What is your intent.... more power or more sound ????

building an exhaust system with more sound is easy enough ....

Increasing power is a whole different game.

Size and length of pipe and muffler can, and does, effect the scavaging and
flow of air from the combustion chamber. ..... you would need a dyno to fine
tune power changes.... match jets .... air intake mods... etc.

 

I had a '59 *****'s with a home made exhaust that my cousin made. It had a dual exhaust made from a well pipe. Anything can be accomplished if you put in the effort.

 

He made header's from a well pipe??? Dang he's good. Past the header's on a car doesn't really matter what you do though. The header's on a car act the same as the entire pipe on an atv.

 

Reply: Just because he is not the kind of person that sits on his rear all day and reads what is going to make it better does not mean that he doesn't understand the basic principles of what is going to make his atv perform better. What would you say if it ended up that his idea came out better than your whole panel? Would you say ahhhhh in amazement? No you and your design team would try to pick it apart to find some reason that your idea is better. LAY OFF AND LET THE MAN TRY IT WHAT IS THE WORST THAT COULD HAPPEN LOSE SOME MONEY AND TIME BUT IF HE CAME UP WITH SOMETHING GENIUS IT MIGHT REVOLUTIONIZE ATVS FOREVER.

 

Go for it Blitz!
the best way to learn about things is to DIG IN!

I just finished my first 2 stroke pipe (Yes, there's a heck of alot more going on in a 2-stroke design)
and yes, I'm an engineer that knows a great deal about Thermodynamics in case you're wondering. (Not that it really comes into play here) PV=nRT On a 2-stroke, you need to understand your port configuration and what's going on, and what your objectives are....

4-strokes are a different animal... just do your homework, and you'll be fine!

If nothing else, you just might stumble onto something that really works well... it not, you can always put your stocker back on.

 

go for it dude..........I chopped 6 inches off of my stocker and removed all of the guts............
and it DID make a power differnce over the stocker with spark arrestor removed..........
I like it.......and I think it sounds perty kewl also!

 

Yes, go for it, cut and gut your factory pipe until you blow the engine up, heck it's just money right?? 2 strokes are very different from 4 strokes and the pipe design is very important to a 2 stroke motor. Read here if you are just curious about how much a pipe design can affect an engine. I personally would never attempt it because I don't know enough about the design of one. Here is a guy that will design you a pipe and make blueprints for you if you are like me and don't know, but want to build your own, good luck.

 

Dude, Lighten up, If a guy wants to spend the time and make a custom exhaust system, let em'. Some of us just like to tinker with whatever we can.

I am also thinking about building a custom exhaust system for my bike as well.

As far as I know, an engine is nothing more than a air pump. I understand that backpressure is important on a 2 stroke, but it seems to me that all aftermarket exhaust systems are trying to do one thing, reduce exhaust restriction. It seems to me that if you built a complete exhaust system that reduces restriction you have the potential to produce more power. Assuming that you can get the air/fuel mixture correct and into the combution chamber efficently.

Before anyone gets all bent out of shape, I am not an expert, I do not claim to be an expert. I know I am probably missing some important "Dynamics" of 4 stroke engines, but hey I call em as I see em.

 

This is off topic but...NCScrambler...I am just wondering why you need a tachometer on your fully automatic polaris ? And what is the point of the EGT ?....it's not secrectly diesel is it ?....lol

 

LOL, no it is not. The tach is for making adjustments to clutching, fine tuning if you want to call it that, and the EGT gauge is for keeping an eye on what my engine is doing at all times and is a very helpful aid in tuning the carb. I have had my engine run lean on me and seize before and with so much invested in mods to the motor, I don't want to see it happen again. The EGT gives a real time picture of just how hot my exhaust gases are at that point and time and by keeping an eye on that I know then if a problem arises. Also, for tuning the carb, if the exhaust is too cool I know that I am running too rich in any given circuit and if it is too hot, then I am running lean, It is really something you can't live without once you get used to it. Scootdog, I think it is great that someone wants to build and design their own exhaust, but I also think it is important for them to know what exactly they are getting in to. An exhaust is not simply just to open up the exhaust gases and let them flow, there is MUCH Much more to it and without a properly designed exhaust, one could easily blow their motor and I think it is important for them to know what risks they are taking before they do it. A 4 stroke may be alittle simpler to design, but a 2 stroke is complicated, there are 5 parts to a 2 stroke pipe and if just one of these parts are not designed properly, it could cause major problems down the road. The pipe not only allows the engine to breath better, but the some of the exhaust waves have to be returned to the piston port for the motor to function correctly. It is part of the pumping effect and is detrimental to engine durability and performance. Here is a nice little page that shows pictures of what goes on with the expansion chamber of a 2 stroke and why it is so important to the engine. Expansion Chambers