[eric]

What about NOISE POLUTION?

 

[Dopey]

what are you guys talking about it sounds just the same as it does with a aftermarket exhaust just not as loud! to me the 250 sounds like a street version of a dirt bike....period! not a bad thing though.... i love the open exhaust sound loud mean agressive! i run my bike no exhaust and it way louder then the 250 and mots bikes too at first it was hard to handel, now it does not bug me infact i try and keep it at high rpms because i love the sound! it wont hurt the bike at all you have a nice 90 degree bend at the headers thats all the back press you need. one thing though is when i ride exhaustless low end tq sucks ass! but high rmps just kills it feels like a 750 or 1000 its awesome, then i put my exhaust back on and i have awesome low end tq but not as much on high rpms you know but whatevere, loud pipes save lives man im telling you! its a cop magnet but atleast your visibale, im sure the deff people will notice you hahaha



plus it gives it a cleaner look, cant beat that!

You're losing the low end power because you lost backpressure when you took the muffler off.

 

[harohanz333]

yah i heard removing the exhaust is bad because there isn't enough back pressure...what does this mean??....

NOOB

 

[Dopey]

yah i heard removing the exhaust is bad because there isn't enough back pressure...what does this mean??....

NOOB

A very basic answer would be its the pressure that your pistons push against when pushing the burnt air/fuel mixture out during the exhaust stroke.

Think about when you're blowing bubbles in milk with a straw. A thin straw you can blow fairly easy and get good bubbles. Get a wider straw with the same amount of force/air you had with the thin one and you don't get good bubbles.

However, if you can increase the amount of force/air you're pushing through the wider straw, then you will be fine.

If you go too big, you will lose the velocity the exhaust flows and then it is harder to push out.

So, when you take the muffler off, its kind of like going with the bigger straw. When starting out you lose that low end power, but you will gain a little in the top end. If you increase the amount of air you're taking in and putting out at the same time (add fuel when needed) then you make a little more of both.

Ok, I suck at explaining things, so I hope that made sense.

 

[Jester]

that was great. Good job

 

[Racer X]

If you pull the muffler off the stock head pipe the cat offers a some back pressure. But Ya you will loose some bottom end. This weekend I will try to post a vid of my bike with the open Yoshi. Maybe if I record the sound from across the yard or down the street it will give an impression of the noise.

 

[Guest]

"Running the bike without exhaust".

I seem to remember hearing about damage to the exhaust valve. The story goes likethis.

The valve is very hot during the exhaust flow, and then becomes cooled afterward. The cooling of the head by water or air thru the valve guide contact draws away the heat. Also contact with the incoming fuel-air mixture. The cycling between hot to cold is what warps or distorts the valve. However, when there is some back-pressure and exhaust-flow restriction the valve is kept a bit warmer. Less distortion and longer life for the valve seats.

Running with no exhaust pipe at all, just an open exhaust port in the head, opening directly to the open air is even worse, with a quicker death for the valve seats.
Sleepy

 

[R6S_2NR]

thats never been proven though sleepy, exhaust off had never been proven that it hurst your bike, plus mots of you are gonna upgrade to another bike so who cares ride exhaustless hahhaa! no but really it dont hurt it but performance wise you will feel a big diff low rpms compared to having your stock pipe on

noise polution? who cares you see the 5-0 pull in the clutch wait for him to pass then go about your biss its what i do

 

[harohanz333]

thanks a lot guys for the awesome info....truely helps a newb.
a special shout out to Dopey, good work man!
I'm attempting red's muffler mod, in the meantime she goes exhaustless. havn't done
any riding without the can on yet, but come spring i shall annoy the neighbors.

-hanz

 

[harohanz333]

hey darkhorse.....i was wondering what you put in place instead of your exhaust?
looks loud?

 

[weth56]

Ya it just scatters the exhaust to fast. I like the clean look too R6. Thats why I am getting a CBR or a 05 or 06 gixer.