Topic: Delkevic stainless exhaust, center stand and decibels?

[Dunk]

Can anyone running a Delkevic stainless exhaust comment on center stand fitment/use and loudness or decibels?

I have a 75 CB750 with Winning Performance (Kerker) exhaust. It's louder than I'd prefer even after repacking a a few years ago. I can use the center stand with it and prefer to keep that functionality. My main issue with the Winning Performance pipe is the muffler sticks out too far, not much gets my heart rate up but I forgot about that the other day and ran out of lean dragging it on the ground. Aside from that it's a shame to keep using a fairly uncommon pipe on a bike that sees snow and salt, gets rained on at work, and otherwise sees the elements... hence wanting a stainless exhaust for corrosion resistance.

[willbird]

I put one on my CB750K2 and the center stand was not an issue in any way.

Bill

[Dunk]

Great, I'm committed. Just ordered one. I'll update with comparison pictures and decibel measurements when it shows up.

[Dunk]

The exhaust arrived. Apparently it requires factory style exhaust spigots and clamps, which I do not have. Bummer. Gotta find some now. Shame, I sold a set or two over the years thinking I'd never need them.

Measured decibels of the winning performance exhaust at at:
idle ear level: 76
20' behind: 69
4000 RPM ear level: 92

I'll get the same measurements form the Delkevic exhaust once I source some parts. I'm not optimistic about the Delkevic muffler being quieter, it seems to be a somewaht straight through design. I'll measure dB and may need to modify the baffle a bit to get to same loudness or quieter. Main goal is not die from lack of ability to turn right at speed, secondary goals are not rot out in rain/salt/snow and less loud.

[beemerbum]

Easy install, tucks in nicely and has great sound. in my case, the entire Delkevic was lighter than just one of the stock pipes

[WhyNot2]

I got them, and they are quieter than the Kerker.

And yes the stand is not an issue, the set comes with a bracket for the right side.

[seanbarney41]

Realize also that Kerker pipe had three very different noise levels available in the form of exchangeable baffles...from full quiet to full race.  I believe the Delkevic has a couple available.

[WhyNot2]

Yep......baffle in.......or....baffle out.

[MauiK3]

Cool that the center stand works too.

[willbird]

Great, I'm committed. Just ordered one. I'll update with comparison pictures and decibel measurements when it shows up.

IMHO they do offer a direct bolt up type, may be for later year bracket of SOHC ?? I got the ones you have though and found a set of spigots on Ebay that cleaned up nice after a dunk in some evaporust. I did not use the huge OEM finned deals, they sell stainless clamps to use instead.

[WhyNot2]

Great, I'm committed. Just ordered one. I'll update with comparison pictures and decibel measurements when it shows up.

IMHO they do offer a direct bolt up type, may be for later year bracket of SOHC ?? I got the ones you have though and found a set of spigots on Ebay that cleaned up nice after a dunk in some evaporust. I did not use the huge OEM finned deals, they sell stainless clamps to use instead.

Where did you source the clamps from? If you don't mind me asking.

[willbird]

Great, I'm committed. Just ordered one. I'll update with comparison pictures and decibel measurements when it shows up.

IMHO they do offer a direct bolt up type, may be for later year bracket of SOHC ?? I got the ones you have though and found a set of spigots on Ebay that cleaned up nice after a dunk in some evaporust. I did not use the huge OEM finned deals, they sell stainless clamps to use instead.

Right from them..............
These are the clamps, not sure on exact size though.
https://delkevic.com/48-51mm-stainless-steel-exhaust-clamp/?srsltid=AfmBOooVF2k2jNzGUm1DkLMK7yKV0aojVCFfGZ3cNfS5tNwn-WQchKFI



Where did you source the clamps from? If you don't mind me asking.

[Magpie]

I went with the Delkevic because it was the cheapest system I could find. It's nicely finished, easy install, and looks good. It is a bit louder than I wanted though. The headers are turning a light bronze colour which I like too. 4 into 4 is preferred but I didn't want to spring for another set.

