thinking of making my own muffler

[Beezil]

with all the "no room for anything" whining I've been doing, I figured I'd throw this out......

there's no room for my old exhaust to fit in the new scheme.

so, I was thinking on making my own....I found some 16ga. 5" diameter tube laying around, and just for fun, threw it on a brakepress with flat dies and compressed the round tubular shape into a nice oval shape, somewhere around 6.25x3.5 wide....its a sexy muffler-looking shape to be sure, but much tighter.

so, I was wondering......

I can either make individual chambers with baffles like the flowmaster uses, or I could perforate the pass-through tube with a bunch of holes and fill the inside of the muffler body with some kind of batting or something.

I'm going for QUIET....I don't want "performance sound" or any of that crap......

any ideas? anyone know anything about muffler design?

[Fullsizexj]

Boy, talk about penny pinching LOL, Just go get one of those tiny little cherry bombs and route your exhaust to go up in front of the gas tank and mount it up in there and then it is a straight shot to the wheel well and then route it back, that is probably how I will do mine, with mine I have to angle over to the center tunnel right after the Cat and then up like that to clear the upper wishbone link but I have checked and there will be plenty of room for it even if the backend is completely squating, I am pretty sure you are looking at the same situation

[RichP]

Well, there are some underground publications on how to make 'mufflers' and various other things like that. Carefule you don't get atf interested :D

[KY Chris]

You nutty. Go for it. Once again, I provide no tech, but I'm sure you'll make it work. Go ahead...put some snakes in yer mouth.

[CW]

Originally posted by Beezil 07-22-2003 10:14
go cherry bomb or go home.

I am going to try one of these (http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=29720&prmenbr=361) in my new exhaust, hopefully it will quiet it down.
http://www.jegs.com/photos/3297232510cutaway.gif
Maybe have a perferated cone at the front and then spiral baffles the rest of the way, kind of like the spiral flows.
http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1338&prmenbr=361

[Beezil]

hmmmmmmmmmm....

I have TONS of pre-perf steel sheets around, with different percentages of "open" (which is combo of hole size, hole centers, hole columns, and hole staggers) I never, never thought of using perf sheets as baffles!

I wonder how it would work?

shit, chris, got yer message....damn I forgot...sorry. please try again, home now.

is my turtle in your yard?

[Chark]

How about a SuperTrapp on the end of the exhaust. They are small and you can tune the amout of flow by adding or subtracting the number of disc.

[Beezil]

funny.....I was just talking to chew....he said the same thing...

there's a chance I may have to run the exhaust above the floorboards and go out above the rear bumper.....kinda like a sand buggy I guess.....

we'll have to see, just trying to stay ahead of the game.

[Flowers]

I meant to ask you about the Supertrapp tonight. YOU NEED TO START LISTENING TO ME! I've been telling you to run the damn exhaust through the cab for weeks. Of course, I don't know if it will work yet. you tell me.

Flowers

[XJZ]

Beez:

Just plumb the exhaust to your cage and have it exit out the rear of the roof rack. :cool:

[Beezil]

flowers....since you are sitting int he passenger seat in moab, there's no telling how I'll plumb it.....how bout some white smoke coming out of your ears? I betcha you'd produce a "throaty" sound......

[Neil]

I say make a 180* bend at the manafold and run the pipes straight out of the hood. :D

[Beezil]

should I put a little flapper thing on there like the big trucks have?

:D

[Scott Mac.]

Than you'll have to put some air horns on the roof and a bull dog on the hood. :gee:

[Neil]

Don't forget the "Truck Nutz"!!!

[Beezil]

a bulldog?

no way man

go KW or go home!

[Jeremyvnc]

okay maybe i'm at the wrong site but i thought we were talking about xj's here? You guys are going all wierd on me now. :)

[Beezil]

get used to it jeremy, just about all naxja threads get destroyed eventually!

[rixXJphx]

Effective mufflers work on two different principles in combo:
Fiberglass stuffing as a sound deadener; and,
Resonation created by plate baffles precisely spaced to reflect sound waves back into each other, causing cancellation of the loudest offending frequencies.

You could prolly autopsy an XJ muffler to determine the ideal reflecting distance, then match that distance in your 'flattened tube' design with some solid (not perfed) baffles.

See:
http://auto.howstuffworks.com/muffler3.htm

[Beezil]

rix, without getting into the science of it all, would a fiberglass batting muffler be easier to get right? if so, could you just use standard attic insulation?

thanks for the link, gonna check it out now...

[Steve88XJ]

hmm! sure would like to see some pics of your progress and when its done!

[Fletchs90xj]

Truck stacks would be cool, then when you go through deep water theres no chance of sucking it back into the engine. Then you could also incorperate (sp?) a jake brake to help on back pressure engine braking on those steep hill decents. It would never work where I'm from cause we have emissions testing every year before you can insure and your exaughst must come out behind the rear tire if thats how it came from the factory. damn rules
Fletch

[XJguy]

Beez, why stop there machine a new engine block while yer at it make it fit around your new suspension ;)

How about capping off all the holes in one side of the frame rail and just letting the exhaust flow into it and exit where there are no more obstructiuons then just continue with a conventional exhaust system. Cover and or coat the floor boards above it to keep the heat from cooking you. Since your running heims and not rubber bushings the heat transmitted wont be a problem. Stainless exhaust flex hose between the headers and frame can be put into service to make the union.

How much life this will take away from your frame is as a good a question as any, but the heat cycling will probably take a toll...but you may have trashed the whole thing by then anyway.

XJguy

[Chark]

Beez...you asked about the insulation. I'd use muffler packing that is available at your local offroad dirtbike shop. I will last alot longer.

[rixXJphx]

Glass-only mufflers (Cherrybombs) give that loud rumble.

However, there are separate resonators that are much smaller than mufflers (more like a small cat). Usually used on luxury vehicles in addition to a conventional muffler.

Maybe install a resonator forward in some available space next to the CA bracket, then flatten a regular cherrybomb and stick it wherever.

[Lucas]

I think it was in Summit, but there was a turbo muffler that was the same dimension and shape as a cherry bomb. they pack all the internals and baffling of a turbo into a tubular case. Small and quiet, but perhaps too restrictive?

[DeadEyeJ]

They are called Turbo-Packs. I just got one put in my XJ. I got it at my local exhaust shop. Looks like an aluminized cherrybomb, fully welded and slim. Mine is a bit long, but they make shorter ones. Pretty darn quiet too. Actually has chambers inside, not just packing.

Call Reed Muffler and Brake at 801-782-6789 for some info. Sure, he is in UTAH but he could probably connect you to a supplier or something. Jerry, the owner is a heckuva nice guy too. Just tell him that Jared McKeeth sent you.

Jared