X vs. Y vs. H =mc2 ?
Re: X vs. Y vs. H =mc2 ? I am strongly considering building another custom exhuast for my Camaro. I had a dual exhaust custom built (horrible construction) that flowed like crap and looked even uglier. It scraped the ground on every bump....but it sounded awesome. There was no drone and NO RASP at all. It consisted of 2.5" crush bent pipe with a custom x-pipe (crap) and two Dynomax bullets. A little too loud for my taste.
I am now considering ordering this:
http://www.jegs.com/photos/50018813.jpg
I will have this custom mated to the 2.5" MAC y-pipe so that the x-pipe is located under the transmission crossmember. I will use 2.5" chambered mufflers instead of the bullets...one tucked into the stock intermediate pipe location, and the other packed tightly into the space beside the torque arm (may require relocating fuel lines) with turnouts before the rear-end housing. I will also install a set of Carsound cats at the stock locations. I think it will be very tame, yet still offer all of the advantages of a loud and freeflowing exhaust.
It will take some time and ingenuity to get it to fit like I want it to. I will be spending the next few weeks designing the system and finding the best way to route it while maintaining stock ground clearance. Cost should be around $500 installed, but I think it will be worth it. That's less than a GMMG cat-back and there will also be considerable weight savings.
I am now considering ordering this:
http://www.jegs.com/photos/50018813.jpg
I will have this custom mated to the 2.5" MAC y-pipe so that the x-pipe is located under the transmission crossmember. I will use 2.5" chambered mufflers instead of the bullets...one tucked into the stock intermediate pipe location, and the other packed tightly into the space beside the torque arm (may require relocating fuel lines) with turnouts before the rear-end housing. I will also install a set of Carsound cats at the stock locations. I think it will be very tame, yet still offer all of the advantages of a loud and freeflowing exhaust.
It will take some time and ingenuity to get it to fit like I want it to. I will be spending the next few weeks designing the system and finding the best way to route it while maintaining stock ground clearance. Cost should be around $500 installed, but I think it will be worth it. That's less than a GMMG cat-back and there will also be considerable weight savings.
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Re: X vs. Y vs. H =mc2 ? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Speedfreaks101:
<strong>This was my reply in a very similar post, so here is my .02.
"Ok I think that the Y pipe will make more power, here is why. If you study exhaust theory you will find that you have a positive and negative exhaust pulse. The negative pulse is a return pressure wave that travels back up the exhaust stream (exhaust pipe) and helps with scavenging. Next you have people comparing X pipe and crossovers, well I think most people miss the boat. An x pipe works so well because it allows the exhaust to use both negative exhaust pulses on both engine banks. If you were to use a Y pipe that was sized accordingly you will see at least the same amout of power as the x pipe if not more (because of the stronger negative pressure wave by only using one exhaust pipe.) The reason so many people are not satisfied with a Y pipe is because they are sized wrong. If you were to have a Y pipe exhaust that would have the same volume as a 2.5 true dual exhaust you would need 2.5 inch tubes in to the Y pipe and a 3.5 in your I pipe. Also I do not like crossflow mufflers, try to stay with a strait through design (Dynomax Ultraflo, Magnaflow). As a side note you can take advantage of the X pipe effect with a Y pipe and you can still us a balance tube on the end of the header collectors."
Later,
Bart</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">How is the negative pressure wave stronger when you use only one pipe? Assuming steady flow, the magnitude of the pulse is related to the cross-sectional area which is the same in both cases right?
<strong>This was my reply in a very similar post, so here is my .02.
"Ok I think that the Y pipe will make more power, here is why. If you study exhaust theory you will find that you have a positive and negative exhaust pulse. The negative pulse is a return pressure wave that travels back up the exhaust stream (exhaust pipe) and helps with scavenging. Next you have people comparing X pipe and crossovers, well I think most people miss the boat. An x pipe works so well because it allows the exhaust to use both negative exhaust pulses on both engine banks. If you were to use a Y pipe that was sized accordingly you will see at least the same amout of power as the x pipe if not more (because of the stronger negative pressure wave by only using one exhaust pipe.) The reason so many people are not satisfied with a Y pipe is because they are sized wrong. If you were to have a Y pipe exhaust that would have the same volume as a 2.5 true dual exhaust you would need 2.5 inch tubes in to the Y pipe and a 3.5 in your I pipe. Also I do not like crossflow mufflers, try to stay with a strait through design (Dynomax Ultraflo, Magnaflow). As a side note you can take advantage of the X pipe effect with a Y pipe and you can still us a balance tube on the end of the header collectors."
Later,
Bart</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">How is the negative pressure wave stronger when you use only one pipe? Assuming steady flow, the magnitude of the pulse is related to the cross-sectional area which is the same in both cases right?
