Expansion chambers?!?!
- Thread starter ty.man
- Start date
famousseajay
Been Around the Block
Chambers are badass. Why would you not want them? Thats one of the reasons 2-strokes rock! 8)
The answer is - It all depends...... Stock pipes are quieter than almost any aftermarket chambers and they are remarkably efficient across the whole power band. Chambers on the other hand are typically tuned to work best at particular engine speeds and that gives rise to the kick in the pants type power band with nothing at the bottom end.
You know what a dyno chart looks like? well imagine it's made out of string and you take a stock low wide curve and pull it up to higher revs and more power. The piece of string is now not low and wide but represents a mountain - tall and pointy. That's sort of what chambers do. They make more power at one point and less everywhere else.
Really good chambers don't actually lose so much down low but add a little more higher up.
It is possible for example to open up a set of stock mufflers and weld in a reverse cone and stinger an muffler to make a little more at the top and not lose much lower down. To get more power the chamber ends up being larger diameter than stock pipes, so they can't be hidden inside.
You could fabricate a set of chambers that follow the same lines as stock pipes and have hidden internal mufflers so that they look sort of like stock pipes.
If you want a set of race chambers hidden inside stock pipes to get around AHRMA rules that's probably not going to be very successful. It all comes down to what your objective is for the project.
You know what a dyno chart looks like? well imagine it's made out of string and you take a stock low wide curve and pull it up to higher revs and more power. The piece of string is now not low and wide but represents a mountain - tall and pointy. That's sort of what chambers do. They make more power at one point and less everywhere else.
Really good chambers don't actually lose so much down low but add a little more higher up.
It is possible for example to open up a set of stock mufflers and weld in a reverse cone and stinger an muffler to make a little more at the top and not lose much lower down. To get more power the chamber ends up being larger diameter than stock pipes, so they can't be hidden inside.
You could fabricate a set of chambers that follow the same lines as stock pipes and have hidden internal mufflers so that they look sort of like stock pipes.
If you want a set of race chambers hidden inside stock pipes to get around AHRMA rules that's probably not going to be very successful. It all comes down to what your objective is for the project.
ty.man
Active Member
teazer said:
@ teazer, im not sure im understanding you correctly, are you saying i can take a muffler and chop it up and kind of make it the same function as chambers?
The stock pipes are soooo ugly, and almost everyone has dg's. Specs are just outta the price range. I suppose if it came down to it i guess i could compromise and get dg's but i really love the look of the attached exhaust system. Wrenchmonkees are genious', i just like how sleek and small the exhaust is, almost as if it doesnt exist, i know on a 2stroke i cant achieve that but how close can i really get? idk how to attach a picture? ive done it before but heres the link
http://wrenchmonkees.com/monkee11.html
theres also an rd400 they did that doesnt appear to have expansion chambers and somewhat of a similar exhaust as the other link
http://wrenchmonkees.com/CB03.html
I hate those bikes. They look cool but are so non-functional that they really aren't motorcycles at all.
A two stroke needs an expansion chamber shape to work. Within limits, the smaller it is the less well it works. A tiny muffler is unlikely to do much muffling and sure as fate won't help power. DG are a reasonably priced, basic exhaust. Spec11 make great pipes. I have a set on my RZ and love them.
Stock exhausts are fairly basic looking but they work pretty well on a stock motor. No good for racing, but on the street, not so bad. You might be surprised what people did to those pipes back in the day to turn them into race chambers and keep them, looking more or less stock. Where there's a will, there's a way.
Seems to me that you need to think about what you want from the bike. If you are OK with less than stock performance, then I'd recommend starting with a CB Honda. What I mean is that a 2 stroke loses a lot more performance than a 4 stroke when the pipe isn't right.
2 strokes just look right with chambers on, and they do cost, but you don't spend any money on valves or springs or cams, so it sort of balances out. if you really don't like the look of chambers, a 2 stroke probably isn't the best bike for what you want.
It's a case of - if that's where you want to get to, you are staring in the wrong place - sort of deal if you follow my drift. So let us know what you really want out of the bike and let's work from there.
A two stroke needs an expansion chamber shape to work. Within limits, the smaller it is the less well it works. A tiny muffler is unlikely to do much muffling and sure as fate won't help power. DG are a reasonably priced, basic exhaust. Spec11 make great pipes. I have a set on my RZ and love them.
Stock exhausts are fairly basic looking but they work pretty well on a stock motor. No good for racing, but on the street, not so bad. You might be surprised what people did to those pipes back in the day to turn them into race chambers and keep them, looking more or less stock. Where there's a will, there's a way.
