Out of final prototype aircraft quality XB race muffler

[Alfatango1]

Inside a Drummer from above, so why-t-f does it cost so much, it looks basically like a subtractive process???? <- Anyone on that??

Exactly what it is but 2.5 times what Randy charges

[bajabomber87]

You're using the louvered tubing inside or did it just happen to be in the pic? I've always read that it is one of the worst things to put in a exhaust because it restricts the flow by causing turbulence.

[freak2180]

Exactly what it is but 2.5 times what Randy charges

Yet dyno testing showed the SS worked better than any other pipe at the time WITH THE STOCK ECM for Hp Numbers............Torque is another story, but thats a diff argument.


Xb12r
Drummer SS 103.19Hp
Orig Drummer 100.12hp
stock 101hp

Small loss With the original

Xb9r
Drummer SS 89.4hp
Orig Drummer 88.76hp
Stock 79.61hp

No one could top the Drummer SS Hp number on a STOCK XB12r ECM..... Now the Original Drummer did not fair so well, so I could see some flack there.

The Micron,Jardine, and Lattus are the only ones to out perform the Drummer SS on the Xb9, but the micron also had the benifit of the micron headers due to the dual inlet on their muffler. Micron, Jardine, and Lattus out performed the Drummer Original also.

I see the point people are making about them being gutted cans, but in the end just about every muffler made for the XB is Straight through or made from some other manufactuers already exsisting muffler. With the exception of Randy's witch I have yet to see a pic of the internals or a dyno sheet with numbers.

Now all my info came straight from ASB's shoot out and does not include any info on any pipes made after that test. Im sure things have changed for most of the pipes since that test so this info may be a bit out dated.

[Alfatango1]

HP and torque at what RPM? Now that's the important thing :) If it's not in a usable range, does it really matter?

[freak2180]

I agree that Rpm levels play a roll, but none of the test show what those numbers would be in a "normal" riding scenario. I agree that the Drummers are a lil over priced, but it seems to out shine all the others in that test. when most people look at those results the thought never cross's their minds that that is peak HP numbers that they may never see, but its what sells the product.

[freak2180]

Mshelta............your pipe looks good. cant wait to get some type of sound clip and real world numbers from it.

[msheltra]

Last pictures in place. I'll share this. Some turbulence factored in to break sound waves-trying to eliminate sharp bark sound like punctured tailpipe-zero negative on flow as we see it. Design factored header length, dia and CUIN displacement and target 3500rpm. Assumed free intake-hence the K&N suggestion. No stats were provided for what ECM steps are. Flow test was where we did most with pulsed flow based on 4cyl O-320 engine as its best power is at 2750 ish rpm and flows higher cfm so we guessed at XB lower cfm and higher 3500rpm pulses. Three chambers let us look at 2700, 3500 and 4400rpm. With all we had, no Harley hard engineering data, ECM design specs or money to chase the last 1%, we believe that other than a straight tuned pipe for a set rpm, its as far as we can go to get both power and tone from this engine. As for overbuilt durability, I haven't learned of anybody else exceeding out materials spec. I can't spend another dime or shop hour on this unless you upgrade to turbine power and offer some research funds lol.

Raw bill of materials and design objectives are already going to weed out the "poke a hole in it and let it breathe better" or "is that as loud as it can go?" crowds-zero offense to any of those sincerely but those who understand that although headers are straight pipes-its their tuning that scrapes out the last of the available power-might love this.

[BuellerPilot]

I'd be interested in seeing how the muffler is assembled, like which cores your using (the spiral wound or that hole/louvered one), what sort of chambers and how and where the packing material is and how it's captured/held in place within the muffler. I would never buy a muffler without knowing how it's designed/assembled.

~Mike....

[msheltra]

Hi Mike,
2 cores are used and lengths of each determined by flow as these are jig made so variance is possible requiring slight adjustments. BTW the flanged perforated core is not a louvered design although there is nothing wrong with a louvered core and its common on many kinds of high-end exhaust applications. The cores are welded obviously and packed to spec. so blowout is not possible. There was strong suggestions of the local superbike talent to use strictly the flanged core and construct the unit without any packing for a sharp louder sound but I didn't go that way with this one and wanted to also kill the radiant heatsoak as much as I could without a heat shield for the crankcase. I thought there were enough simple fix designs already available and wanted a full featured product. I know some states would not permit many of whats out there due to lack or flame arrestors and am prepared for that if we made more. The chamber designs are based on the specs I gave in the previous posts, and after seeing the copying and seeming knock offs of each other's designs, that I have today while browsing this site, I'm not inclined to teach would be competitors for free what we spent good money on and I assume you can appreciate that. I have also seen today while poking here that there are a good many choices out there at prices well below what we can make this for understanding its not anywhere the same materials or front end work we have here but it might have shown me there is no market for us. Most I have seen are happy to gut the can or add a second outlet or just fancy up a "Cherry Bomb" concept. Some rethinking on the table tonight.

