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-   -   A Call To All Great Exhaust Builders (http://www.xs11.com/forum/showthread.php?t=26440)

Mashermoto 01-31-2010 05:13 PM

A Call To All Great Exhaust Builders
 
I think most of you know I spent nine months with a Laser Exhaust dealer in the USA trying to get a Marshall Deeptone 4 into 1 system, but we couldn't make it happen. I chased a guy around for a year who was offering a SuperTrapp 4 into 1 system, but he ended up just jerking me around. I've tried for a month now to obtain a MAC 4 into 2 taper tip system, but from east coast to west coast and all points in between, there are none in stock. Two of my emails to MAC have gone unanswered. What dealers are telling me is that it will be late February or March before MAC will supply another batch, but the company is sometimes late on production schedules. In the meantime, I'm dying to start this bike up to see what I got :(

http://i139.photobucket.com/albums/q...0/P1170448.jpg

The UK has several suppliers of exhaust systems for the XS1100, but the dollar exchange rate requires USA customers to pay over 60% more on the advertised price, plus add shipping, plus add the fact that most I contacted won't even ship to the USA :( BTW, please don't read this and think I am bashing our XS1100 friends overseas :) I frequent their XS forum and find them friendly, helpful and very creative in their bike building ideas. As far as I can tell...they don't have anything to do with the exchange rate and shipping overseas isn't something I do either simply because I don't understand how to do it.

So, on this side of the ocean we have to rely on MAC, or keep watching Ebay for that rare exhaust system that isn't too dinged or rusted to consider as anything other than junk :mad:

Guys...we have a problem. If your exhaust system wears out, gets damaged in a crash, or you just want to replace it because of rust or you just want to try something new, good luck :eek:

So here is my call to arms...or welders :p And this includes our friends overseas, or MAC, or Jardine, or SuperTrapp, or anyone else that want to jump into the game :)



Take a look. Here are some sketches of a couple of proposed exhaust designs.

http://i139.photobucket.com/albums/q...0/P1310453.jpg

From what I have read, the 4 into 1 system is really a full race performer. It has weaker performance over a stock system in the low to mid RPM range, and a slight gain in the high RPM range. Now, nobody can argue that the sound of most 4 into 1's is awesome :cool: but most of us ride in the low to mid range and would probably enjoy a little boost in that area. If you agree...read on :D

According to a link posted by Mathh (an awesome bike builder from the Netherlands), click here: http://www.billzilla.org/engexhaust.htm , our bikes should have a system that brings cylinders 1 and 4 together and cylinders 2 and 3 together. The challenge becomes how one achieves that goal. An exhaust builder could cross # 1 or #4 over as they exit the cylinder head, but it looks a little quirky :o

The design above gets around that by crossing them under the engine, but I'm not sure there is enough ground clearance :confused: There is lots of low hanging 4 into 1 systems on XS1100s, but a lot of them are also damaged by speed bumps :( For example, look at how low this Jardine can system hangs :eek:

http://i139.photobucket.com/albums/q...r-preview1.jpg

OK, letís talk about design :rolleyes: Please take into consideration that I've never built an exhaust system and what I know is what I read. Some of what I've read may be BS...so here I go with what I know or believe to know :rolleyes:

The 4 into 2 into 1 systems are supposed to be good low and mid range systems. My 4-2-1 design is the one on the right, viewed from the bottom looking up. The circle is the oil filter, and designing a system that allows oil filter changes without having to remove the header is one feature I'm death about. EVERY exhaust system designed for non-race applications should allow easy access for such maintenance. Also, pipes might cover the oil pan drain plug, but that can be overcome by making a drain extension pipe. Also note that I designed the muffler to exit the left side. That is because I think the left side looks a little awkward with the drive shaft exposed. The right side with the traditional swing arm section and disc brake equipment looks better exposed.

I don't know the performance characteristics of a 4 into 2 system with the cylinders matched, but the 4-2 is the system I think looks the best on a XS1100, and the one I would like to obtain :cool: I think the mufflers on each side provide a more balanced look. And to really sex it up, I like a reverse cone shorty muffler style kinda like the XS1100 Specials. The exhaust should extend past the rear foot pegs, but no farther than the rear axle bolt. Anywhere between the two would work out nicely.

