| Author | Message | ||
     Easyrider |
Buellishness, I am in a learning curve also, Wait untill I have finished my complete 1125 system,We also make a complete new design exhaust It will have the looks and a good price and perform outstanding. | ||
| Pariah |
Buellishness, I think your treatment of Easy is a bit over the top. Give him a break. Show him some American hospitality, dude. Besides, there are several respected members of this board who can vouch for how good the Torque Hammer is... | ||
| Curve_carver |
Take a chill pill folks. It is what it is. Just because someone is doing the tests doesn't mean that the results are final. There's so much to do with tuning . Al has just scratched the surface . Easy on the other hand gas taken extensive time testing the pipes. I can vouch for his efforts as I've read his articles. Lay off easy!! | ||
| Crazyhawk99 |
Easy, I will be very interested in your newly designed pipe. Hopefully it will capture the sound of your first one. I have not heard one, but everyone seems to think they sound good. While you are developing it, it would be nice to know what the dB levels are compared to stock for us Buell riders in Germany, where really loud pipes result in a REALLY large fine. Keep us posted! Hawk | ||
| Easyrider |
Crazy, I just finished my XR1200 pipe: http://www.twinmotorcycles.nl/artikelen.asp?aid=75 Then the version with Catalyc convertor with TUV and E-mark Then the new Torwue Hammer for the XB with TUV and E-mark and then the 1125 slipon with TUV and E-mark and then the complet 1125 with TUV and E-mark So enough to do. For the 1125 I have to make a new design for the catalyc convertor.. | ||
| Drhodes1970 |
Littlebutquick seems to like the performance of the TM exhaust just fine. | ||
| D_adams |
Imagine if he could knock another 3 or 4 tenths off his time... or even more. Just from a pipe change.... Nah, couldn't happen. | ||
| Mountainstorm |
Talk about some crazy looking full systems...the XR1200 seems to be a magnet for butt ugly exhausts  The Free Spirits looks very nice...the rest...meh. | ||
| D_adams |
I've had several people ask when I'll be getting into doing systems for the XB's and other older Buells. I'm just trying to catch up with what I'm doing now, but I'm thinking about buying one (XB9) or something like it to play with. I'm also planning on buying a used or crashed 1125 to mess with in the winter (build the motor, 1190? and full system?) if stuff slows down on me, but right now, it doesn't look like that's going to happen for a while. I wonder how far this could go..... | ||
| Tbarker |
as far as you want it D I started in a garage a long time ago it just takes time and lots of money to go into full production for many different systems plus many more things but there is not enough server capacity to list it all  | ||
| Tbarker |
off to the I96 pro dirt track races to cheer Henry Wiles on he uses our exhaust. hurry up Al everybody is waiting.  | ||
| Dannybuell |
All I want is a smooth torque curve from idle right up to 7-8000 RPM. I could care less about peak HP and the last 2-3000 RPM's. If it sounds good so much the better. | ||
| Xbud |
+1 Danny | ||
| Datsaxman |
+! for me. Not going to the track, so I want big fat flat torque right from the bottom. A little lighter, a nice sound, and that's it. | ||
| Easyrider |
Open pipes, don't make torque from low, they make that from 5000 RPM and up, you need back pressure to make LOW RPM to arrange that. Open Pipes do make HP at high RPM, but they are loud, That is why i hoped they make the dyno runs from 2000 RPM, like I do I think it was a too big hassle to tune pipes from low RPM that is why they made the choice to do that from 4500 RPM. | ||
| Datsaxman |
Easy, who wants an open pipe? I did not see any recent posts calling for open pipes. Thanks for the physics lesson though. | ||
| Easyrider |
Datsaxman, You should read between the lines (-: Because it is a cheap system to build a lot of people. Everybody wants a good quality and performing pipe for cheap. That's why 70% of the people have a open pipe, it is or cheap, or loud The 30% of the people that are bounded by law or noise or race orientate for a good performing pipe that is not too loud, they do the matt before they purchase. | ||
| Highscore |
Easyrider says: "Open pipes, don't make torque from low, they make that from 5000 RPM and up, you need back pressure to make LOW RPM to arrange that. Open Pipes do make HP at high RPM, but they are loud." Some special (mismatched?) exhaust designs may react in that way, when there is an restriction, for example a db-eater, is installed into the muffler´s outlet. But this is the exception of the rule. In general 8 of 10 pips show the the exactly opposite behavior: Increasing back pressure by restriction of the outlet area (by the installation of a thin db-eater -tube for instance) boosts peak power at the end of the range for the expense of low end grunt and vice versa: straight-thru without db-eater makes good power in the first part of the range, but the engine stops pulling hard close to red line. To explain this thesis, please allow me an reflection about the nature of "back pressure": Some "Back pressure" is always within any exhaust tube attached onto the engine´s exhaust port. The reason is the unavoidable friction at the tube wall, which slows down reasonable the high-amplitude and violent gas flow out of the port. So the only "exhaust" design without any restriction would be no tube at all at the exhaust port, blowing the gases directly out into the atmosphere. But this does not work. It is a matter of fact, that an engine with same tube length at the ports simply performs better as without. And so there are at least some stubs installed at the ports. In that way the general rule "any engine needs some back pressure" means nothing more than the general design rule. "an engine with an exhaust at its ports runs better