[BuellerPilot]

So, no info on how / what is chambered and how or where the cores are run? I'm not interested in volumes or tuned lengths of internal pipes, just how it is constructed such as.....

EXAMPLE: [from header stock header a J/down pipe goes into the muffler which dumps into chamber one (like a stock muffler). Chamber one has no packing and / or baffles. Chambers one and two are separated by a solid wall/divider and chamber two has two entrances (entrances are bell mouthed / has rolled smooth lips) to two separate perforated cores. Chamber two has acoustical packing material stuffed completely inside all the way to the cores (not a hollow chamber with a cage holding the packing into place like with a Drummer). Both perforated core/tubes dump into chamber three which has the exiting single tail pipe. The tail pipe section also has a bell mouthed / rolled/ radiused entrance). Chamber two and three are also separated by a solid wall/divider}. Chamber 3 is hollow and is designed to give a Helmholtz effect using the exhaust pulses.

What you mentioned thus far isn't any magic or anything innovative (it is after all just a damn muffler, there's no magic that will make a muffler produce more power than a straight piece of pipe and a properly tapered megaphone style exit). So I'm confused by the secrecy route your taking. Again, keep the dimensions and volumes to yourself, as this is where the actual design and calculations not to mention testing is done.

Again, I'd never purchase a muffler without knowing whats in it (or anything mechanical for that matter). And I'd never purchase a muffler that had acoustic packing that was NOT able to be re-packed (EX: Welded shut).

Good luck on the sales. Just a hint though, stop with the whole salesman sounding technique and talk to people on their level, if not on a layman's terms be highly technical without using empty buzz phrases (know what your talking about and describing).

Also, if your going to criticize others work/mufflers/products, or others techniques and especially how they are designed and constructed you should explain how yours is constructed and explain why yours is better. I am an engineer (over here at NASA Langley) and am also in the Aerospace industry. As of right now, your muffler looks extremely well constructed, but the way you talk (or at least write), your design and all this "testing" sounds like a load of BS. Especially without explaining anything about how it is designed. As for performance being the priority, a single perf tube is hard to beat. Now if you have other considerations such as sound, or fattening a particular part of the power band, then chambers can be effective, but a chambered muffler will almost always have dips and peaks and not be as linear as a well designed straight perf core (look at the factory Buell Race muffler for example with it's HUGE hole in the middle of the power band). Also, louvered style cores are complete JUNK as the flow is extremely restricted and the sound absorption is minimal. If your main objective is easy sound control with minimal effort a louvered core can be effective in this case, mind you it will have bad flow dynamics and still be ****ing LOUD (lose/lose in my book).

Furthermore.... testing an exhaust, ANY exhaust system be it a set of headers or a muffler is a complete waste of time testing it on any other engine other than the EXACT engine the design is intended for. Also, flow benching is useless on a muffler unless it is strictly for comparing before and after tweaks of certain design elements all of which needs to be backed up with a loaded dyno result. Exhaust flow is very dynamic, especially when we are talking about larger displacement V-Twins with a very uneven pulse. A flow bench can never even come close to real world exhaust dynamics that an engine makes. The pushing and pulling, pressure, and sound waves are very strong and nothing like a constant flow that a flow bench makes.

I'm not trying to come across as a jerk, just trying to clear some smoke out of your little thread. I hate sales men, especially when they are trying to sell me something technical and can't explain or even speak technically.

Again, Kudos to the construction. The construction (at least exterior wise) looks FANTASTIC and I commend your choice of materials thus far. Workmanship is indeed indicative of aerospace quality. It really is a work of art. But how about some technical talk and real proof (Dyno results on an actual Buell engine) and most importantly for many (though not me) a sound clip and or vid of the thing mounted on a running bike! If you didn't hype it up and attempted to make your design (which you haven't even touched on explaining) sound so superior to everyone else's "junk" (the tone that comes across by you), then I wouldn't care about a dyno or test result, as I would have chalked it off to just another well constructed muffler. But I feel the need to call you out now, hopefully you will comply.

Again, hope you don't take offense to my reply, I just would like a little more technical instead of salesmanship.

~Mike....