I've been using the fix ram air lid on all my apexs that I have owned and test 3 sleds this year and on back to back GPS runs it gains 2-3 mph on every sled and that was without adding any fuel at all. The GPS doesn't lie and I have had an A/F gauge on 2 of those sleds and it definatly leaned out the motor from 12-8 to the 13-5 so it does work.
kuvasz
Expert
UP Michigan rider
Expert
Do you guys sell these things or something? Please post mechanically as well as electronically how the ram air works. How does it bypasses a computer controlled fuel injection computer? Ok we all want to learn that is why we have these boards. I am wiling to learn.
How does this effect the fuel injection phenomenon of reflected pressure waves in the intake duct (when the valve is closed?) Everything is fine until the intake valve shuts. How does this effect the "bounce" to match its return with the opening timing of the intake valve. based on 'resonant conditions' (the high pressure bounces back and forth along the intake manifold until the inlet valve opens again, creating pressure waves.)
Here is the 2011 changes to the Apex that mention this
Airbox/intake
The Intake tracts on the new Apex SE have been lengthened by 11 mm, as compared to the previous model. The engine utilizes the pressure waves in the longer intake tubes and in the airbox to boost airflow and maximize high RPM performance.
Injector
The distance between the throttle valve and intake valve has been redesigned for optimum fuel delivery. In addition, the 4-hole injector on the throttle body creates a spray of finely atomized fuel, with droplets of just tenths of a micron in size. The spray is aimed directly at the intake valve skirt for maximum efficiency and performance. The result? Simply unmatched throttle response.
EXUP and new exhaust pipe
Yamaha-exclusive EXUP valve technology controls the exhaust pressure waves for optimum intake and exhaust efficiency, delivering unmatched overall performance with more midrange torque. Additionally, the exhaust pipes have been enlarged to 38 mm from 35 mm for added exhaust pressure wave efficiency.
The same type info is right on the specs of the 2014 Apex.
Airbox/intake
The intake tract on the Apex is 11mm long which maximizes air intake and betters performance. The engine utilizes the pressure waves in the intake tubes as well as the airbox to boost airflow and maximize high RPM performance.
Here is a movie on it http://yamahapart.com/page/pressurewavematching
http://www.yamahapart.com/page/yamahaycci
http://www.yamahamotorsports.com/sport/ ... tures.aspx
http://www.yamahapart.com/page/yamahaycci
http://www.snowgoer.com/snowmobiling-fe ... play/0202/
How does this effect the fuel injection phenomenon of reflected pressure waves in the intake duct (when the valve is closed?) Everything is fine until the intake valve shuts. How does this effect the "bounce" to match its return with the opening timing of the intake valve. based on 'resonant conditions' (the high pressure bounces back and forth along the intake manifold until the inlet valve opens again, creating pressure waves.)
Here is the 2011 changes to the Apex that mention this
Airbox/intake
The Intake tracts on the new Apex SE have been lengthened by 11 mm, as compared to the previous model. The engine utilizes the pressure waves in the longer intake tubes and in the airbox to boost airflow and maximize high RPM performance.
Injector
The distance between the throttle valve and intake valve has been redesigned for optimum fuel delivery. In addition, the 4-hole injector on the throttle body creates a spray of finely atomized fuel, with droplets of just tenths of a micron in size. The spray is aimed directly at the intake valve skirt for maximum efficiency and performance. The result? Simply unmatched throttle response.
EXUP and new exhaust pipe
Yamaha-exclusive EXUP valve technology controls the exhaust pressure waves for optimum intake and exhaust efficiency, delivering unmatched overall performance with more midrange torque. Additionally, the exhaust pipes have been enlarged to 38 mm from 35 mm for added exhaust pressure wave efficiency.
The same type info is right on the specs of the 2014 Apex.
Airbox/intake
The intake tract on the Apex is 11mm long which maximizes air intake and betters performance. The engine utilizes the pressure waves in the intake tubes as well as the airbox to boost airflow and maximize high RPM performance.
Here is a movie on it http://yamahapart.com/page/pressurewavematching
http://www.yamahapart.com/page/yamahaycci
http://www.yamahamotorsports.com/sport/ ... tures.aspx
http://www.yamahapart.com/page/yamahaycci
http://www.snowgoer.com/snowmobiling-fe ... play/0202/
UP Michigan rider
Expert
"Years ago, before airboxes were designed as resonant systems, it used to be popular to cut additional holes in the air box to allow more air flow for high rpm. This is no longer a good idea. Modern air boxes can flow much more air than the engine will ever use"
http://motorcycleinfo.calsci.com/Airboxes.html
http://motorcycleinfo.calsci.com/Airboxes.html
race24x
TY 4 Stroke Master
Yamaha designs things to be efficient QUIET and have throttle response through the entire RPM range. I am not saying you are wrong, but I think if you see some of these things on a dyno you will see that improvements can be made. I am not an expert , but I have seen my Hayabusa on the Dyno make more power with an airbox mod and a BMC race filter with proper tuning.
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