Obviously neither of these two sketches is to scale and the oil pan would be just above the pipes. So there might need to be some improvements to the design in the real world :rolleyes: For example, the Y sections in the 4-2 sketch could be moved much further back toward the rear tire if needed.

Now then, please note that I don't really care if one of these systems performs 0.00004569879879% better or worse than the other design, or anyone elseís design. My desire is that somewhere there is a person who can offer a quality exhaust system that performs in street bike RPM ranges at least as good as OEM, has a nice sporty look about it, and can do it for a price we can all afford :cool:

I've seen some really good home spun XS1100 stuff on this forum, like XSChops chain drive converter :cool: TopCats spin on oil filter :cool: TKats fork brace :cool: and whoever made that tool for removing float bowl pins (Talbolt?) :cool: So I would place odds that someone out there can do this. I can't...I do nothing but burn holes in metal this thin :o

It is very likely that I will buy the MAC 4-2 taper tip when they become available. But, if someone could put together the 4-2 I designed above fairly soon, I just might be willing to work with you :rolleyes:

Comments are welcome :D

bikerphil 01-31-2010 05:29 PM

Back a couple of months ago, a fella on here, Meat Tooth, was thinking of building exhausts for these bikes. IIRC, his family is in the exhaust fab business. Might want to give him a holler. JAT

Mashermoto 01-31-2010 06:33 PM

Thanks, Biker. Sent Meat a PM.

Bigge_al 01-31-2010 07:00 PM

Saw this one on ebay item#170438709062
 
http://cgi.ebay.com/ebaymotors/Yamah...Q5fAccessories

Ivan 01-31-2010 07:16 PM

Yup, here in the states, we are shafted on getting a decent exhaust.

The 4-2-1 you suggest is often called a Tri-Y system and works by spacing the exhaust pulses equally into the main pipe. It's used frequently on four cylinder performance applications in automotive, along with fart cans and gay looking spoilers on Hondas and Acuras. It is pretty much the 4 cylinder equivalent to a 180 degree header setup on a V8.

The 4-2 is pretty much a Jardine "Spaghetti" setup, which I have and it works OK.

I have theories on exhaust tuning, which still need testing. At this point, I am pretty sure the factory exhaust was tuned to the engine to give both torque and upper end as well as possible. Dyno guys say it has more area under the curve, meaning it has more usable power than one tuned for peak torque or horsepower. Although, my theories still need testing, and not many are willing to let me cut their stock exhaust into pieces to unlock their secrets.

joceiphus 01-31-2010 07:46 PM

What would a 4 into 4 perform like?

Mashermoto 01-31-2010 08:40 PM

Biggie,

Yes, there are some MAC 4-1 systems around, but the performance of a 4-1 isn't what we want here. That system is also kinda homely looking :o

BTW, where did you get that avitar :eek:

Mashermoto 01-31-2010 08:44 PM

Joceiphus,

As I mentioned above, I'm not to far up on the experience curve when it come to exhaust design, but I read somewhere the 4-4 doesn't work well either. I can't remember why...but there is your research assignment :D

cywelchjr 01-31-2010 10:48 PM

Quote:

Originally Posted by Mashermoto (Post 255133)
Joceiphus,

As I mentioned above, I'm not to far up on the experience curve when it come to exhaust design, but I read somewhere the 4-4 doesn't work well either. I can't remember why...but there is your research assignment :D

I don't know, Honda did pretty good on the CB750's with their 4-4 and with the CBX with it's 6-6 system. I think you DO have to jet properly for it, and the jetting would be just a different from stock as a 4-1 is. Maybe even the other way.