Seems to me that you need to think about what you want from the bike. If you are OK with less than stock performance, then I'd recommend starting with a CB Honda. What I mean is that a 2 stroke loses a lot more performance than a 4 stroke when the pipe isn't right.
2 strokes just look right with chambers on, and they do cost, but you don't spend any money on valves or springs or cams, so it sort of balances out. if you really don't like the look of chambers, a 2 stroke probably isn't the best bike for what you want.
It's a case of - if that's where you want to get to, you are staring in the wrong place - sort of deal if you follow my drift. So let us know what you really want out of the bike and let's work from there.
If your gonna be a bear be a kodiak
even know nothing harley guys shut the hell up when they hear a proper ring ding and there ass wipes. a real deal 2 stroke demands respect out of everybody around it including the rider. In short it ant no joke ass cb350, what kinda bike do you want. One like all the other sheep or one that would spit at a cb750 and hope for, no pray for a reaction. The choice is your you make it.
even know nothing harley guys shut the hell up when they hear a proper ring ding and there ass wipes. a real deal 2 stroke demands respect out of everybody around it including the rider. In short it ant no joke ass cb350, what kinda bike do you want. One like all the other sheep or one that would spit at a cb750 and hope for, no pray for a reaction. The choice is your you make it.
stroker crazy
crazy as a fox
The wrenchmonkees pipes are beyond useless. Even if you could set up the carbies so it would run it would be totally without power and probably waste fuel at an incredible rate. All fashion and no function.
Dumb, dumb, dumb!
Crazy
Dumb, dumb, dumb!
Crazy
crazypj
Split personality, I fake being smart
That's a terrible thing to do to an RD
wrenchmonkees are all form without function.
If stock pipes are too 'ugly' just sell the damn thing and get a bike you can modify to look good and perform shite then carry it around in a glass trailer so it doesn't get dirty
wrenchmonkees are all form without function.
If stock pipes are too 'ugly' just sell the damn thing and get a bike you can modify to look good and perform shite then carry it around in a glass trailer so it doesn't get dirty
Ty.man, we know that the bike is your first and the motor was a mess and you are trying to work out what to do, but as you can sense from some of the replies, you might be better off with a bike that better suits what you want to do. That motor will cost a fair amount of cash to repair and then you still need a bunch of stuff.
Have you considered selling the RD and using the cash to get a more complete running bike - that would get you up and running much sooner.
Have you considered selling the RD and using the cash to get a more complete running bike - that would get you up and running much sooner.
Second that if its priced right it will be a quick sell and there is plenty of cb s out there if thats more your speed the 4 vs.2 stroke debate is not a new one both have there ups and downs pros and cons its pretty much a matter of what your able and willing to deal with. eather way get a bike, fix your bike and enjoy the roller coaster that is vintage jap motorcycles. Every body on there store bought rockets will roll there eyes and tell you your wasting your money and time. You see the first time you roll on the loud grip in anger on a 100 dollar bike you drug out of a old shead or off a wood pile, and brought back to life it will all be worth it. Were all hear to help if you can see through the wise cracks and realize its just how friends that eat breath shit and sleep motorcycles talk to each other, well get ya there if ya need us.
ty.man
Active Member
I understand the tough male camaraderie that brad is talking about but jeez some of you guys are quick to pull the trigger. Calm down fellas it was just a question that sprung up from my liking of the aesthetics of a 4 stroke exhaust, thats all. I said if it came down to it id go with dg's its just that everyone has them. And yes in my opinion the stock pipes arent the best looking thing in the world. There'll be 100 more newbie questions so save your ammo for a good one. Thanks for the input and the new asshole guys!
Another way to approach this is to look at what you dislike about stock pipes and DGs and what you like about those small WM pipes and see if there's some way to combine some of the design elements in some way. We can't go with a small volume chamber, but are there other chambers that you do like the look of? It might be possible to fabricate a set or modify the DGs to better suit the look you like.
ty.man
Active Member
thats exactly what im saying. I like the aesthetics of the 4stroke exhaust, so sleek and small that its almost not there. What kind of expansion chambers should i look into that have a sleek look to them? I think fabricating my own would be far to difficult, i read a thread earlier that said theres a whole lot of dimensions that go into making expansion chambers, and i wouldnt know where to begin modifying dg's
crazypj
Split personality, I fake being smart
Micron started by making two stroke exhausts, they only progressed to 4 stroke years later
If you want an exhaust that actually works, it's going to be long and angled, short little dumpy thing is for looks only and will probably get pissed on by CB100's
If you want an exhaust that actually works, it's going to be long and angled, short little dumpy thing is for looks only and will probably get pissed on by CB100's
