WHY stock pipes?!

[Finesse]

xr50 is a four stroke 50cc.

[allanoue]

Originally Posted by Finesse

I rode my honda xr50 last night with A STOCK PIPE and some fuddy duddy came out of his house and told me I have no business keeping people awake. I was in a county park on a small strip of paved driveway for their summer camp facility at 11.30pm maybe 200ft from the nearest house. practicing wheelies

so the argument for not bothering people with an aftermarket pipe is now invalid

If someone was weed-waking the yard 200 feet from my open bedroom window @11:30pm , I would call the police.

[alex.s]

Originally Posted by spooph

Others have addressed this, but let me offer this:

The stock ninjette dyno graph tends to fall off heavily after 9K or so (I forget the exact region), which is the entire upper register of the rev range. On any other bike, this wouldn't be a problem, however, my 250 sees redline on a regular basis, and simply for the health of the exhaust valves, a slip-on can produce reasonable gains. Of course, as you have mentioned, the rest of the system will have to be balanced again...

Not trying to

the restriction on the output side for these bikes is in the header. the muffler slipon doesn't do anything but reduce the noise. but even if that wasn't the case... as with just about any fixed timing 4 stroke, there is a little bit of valve overlap, and so at the end of the exhaust stroke, theres a short time where both the exhaust and intake are open, which partly siphons the intake air into the cylinder and out the exhaust a bit... its sorta counter intuitive but too large of headers compared to the intake can reduce that siphon vacuum pressure and make it run lean for that little spot, and as we all know that nice unburnt fuel is a great coolant for the interior until it burns... so less air and fuel going out that exhaust valve before it closes means more overall heat in the exhaust valves... so....its actually worse for your exhaust valves unless you open up that intake side to compensate the lower overlap vacuum....... or something.

[capt_bugaloo]

Originally Posted by Finesse

I rode my honda xr50 last night with A STOCK PIPE and some fuddy duddy came out of his house and told me I have no business keeping people awake. I was in a county park on a small strip of paved driveway for their summer camp facility at 11.30pm maybe 200ft from the nearest house. practicing wheelies

so the argument for not bothering people with an aftermarket pipe is now invalid

I have to say that if someone were popping wheelies 200 feet from my home, even on a stock little 50cc, at 11:30 at night - you bet I would hear it. I don't think a guy getting pissy because you're keeping him awake at 11:30pm is all that unreasonable.

[Finesse]

well the point is that stock pipes aren't really all that stealthy.

[Jasonm163]

Originally Posted by choneofakind

Ha. Sorry, no idea on that one.

Hey what kind of engineer are you?

[allanoue]

Originally Posted by Jasonm163

Hey what kind of engineer will you be?

FTFY
He is a college Sr.

[Jasonm163]

Originally Posted by allanoue

FTFY
He is a college Sr.

Ahh okay. That's the best year lol I just finished my mechanical engineering degree a little over a year ago. Hang in there man it's worth it!

[MrAtom]

Originally Posted by Jasonm163

Hey what kind of engineer are you?

Currently he's just a backyard engineer like most of us lol.

[choneofakind]

What type? A 3/4 type 5th year senior due to co-op

[Jasonm163]

Haha most people drag engineering into 5 or 6 years so nothing unusual there. I co oped my sophomore junior and senior year as well. I meant more are you mechanical, electrical, petroleum, chemical, etc.

Edit: idk if it's this way on this forum, but on my evo forum, I was astounded at how many people were engineers of some sort in the "what is your career" thread.

[Alex]

That "what do you do?" thread is right over here...