Mathh 02-01-2010 05:03 AM

I have been following your search for the Marshall. I've had lots of different exhaust systems on my XS1100's. Only one came close to the performance of the stock system and that was the Marshall Deep Tone 4-2 which is no longer available. Maybe you feel good if I tell you that the Deep Tone 4-1 is one of the worst functioning exhausts I ever had. But it will do the trick if nothing else is avalable ;)

Last week I have been discussing my new exhaust with a motorcycle tuner in my neighbourhood. What I understand from him is that it seems exhaustbuilding is all about scavenging now instead of the good old backpressure.
He also says combining numbers 1 and 2 and numbers 3 and 4 is the way to go. I have been checking different exhaust systems I have lying around from several road bikes (RF900R 4-2-1, GSXR750W 4-2-1, GSXR1100 4-2-2, Blade 900 4-2-1, Blade 1000 4-2-1, CBR600 4-2-1, Triumph 1200 4-2-2) and they all combine cylinders this way.... so he must be right, i guess. He also tells me that, because the system will not be a factory calculated one, best way to go is with longer downpipes to prevent pulses from interfering with eachother. So my conclusion until now is that petejw's system, the Tranzac 4-2-1 is a nice example to follow. Or for you maybe converting this one into a 4-2-1-2 as petejw suggested. A dual muffler setup will improve torque at some cost of horsepower resulting in more drivability and the lower gas speed in both mufflers will lower the noise level that seems to be normal for a 4-1.
But i have stil not finished my research yet :D

81xsproject 02-01-2010 07:22 AM

What about the X-pipe?

RODS454 02-01-2010 07:39 AM

Campbell X-Pipe
 
http://www.x-pipe.com/motorcycle.html
This is intriging to me. Anyone have one. Can't retain the center stand.

xs11lover 02-01-2010 07:46 AM

I just put a new Jardine 4 to 1 on my bike on Sunday. I bought it about two years ago from the Jones over in KS. Thanks, Kara :D

T99Ford 02-01-2010 07:56 AM

Quote: Last week I have been discussing my new exhaust with a motorcycle tuner in my neighbourhood. What I understand from him is that it seems exhaustbuilding is all about scavenging now instead of the good old backpressure.
He also says combining numbers 1 and 2 and numbers 3 and 4 is the way to go.

Do you mean combining 1,3 and 2, 4? Anything I have read and observed on scavenging combines these cylinders in order to space them 180 degrees apart from intake and exhaust strokes, in order to align these strokes to assist in scavenging, as is not possible with combining 1,2 and 3,4.
This is why the 4-1 is weak in the midrange; When the 4-1 is not in its "tuned range" (which is top end on every one) the exhaust pulses in the pipe are travelling the wrong direction (from exhaust to carb). The scavenging cylinder actually dilutes the intake mix of the next cylinder with exhaust from the previous fired cylinder. Then since the scavenged "up" exhaust pulse (travelling from can to carb) can actually fuel through the carb twice (since a carb works in both directions), you run a very rich midrange mixture. So with 4-1 systems, you will end up with exhaust diluted and twice fuelled mix in the intake cylinder, until you reach and RPM in which the exhaust pulse is a "down" pulse (from carb to can) at the intake stroke of the next cylinder, in which the pulse assists in filling the intake cylinder.
4-2-1 alleviates this by placing the combined pulses of all cylinders further from each cylinder. It will not eliminate the problem, but pretty much makes it a zero. There is no gain and little loss. It will not increase midrange horsepower over a 4-2 system. A dyno chart on a properly tuned 4-2-1 will show a flat midrange mixture, rather than the super rich one of the straight 4-1.
A 4-2 system will not have the midrange problem at all, but has virtually no scavenging effect, thus the lower top RPM horsepower gains.
I have expermimented with my Mac 4-1, since it was originally nearly unrideable in the midrange. After adjusting the carbs and fiddling with needle heights and shapes for awhile, I cut the collector out of the exhaust. I made an internal baffle for the collector, to join 1,3 and 2,4 prior to exiting into the can. This greatly improved the midrange (there is no noticeable "Bog" in the midrange), and the A/F curve drop that I had seen before this mod was cut to about half on the dyno chart (but not eliminated completely). The power curve of this setup is nearly a flat climb, with just a slight drop at the lower midrange. If I can find my dyno sheets I will post them.