than without". When talking about exhaust systems we should separate its components: the header, especially its primary tubes attached directly onto the ports, makes the power, the muffler or silencer makes that, what its names stands for: it calms down the noise. So there is no reason not to build an exhaust system as a full "straight thru" without any back pressure beside of said unavoidable due of tube friction. In deed most aftermarket exhaust are designed this way, featuring commonly a straight thru absorber-muffler with a perforated tube inside, guiding the gases to the outlet with the same diameter as the collector tube in front of the muffler. Such a "straight thru" pipe arrangement is the best for performance hindering the gas exchange within the engine as little as possible. So this is the common race-design. Its only disadvantage is - of course - its noise output: the little wool around the perforated core tube inside of the "can" damps the high pitch of the exhaust rumble but nothing more. The tune of such an "open" and "low back pressure exhaust design works in the same way, as any exhaust is "dialed in" for the desired range: by altering the tube length of the header. Any exhaust works by wave reflection at the "open" end its tubes, arranged to a system. The dimension of that tubes - the most important ones are the "primaries" directly after the port - dial in the time of the waves inside of the tubes are travelling: longer tubes retard the reflexion of a wave, shorting of the tubes times the wave earlier. This is common knowledge, this phenomenon explains. why short pipes are designated" for high-rpm usage and longer ones promote low rpm - efficiency. What is "dialed in " by altering especially the length of an exhaust tube, is the timing of the wave propagation inside. But this speed depends also, this is valid for any wave propagation within a media - on the actual physical properties and circumstances within that media. That means the speed of an exhaust wave depends also and by an huge extent on the temperature and pressure level inside of the exhaust ducting. So the wave speed inside of the exhaust is much faster as the average propagation speed of a wave in the free air due of the heat and pressure inside: an exhaust wave travels approx. with the double of that "average sonic speed", that means by 2000 ft/s. When "calculating" and calibrating that "wave-timing" it is therefore necessary to keep in mind, that its traveling speed depends on the LOCAL physical circumstances WITHIN the exhaust tubing. So what happens then, if there is a nozzle, a db-eater applied to the outlet of an exhaust system: This device necessarily pushes up the average pressure level within the exhaust ducting. Higher pressure within the exhaust gas, the media of wave propagation means a faster propagation speed of the internal wave action within an exhaust. In that way applying more "back pressure" to an exhaust by increasing its internal pressure by a restriction like a db-eater, has the same effect to the exhaust tune as shortening the header tubes: For the engine it makes no effect because of which reason the reflected wave returns earlier. What is the conclusion of that story I try to tell here: An exhaust should be tuned for its internal pressure level. If this level is "high" (back pressure by sound damping of the muffler) or "low" (straight thru race can) has nothing to do with the potential performance of the system (as long as the restriction is not to strong). Furthermore the "civilization" of a straight thru race design by simply adding a nozzle, a restriction to the tail pipe, will not work. A perfect designed exhaust for the street with some damping inside needs essentially headers, tunes for the faster wave propagation because this increased back pressure. One last remark regarding the 1125 exhaust: I have measured the "back pressure", that means the internal relative pressure inside of the stock muffler at its 1st expansion chamber in front of he catalytic converter. The reading here was 150 mbar. Optionally I have added to the stock primary headers a straight thru tube with 60mm diameter discharging via a race can with also 60mm inside, I think I may call this arrangement "straight thru", offering smallest restriction and possible. The measured "back pressure"was 100 mbar for this race can. This data proof that, although the stock muffler does not like like, it offers minimal restriction and "back pressure" to the engine. Therefore the potential power gain by a simple muffler swap is also very limited. For this reason I is hard for me to believe, there are 10 HP waiting inside of the stock muffler for release. For this gain there has more to be done than just changing the can. | ||
| Curve_carver |
Open pipes, don't make torque from low, they make that from 5000 RPM and up, you need back pressure to make LOW RPM to arrange that. I agree I agree with highscore about a 10 hp peak over stock. No way!! I was told by good source that 3 hp over a stock pipe is what you will get with a ignition / fuel map over stock. Why did i see pictures of the pegusus team running stock exhasts on thre race bikes ?? I could be wrong? I was also wondering why al sent the data to the manufactures first before publishing them ? Why would that matter? | ||
| Dannybuell |
Highscore - IDK so all I can really do is ask questions and read. Does ceramic coating the exhaust system inside and out accelerate and lengthen the waves? | ||
| Court |
