kerker 4 1 too loud with 2.5 inch competition baffle

[joshua cohen]

hi im new to the group i just bought a 2001 vmax with a stage 7 that has a 4-1 kerker supertrapp muffler with the 2.5 inch baffle and its way too loud i was told i could find a 2 inch medium competition baffle or an even smaller one but i cant find one anywhere? can someone please help me

 

[gentsvmax]

I have(had) that excellent,killer deep baritone sound at idle, then a really raspy,aluminum can scream up through mid range to top end. Same kerker can, same dimensions. I scoured the net for a different baffle, nada! I started looking at the guys on youtube making baffle's out of everything from chicken wire to fiberglass insulation. Finally started reading about the ceramic filler sheet material 12'x32' blanket AMAZON. It doesn't blow through the inner baffle perforation's like fiber glass. The stuff is easy and clean to work with and really sounds great. We think it solved a perceived lack of back pressure issue I was having. The bike seems to have a more manageable, ride-able power curve and again it sounds great! Pics of the finish wrapped baffle, I used safety wire to really tightly secure that ceramic blanket.

 

[user 16790]

2.5 inches isn't a baffle, that's another exhaust

 

[Fire-medic]

Either another baffle, 1-1/2" or another can/baffle of whatever size you desire, is what you need, try Sean Morley, [email protected]. Going to another baffle will probably require another canister cap.

As a suggestion, you could try fabricating your own baffle, go to a muffler shop and show them your canister, disassembled. they can use stock sheetmetal components like a reducer flange to make a smaller insert. Use one of those at each end, connected by a tube of the reduced size, and drill the middle tube full of holes, wrap the assembly with some acoustic material, and make sure that the assembly fits tightly into the canister so it doesn't have any free-play, to eliminate wear or rattling.

Here's a crude drawing of what I am describing, this is for a megaphone, yours would be easier as the two end pieces (shown in the drawing as reverse-'C's) should be the same diameter. You might want to try drilling fewer holes in the middle pipe, at first, then try it out for sound, and add more incrementally, to reach the sound you want. This way, you don't need to buy a replacement end cap, those can be very-pricey. You could fabricate the entire baffle for the cost of one brand-new end cap replacement, I'm sure. I've done something similar to make entire canisters to-fit a VMax exhaust.

Gentsvmax's idea of using SS safety wire is a good way to secure the material. Of the McMaster-Carr ceramic cloth below, 1/8" thick, I think two 360-degree circumference wrappings of the center baffle secured with SS wire, should provide the sound-reduction you want.

Source for the ceramic material:
https://www.gasketsinc.com/product-...MI0eniu6zW6AIVTj0MCh0RIAxKEAMYASAAEgIYUfD_BwE

12" X 10 ft X 1/8" thick, $37.36 McMaster-Carr ceramic high-temperature cloth
https://www.mcmaster.com/ceramics/thermal-insulation/

12" X 24" X 1" ceramic high-temperature cloth $23.50 free shipping. Amazon
https://www.amazon.com/CM-Ceramics-...=ceramic+sheet+material&qid=1586264730&sr=8-7

 

[Traumahawk]

Sean Morley is where I bought my 2 inch and 2.5 inch competition baffle. The outer cans are the same. The only difference is the inner removable baffle.

 

[Traumahawk]

2.5 inches isn't a baffle, that's another exhaust

Lol......that's why I adapted 1 to my gen 2.

 

[joshua cohen]

will this be a quieter muffler https://www.summitracing.com/parts/sup-443-2517

 

[gentsvmax]

I humbly stand corrected, mine is not a tapered can and had simply blown out it's original packing. I may have just simply gotten it back to its intended sound level.

 

[gentsvmax]

This is on ebay right now for 91 bucks for Honda.Could that inlet be the right size?

 

[Fire-medic]

The Summit racing canister is a Supertrapp, you add, remove discs at the end cap to tune the sound.

gentsvmax's Honda canister is a deal, if the inlet is correctly-sized.

https://www.vmaxforum.net/threads/ufo-4-1-dragstar-shhhh.31804/#post-342487 Take a look at this.