I think it would be pretty cool to make a good running full on 4-2-1 performance exhaust for these bikes. I have thought about it for awhile now.

trbig 02-01-2010 08:02 AM

From what I remember about Meattooth's exhaust, was that we were wanting a dual walled stainless and they couldn't do that. Since Mac's systems are a single wall and really thin metal, (The chrome blues even when you are tuned right) if he can get a system that works well and a muffler(s) depending on what he comes up with stainless at a comparable price... I think he'd have a few takers. As much as I ride in the rain, a stainless system sure would be a draw for me even though I sure like the chromed look.

As a matter of fact, I think there would be many takers for just a good stainless muffler option.

Tod

foreda 02-01-2010 09:04 AM

Exhaust
 
If we could only reproduce the original exhaust!! Most of you have probalby seen my 79 with the original exhaust and I can tell you the performance is better than any after market exhaust that I have ever tried. If I could find another orignal exhaust for my 78, I would have to jump on it.
If someone were to start building a new exhaust system, you would surely have to also build for other bikes to make a profit simply because there are not that many XS 11's on the road today. Another reason would be most people usually buy these old bikes because they are fairly cheap and don't spend a whole lot of money on them. I spend more than the average guy because I truly love these old machines.

Mathh 02-01-2010 01:01 PM

Quote:

Originally Posted by t71ford (Post 255189)
Quote: Do you mean combining 1,3 and 2, 4? Anything I have read and observed on scavenging combines these cylinders in order to space them 180 degrees apart from intake and exhaust strokes, in order to align these strokes to assist in scavenging, as is not possible with combining 1,2 and 3,4. .

I mean combining 1 and 2 and combining 3 and 4.. That's what i was trying to tell. I also have read about the opposite, but things have changed. The exhausts hanging from my wall all show 1&2 and 3&4.

I'm seriously thinking the Bilzilla exhaust page is outdated. I have just been reading this page:

CLICK

It's about the honda integra that has the same firing sequence as the XS1100 (1-3-4-2-). Chapter 4 explains the difference between the two versions of combining cylinders.

We cannot forget that exhaust configuration is absolutely linked to engine configuration. Is the engine meant for racing or road? That is also what i meant with dual mufflers: on a road configured bike they work better than a 4-1.

And reproducing the stock exhaust.... please make my day:D There is a guy in germany that makes a neat replica in stainless.. only problem is that it is too expensive. Three years ago I sent a complete stock system (old and rusty) to Poland to a factory that had convinced me they could replicate everything for a decent price. After six months i contacted them and they told me it was impossible for a decent price. But they knew a company in Taiwan that could, so they sent the complete set to Taiwan. I have seen prices for the kwakker KZ900 and H2 sytems and thought if it was in that pricerange i would be satisfied. Only problem is I have never heard from them again....:D the factory in Poland explained to me they were too complicated to make cheaply....

cywelchjr 02-01-2010 01:55 PM

Quote:

Originally Posted by Mathh (Post 255256)
I mean combining 1 and 2 and combining 3 and 4.. That's what i was trying to tell. I also have read about the opposite, but things have changed. The exhausts hanging from my wall all show 1&2 and 3&4.

The Jardine Spaggetti pipes do 1,4 and 2,3 and are supposed to work well. I know I like mine.

Quote:

Originally Posted by Mathh (Post 255256)
And reproducing the stock exhaust.... please make my day:D There is a guy in germany that makes a neat replica in stainless.. only problem is that it is too expensive. Three years ago I sent a complete stock system (old and rusty) to Poland to a factory that had convinced me they could replicate everything for a decent price. After six months i contacted them and they told me it was impossible for a decent price. But they knew a company in Taiwan that could, so they sent the complete set to Taiwan. I have seen prices for the kwakker KZ900 and H2 sytems and thought if it was in that pricerange i would be satisfied. Only problem is I have never heard from them again....:D the factory in Poland explained to me they were too complicated to make cheaply....

What about getting the Jardines reprod? Somehow I think they might be easier to reproduce than the stock, although I didn't think the stock pipes were that complex.

