Idea for mod to stock silencer

[1911user]

Would it make my 1990 kdx quieter to replace the front half of the silencer internals with a straight, ported pipe wrapped with fiberglass? Essentially it would eliminate the section that forces the exhaust to reverse flow direction twice. The replacement would be like the current 3-inch wide, fiberglass-wrapped section only extended all the way to the front; roughly a foot of pipe to wrap. I'd keep the spark arrester and all of the rear components stock.

The reason for the question is the welds are broken on the piece that reverses the flow direction. Currently that piece is not installed to prevent any possible severe blocking of the exhaust. I'd like the bike to be quieter without killing the power or spending much money.

 

[KAY DEE EXER]

Can you get it any quieter than with a stock pipe?

 

[Nice Guy Eddie]

if my understanding of silencers is correct, reversing the flow against itself is integral to reducing the sound... it helps take away the 'pop' as each compression comes out the rear... ergo, I think it would be louder.... much

I could be wrong though...

 

[YZ165]

Did you ask if anyone had a stock silencer for sale cheep? Lots of KDX guy's go aftermarket and might have one you could buy.

 

[JasonWho]

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[Nice Guy Eddie]

Like what'shisname said

??? .... I feel so loved... :laugh:

my understanding actually comes from knowledge of firearm silencers (hence the "I could be wrong")... but they were first designed after internal combustion engine mufflers... funny how life crosses like that eh?

 

[JasonWho]

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[1911user]

okay, I'll concede my idea was original but the stock config is better. I'll see what it'd take to get the pipe rewelded or maybe try some epoxy designed for exhaust systems. I've got a few days down time waiting for new spokes to arrive.

There is a layer of cystalized black crud all over the silencer internal parts. How important is it to scrape all of that clean assuming a stock exhaust configuration? I don't think I'll like this answer but need to know anyway.

PS: How did the name "silencer" get applied to a dirt bike muffler? They darn sure aren't silent.

 

[Nice Guy Eddie]

PS: How did the name "silencer" get applied to a dirt bike muffler? They darn sure aren't silent.

well you should hear the shoddy job it does of making a gun silent too.... lol...

 

[JasonWho]

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[Nice Guy Eddie]

Nice Guy Eddie: What the heck are you talking about? Don't you ever watch TV? They work fine on there. :-)

Yeah..... even on revolvers and long range sniper rifles....

 

[1911user]

well you should hear the shoddy job it does of making a gun silent too.... lol...

It would be kind of hard on the bulllets; at least the first few anyway. :rotfl: Suppressors are a subject I'm interested in but don't have the finances to pursue at this point in time. I've heard a few good ones in different calibers but the 22s are so quiet it's spooky.

 

[Nice Guy Eddie]

It would be kind of hard on the bulllets; at least the first few anyway. :rotfl:

oddly enough, some very simple homemade suppressors (to be technically correct) use this technique to align the inner barrel hole.... placing each barricade in (thin metal sheets) and shooting through to align the next.... The bullet itself plugs the hole to cause the gas to backlash against itself for the desired effect...

A .22 is the most logical to try to suppress... if you're looking for quiet... but at subsonic speeds (which is required to effectively suppress a weapon) it has very little stoping power... therefore the 9mm (and other compact submachine gun rounds) is a common one to use....

I have heard some pretty quiet suppressed .22's with integral barrel suppressors.... I have heard some nearly as quiet with a 2 liter bottle filled with insulation taped to the end!!! (again, you just shoot through to make the hole)

 

[G. Gearloose]

My '91 is whisper quiet..
Put a 2" x 5" wrap of packing around the center diffuser , and I added a 1" copper pipe 45 degree to the outlet, to point the sound at the turf.

There is lots more noise coming from the front of the bike, vs the rear...

 

[Nice Guy Eddie]

can you post a picture please?

 

[G. Gearloose]

Sure, but it could be a while, so just give me a few days....

 

[G. Gearloose]

Here is the piece I made...

Its a 1" copper pipe 45 degree elbow, but its the type that is std 1" pipe on one end (I forget the proper name) .

From another 1" copper pipe adapter, I cut a 1/4" ring off, and soldered it onto the 45...

A band clamp (this one time, at band clamp... :yeehaw: ) keeps it attached to the silencer..

It looks much better painted black

 

[JasonWho]

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[KAY DEE EXER]

I have heard some pretty quiet suppressed .22's with integral barrel suppressors....

You right I shot one few years ago. From what I can remember the bolt is the loudest part. You must use a sub-sonic (slower than the sound barrier) round for it to be really quiet Not to change the topic or hijack this thread but have you heard of a coke can packed with polystyrene foam. I could let rounds off in my bedroom inside a block of units with no problems from the neighbours (.22). I love the movies that have a .44 magnum with a huge sniper scope and a suppressor. LOL I bet she'd be quiet...

 

[r6demon]

Hi Guys just so you know, the guy who owned my 90 KDX200 has made this change to the internals of the pipe ie cut out the section that forcves the flow back on itself and added a straight piece of pipe surronded in packing but leaving the spark arrester.

Now I have never heard a standard pipe but with some careful packing my pipe will just about get through the UK MOT. Its not REALLY loud but it ISlouder than a normal road legal can.

From my basic knowledge of cans this should give you a marginal performance increase as the gases are more free flowing.