exhaust fail

[Nails]

I had a way kool idea: replace the exhaust tips with something shorter and straighter. Well, I got the idea from somewhere in webistan -- somebody else did this and had a sound recording. I liked what I heard.

But when I cut off the old tip (red arrow), it didn't fall. There's some inner pipe.

Not sure what the other guy did. I should've looked at it closer - I don't need to wreck the whole exhaust system just for a little different sound. I'm just gonna weld it back closed.

[Scott-(Altoona, PA)]

Nails, if you look close at the two turn down tips only one is actually used the other is a fake exhaust tip. So even though I've never performed an autopsy on the exhaust or the Voyager it self I think one could assume that the inner pipe you found goes to the one turn down tip that is functional.
Hats off to you for taking the leap and trying something! I'm to dam afraid but them I have limited wrenching experience on bikes and stand tall on the "if'in it aint broke...." mentality!
Basically you are braver than I!

[Nails]

I've edited this post after taking a closer look.

if you look close at the two turn down tips only one is actually used the other is a fake exhaust tip. So even though I've never performed an autopsy on the exhaust or the Voyager it self I think one could assume that the inner pipe you found goes to the one turn down tip that is functional.

I think this is partly true. The outside pipe has a lot more soot, but the inside one also has some soot. The outside pipe connects to that inner pipe (further upstream), but there's some complication and partial obstruction. I originally thought the inside pipe also hooked to the inner pipe, but I checked again and that might not be true. I suspect the inside pipe only gets flow in high-flow conditions, but I have not idea how that might be hooked up.

On the header end, I see no inner pipe. There's some complicated plumbing here, too. I don't want to mess with it any more.

(The tips apparently come apart by grinding off those rivets. But I don't have SS rivets to put it back.)

Basically you are braver than I!

No, just stupid. Those often are confused. Somebody in some web vid "cut off the tips and replaced them with straight pipes". I was just following them ... like a lemming.

Apparently they hacked it off with a chop saw and left the inner pipe open. The resulting sound wasn't much louder than stock and quieter than a Cobra -- they had vids of all three. Dumping the plumbing at the tip didn't really seem to do much of anything.


And talking of the headers (and stupid): I cut a bad bash out of a header, to replace it with a piece of stock pipe. As it turns out, the headers are double-thick. I mean, two pipes, one basically lining the other. (No wonder it's so hard to hammer dents back out.) To fix this right, I'll need to weld in two patches: the inner pipe, and then a larger outer patch -- larger because welding the inner patch will enlarge the outer hole.

Like my dad used to say, "there's the easy way, and then there my son's way."

[SgtSlag]

I owned a '79 Honda CB750K, with CV carbs on it. Many folks on the CB750 forums tried to mount pod air filters onto their CV carb bikes: "Hey, it worked on the 1969-1978 models, why wouldn't it work on the 1979+ models?..." Because the CV carbs require the air flow restrictions of the the OEM air box, that's why! These owners tried so many different jets, tunes, etc., but they always had one, or more, flat spots, which they could never eliminate. They wasted a lot of money, a lot of time, and a lot of effort... For nothing.

To put it simply, the Honda (insert: "Kawasaki") engineers calculated everything dozens of different ways, to come up with the best set of compromises, for the best economic performance, overall. Suspension allows manufacturers to play games, to save money. The fuel system, is another matter, altogether! They can't take shortcuts, with that.

If you wish to pursue this, go ahead. You have been warned. Cheers!

[Nails]

To put it simply, the Honda (insert: "Kawasaki") engineers calculated everything dozens of different ways, to come up with the best set of compromises, for the best economic performance, overall.

That seems to preclude any modifications whatsoever -- they "engineered" the whole bike. "Value engineering", as you say? And some folks might not agree on "best". For starters.

Suspension allows manufacturers to play games, to save money. The fuel system, is another matter, altogether! They can't take shortcuts, with that.

Well, they can. And they do.

But I hear you, that you're limiting this to the "fuel system", including the whole induction and exhaust systems. And I generally agree with that: it's kinda silly to think we can "dial in" more performance at all, much less to do that without upsetting some other performance compromise -- as if we're the only ones to notice the adjusters.

Folks wrongly think that pods flow more air than an engineered airbox, even if more air is necessarily good (I'm thinking of uniform air flow). I used to think that too; and I've wasted money on pod filters.

