macmac, you are wrong.

With all due respect. :)

I am a uncertified xpurt on the debaffle of stock mufflers. I have done xtensive testing and trust me, wasted a hell of a lot of money. I was also one of the biggest people, (275) pounds, of why it was a waste. But now I think I differ on it. Let me first address the loss of torque issue.

If you look at the pipe size from the heads coming down, going into the goat bladder and the pipe size of the end of the muffler itself that goes into the goat bladder, it is the same diameter of the silencer, baffle, whatever it is called. So you have a reducer going in and coming out as far as pipe size as the baffle. The baffle offers you no reducement in size of pipe so you are basically getting the same back pressure.

The difference is it isnt backed up into an exspansion chamber before exiting like the baffle has. This is what also causes the poor throttle response and to me the lack of smooth acceleration.

Now as far as leaner. If it is dripping in blood, how damn lean can it get. :) I really dont think the air/fuel ratio changes at all. You are not pumping in any more air, or out. It is just a smoother bowel movement. I agree the marble is needed as it accomplishes or tries to what you recomend with the reed valve removal. I may pollute but my lawn tractor is a lot worse at it.

So, after doing this test back and forth and back and forth and back and forth for a year, I say it is ok. The powerband does change from the low to the high side, but isnt that what is needed so you dont lug the engine. I rev my gears out a lot further but dont get that teeth vibrating chatter that I did with stock pipes. So Mr. Maple Man, what do you think? Can I be right, or do I just need commiting to a good VA Hospital, if there was one.

Also when Trip gets back, I have a question I want answered. Dont worry, I support paypal here. Trip I know is debaffled and has been for a long time with no issues, but yet he is selling a set of stock pipes. What gives Trip?

BlownDodge, I am in your corner and say anyone who doesnt debaffle should, well, vote in the Iranian election.

[billmac]

I have learned a bunch from Mac's rantings. I hope he keeps them coming.

I started up my Nomad with the headers and goat belly in place, but no mufflers. I expected much noise. Heck it sounded about the same as with the mufflers.

[macmac]

LOL, I am never wrong, unless my wife says so!

I never get lost either, and I have no GPS! When I rode from NH to Cal and back I didn't even need a map. I mean what fool can't figure out where west is and turn back east once you hit that big salt pond in Cal?

Well so what if I ended up in east Fla? Thats still on the east coast ain't it?

And yeah so I made one wrong turn and ended up in Arkansas, after all it was just one wrong turn leaving Fla.

So far I ain't never had any marbles anywhere, muchless on my Nomad! I just get rid iof the whole mess, and once you do there is no place for any marble at all to go.

I skin cats, never gut them, so maybe you don't loose much back pressure with the maze of twisted, bent, and sick piping on that 400 pounds of so called exhaust system.

I do know for lots of low end torque ya gotta have some back pressure, and with out it, it acts like a sneeze a woman does a wee poof of a sneeze... No Power..

As to lean most of these bikes are just too lean from the factory, so anything you do only makes it worse untill some fuel modual gets installed.

I run my Nomad on 87 Oct and ride 2 up in 'My Mountains" seeking new maple tress to tap! No pinging either!

Last when my wife does say I am wrong, I fix her just like anything else.. I start by soaking my tomahawks in the toliet!

[macmac]

And Oh YEAH! Last time I looked at my stock system it was in a box in the cellar, with a lot of other stock parts I see no need of having in the first place.

Some day I might have a yard sale and sell the dog dishes, swap for more mufflers so I can build a chrome fence, and grill burgers on the cat goat bladder thang.

All that goat bladder did was make me hot, but not in the right way! I got a wife who makes me hot!

Lean it is.

[dogdoc]

hot she is.

[redjay]

Hi. I gutted the mufflers and goatbelly of a spare exhaust system I bought. (To me) the bike lost torque with the gutted goatbelly installed and was too noisy for my taste. With just the gutted mufflers the bike is how I want it. Not too noisy and no loss of power that I can feel.

[phenrichs]

mac you are a mechanical poet.

you should put this stuff in a book.

And you are right and I will back you all the way on the lean issue. Mine starting pinging a week after the debaffle with everything else stock.

tfi installed, disconnected the solenoids, marble ( cause I didn't have time to remove before custer) and now I have a whole new set of noises to get used to.

[macmac]

Originally Posted by OP

mac you are a mechanical poet.

you should put this stuff in a book.

And you are right and I will back you all the way on the lean issue. Mine starting pinging a week after the debaffle with everything else stock.

tfi installed, disconnected the solenoids, marble ( cause I didn't have time to remove before custer) and now I have a whole new set of noises to get used to.

