Originally Posted by
skr00zloose
No offense, and I'm not trying to start shit, but scavenging is a good thing (to a degree), it removes the unburnt fuel from the exhaust, thereby allowing more of a fresh charge to enter the combustion chamber, and at the same time pulls more mix into the chamber to be burned on the next combustion stroke.
Exhaust design is black magic, there's ALOT to be taken into account. I'm never gonna pretend to comprehend it all, but I know a bike with a stock motor that has had most of it's exhaust removed is going to ONLY produce more power at VERY (and I mean VERY) high rpm, and everywhere else, it'll probably lose power. There's a balance to be had, and achieving it is not easy.
Comparing drag bikes to civics doesn't mean much. A full-on drag bike is built to run at a certain RPM, and make the most power in that range, a civic is meant to run you to the grocery store, at all RPM's, and do so as efficiently as possible.
Hell, a full-built drag bike probably burns more fuel in a 1/4 mile than a civic does driving from VB to NN. It's apples and oranges.
Originally Posted by
FairladyZTT
Less back pressure would increase top end power, which would be exactly the type of race that would occur in a rolling second gear run.
You are not starting shit with me. If I am wrong, I will openly admit it.. but I dont see that I am in this case. So, I stick to what I have said from the beginning.
Which you stated, pretty much exactly what i was saying to begin with.
And exhaust systems are a science and takes alot of knowledge and research to know the perfect application. I dont pretend to know how to begin to do it. But I completely understand the concept.
I have not gotten upset this entire time... but statements like this...
Originally Posted by
j4k3
No no no no no. Your bike needs back pressure to run correctly.
Please don't argue back if you don't know what you're talking about.
are uncalled for and not needed, especially when they are coming from somebody that evidently has no clue as to how the shit works.
As far as scavenging being a good thing, its my understanding that you want no back pressure but not yet scavenging. You just want the exhaust to flow as freely and effortlessly as possible. Yet, you dont want the scavenging to suck the air from the next rotation.