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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Muffler ideas /cgi-bin/YaBB.pl?num=1749742637 Message started by Surviving Philly on 06/12/25 at 08:37:17 |
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Title: Muffler ideas Post by Surviving Philly on 06/12/25 at 08:37:17 Yo savages!! I've been running this slash cut, 3" diameter baffle-less straight through the last three years. It's too loud and I believe does not allow efficient scavenging -- I think I need more restriction for better low end torque. I know the dyna is often praised on the forums and can be quite cheap to purchase used, but am interested in other suggestions as well. The supertrapp metric megaphones look nice with the modular disks and all, any thoughts about those? Also, thumper if you read this and still have that old supertrapp for sale I'll purchase that off you. Thanks all |
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Title: Re: Muffler ideas Post by zevenenergie on 06/12/25 at 11:07:52 If I read it like this, you've already made up your mind. ;) I recognize that, you want it and you also want to know what's so great about it. So here I go: SuperTrapp exhausts are often more open than the original exhaust, which means that exhaust gases can escape faster. This results in: Improved throttle response More power, especially in the mid and high rev range Better airflow, which is beneficial if you also have a better air intake and carburetor setup. A unique advantage of SuperTrapp is that they use removable discs at the end of the muffler. This allows you to: Adjust the sound level and back pressure Fine-tune the performance for your specific engine setup if you have changed things. Weight saving. Better sound ::) |
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Title: Re: Muffler ideas Post by Dave on 06/12/25 at 11:11:29 These Emgo mufflers were used by RYCA on their Cafe' bike kits. https://www.amazon.com/Sporacingrts-Stainless-Motorcycle-Silencer-Moveable/dp/B09S5PNTKL/ref=sr_1_1?dib=eyJ2IjoiMSJ9.dsR3VQZGcmR6DQAuSyZnFnmz9C8VLZHPxZxG46Xl4sTQOgAAdEfSZgYJvhVkM-YYZ-6m9BYgTHTVNRXZvyVLrPH-2WNwQdVtyy1KgN26gi7jxQA0s-nVI55DQYfbopA55x0-fPq7rubLRdqWT7fkMTvcFXSQOVVIzu9-rlzbTWYV7GYGbMNfBWFQ1I12WLZEw6KuTWW_uwpJRLF5Fw6BXekWQKm96W4pw6xcIAqlm0OhylryAR-aY5YNrFiGTwMWL-w0ZZVBINLacF3SXGpLxsdp4Cc59rX0L3fCdERmDG8.BQo-Dj0itwGQOpTsn9nLPf8c9xlHaDOfxhISRwoSAKc&dib_tag=se&hvadid=698122864792&hvdev=c&hvexpln=67&hvlocphy=9015682&hvnetw=g&hvocijid=6388413598597649135--&hvqmt=e&hvrand=6388413598597649135&hvtargid=kwd-4472731364&hydadcr=7466_13212130&keywords=emgo%2Bmufflers&mcid=f632aeaa44353e77937036dc92846a58&qid=1749751553&sr=8-1&th=1 They are incredibly loud as delivered - you can find YouTube videos for doing the Crumb Cup modification to reduce the excessive noise. You can also modify the perforated core by blocking the center pipe and turning it into a baffle (rather than just a perforated pipe where the exhaust blows straight through). If the exhaust passes out the holes into the area between the core and muffler body then comes back in they muffler muffles more. [media]http://www.youtube.com/watch?v=SIelY9gMqX0[/media] Later on they made a replacement baffle that did a better job. [media]http://www.youtube.com/watch?v=kSgyren9rHg[/media] |
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Title: Re: Muffler ideas Post by FinnHammer on 06/12/25 at 13:32:37 SurvivingPhilly: Try this one by DragBikeMike, I use it myself, it sounds great, looks even better, flows twice as much as the standard and is real inexpensive if you can roll your own. https://suzukisavage.com/cgi-bin/YaBB.pl?num=1609379913 Chers, Finn Hammer |
