Sports Mufflers

[r90s]

Try this tool:

http://www.mez.co.uk/mezporting/exhaust_length.html


Cheers,
Jon-Lars

[Major Softie]

Try this tool:

http://www.mez.co.uk/mezporting/exhaust_length.html


Cheers,
Jon-Lars

How exactly does that work without paying any attention to displacement, valve size, or valve count? Without even getting into the difference in flow between a 50cc cylinder and a 900cc one, a 4 valve head is going to behave very differently than a 2 valve head at the same lift.

[Chuey]

Try this tool:

http://www.mez.co.uk/mezporting/exhaust_length.html


Cheers,
Jon-Lars

How exactly does that work without paying any attention to displacement, valve size, or valve count? Without even getting into the difference in flow between a 50cc cylinder and a 900cc one, a 4 valve head is going to behave very differently than a 2 valve head at the same lift.

I don't know that much about engines but they don't ask about the actual lift. I think it may work because they are dealing with pulses and they may be a constant. How'd I do?

Chuey

[Major Softie]

I don't think so, but I did miss that it DOES ask displacement.

[vanzen]

There are a number of FREE exhaust system calculators on the web.
The link that Jon Lars has provided
may provide some good basic information to begin a design.

Displacement as well as valve timing, lift, duration, and overlap are considered (re: Major and Chuey)
Valve size, however, is not part of the criteria ... and to my simple way of thinking
primary I.D. will be a function of valve size in order to correctly establish a torque peak RPM.

Intake runner size (esp. cross-sectional area), length, and port shape should also be contributing factors ...
I suppose that this may explain why there will be "free" exhaust system calculators
and / or $600.00 software –
and the value of expertise from the likes of Craig Hanson !