79XS11F 02-01-2010 03:01 PM

There's more to building a performance exhaust system then just making it fit the bike. Designing a good exhaust system that will deliver additional power takes some serious engineering and testing. If I were you I would keep my eyes open for a good used RC engineering, Kerker, V&H or Super Trap pipe and refurb it as necessary. Kerkers are not that difficult to find and I see new baffle-less V&H new in the box on e-Bay from time to time. They've already done the research, designing, testing and produce good performance pipes for these bikes. I think in the end you will also be further ahead in cost as well.
Rob

Larrym 02-01-2010 03:46 PM

The original exhaust for my special is hanging in the garage. I took it off to have some rusted out sections of the mufflers welded. In the meantime I installed an original header modified to accept the JCW mufflers. Performance had been compromised a tad and the sound is definitely different without the crossover pipe.

The original exhaust design, material, and construction has some interesting characteristics. For example, while it may not achieve the peak theoretical exhaust scavenging level it is matched to engine in all the ways the engineers chose. One of the major factors that I liked was that the bike didn't sound like it was announcing to world that "something wicked this way comes." Didn't matter whether it was idling or under WOT between 5-8K RPMs. I believe that this was a deliberate move by the engineers who came from a culture where loud, brash, and overt display of power/force was/is considered barbaric/uncivilized. So the exhaust sound or lack of it was a display of that strong "Kung-fu".

The biggest beef I have with the system is that the engineers constructed the system in an "all-in-one" way where once any part of the exhaust failed, the entire side had to be replaced. No way to slide on a replacement muffler. Header pipe dented, broken or crushed? Scrap that entire side. I see this as a major flaw.

If there is to be an affordable exhaust system made for this machine I'd like to see it broken into front header section, middle, and muffler. Each section replaceable/affordable as it wears out or suffers damage. And of course I'd want the crossover pipe for the sound and equalizing backpressure function.

Mashermoto 02-01-2010 05:18 PM

Looks like you gents are in full chat mode...so I've got some work to do :D

81XS,
I talked to the guy who builds the X-Pipe a couple of weeks ago. The system is probably a pretty good performer. He claims is kicks the rears of other systems. I'm not real crazy about the looks of the standard X-Pipe that only extends about as far as the front side of the rear tire. The system with the MX-3 mufflers looks excellent, but I would like to see it mounted up first. No XS1100 pictures are available. Access to the oil filter is restricted as well. However, the deal killer is the price :( Those costs shown are for a bear metal system :eek: But like I say, I don't doubt the performance claims.

XSLover,
So whatís up with the Jardine :rolleyes: Does it look like the one on Bob Jones picture above :rolleyes: Does it drag the pavement :rolleyes:

T71Ford,
That's excellent information :cool: I hope Matth will drop back in a clarify the cylinder match. I understood his post to say that #1 can match with #2, and #3 can match with #4. If they can, that would certainly make the design much simpler. Hope you hang around for a while :rolleyes:

TrBig,
I got a PM reply from MeatTooth. He has a new born baby and probably won't be available for a little while. He knows about the post and hopefully will keep in touch. I think he has the means to make something happen.

79XS11F 02-01-2010 05:29 PM

What is the firing order on these engines?
Rob

Cobia 02-01-2010 05:33 PM

Exhausts
 
Although I do not have access to a dyno system, I've had some experience with several types of exhausts.
My '80G came with a 4-1 Kerker, loads of power and sweet sound, not very loud but authoritative at WOT. Sounded and performed a lot better after wrapping the internal baffle, and no rattling. Great powerband response to this day.
The XJ came with the RC Engineering 4-1 and like the G, sounds great and the power just pours on. Had trouble in the 1.8k to 2.2k rpm range until I installed larger pilot jets. That smoothed everything out.
The '79F came with SS Jardine spaghetti 4-2 turn outs. I loved the sound of those so much that I kept them when I found a set of 'like new' stock replacements closeby, for $40.00 on ebay and 45 mins away!!
I replaced the Jardines with those and sold the bike. Didn't notice much performance difference between them but the difference in the quality of the sound was significant. Looking to eventually install them on the G and store the Kerker for when any of them suffer the inevitable.
In reality I thought the Jardines performed better than the stock replacements I found, but it could just be a sound thing.
Just my 2 cents worth.