Oh sure take my wife's side on books.... She wanted me to co author a book sort of about our trip west, and so I did, to prove i couldn't write, and she thinks what I wrote is funny!

I am not funny, now and never was, so get over it, besides all I saw was rocks anyway. I mean this whole country is plain loaded with rocks! Big rocks, little rocks, and every kinda rock inbetween.

None of these rocks bothered me much except the type called obsidian where I got cut in Yellow Stone messing with things I shouldn't have been messin with!

I lost the few flakes I had of them along with flint I found in Tn, when my 01 was stolen.

As to lean, IMO any Nomad would benifit from either a Cobra or a TFI fuel modual.... even all stock. An all stock bike atleast would run on regular and not ping.. I have no idea what the settings would be for that.

[claybuster]

Originally Posted by billmac

I have learned a bunch from Mac's rantings. I hope he keeps them coming.

I started up my Nomad with the headers and goat belly in place, but no mufflers. I expected much noise. Heck it sounded about the same as with the mufflers.

Yes, your right. I did that too when I had my mufflers off. My wife was standing there and I told her to get ready to cover her ears. When I started the engine I was really surprised how quiet it still was. Like you said not much louder then with the debaffled mufflers except a slightly deeper tone. When accelerating in neutral though I could feel the lack of back pressure and loss of power.

[macmac]

What back pressure does is hard to explain. People don't work on this method of breathing. We tend to breath in, stop, and then breath out and stop. When we are calm we exhange only a part of the air we breath, and at hard work change something more but not all still.

Now if you have a sucking chest wound, then we breath something more like a engine does in the first place and this action ends up a lot like no back pressure.

Engines have valves which over lap the breathing, so when waste gasses go they draw in fuel and air as the next new mix. With a too open exhaust system you loose the effect of drawing in a new mix, and breaking the fuel air mix into small parts called atomization.

The deal is to make the most possible suface area of a air fuel mix. Each molecule of fuel is maximized by ramming it into air and smasshing it with compression, which raises the temp of the mix to the point a small spark will set it off.

Don't do this but there was a time when I was a wildman, and knew I could toss a lit ciggy butt into a bucket of gasoline, and the butt would simply be put out.

In fact you could light up a piece of birch bark and float it on the gas and it would just burn a little better.

The air on the suface was mostly burned away, and it looked like a big candle.

Now go kick that bucket and all sorts of havoc is the end result, because that fuel just got mixed with lots of air, but still not all the air the mix could use, so the end result is a big flash (very dangerouse to people) and lots of smoke.

With more air there would be very little smoke, and if there was a way to heat this mix like in a contained clyinder there would be a huge explosion from a few quarts of gasoline.

Now if you like buy a common oil lamp and mess about with the oils it uses, as it too is no more than a primitive carburator.

You can add a tin can to the chimney (adding back pressure) and get more light and more heat. You can change the mix by trimming the wick, and firm different shapes which will affect the type of flame, and everything else.

You can pull off the chimney and get black sooty smoke (no back pressure) of course there are no valves, and so still how back pressure works in a internal combustion engine is hard for me to explain.

I am not what you would call a school educated man, so I do have troble explaining things.

One other thing that comes to mind is if you have a small foreign car that has a bad exhaust...

Many of these smaller 4 bangers have big power problems with no back pressure. Not only do they get loud, but they get real slow getting moving from stopped.

Carb icing is another problem, but I have never seen it on a bike. I have had it happen with side draft SU carbs in winter, and what happen is usually you are on some inter state for a long time, where the steady speeds allow ice to form in the carb body, right at the venturi, and throttle plate.

This tends to hold the movable venturi up (a slide in a carbed bike). SO if you slow down or stop and the slider is hanging on ice, you have a very lean mix air wise, and a overly rich mix fuel wise because the main jet needle is held open too much.

This ends as no power, but the car can usually go, and once you get to the speed you were at on the interstate things are basicly ok again. Or you yank the air filters and bash up the ice...

[jesse]

I'll take a copy of Mac's book. I think he is rarely wrong. Mountain men learn by experience and store this knowledge for later use.

[ridemslow]

So... simplify this for me.. Leave the Goat belly alone and just debaffle? Is that what you guys are sayin? Hell I'm confused.

be smart and leave your bike stock, or buy a set of aftermarket pipies with a TFI.

[ridemslow]

10-4 -- I had planned to gut the goat, debaffle was something I didn't really plan on, but allowing it to breath out(exhale) was what I was thinking. ::) Hell what do I know? ???

Originally Posted by trjam

be smart and leave your bike stock, or buy a set of aftermarket pipies with a TFI.