Baffling the Cobras, I mean reaaaaaally baffling

[Hellcat]

I don't particularly like loud pipes, but I bought the Cobras because they look AWESOME on the Valk. What other Cruiser can have six tubes running out the back? None. Zero. Zip. I have to keep these pipes.

For me, though, unnecessarily loud, and I would like to quiet them as much as possible. (Seriously, if I could get them to sound like stockers with the piggies cut I would do it. Impossible, I know, but it gives you an idea of how quiet I wouldn't mind the pipes being.)

I did some looking in the old tech archive and found posts referring to ideas people had, but not the posts that discussed installs or results.

Examples:

1. Wrap baffles with stainless steel pads found at Walmart.
2. Get a second set of baffles and weld them onto the first set, making them twice as long
3. Put a washer on a bolt at the end of each pipe ("tuneable" performance, but noise effect?)

I'm wondering about #2 also, in terms of just punching some holes in some cheap pipe and welding on that extension. Or what kind of pipe is made that already has a bunch of holes? Maybe could get some at McMaster-Carr.

Finally, saw these Smartpartz baffle add-ons, some of which claim to reduce sounds 6-12 decibels (a lot!)

I don't think they make them for 2" pipes, and anyway six of them would be $$$. Any suggestions from you machinists about how they work and how to fabricate some on the cheap? They don't look like anything special even though they say "years" of sound research is in the design. Really it just looks like a steel tube with a flat piece of steel running down the center (though it's hard to see from the pic if anything else is going on inside.)







http://www.smartpartz.com/baffles.html



All thoughts appreciated. Commentary on loud vs not-loud is unnecessary - I know what I like.  

[Printer Mike]

My "new to me" Valk came with Cobra 6 into 6 pipes. I'm probably gonna get some earplugs for long rides...(the sound is awesome though)

I'm also interested in a way to quiet them some. The headers have turned blue. The stock jets are still in the bike. I wonder if restricting the exhaust flow a little would correct the lean condition without rejetting...

[MP]

ANY single wall pipe will blue. Not necessarily because it is too lean.
MP

[Chrisj CMA]

I seem to remember that the few folks that actually removed and wrapped the baffles were pleased with the results.  Id use actual muffler glass from a performance shop.  I think it will outlast some steel wool pads that are not designed for that purpose and they wont rust........but that sounds easy enough as long as you can get all the baffles out, it may not be as easy as it looks.....I tried and some were very stubborn

[pvan]

On my second Valk I installed new Cobras and immediately thought they were too ear piercing so after a couple months of irritation I tightly wrapped 1/4" fiberglass matting around each of the 6 baffles.
By my butt dyno the performance improved due to the slight increase in back pressure and the nasty raspy tone was relaxed... yet the overall sound was still very authoritarian.

[sugerbear]

good place to get muffler repacking is at a dirt bike shop.

[Hellcat]

I think I'm gonna try everything.  

The main thing I want to try is making the baffles longer. Buying three new cobra baffles and cutting them in half seems cost-prohibitive, but I see some 8" long baffles for 2" drag pipes in some Harley catalogs that would look to serve for less than $40 total. They aren't as heavily perforated as the Cobras, but a lot cheaper.

I also wonder where I might advertise for some of the above but used and forgotten?

I'm not sure what effect wrapping with steel mesh would have versus fiberglass. Have to try both I guess! Fiberglass seems like the quieter option, though.

I'll probably try to do a homemade version of the smartpartz add-ons above, too. Looks like it could be done pretty cheaply - an automotive freezer disc with a hole the same size as the piggies, a short pipe welded in, and a flat piece of metal running through. Even if they don't reduce the sound appreciably, I read some posts in the archive that said that closing the pipe down to 3/4" - the size of the stock piggies - brought back the six to ten HP that the Cobras "automatically" lose. Worth a try!

