Red2000SS

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 01-Z:

Any reply?
This alone will dissuade me from buying these.</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Every header made for the LS1 has this same problem. If this dissuades you from buying these headers, you shouldn't buy any LS1 headers. <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />

Each header is connected to 4 cylinders. Ideally, the primary tube leading from each cylinder would be the same length, and each connected cylinder would fire at a fixed degree offset from the other cylinders connected to the same header. Unfortunately the LS1 has a non symmetric firing order - I don't know it off the top of my head, but I'm sure someone does.

This is the key thing you are missing.

thechef

iTrader: (13)

barry if ya need a healthy ls1 for dyno testing let us know at East Side Performance we would love to test your new set up and i will donate my car as a test vehicle let me know <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Quick Time

iTrader: (1)

The primaries are just fine. If they were not then they would not be the highest hp header out there. I have updated the design with the turbulance spike and using stainless steel. Rapid Motorsports pulled 440+hp with my header and there stage 2 package. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

I will be offereing a step header. 1 5/8- 1 3/4 and 1 3/4- 1 7/8. Call for pricing.

Gary Z

Red2000SS, Thanks for your very clear comments. I now think I understand Ferris Ulf’s claim. Cylinders 1 and 3 on the driver’s side are related in the same way as are cylinders 2 and 6 on the passenger side. The tubes from 2 and 6 enter their collector side-by-side while 1 and 3 enter their collector diagonally. Thus the 1-3 tube centers are square-root of 2 farther apart than the 2-6 tube centers. I find it difficult to believe that this makes a significant difference. BTW, the firing order is: 1-8-7-2-6-5-4-3-1...

And Barry, if I didn't need to pass California emissions, I would order a set today.

<small>[ March 11, 2003, 03:14 PM: Message edited by: Gary Z ]</small>

BTL FED

iTrader: (9)

Is there any way to get a 1 7/8 header with Air/EGR, I cannot seem to find any anywhere.
Thanks

02 WS6 Silver Bird

TTT

Z06PSI

iTrader: (33)

GaryZ you could order me a set... <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Quick Time

iTrader: (1)

Any combo can be made. Just have the most popular styles on the site listed. Call me for a set you dont see listed on the site.

The Juggernaut

iTrader: (7)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Red2000SS:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 01-Z:

Any reply?
This alone will dissuade me from buying these.</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Every header made for the LS1 has this same problem. If this dissuades you from buying these headers, you shouldn't buy any LS1 headers. <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />

Each header is connected to 4 cylinders. Ideally, the primary tube leading from each cylinder would be the same length, and each connected cylinder would fire at a fixed degree offset from the other cylinders connected to the same header. Unfortunately the LS1 has a non symmetric firing order - I don't know it off the top of my head, but I'm sure someone does.

This is the key thing you are missing. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">This makes perfect sense,I want Barry to set my mind
at ease.
I don't know why it would make a difference,
I would just like the arguement settled.
Any chance of getting a 1 3/4 stepped? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Fenris Ulf

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Gary Z:
<strong> Red2000SS, Thanks for your very clear comments. I now think I understand Ferris Ulf’s claim. Cylinders 1 and 3 on the driver’s side are related in the same way as are cylinders 2 and 6 on the passenger side. The tubes from 2 and 6 enter their collector side-by-side while 1 and 3 enter their collector diagonally. Thus the 1-3 tube centers are square-root of 2 farther apart than the 2-6 tube centers. I find it difficult to believe that this makes a significant difference. BTW, the firing order is: 1-8-7-2-6-5-4-3-1...

And Barry, if I didn't need to pass California emissions, I would order a set today. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yes it does make a difference.

Yes those are the most powerful headers out, but they could be better. Barry told a friend of mine over an email that it would not be cost-effective to improve on this five-year old design. Oh well.

Gary Z

Ferris, I was just trying to be polite when I said “difficult to believe”. Without any explanation you are sneering at everyone who doubts your preposterous assertion that the driver’s side makes more power than the passenger side. I do sympathize with the difficulty of explaining matters as complex as gas flow and the still greater difficulty of explaining something that is not true.

<small>[ March 12, 2003, 08:13 AM: Message edited by: Gary Z ]</small>

CHRISPY

What is the cost for the race header with merge collectors?
What primary size would you recommend for a 360 ci motor?