Mashermoto 02-01-2010 05:33 PM

OK, I just posted my reply without seeing that there was another page of information posted :o

Mathh,
If #1 will match with #2, and #3 will match with #4, then the design is much simpler. In fact the MAC system shown above would work out if only it had a better looking muffler design :rolleyes:

crazy steve 02-01-2010 06:10 PM

Quote:

Originally Posted by Larrym (Post 255281)
....One of the major factors that I liked was that the bike didn't sound like it was announcing to world that "something wicked this way comes." Didn't matter whether it was idling or under WOT between 5-8K RPMs. I believe that this was a deliberate move by the engineers...

The biggest beef I have with the system is that the engineers constructed the system in an "all-in-one" way where once any part of the exhaust failed, the entire side had to be replaced. No way to slide on a replacement muffler. Header pipe dented, broken or crushed? Scrap that entire side. I see this as a major flaw.

I think the quietness of the bike had several origins. One, federal noise standards were already in place to some degree (and stiffer ones were coming) so they were meeting current ones and getting ready for the future. But maybe the biggest reason is this bike as originally introduced was touted as a 'do it all' machine, equally at home putting fear into it's competitors yet able to cruise as the equal to any touring bike. Listening to exhaust drone while going at a steady 70 mph was considered poor form and if you wanted to out-do BMW it had to be quiet.

And yeah, the exhaust design is a crime. But in Yamahas defense, this was fairly standard practice among the Japanese manufacturers at the time and you'll find this among all of them. The real crime was their use of light-gauge metal for too much of it (leading to cracks and rust-though) and it's replacement cost. Even when new factory exhausts were still available, they were horribly expensive.

And if you want to see some 'design flaws' right next to some excellent engineering, buy a Jaguar V-12 car....

'78E original owner

Pat Kelly 02-01-2010 09:11 PM

[quote=Mashermoto;255292]Looks like you gents are in full chat mode...so I've got some work to do :D

81XS,
I talked to the guy who builds the X-Pipe a couple of weeks ago. The system is probably a pretty good performer. He claims is kicks the rears of other systems. I'm not real crazy about the looks of the standard X-Pipe that only extends about as far as the front side of the rear tire. The system with the MX-3 mufflers looks excellent, but I would like to see it mounted up first. No XS1100 pictures are available. Access to the oil filter is restricted as well. However, the deal killer is the price :( Those costs shown are for a bear metal system :eek: But like I say, I don't doubt the performance claims.

[quote]


A while back I sent a message via Ebay to the person making the X-pipe. I was wondering if it was my old friend Pat Egan. Pat designed and was the original maker of the X-pipe. This guy said he wasn't Pat but he was very curious how I knew Pat.
Pat and others I knew were using the X-pipe on their KZ750's they were racing (Pat wasn't racing anymore at that point). The X-pipe was a well balanced, light system. It was one piece with removable baffles. Pat showed me a quirk with the exhaust. With the bike idling he put a small piece of paper by the outlet of one muffler and let it go. I was sucked in and would pop out the other muffler. The body of the 'X' is a large chamber. All 4 headpipes dump into this common chamber, almost like a large volume collector. It was designed for racing, but in the late 70's we were at the leading edge of what was to become the sportbike genre.
I still have the original exhausts for both my bikes. You guys have almost talked me into putting them back on.

T99Ford 02-01-2010 09:25 PM

D-oh!
 
Sorry for my mistake!I mistyped in my earlier post. :oIt should have read 1,4 and 2,3 connected in a 4-2-1, just as with Cy's X-pipe configuration. This is for the reasons I listed earlier, namely the 180 crank design of the four stroke engine. I had to go and look at my bike to make sure, but 4, 1 and 2, 3 are baffled together, prior to the can. In addition to the scavenging benefits listed above, the header lengths for this cylinder configuration are the same. I can't say I really understand the advantage of the 1,2 and 3,4 design for scavenging, unless that is used on a bike with a different firing order than the XS. I may be wrong, though, and am simply unaware of the changes in exhausts that make this possible. Most of my research prior to my exhaust mods indicated the configuration I used.
As I said earlier, this took a dropping power curve from 50-60 mph and made it a flat one, with a slight rise. The A/F ratio is still rich at this point, but the bike was very streetable (and the midrange A/F was adjustable with needle shape/ position).This was all verified on a Dyno Jet dyno.
I will go out on a limb, and say that just because the engineers at Yamaha designed and built the XS11 with a 4-2 that it is the best system for the bike. The engineers were attempting to achieve the most rideable through most of the power band with this exhaust. As many here will attest, they succeeded marvelously. But as with everything there were compromises. At least top end would have been sacrificed. An important part of the whole "make our own exhaust" needs to include a careful study of the specific end use of the bike. This will ultimately determine the exhaust that would be made.
I would venture most would want a 4-2. But there are some (maybe only a few:eek:) that still desire the howling death wail of the 4-2-1 wound to 8000 RPM!:D