[WhyNot2]

Great, I'm committed. Just ordered one. I'll update with comparison pictures and decibel measurements when it shows up.

Thanks, I'll be ordering some as soon as I get back from vacation. (1 oct)

IMHO they do offer a direct bolt up type, may be for later year bracket of SOHC ?? I got the ones you have though and found a set of spigots on Ebay that cleaned up nice after a dunk in some evaporust. I did not use the huge OEM finned deals, they sell stainless clamps to use instead.

Right from them..............
These are the clamps, not sure on exact size though.
https://delkevic.com/48-51mm-stainless-steel-exhaust-clamp/?srsltid=AfmBOooVF2k2jNzGUm1DkLMK7yKV0aojVCFfGZ3cNfS5tNwn-WQchKFI



Where did you source the clamps from? If you don't mind me asking.

[WhyNot2]

I went with the Delkevic because it was the cheapest system I could find. It's nicely finished, easy install, and looks good. It is a bit louder than I wanted though. The headers are turning a light bronze colour which I like too. 4 into 4 is preferred but I didn't want to spring for another set.

Nice, clean bike.

[Dunk]

I had to get original style exhaust spigots and clamps, but finally got around to installing this today. The Delkevic megaphone style exhaust sits much tighter to the bike than the Winning Performance/Kerker. Doubt I'll be scraping it on the ground. Install was fairly easy, I had eyeballed the pipe positions correctly before realizing they put stickers on each pipe and collector for position.

Got it all on, tightened muffler mount bolt first holding it up as high as it would go, then installed springs from header pipes to collectors, tappy tap with dead blow to get pipes fully on spigots and into collector, then tighten the rest starting at the cylinder head. The muffler bracket has a rubber bit that the center stand rests on when up, and the center stand works without interference. Looks good, hopefully won't get crusty after it sees salt and snow this winter or regular rain all year.

Started it and it sounds nice at idle. Deep and maybe a hair quieter than the Winning Performance pipe it replaced. The baffle is cone shaped packed with fiberglass and has a removable center perforated tube that is closed/rounder on the forward side, which presumably quiets it down appreciably when installed. I forgot to take pictures while I had it out. Haven't rode yet but I'll update after some commuting and dB measurements.

Anyone looking for a Winning Performance/Kerker exhaust?

[HondaMan]

I went with the Delkevic because it was the cheapest system I could find. It's nicely finished, easy install, and looks good. It is a bit louder than I wanted though. The headers are turning a light bronze colour which I like too. 4 into 4 is preferred but I didn't want to spring for another set.

Magpie: aside from the color, your looks just like the one I just finished for a fellow SOHC4-er who lives an hour north of me. He has the very same Delkevic setup as yours. When I rode it around the wind took away the sound of it above about 45 MPH. In city traffic it is a reliable audio tachometer. It does reduce the clearance a bit on the right side at the passenger footpegs' position where that last weld joint is located, but I only bumped it when parking next to a curb, not while riding anywhere.

Taking it off and putting it back on (I had to R&R the engine in this bike) requires determination, patience, and character.
So, I had some troubles with that part of it...

[MauiK3]

Looks great!

[Dunk]

I rode the bike about 80 miles today. Initial impressions are this muffler is louder and annoyingly buzzy or droney. It gets very loud under load. Half my ride was highway. It is very loud at 80+ MPH through filter ear plugs (Eargasm 16 NRR). I don't recall noticing the Winning Performance muffler being particularly loud under similar load. Stop and go and two lane blacktop it's quiet enough at light load steady cruise, but seems obnoxiously loud under load accelerating. I strongly dislike how loud this muffler is, it is unacceptable. I do like that it's stainless so shouldn't rust or corrode and that it doesn't drag on the ground.

The baffle is relatively short compared to the muffler length. The baffle ID is fairly large, about 1/2" larger than the Winning Performance. I'm thinking I need to get some perforated tube to significantly lengthen the baffle and wrap it in fiberglass.