[Hellcat]

The factory pro jet kit got tons of good reviews in the old tech archive. Not just a needle kit, but has the "38 slow jets" that are very popular among VRCCers. $131 at HDL. I went ahead and sprang for it, both so I'd know I had rejetted properly for the Cobras, and because my 97 with 26K doesn't seem to have as linear a power band as I'd like (and am used to coming from a fuel injected bike).

I don't know if I'll get the kit installed this weekend, but I hope so.

My "new to me" Valk came with Cobra 6 into 6 pipes. I'm probably gonna get some earplugs for long rides...(the sound is awesome though)

I'm also interested in a way to quiet them some. The headers have turned blue. The stock jets are still in the bike. I wonder if restricting the exhaust flow a little would correct the lean condition without rejetting...

[woefman]

What ever you do keep us informed. Pipes are on my list of things to do.

End Post !!

If bored and don't mind a hijack thread read on below .........
 

I for one like Loud Pipes , and the cobras but I dislike the bluing.

I also enjoy riding at night , it gets hot here in Arizona so I often ride at night.

However I have not got cobras because I do not like to make my love for loud pipes someone elses nightmare. I'd rather not wake up living or the dead for that matter  as  I try to enter a neighborhood at night.

My Pipes Have been moded from previous owner I like the way they sound at a stop light at idle.

But I sure would like to get rid of what I call a Suzuki Sound when I rev it at idle. (Cobras might be the ticket)

Has anyone experimented with like Canon style Pipes but Skinnier like Harley Long shots  ?

I see many straight Pipes ( canon's)  but not any that are say only 2 inch in Dia.

[Gunslinger]

I have Cobras on my '01 Interstate. When I installed them I took 6 freeze plugs and welded them to the engine side of the baffle after drilling a 3/8" hole in the center of each. This had a dual effect of reducing the noise and increasing the back pressure.

Idea was not mine, it came from another Valk Tech site.

[Hellcat]

How much would you say they reduced the noise?

And why the engine side?

And how has 3/8" worked out. I had read a post somewhere on the idea, where the guy had tried a hole smaller than a stocker piggie and it had been too small, so he'd redrilled to the size of the stock piggie.

[Thunderbolt]

on my 97 Tourer.  The kind you buy at the auto parts store to fix a hole in your boat.  Used some 20 ga stainless steel wire to spiral wrap and hold it on the baffles.  For me it was enough to make it tolerable.  Took out some of the tinny sound.

[mikeb]

no baffles at all in mine if its to loud your too close to me or to dam old to ride with me :

[R J]

no baffles at all in mine if its to loud your too close to me or to dam old to ride with me :

And I'll bet you wear hearings aid when not on the bike.

[R J]

I have not read all of the responses, but here is something you can do.

Remove baffles.

Weld a round piece of steel on the FRONT end of the baffle.

Drill about a 3/8 to a 1/2" hole in this piece

Rewrap - repack your baffle

Insert in pipe and happy motoring.

[Hellcat]

By "front" do you mean engine side or exit side? Still trying to figure out if one is better than the other and why.

Piggies put the smallest points at the exit, and so do the hard kore add-ons referred to in the OP.

[R J]

By "front" do you mean engine side or exit side? Still trying to figure out if one is better than the other and why.

Piggies put the smallest points at the exit, and so do the hard kore add-ons referred to in the OP.

Put it on whatever end ya want.   But, I'd recommend the end closest to the header pipes or the front wheel........

Ya put it on the exit side, you will burn your fiberglass a lot quicker, and loose some back pressure...

You need some back pressure in these pipes, or ya lose horse power....

[Smokinjoe-VRCCDS#0005]

I have some Vance And Hines wrap but could'nt get the baffles back in after just one wrap of the material  All three of my bikes have Cobra's but the ones on my yellow bike are damn near twice as loud as the others and they all still have the baffles in.I don't mind loud in fact I dig it 

[gregc]

   The inside dia. of Cobras is 1.750,  and J&P cycle makes a couple of different aftermarket baffles you could add.  I took out the factory baffles and just added their short  ones.  Its loud but not like straight pipes.