Kawasaki Motorcycle Forums banner

Status
Not open for further replies.
1 - 20 of 21 Posts

·
Registered
Joined
·
105 Posts
Discussion Starter #1
Hey stupid question and all but can anyone tell me what the ram air does (and no replys stating that it rams air :()? I know the bike is better for it (supposedly produces more speed) and sounds cool :D, but does it act like a turbo compressing the air or does it regulate it somehow?


Also I've not fully stripped the bike but what does the unit comprise of?
 

·
Registered
Joined
·
1,606 Posts
Ram air is a supercharging effect caused by the forward motion of the bike. It is probably good for about a 10% hp boost at speeds above 130. The systems consists of the airbox, the plenums, the tubes connecting the airbox to the openings in the front of the fairing and the fairing.
 

·
Registered
Joined
·
3,190 Posts
Sportrider mag had a really good article about this over a couple of issues. They tested a few bikes, a TLR, Hayabusa, GSXR750, ZX9, ZX7, R6 among others, and a ZRX1200 for comparison to a bike without ram air.

The Kwaka's did best (of course), with airbox pressure going positive at about 100kmh (60mph), where others didn't get positive pressure until about 120kmh or even 160kmh (100mph). In comparison, the ZRX1200 constantly had a vacuum in the airbox.

The power gains were pretty impressive in some cases too. They probably weren't 10% though.
 

·
Registered
Joined
·
479 Posts
Well for one thing the sound that comes out of it sounds cool...
As for how it works... Basically, at speed the bike compresses the air in front of it, some of that compressed air gets trapped in the airbox/plenum, and when the throttle bodies are open, the compressed air is forced into the intake manifold where it is mixed with vaporized gasoline to create a combustable mixture that gets sucked into the cylinder when the intake valves open. With the positive amount of pressure in the airbox, the air is actually blown into the engine rather than the engine having to create a vacuum in order to get it. As a result, the engine is able to mix a higher volume while not suffering from parasitic loads due to air intake. [8D]
 

·
Registered
Joined
·
3,190 Posts
Yep, so basically what happens is that the engine is fed compressed air (which is denser than normal due to the compression, so you get more air in a given space) instead of drawing air from an airbox with a slight vacuum in it (which means you get less air in the same given space), so you effectively get more air into the cylinders.

The greater volume of air you get into the cylinders the more fuel you can put into the cylinders, and the increased amount of fuel in the engine means it will make more power. The more fuel you can burn at or near an air/fuel mixture ratio of 14:1 (the optimum ratio), the more power you will get.

You won't ever feel the effect though. Just accept that it makes more power at high road speeds than it would without ram air
and smile at the sound of the induction roar.:D
 

·
Registered
Joined
·
3,190 Posts
If you want a better explanation, I'll give you one but it will be long.[:I]
 

·
Registered
Joined
·
534 Posts
the added pressure into the zx6r/rr's air box is due to the NACA duct's property. NACA ducts actually speeds up airflow into where ever it's designated for. for the zx, more ram air than your average openning to allow ram air.
 

·
Registered
Joined
·
3,190 Posts
Hey t-type, how do the NACA ducts do that? I can understand how they could slow down airflow, but not how it speeds it up.[?]
 

·
Registered
Joined
·
3,190 Posts
Thanks for the link.
 

·
Registered
Joined
·
3,106 Posts
It allows for more efficient air intake. Everyone knows that an engine needs air to run. Well, an engine can only consume so much air at one time. When the engine is running hard with the bike at speed, the ram air provides greater air flow preventing the engine from being limited due to an insufficient amount of air.

Think of it sort of like breathing through your nose with a cold. Not too efficient getting the oxygen to your lungs, huh? Well, in that case, your mouth would be your ram air (only difference is you don’t have to run 60mph with your mouth open to force it into your lungs lol).;)
 

·
Registered
Joined
·
3,119 Posts
Originally posted by speedvlaze
Think of it sort of like breathing through your nose with a cold. Not too efficient getting the oxygen to your lungs, huh? Well, in that case, your mouth would be your ram air (only difference is you don’t have to run 60mph with your mouth open to force it into your lungs lol).;)
wow, I must be getting lazy. I got winded thinking about doing that. :D:D
 
1 - 20 of 21 Posts
Status
Not open for further replies.
Top