Decibels Winning Performance at:
idle ear level: 76
20' behind: 69
4000 RPM ear level: 92

Decibels Delkevic at:
idle ear level: 74
20' behind: 68
4000 RPM ear level: 93

If I could measure both accurately under laod I'm certain the Delkevic would be significantly louder.

[Dunk]

Attached are the baffles installed, pictures from Delkevic site.

[HondaMan]

I might suggest a Snuff-R-Not addition to the exit hole? Those were/are effective at breaking up the sound pulses. I haven't seen them for sale lately, but they aren't hard to make.

[Dunk]

Delkevic got back to me and said they don't offer any quieter baffle but said someone had asked before and said they got this baffle off eBay that quieted it more. 48mm for the exit hole of muffler body. https://www.ebay.com/itm/357605748073

I installed it today with the end cap installed where it came at the rearmost position, and took measurements. 3 dB reduction at ear level no load 4000 RPM. Tone seems deeper and less raspy, less high pitched goofy new rice burner car sound.

Decibels Delkevic w/ eBay baffle many small holes at:
idle ear level: 70
20' behind: 67
4000 RPM ear level: 90

I have not rode it yet but I'm optimistic it will quiet it appreciably and remove a lot of the harsher higher pitched sound under load, particularly 5000 RPM and up where it is most obnoxious.

Downside is it's no longer a straight through muffler, so we'll see how noticeable the impact to performance is. The shame of it is this muffler body is very long, there is room to have a long straight through baffle and have dB the same or less than the medium baffle currently in the Winning Performance/Kerker pipe. They made a quieter baffle for that which was the same straight through design just a longer baffle with more length of fiberglass wrapped around it.

I may end up making my own baffle eventually to keep a simple straight through design and have a mellow/deep tone of the Kerker without the harshness and probably be quieter with the available room in this muffler. The mind boggles as to why Delkevic wouldn't do this.

In any event, I'll update after a commute with this baffle. I also have another coming, that instead of hole has the OD of the baffle bent in to disrupt flow, with holes on the outside, and no end cap. I'll try that one too and take measurements and give my subjective impression. https://www.amazon.com/LONG-Exhaust-Baffle-Pipes-Mufflers/dp/B0BRTH3ZHK

[HondaMan]

Do you remember (or have you ever seen) the "Snuff-R-Not" silencers? They were popular on straight-thru 'Scrambler" Hondas (among others) because you could install them using the single bolt hole at the end of their pipes. They were a washer, welded to a small post that had 2 positions: one was flat across the end of the pipe(s) and the other was turned 90 degrees to the flow for less restriction. They were very useful, and mighty quieting when turned to the 'blocking' position. The clearance around the OD of the washers to the ID of the pipes on, for example, the CL72/77 Honda scrambler was 3mm (~1/8") and the hole in the center, which was also crossed thru by the shaft that mounted it, was about 1cm (about 1/2"). In pipes with the Honda baffle removed they were about the same sound level as when the baffles were in it. While they restricted high-end power when "closed" they increased low-end torque, useful in traffic. I've installed something similar (with much larger washers) into 750 open-ended pipes before, mostly to prevent my customers from getting a ticket from the local gendarmes on Saturday nites. They were both distinctive in sound and helpful when the early 4-2 and 4-1 headers made the 750 too loud for the local townfolk who didn't ride.

[Dunk]

I looked those up after I saw you mentioned it. Never heard of them but seems like a simple way to have a selectable exhaust. Makes sense for the high pipe scramblers, those small twins are surprisingly loud, at least to me. I have a CB350 twin, I ended up putting newer Triumph takeoffs on it and it's finally reasonably quiet, knocked the catalytic converters out of them.

[HondaMan]

I looked those up after I saw you mentioned it. Never heard of them but seems like a simple way to have a selectable exhaust. Makes sense for the high pipe scramblers, those small twins are surprisingly loud, at least to me. I have a CB350 twin, I ended up putting newer Triumph takeoffs on it and it's finally reasonably quiet, knocked the catalytic converters out of them.

I'll bet those pipes look good on the 350.