KZ650 C2 Fuel Injection Conversion

Could you not do something similar to the box for my build where the majority of the rear wall is a K&N panel filter (mine was intended for a 3.7litre V6 Infinity so should flow enough) K&N's website has an area for generic panels where you input your dimensions and it tells you what they have that matches the best

I did think about doing that but I am trying to copy the way the air comes in like the stock air box. On the stock unit the air has to turn 90 degrees to get to the inlet ducts. There is more air draw distance turning 90 degrees which may have something to do with it.

I have to believe Kawasaki thought this worked better or else they would have used a panel filter on the back like the way you have it. It could have also been just a cost and manufacturing issue, I guess we will never know.

I got my sheet foam filter sizing off the K&N web site using sizing from a Honda 750 4V engine filter.

Did many bikes use a panel filter in late '70's early '80's? What you have done there is not stock, correct?

 

Correct, I removed the back half of the box as that is where the shock and catch tank are - I believe some of the OEM considerations are linked to reducing induction noise rather than performance improvements 

I certainly do not know why the factory air boxes were designed as they were. But while attempting to learn more about air boxes found this info and thought it might add to the discussion.

www.saltmine.org.uk/randy/airboxdesign.html

motorcycleinfo.calsci.com/Airboxes.html

wrote:

I certainly do not know why the factory air boxes were designed as they were. But while attempting to learn more about air boxes found this info and thought it might add to the discussion.

www.saltmine.org.uk/randy/airboxdesign.html

motorcycleinfo.calsci.com/Airboxes.html



 

I have known about Helmholtz frequencies with applications to engine tuning since I read a SAE paper Honda published back in 1982 when I was at College. That SAE paper was about exhaust tuning, but the formulas take into account the whole intake tract from the air box to the exhaust tip.

I did not think about the noise component in a air box, but that is one of the important reasons it use one. I cited the air draw length not as a performance enhancer but as a way to straighten out turbulent air to a more lamina flow path. I believe increased smooth air flow would help increase VE, and improve fuel economy.

If you look at a typical "bread box" air filter housing design they have air coming in from all sides. I have used these type of filters in the past and while they are a slight improvement over pods they seem just as noisy and subject to cross winds if you do not add some sheet metal to the sides.

 

 

VM26 with KZ900 air filter on KZ650 with 831cc engine (ends blocked with aluminum sheet)