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Feb 5, 2017 | 02:06 AM

#11

Bone Doc

Seasoned HDF Member

Joined: Oct 2012

Posts: 13,040

Likes: 12,960

From: Texas, USA

Quote:

Originally Posted by mkguitar

... the idea is to control the velocity of the exhaust gasses- a smaller pipe will require the gasses to go faster...but you don;t want to reach the point where the gasses back up...a too wide pipe will make for slow gasses...

You just described Bernoulli's principle.

When a fluid, liquid or gas, moves from a larger diameter pipe to a smaller diameter pipe, the fluid will increase in speed and the pressure of the fluid will decrease. It is certainly more detailed than that but that is the gist of the principle.

The Bernoulli principle is in accord with the Law of Conservation of Energy and Newton's Second Law of Motion (F=ma).

That is your Physics lesson for the day

Feb 5, 2017 | 07:47 AM

#12

kojak

Seasoned HDF Member

Joined: Jan 2007

Posts: 5,535

Likes: 3,941

From: Virginia

Quote:

Originally Posted by Bone Doc

You just described Bernoulli's principle. .

The Bernoulli principle is in accord with the Law of Conservation of Energy and Newton's Second Law of Motion (F=ma).

That is your Physics lesson for the day

Here's the second. Exhaust leaves on the exhaust cycle in pulses, the timing of which is what helps the engine to have a good AFR on the intake cycle. This is called the Wave theory. Poor OP, he's probably scratching his head by now.

Feb 5, 2017 | 02:37 PM

#13

OldPhat

Elite HDF Member

Joined: Dec 2007

Posts: 3,617

Likes: 165

From: Sparks Nevada

Quote:

Originally Posted by GLIDE50

Does removing the cat require remapping of the computer because of reduced backpressure?

No. If you have almost stock Bike, and you just put a non catalytic header pipe on
your Bike the computer will take care of the Air Fuel Ratio.

Glide50, you didn't tell us what if any modifications have been done to your Bike.

So we can't really answer, not knowing what has been done, but a set of FL-Vied-10
from (www.nightrider.com) can't hurt.

With a set of FL-Vied-10 you will be able to adjust your own AFR. That is all you
will need if the only thing you have done to your Bike is add a cat-less header pipe.

Last edited by OldPhat; Feb 5, 2017 at 02:39 PM.