Will header extension (proper length) hurt very much with the merge collectors?

thanks!!
Chris

<small>[ March 12, 2003, 08:51 AM: Message edited by: Chris ARE 360 ]</small>

Speedfreaks101

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Fenris Ulf:
<strong> Barry, the passenger side header is improperly phased. See if you can get the bottom two primaries swapped (#'s 6 and 2). Otherwise they are looking good <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> How did you decide on the vena contracta diameter of the merge collector and the expansion angle? What rev range are you looking to improve? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Ferris I am not trying to flame when I ask this, what headers are you using? Also what reading material would you recommend to learn more on exhaust dynamics and headers design?
Thanks,
Bart

RAGEman

iTrader: (4)

I don't think Fenris Ulf is arguing that Barry's headers aren't the best out there, if you'll go back and look. He's saying that IF they changed the design, they COULD be better. And that would apply to any LS1 longtubes out there, I would think. I'm glad he brought it up, because maybe now someone will start working on that. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Fenris Ulf

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by RAGEman:
<strong> I don't think Fenris Ulf is arguing that Barry's headers aren't the best out there, if you'll go back and look. He's saying that IF they changed the design, they COULD be better. And that would apply to any LS1 longtubes out there, I would think. I'm glad he brought it up, because maybe now someone will start working on that. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thanks for reading my post at face value Alan <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> I was never trying to flame QTP of any of the other Grotyohann header clones, just point out something to improve the design.

Fenris Ulf

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Gary Z:
<strong> Ferris, I was just trying to be polite when I said “difficult to believe”. Without any explanation you are sneering at everyone who doubts your preposterous assertion that the driver’s side makes more power than the passenger side. I do sympathize with the difficulty of explaining matters as complex as gas flow and the still greater difficulty of explaining something that is not true. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">My assertion is not preposterous, sorry you feel that way. Properly phasing a header is not something that would show up on a flowbench or anything like that. If you want a visual aid to understand what I am talking about, which is what I gather from your tone <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> , fill up a 2L bottle with water. Time two trials: one where you simply uppend the bottle and another where you swirl the bottle once its upside down to get the fluid spinning when it comes out. The swirl creates a velocity distribution that better fills the bottles neck shape and will show a significant improvement in flowrate. The dynamics going on in the bottle are not exactly what is going on in a header collector obviously, but that was the best simple example I can think of.

Difficulty of explaining something that isn't true? LOL, don't get your panties up in a wad. If you are still having doubts why don't you pick up the phone and talk to LG, he can explain all of this to you in terms you might understand.

Gary Z

Ferris, I admit it did not occur to me that swirl might be a significant factor. On the other hand, you didn’t mention swirl until challenged. I objected to your unsupported nattering about QTP’s supposedly obsolete design. My reasoning was as follows: The individual tubes enter the collector in a square pattern. In a square pattern each tube is adjacent to each of the other three. Rearranging which tube occupies which quadrant can not significantly alter scavenging. So I thought, so I still think. I am aware that my reasoning ignores the "turbulence spike". Interesting discussion. Beautiful headers. No hard feelings.

-Gary

<small>[ March 12, 2003, 04:03 PM: Message edited by: Gary Z ]</small>

ws6-speed

Um..actually, the reason that a swirled 2 liter bottle of liquid comes out faster has nothing to do with the fluid velocity or swirling per se. It has to do with the fact that the swirling motion creates a small "hole" in the opening in the bottle, through which air can enter and displace the fluid. In a "non-swirling" bottle, the air has to first break through the liquid's interfacial tension and then through the liquid itself until it gets to the top of the bottle and can then displace fluid out of the bottle.

I don't have a clue about exhaust gasses, but Fenris' notes due make sense. If the drivers side is designed that way, the passenger side should be as well.

Russ

Chris99WS6PWTMET

These in-depth physics theories concerning these headers is great and all but what I really want to know is:

Will these headers fit on a lowered car? What is the measured amount of ground clearance at each collector (which tube goes where, in what order is irrelevant for this question)? <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Thanks

Red2000SS

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Gary Z:
<strong> Red2000SS, Thanks for your very clear comments...


BTW, the firing order is: 1-8-7-2-6-5-4-3-1...

</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thanks for the firing order by the way - I knew someone would know it off the top of their head.

The problem is the firing order is not symmetric - it doesn't alternate from left to right, so the exhaust pulses in a single header are not evenly spaced in time with respect to the crank rotation.

In a V8 the spark is fired exactly 90 degrees after the previous cylinder regardless of firing order. In a symetric firing order, for a given side of the engine, the spark is fired exactly 180 degrees after the previous cylinder on the same bank. Imagine a firing order of 1-2-3-4-5-6-7-8, for the driver side header the exhuast pulses for the left side header would be 1-3-5-7 exactly 180 degrees apart, and for the right header would be 2-4-6-8 exactly 180 degrees apart.

The LS1 does not have a symmetric firing order...
Looking at the driver side header: cylinder 1 fires, then 7 fires 180 degrees later, then 5 fires 270 degrees later, then 3 fires 180 degrees later, then 1 fires 90 degrees later - the exhaust pulses will not be timed for maximum scavenging. The only optimum way for equal length headers would be for the headers to cross-over - have the exhaust tube from certain cylinders cross-over and enter the header on the other side. Yikes! <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> - I would hate to have to install headers like that... There is a reason all the headers for the LS1 are the way they are.

<small>[ March 12, 2003, 11:53 PM: Message edited by: Red2000SS ]</small>