81xsproject 02-02-2010 06:41 AM

Quote:

Originally Posted by t71ford (Post 255323)
...I would venture most would want a 4-2. But there are some (maybe only a few:eek:) that still desire the howling death wail of the 4-2-1 wound to 8000 RPM!:D

Me for one. I not only love/prefer the sound of a nice all-to-one exhaust, but like the looks as well. I would do 4-2 for the x-pipe, though.

I only have experience with one 4-2-1 and it mated #1-#4 and #2-#3. It was on my buddies KZ. It was replaced by a V&H street 4-1 which was a noticeable drop in performance.

daveyg 02-02-2010 07:44 AM

When I worked as a technician at a local Yamaha stealership, I noticed almost all 4 cylinder bikes I worked on (From the R6 and R1, to CBRs, to GSX-R) almost all used a 1,2 and 3,4 tri-Y system, and all of which, from my research, were 180 degree engines with a similar firing order, if not just flipped, to our beloved XS11s (With the exception being the latest generation of R1 that uses a 90 degree crank) So if those wonderful Japanese engineers think it works so well... Maybe it does...

cywelchjr 02-02-2010 11:51 AM

Quote:

Originally Posted by daveyg (Post 255350)
When I worked as a technician at a local Yamaha stealership, I noticed almost all 4 cylinder bikes I worked on (From the R6 and R1, to CBRs, to GSX-R) almost all used a 1,2 and 3,4 tri-Y system, and all of which, from my research, were 180 degree engines with a similar firing order, if not just flipped, to our beloved XS11s (With the exception being the latest generation of R1 that uses a 90 degree crank) So if those wonderful Japanese engineers think it works so well... Maybe it does...

I suspect that the reason it's that way on factory systems that do that is really more because of ease of production really. While they are after performance, they are also after easy and inexpensive production at the same time, so if they can make it perform almost as well with 1,2 and 3,4 paired as with 1,4 and 2,3 paired, cost and complexity would tend to push them towards the simpler option.

T99Ford 02-02-2010 12:30 PM

I would tend to agree with Cy. Remember that while engineers have performance in mind, it is not extreme performance. And, they are considering emissions, manufacturing and assembly costs, longevity, and rideability. I think it is for these reasons that the aftermarket offers the gains that it does. This is even more prevalent today, if one looks at modern sport bikes. The R6, for example, is reputed to show the largest aftermarket exhaust gains, and has the most restricted stock exhaust on the market. The aftermarket products improve performance tenfold over stock, not because the engineers can't design it, but because they are hamstrung by other (non-performance related) influences. Stock is rarely the best performer, but probably rather the best "all around" performer for those who don't know better. So just because the engineers designed it one way does not make it the best. It just makes it compliant with the engineer's requirements.
There have been major advances in exhaust technology in the 30 years post XS production, and I would venture that if modern engineering of exhaust were to be applied to an aftermarket exhaust for one of these bikes, one would see larger gains than any of the period aftermarket exhausts.
This is not denying that the Yamaha engineers knew what they were doing, but rather stating that the goals of the Yamaha engineer was not to optimize every aspect of performance. Mass production and having to make a bike anyone could ride limited the performance characteristics of their bike.
But this is great! Those like me who want to mod and then fool with specific characteristics of a modded bike can, and those who would rather jaunt around the countryside and not worry about their bike can do that as well!:D

daveyg 02-02-2010 12:49 PM

I understand that it makes sense that a 1,4;2,3 exhaust "should" work better, but many aftermarket exhausts even use the 1,2;3,4 method, I have on my shelf a titanium header for a GSX-R 1000, not a very cheap hunk of metal, yet it also uses the 1,2;3,4 Tri-Y design. I'm just saying that the costs vs benefits appear to lead toward the simpler design. One of the costs with our beloved 11 being ground clearance, another being oil filter access. Both of which would be extremely difficult to attain with a 1,4;2,3 system.