A place to start, if you want to roll your own, like I did.
https://www.ebay.com/itm/00-01-HOND...531131?hash=item4b73a1ce3b:g:W48AAOSwqUleOFwD

 

[65Corvair]

I replaced my missing baffle insulation with furnace insulation (refactory fiber insulation). Comes as 1" thick rolls. Tried different lengths as far as sounds. Couldn't tell if the performance was different but the sounds are drastic. Without a baffle it sounds like a NASCAR stock car roaring. With the baffle it sounds like the old 6 cylinder Busch race cars.
https://www.woodstoves-fireplaces.c...MIjO3vuufY6AIVVtyGCh2h9gFQEAQYBSABEgJEJPD_BwE
https://www.homedepot.com/p/Ceramic...urnaces-Forges-Stoves-CF6-1-24X60in/305578021

 

[joshua cohen]

well i tried that muffler and it was too much backpressure and the bike wouldnt rev out

 

[gentsvmax]

What muffler? Which one, did I miss sumptin?

 

[joshua cohen]

the supertrapp with the plates

 

[joshua cohen]

because i have a stage 7 it cant have too much backpressure

 

[Fire-medic]

Did you try operating it w/o any plates? Just to-see what's up? Few plates=more backpressure, more plates=less backpressure. How-many plates were on the Kerker-Supertrapp (Kerker now-owned by Supertrapp) canister you tried?

 

[joshua cohen]

yes i tried with all the plates and it was still too much backpressure yes i tried with out any plates but it was too loud im curious to know what people are running with a stage 7 kit

 

[Fire-medic]

because i have a stage 7 it cant have too much backpressure

Respectfully, backpressure needs have pretty-much nothing to-do with your jetting. I am not a pro mechanic/tuner, I am not a mechanical engineer, I don't own a flow-bench. I do own a stock VMax w/a Dynojet Stage 7. If you look in one of my posts on this thread, you can see where I've tried a complete exhaust, a UFO 4/1, with different ends. All were of sufficient flow to allow the bike to run to redline. They produced different amounts of noise. The two UFO (Dragstar and megaphone) were loud, the megaphone was noticeably-quieter than the Dragstar. Both were louder than I would want for running-through a tank of gas, but good for a trip to Bike Week, if you wore earplugs. The long canister I modded from another large-displacement bike. I had welded-up an adapter from the UFO 4/1 collector, to the diameter of the canister. As Sean Morley commented, 'ugly, but quiet.' I don't think it's really that-ugly, it is a bit long, but I haven't had the initiative to cut it up to shorten it. That looks like for this canister, it would require a good deal of work to get it sealed-up, and not to-rattle. I can live with it. It's quiet, and I didn't have-to change my Stage 7 jetting to make it work.

From my research and reading, backpressure is there to use the flow to keep the fuel/air charge in the combustion chamber, especially-during valve-overlap (both valves or in our case, four valves) when they're open at the same time. Backpressure is designed to happen at some target RPM, and if it's suitable for high RPM effect, low and midrange suffers, this is probably a characteristic suitable for a racing engine, where low and midrange RPM isn't needed, as the engine is operating at high RPM. For most bike owners, something which works in the midrange is best, because that's where you spend the bulk of your time.

 

[Woody]

Check summit racing.for an open end cap.to replace the final disc.on a super trapp.

Not to many people.know about these.they are made for closed course racing. Worth checking into.

 

[joshua cohen]

i got it sorted out bought a 2 inch la customs baffle and a 1 5/8 piece of pipe screwed it to the end of the baffle. i screwed that to the main baffle in the muffler along with alot of packed insulation. its much better but still loud seems like i gained alot of low end torque! the bike does backfire out the carb sometimes the front right cylinder idles alittle stronger then others i want to sync and fine tune them but i dont know how to as my v boost is fully removed with just a straight pipe also the front right header pipe is turned blue