I "generally agree", but this isn't always true. One compromise I encountered (different bike) was an undersized air box. Like others before me, we found a noticeable performance increase (particularly throttle snap) by drilling lots of holes in the airbox. (Also had to fuss with jetting, which became very complicated because it was a single-cylinder bike but had two carbs, of totally different designs. A major nightmare. But it really is better after all. And I had to fuss with the jetting anyway, mostly because it came heinously lean.) And many have improved performance by adjusting carb settings, even if these adjustments were plugged at the factory. Especially those of us living at high elevations, where lots of compromises get compromised.

But for the simple modification I had in mind, I didn't expect any performance effect at all. It was an aesthetic issue: I disagree with the apparent original compromise. I want a little more exhaust note. And I don't want an XII just like everyone else's.

I edited my original post after looking closer and finding that this exhaust system is more complicated than I expected. As you suggest, I'm not going to screw with it any more. But it could've gone the other way: the complicated plumbing might not have involved the tips (as I expected), and switching the tips out could have been simple and fun. I wish I'd looked closer before making that cut, but it's easy to put back. No harm, no foul.

(Still want a bit more exhaust note, if not a more induction "noise". And still won't hesitate to make the bike mine.)

[Draxxis]

Depending on how much throat you want on a sound, you could go and do what I have done... At the beginning of the riding season I decided to pull off my exhaust and run straight pipe. Basically I still have the factory headers. But where the exhaust would slip on after the first crossover, I had my local muffler company Bend me two straight pipes. And then I put on tips. Basically the exhaust all the way back to under the bags is 1.75 inch and then a reducer was put on and the tips are 3.5 inch. Then I painted everything black. Definitely has a scream to it now. Did not adjust the carburetors and my fuel mileage is about 5 miles per gallon more then what it was with stock or Cobra exhaust

[Nails]

Yeah, I don't want a loud exhaust. I was shooting for something between stock and Cobra.
But I'm a little surprised that you got a performance improvement.

[Nails]

Has anyone tried slipping on a discarded Harley stock muffler, like this: https://www.ebay.com/itm/09-16-Harley-D ... :0&vxp=mtr? I think they're all 1.75" inlet, which should fit on our headers.
Lots of YouTubes if you Google "harley muffler on GoldWing". https://www.youtube.com/watch?v=nFsFPs34wLA sounds pretty good to me.

https://www.goldwingfacts.com/forums/2- ... -help.html

Has anyone ever measured our exhaust loudness? These are rated 80db, which seems pretty quiet. (I think noise restriction laws often are 96db, measured by EPA method.)

I might have to wander by some Harley shops.

Edit: Okay, I did get a couple hits when I searched "Harley muffler", but mostly for 1300. The Exhaust!! thread that caused so much fuss brought this up but got into a fight about loud exhaust. But I'm talking about stock Harley pipes, not straight pipes. 80db.

[Nails]

https://www.hotbikeweb.com/tech/exhaust ... cs#page-11 is the best quick description of exhaust system design I've come across. The chatter on https://www.reddit.com/r/Harley/comment ... 2_exhaust/ is informative.

I'm not even thinking of messing with the header or collectors. But the muffler seems to be less complicated, and replacing the muffler isn't necessarily stupid for me provided it's large volume and tunable. I think the major compromise here boils down to flow restriction versus noise versus physical volume -- the pulse voodoo &etc mostly happens upstream. One big constraint for the HD crowd is limited room on the right side for their common stepped-muffler designs. I have no problem with a large muffler under the saddlebags, which could allow both low noise and good flow. Duh.

For the record, I'm not really looking for torque or horsepower. I don't expect much if any improvement. I want to add a pleasing exhaust note, and I want to explore making my XII more unique. That's all. I think that the stock design might be tilted too far to "no exhaust noise at all" and adding the right kind of tone (in moderation) would be nice. Especially if this mod is pretty much free: stock mufflers litter just about every Harley rider's garage. (Any of you HD folks want to disencumber your garage?)

I'm still working through the True Duals stuff, which is all new to me. (Disclosure, I did wrench on Harleys for a couple weeks while the real mechanic was recovering from surgery. That was 30 years ago, and I didn't learn much except that the folks who lurk at Harley shops after dark generally are weirdos. Mostly good weirdos.) I understand that the left muffler of pre-2009 touring models (dual exhaust coming out under the bags) was more of a "sonic box" than a muffler -- about 3/4 of the exhaust came out the right muffler. The left one had a plug and was otherwise different. This system relied on a cross-over. The Goldwing forum (previous post) addressed this, saying that using these mufflers didn't matter. Like us, they have a cross-over in the headers. I gather that for 2009-and-later Harleys, 2-into-2 mufflers both flow the same, so that's what I'm looking for, cross-over notwithstanding. I notice that "True Duals" means different things to different people. For the HD crowd, it's often just getting rid of the cross-over that cooks your right leg.