T99Ford 02-02-2010 12:57 PM

Ground clearance is a huge issue on these bikes for a 4-2-1. The stance of the bike does not allow for mounting like on a sport bike. There would need to be some engineering work there for sure.

daveyg 02-02-2010 12:57 PM

And in my opinion there are some very large flaws with the current model of R6, namely on exhaust, that could be easily fixed with "off highway use" parts. The greatest of all being the catalytic converter/pre muffler that sits under the bike, where the only muffler seen from outside is the tiny 6" long piece that acts merely as a glasspack. A 1,2;3,4 tri-Y design would obviously be more effective, but the US government doesnt care about hp...

cywelchjr 02-02-2010 01:05 PM

Quote:

Originally Posted by daveyg (Post 255381)
I understand that it makes sense that a 1,4;2,3 exhaust "should" work better, but many aftermarket exhausts even use the 1,2;3,4 method, I have on my shelf a titanium header for a GSX-R 1000, not a very cheap hunk of metal, yet it also uses the 1,2;3,4 Tri-Y design. I'm just saying that the costs vs benefits appear to lead toward the simpler design. One of the costs with our beloved 11 being ground clearance, another being oil filter access. Both of which would be extremely difficult to attain with a 1,4;2,3 system.

Actually my Jardine system provides almost 0 interference with the oil filter or the oil pan for that matter. For that matter, as I understand it, they also achieved the same length on the pipes to the collectors for each cylinder which is also hard to achieve. I have to say I also love the sound of it, with it being a bit aggressive without being overly loud. I can still blip the throttle and set off car alarms with it though. :D

Pat Kelly 02-02-2010 05:14 PM

My Jardine 'spagetti' pipes are quieter than the stock pipes. Ground clearance is fine but lean angle is less as the system is wider than stock.
My RC Eng 4 into 1 is tunable for loudness and back-pressure. Lean angle is no issue but ground clearance is (bottom 2 pipes are now 'D' shaped). This system was designed for track use, not real-world. I have mulled the idea of making a 'Y' pipe from the collector to run 2 (tuneable SuperTrapp) mufflers for astetic reasons. The bike just looks naked on the left side with no muffler.
Both systems retain the centerstand and don't require removal for acessing the oil filter.

Mashermoto 02-03-2010 05:15 PM

Pat, I agree that the XS1100 looks naked on the left side with out a muffler. With a 4-2-1 system or 4-1 system, I don't understand why every manufacturer's systems exit to the right :confused: I guess when they designed their systems, they checked the file to see what they did for the last bike built and it was to exit to the right :D

I called MAC yesterday and they actually returned my call :eek: They are not going to start production on their 4-2 taper tip system for 6 more weeks :( They are also not open to any of our suggestions for a new exhaust design. Because they are the only US supplier of exhaust systems for our bikes, any new design has to be home grown.

IMHO, I think the reasonable solution is a 4-2 system with shorty reverse cone mufflers that extend out half way between the rear axle and rear foot pegs. It would look good, sound good, should perform reasonably well, provide easy access to the oil filter, allow oil coolers, and might allow center stand retention :cool:

Now then...who is going to build it :rolleyes:

Pat Kelly 02-05-2010 09:17 AM

Possible reason for right-side exit is for flat-trackers. If it only comes out one side have one part number for everyone.

bikerphil 02-05-2010 11:26 AM

Another theory. The right side exhaust exit doesn't interefere with the side stand.

Mathh 02-05-2010 11:51 AM

I think it has something to do with the mess the chaindrive on normal bikes makes. I know there were some left side models in those days,merely used by side car owners..


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