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Joined: Nov 2001
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From: Indianapolis
Re: X vs. Y vs. H =mc2 ? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> We've done one cam only LS1 with an H as well and it dyno'd 407 rwhp. Stock heads. Not too shabby, but I didn't get a chance to see the curve. Torque was good too.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I remember (from my Cobra days) that a guy did a direct comparison from an O/R H pipe to an O/R X pipe and they made similar numbers up high, but the H pipe had a lot of low end tq. over the X.
I'd like to see more H pipe results. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I remember (from my Cobra days) that a guy did a direct comparison from an O/R H pipe to an O/R X pipe and they made similar numbers up high, but the H pipe had a lot of low end tq. over the X.
I'd like to see more H pipe results. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Re: X vs. Y vs. H =mc2 ? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by jawsk2:
<strong>Lane, do these duals that you are building have any problem with banging or rattling? They look perfect, and I wish you were in Houston!</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I don't on my car whatsoever. My 3" custom Y was aweful.. The duals don't seem to 'twist' under torque like the Y's, so we've been able to get closer under the drivers side for more ground clearance w/out issue. However, we'll soon be using these for added clearance if some choose. It does up the cost a bit.
<img src="http://www.drgas.com/photos/gfx/frameclearancetube.jpg" alt=" - " />
<strong>Lane, do these duals that you are building have any problem with banging or rattling? They look perfect, and I wish you were in Houston!</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I don't on my car whatsoever. My 3" custom Y was aweful.. The duals don't seem to 'twist' under torque like the Y's, so we've been able to get closer under the drivers side for more ground clearance w/out issue. However, we'll soon be using these for added clearance if some choose. It does up the cost a bit.
<img src="http://www.drgas.com/photos/gfx/frameclearancetube.jpg" alt=" - " />
Re: X vs. Y vs. H =mc2 ? I had a customer with this system here:
<img src="http://www.dfwstangs.net/hosting/Lane/gregtd2.jpg" alt=" - " />
dyno his cam only/bolt-on car with the Hooker Y(open, no cat-back) and the car made 391 peak rwhp and 369 rwtq. That's with an OPEN Y, not very pleasant sounding. Then he dyno'd with the 3" X with 12" bullets as pictured above and got the same peak power of 391 rwhp, but picked up 12 rwtq to 381. However, at 5000 rpms, the X was good for 17 rwhp OVER the open Y. My car and every other car I've seen with an X is the same way. A higher, flatter power band. My car is at peak power from 5300-6300 rpms.
We've done one cam only LS1 with an H as well and it dyno'd 407 rwhp. Stock heads. Not too shabby, but I didn't get a chance to see the curve. Torque was good too.
IMO - the X sounds more 'refined' and probably gives you a flatter power band over the H. The H sounds nasty and mean, as well as louder. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> From my Mustang days, there were always big debates about the X vs H - and they seemed pretty even most of the time. ANYTHING is better than the Y to me. I'll NEVER go back to the Y set-up..
<small>[ October 18, 2002, 12:14 PM: Message edited by: Lane ]</small>
<img src="http://www.dfwstangs.net/hosting/Lane/gregtd2.jpg" alt=" - " />
dyno his cam only/bolt-on car with the Hooker Y(open, no cat-back) and the car made 391 peak rwhp and 369 rwtq. That's with an OPEN Y, not very pleasant sounding. Then he dyno'd with the 3" X with 12" bullets as pictured above and got the same peak power of 391 rwhp, but picked up 12 rwtq to 381. However, at 5000 rpms, the X was good for 17 rwhp OVER the open Y. My car and every other car I've seen with an X is the same way. A higher, flatter power band. My car is at peak power from 5300-6300 rpms.
We've done one cam only LS1 with an H as well and it dyno'd 407 rwhp. Stock heads. Not too shabby, but I didn't get a chance to see the curve. Torque was good too.
IMO - the X sounds more 'refined' and probably gives you a flatter power band over the H. The H sounds nasty and mean, as well as louder. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> From my Mustang days, there were always big debates about the X vs H - and they seemed pretty even most of the time. ANYTHING is better than the Y to me. I'll NEVER go back to the Y set-up..
<small>[ October 18, 2002, 12:14 PM: Message edited by: Lane ]</small>
Re: X vs. Y vs. H =mc2 ? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by jawsk2:
<strong>Can you make up the whole thing as a kit and ship it to me? Or are there parts that have to be fabbed hands on?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Probably - what type of headers do you have?
email me at lane@laneswheels.com
<strong>Can you make up the whole thing as a kit and ship it to me? Or are there parts that have to be fabbed hands on?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Probably - what type of headers do you have?
email me at lane@laneswheels.com
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