And then there's ghost pipes -- not willing to go there at this time. I suspect our mufflers, with their own cross-over, are designed to function a bit like a single muffler. From what I read, HD 2-into-1 setups tend toward greater peak torque at some sacrifice to low-end torque. Dunno. (Somewhere in here might be where I'll screw up and just go back to stock.) Since we have 4-into-2, our systems are a blend of both anyway.

I've got a wanted-to-buy ad for stock Harley mufflers, 2009 or later, 1.75 inlet (I think they all are), "the longer the better", and "must be cheap". I'll also hit some of the shops. We'll see.

[Nails]

I just dropped $65 for some mufflers at the Harley shop. Could've gotten them cheaper on the web, but shipping. Don't know what they're off. They appear identical (no plug in the left, but something like spark arrester in both sides). I'll talk to a muffler shop about fabbing a s-bend to offset about 2" and to extend the ends near the back of the bags. I'll fab a mount for the front of the muffler, hanging off the stock muffler mounts. I'll need a new mount off the bags bracket. But I'll probably just stick blocks under it to see how it sounds first.

[Scott-(Altoona, PA)]

Pics, pics, send some pics!
Once you get it mocked up that is.

[Nails]

I have some photos, but PC died and I can't deal with them. Haven't really even started -- just replaced hot water heater and furnace. Snow on the ground this AM, the better for welding. But another riding season, come and gone.

[SgtSlag]

I have heard that a super-majority of new Harley owners remove the stock mufflers before they take delivery. Allegedly, there are piles of brand new mufflers outside of the dealership shops... Read a post some years ago that these mufflers can be had for a modest price, if you want quiet mufflers. Apparently, the super-majority of HOG's want loud pipes. I've had this in the back of my mind since I heard it. Always wondered if it would be much of a chore to adapt the Harley mufflers to our 1200's. Keep us posted -- "Inquiring minds want to know." Cheers!

[Nails]

The local shop had a dozen pair. Most were short -- I wanted long ones off an Electroglide or so. Pre-2009 have a plug in the left muffler, and they send a lot through the crossover. I actually picked a pair with a plug in both sides -- I'm not worried that they'll be too quiet.

They asked $75, I balked, and they said $60. Probably could've gotten them for $40 if I had cash.

I ran a Craigslist a couple weeks but didn't turn up a better deal. Might go better in a less rural area.

I plan to visit the muffler shops to make the short pipe I need. I'm inclined to try cheap pipe for now and SS for later.

The Harley pipes are chrome, weigh about the same, and likely perform the same or worse. Makes no practical sense, but what about motorcycles does?

[Nails]

Apologies for resurrecting this old thread, but I just got my PC fixed.

Here are some photos of the FLT pipes I bought. One shows the plug. Earlier HD pipes had a plug in only one side. I thought the later ones had no plugs, but mine ended up with a plug in both sides. I don't really know what this means in terms of restriction (the rest of the design), but at least both pipes appear to be the same.

The other two photos compare with stock.

I think I can hook them up to the stock headers by cutting a 30-degree 1.5" SS elbow right in the middle and then welding it back into an S-curve. I'll mount these pipes to the saddlebag brackets, somehow.

But for now I put the stock pipes back on because I have some other mods in mind. I'll make all the changes to the saddlebag brackets at once.

I mean, I probably wont get back to this very soon.

[Nails]

And since I'm talking about the exhaust, here's a repair to a bad bash in one header. (The other header has a minor bash.) I tried drilling a hole and pounding it out with a slide hammer, but it was too tough. Turns out, the headers are double-wall.

These photos show the inner wall replacement, as well as the piece destined for the outer wall. I cut these replacement pieces from a 30-degree elbow of stock SS exhaust material.

This shows the final outcome.

I used a reducing flame and Solar Flux B to avoid an oxidized, brittle weld. I like to think that it worked, but I'm looking at making a bash plate all the same. Also, the header alignment messed up and I had to reheat the repair and use hand hydraulics to bend it back -- coulda been a wreck, but it went back on without leaks.

[cushman eagle]

Nails,your header repair looks better than I would have imagined!
I would not be brave enough to try something like that.

[VoyKimmer]

Are you going to get them chromed like the originals?

[Nails]

It's all stainless steel. Just needs some steel wool. (Yours probably does, too. ;)

It's that 400 series SS (magnetic) common in exhaust systems. 409? The rod is some 300 series, maybe 306? -- the best I could find.

The Harley pipes also are SS -- thought they were chrome at first.

[SgtSlag]

Harley pipes are SS?... Dang! They are looking better and better, all the time! Thanks for sharing that tidbit. Cheers!