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Title: Re: Muffler ideas Post by Surviving Philly on 06/12/25 at 14:34:56 Great suggestions here thanks guys, Finn that thread on mokes project is amazing, I was actually searching for that before notice you posted it so thank you. Couple of questions here -- Mike in that thread comments on the back pressure myth. Hopefully Mike can grace us with his presence if interested, I have a lot of questions about this. As many know "back pressure" is often referred to by people, usually in the context of free flowing straight throughs, that torque can be limited by not having adequate "back pressure". I believe this to be a misconception, that a free flowing exhaust is always preferable -- however, back pressure and scavenging are different things. If I understand correctly scavenging is the phenomena of increased exhaust gas velocity due to the inertial slug generated by a high pressure environment in the exhaust, typically achieved by in some way limiting flow, like with one of those "lollipop" inserts (washer tac welded to a bolt) or another type of obstruction. This increased exhaust gas velocity due to obstruction has a positive influence on torque on the low end, however is not desirable with a WOT, which is why some much fancier bikes have those variable exhaust systems, among other such considerations (scavenging is very complex and valve/head design etc are factors in efficient scavenging.) What are your guys thoughts about this? My inclination is that our big singles CAN benefit from some obstruction to increase exhaust velocity, but my knowledge is minimal about such things. |
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Title: Re: Muffler ideas Post by Needles on 06/12/25 at 15:56:41 Use what you like and are capable of jetting for. I'd advise against the EMGO glass packs, though. I tried one, and on maybe the 3rd time I started it up, the rear disk and fiberglass blew out! I think there were only 3 pop rivets holding it in. |
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Title: Re: Muffler ideas Post by Fast 650 on 06/12/25 at 23:46:04 1A2B3F262425262B244A0 wrote:
No engine likes backpressure. If it runs better with backpressure then you have something way out of whack with the build. Watch David Vizard's videos on youtube about his exhaust and muffler designs. The man designed a muffler that was street legal and made the same power as an open pipe. When it comes to airflow the man is at the top of his field. |
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Title: Re: Muffler ideas Post by DragBikeMike on 06/13/25 at 17:09:16 Philly, I don't think the restrictions in a muffler (baffles, perforations, etc.) will do anything to aid inertial scavenging. Inertial scavenging is pretty much controlled by the cross section of the header pipe. The resonant wave can be used to help hold the fresh charge in the cylinder, but IMO, that resonant wave can only be harnessed with an open exhaust system where there is an abrupt change at the end of the pipe (i.e. drag pipe). If you run a muffler, you want something that changes the cross section of the system or forces the hot gas to turn. That change in cross section, or the abrupt turn, will break up the resonant wave and prevent reversion (drag pipe sag). This is a good video that discusses drag pipe sag. https://www.youtube.com/watch?v=KjKUKhHQLHg That David Vizard system that Fast650 referred to is a pretty cool system. He installs a big empty cannister at the end of the header. As I recall, the cannister must be at least eight times the volume of a single cylinder. The cannister simulates the abrupt change in pressure associated with the end of a drag pipe and also provides a nice big container for the hot gas to accumulate and then bleed off through the muffler. It keeps back pressure to an absolute minimum. It would be pretty hard to make something like that for a motorcycle, but it is a way cool idea. I believe that I might be able to make one from a 4" automotive resonator, or possibly a much longer 3" resonator. Always something to do, something new to try. |
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Title: Re: Muffler ideas Post by ThumperPaul on 06/13/25 at 17:16:30 Hey Philly! SuperTrapp is long gone. On the topic of scavenging, it can only occur when there is valve (camshaft) overlap. The stock LS650 cam has no valve overlap if I recall correctly. I beleive the DR650 cam does. So nothing to really worry about if you have the stock cam. I'd look at DBM's muffler shootout. A dressed up Cherry Bomb could be kinda cool. Delkevic also has a few options. Kinda pricey. I haven't heard it on the LS650. It's a popular exhaust on some Kawasaki. https://delkevic.com/bull-nose-tip-21-round-stainless-to-fit-s40-boulevard-1986-2019/ |
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