficult to find at all.
http://www.mandrelbending.com/stock.htm

 

I noticed... Thanks, I did the same from that point forward.

I think my questions were fairly straight forward, however they were not easy questions to answer. But, maybe I should have stressed more that I wanted to get detailed information on how and why.

Well, thats not correct. I did think your info was good. However most of the original info posted did not address the questions that started this thread.

The first portion didnt answer my questions, however the later portion was useful.

The knowledge I seek may have to come from R&D, but that doesnt have to done by me if someone who has done the R&D would elaborate more on the details.
As I said earlier, I do believe it is better. However, I want to KNOW why and how it is better. The answers "flow and balance" can be found without starting this thread. I wanted to find out why/how the flow and balance made a difference.

I have yet to find an article regarding dual exhausts and the process of balancing pressure in comparison to a single exhaust. To believe what people say would require you to have trust in them to have the correct info. The problem with that is you would not know if the info they base their claims from is correct. I trust facts. You are a trustworthy source in this realm and so I do believe your claims to be true, however that does not quench my curiosity to know why.


Overall, I am disappointed to see you go, since we had only recently begun to address the issues.

 

Ah, I see. I have never been in that situation, so I cant compare.

I guess you would be totally correct to say that overall performance suffered due to the leak.
I re-read and see that you already mentioned this scenario (However, how was the peak performance? I would imagine that at the highest RPM's, the engine would need to breathe the most and therefore require less exhaust restriction to perform optimally. Since oem and aftermarket exhaust systems are designed to promote overall performance, they would still be restrictive at peak RPM's.)

I wonder what #'s we would see at peak power for our engines...

Sorry if I seemed inclined to argue with you, but I want to be sure that we covered all the bases.

 

I thanked you for the information you provided... and I'll thank you again. As far as removing your posts... Smart move. If I had something to hide, I'd do the same. I'd also hate to lose whatever respect I had left with the community if I was a forum sponsor. As for agreeing with your answers? That wasnt even the issue. You never gave a straight answer that addressed the question. As for finding an answer, as I said ealier... I know Gurgen will know. Hes helped many of us, and myself many times. The actual burden was for me to try and make you understand how you danced around the question and never really answered it. Unfortunately, it seems that I have failed you... and I'm sorry Rick.

 

What you have done is failed this forum and thread. By coming back at me, like above, and insinuating that I purposely evaded giving an answer, is ludicrous.

The fact that you seemingly want a scientifically noted version of the answer, that was never specified in your requests, is why you didn't get that kind of response.

Can I give you that kind of answer? No...and I wouldn't have tried to do anything else, if that was the kind of answer you were looking for from the beginning - but again, that was never specified.

Knowing how to ask a question properly, to get the answer your looking for...is key. Bashing those who try to legitimately answer an improperly formed question, is inappropriate and just plain rude.

The only thing I am sorry for, is how I was forced to defend myself when I was being attacked and flamed for no apparent reason, and having to stoop to the lower level to do so.

I have sent CLEAN a PM, yesterday, and am trying to work that out, as I believe he truly has good intentions in all of this and I do understand where he is coming from, NOW.

I can't afford you the same courtesy, for this I am sorry as well, but only to this forum and thread, not you.

Rick

 

You bashed CLEAN first, and insulted his intellegence. I was just pointing that out, in hopes that you would stop.

I'm glad to hear that. He defintely deserves an apology from you.

Your immature behaviors made all respect I had for you dwindle to nothing. I dont care for your courtesy... but as I said before... at least you PMed CLEAN and apologized. Durring this whole mess, I'm glad you showed at least one sign of maturity. For that, I aplaud you. Please let this drama you created die now, and dont bother trying to reply or bash anyone else. Thank you, and good day sir.

 

SILVERBOLT -

Your the master of assumption - you have no idea what the discussions CLEAN and I have had over the last 2 days with you out of the way...and I didn't apologize either.

I chose to have discussion with him away from the drama king, you, and everything seems to be fine now.

He and i will continue our discussion in private - and as I told him, you are now on my ignore list.

After all - he and I are being very civil to each other now ...

Rick