A Call To All Great Exhaust Builders

[Mashermoto]

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



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

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

So here is my call to arms...or welders 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.



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 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

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

The design above gets around that by crossing them under the engine, but I'm not sure there is enough ground clearance 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



OK, let’s talk about design 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

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 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 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 else’s 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

I've seen some really good home spun XS1100 stuff on this forum, like XSChops chain drive converter TopCats spin on oil filter TKats fork brace and whoever made that tool for removing float bowl pins (Talbolt?) 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

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

Comments are welcome

[bikerphil]

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]

Thanks, Biker. Sent Meat a PM.

[Bigge_al]

http://cgi.ebay.com/ebaymotors/Yamah...Q5fAccessories

[Ivan]

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]

What would a 4 into 4 perform like?

[Mashermoto]

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

BTW, where did you get that avitar

[Mashermoto]

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

[cywelchjr]

Originally Posted by Mashermoto

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

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]

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

[81xsproject]

What about the X-pipe?

[RODS454]

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

[xs11lover]

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

[T99Ford]

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]

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