>>>I was also wondering why al sent the data to the manufactures first before publishing them ? Why would that matter? Al is an Engineer and a Scientist. He's uniquely qualified in terms of training, expertise and experience to conduct a valid test. I'd be willing to wager that prior to starting he had a documented procedure. Part of that procedure likely included a "second look" from the manufacturers at derived data. The purpose of this is not to refute, argue or change design but to look for test anomalies that a manufacturer might recognize. I have no interest in the test, no interest in an aftermarket pipe either for noise or performance. I am however continually fascinated with the amount of smoke and mirrors folks buy into with regard to performance parts. What I am more interested in that the results are Al's methods. He always does an impressive job of thinking these things out and executing them at a level we'd collectively not be able to afford to have done my a testing lab. I'm betting that his report will detail everything. Court | ||
| D_adams |
+1 Court, well said. It was just to proof read it and look for anything really off or out of the ordinary. | ||
| Xoptimizedrsx |
Very Nice Easy... By far the best so far. | ||
| Pariah |
I recently read through Al's XB Exhaust shootout and I was very impressed by how comprehensive it was. I have no doubt the 1125 exhaust shootout will be equally impressive. One issue that I thought was interesting was Al's point that the pulls were generally made at WOT... and to take this for what it's worth. I don't know about most of you, but I rarely use full throttle in everyday situations. I would like to have some idea of the streetability of the exhausts (with or without the Race ECM) and, for example, how the bike behaves in a parking lot situation (riding like a motor officer pro, for example) at partial throttle (and even with the clutch partially engaged). I don't want the rear tire chirping as I ride a figure eight in the parking lot, but some grunt down low would be useful in keeping things upright. Arguably this is not what the 1125R was "meant" to do, but it is part of the reality of commutes and riding in town... | ||
| 1_mike |
Pariah has a very good point. This also relates to the internal pressures at what RPM vs. throttle opening vs. engine load the exhaust system is seeing. Saying the mufflers see's xx bar pressure is an open ended statement. As noted...at what throttle opening vs. RPM vs. gear selection or load. I'd bet the internal pressure varies a significant amount when throwing the three parameters above. Mike | ||
| Tbarker |
versus cyl head flow,cam timing,intake length,etc. | ||
| D_adams |
My personal favorite was from the man himself, "exhaust wave attenuation". It didn't apply to the pipes I submitted for the testing, but it was still cool to hear him theorizing when he looked at that particular pipe in question. | ||
| Highscore |
Sorry, I am no native speaker, the stuff is delicate, so it looks like as I am struggling to explain my thoughts. What I tried to tell is this: If an exhaust system is tuned for High-RPM or Low has nothing to with its internal "back pressure", if it is straight thru or silenced by a restriction of a muffler as device, worth to be called by this name. The working range of an exhaust is defined by its lay out, by the diameter and length of the headers arranged within the system. That dimensions are crucial, if the pipe is designated to work at high or low rpm. When talking about "social compatible" pipes, which avoids potential conflicts with the neighborhood, we are talking about pipes, which have the disadvantage of some additional restriction compared to a full open race can. To calm down the noise out the outlet to an acceptable level, there has to be something inside of the muffler, something more as in a straight thru system. The question here is: What is the level of that restriction, that it throttles down the engine output reasonable? I have also had a time of extensive dyno testing with hundreds of hundreds of hours to get an idea of hat magical margin: The value is 200-250 mbar restriction as average pressure build up within the collector tube in front of the muffler. This value is an empirical one and therefore at the very end a rule of thumb. But is works pretty well to identify an restrictive pipe. In the case of the stock 1125-muffler this value is with 150 mbar absolutely "within the margin". So of an new aftermarket pipe adds some new performance to the engine, this is not caused by a better flow, but by a change of the exhaust lay out: All aftermarket slip on system convert the stock 2-2 working scheme into a 2-1, adding am additional collector pipe and length to the system. The "back pressure2 for itself is just a secondary design parameter, also it has an reasonable effect. A similar effect - @ Dannybuell - like "blowing up" the exhaust by a restriction at its outlet, may be created by heating the system up by isolating and warping the exhaust tubes. More heat here means also a condition inside of the exhaust gas, which speed ups the internal waves action An exhaust, whose internal waves act faster, works in the same way, as it has been shortened at the headers without that insulating. Therefore covering the expansion chamber with some layers of asbestos was a common trick in the past to tune a pipe, as it was, for some 200-300 rpm more performance at the peak. This worked amazingly well, especially for expansion chambers of 2-stroke-engines. | ||
| D_adams |
Shushed for now.. (Message edited by d_adams on July 12, 2010) | ||
| Pariah |
Putz around on parking lots? Have you heard of Battle Trax courses or have you ever seen/heard of a Lee Parks Total Control Clinic? Everything happens in a parking lot, but that does not mean there's anything sedate about these experiences. Anyways, the 1125R is a flexible platform, and all I'm saying is that I want a bike (and a complementary exhaust + tune) that is well-rounded. More fun at trackdays (like it isn't fun already stock), but also let's be realistic and not sacrifice low speed drivability when I'm commuting. Also, since I'm riding an '08, I'm looking to enhance the low speed ride as much as I can... hopefully Al's shootout will shed some light on this latter point, even if only qualitatively. |
