k&n air filter

blackgpz at rochester.rr.com blackgpz at rochester.rr.com
Wed May 16 06:15:17 PDT 2007

Charles is right when he says the airbox volume is too small for an 
1100cc motor. The airbox for a typical late model 600cc bike is 
probably 3 times the size of ours. The biggest problem though, is the 
size of the snorkel opening. From what I remember, the opening is about 
3/4" x 5". As a comparison, the airbox opening on my 955cc Daytona is a 
4" x 8" oval. The small opening promotes low rpm cylinder filling with 
a high velocity intake charge, but it just cannot provide the volume of 
air required to make high rpm power. This is why you feel a little of 
the low end grunt go away when you get rid of the airbox. With pods, 
the great outdoors is your airbox and the engine is able to get all the 
air it needs at high rpm and it must be re-jetted accordingly. To 
clarify for Jerry, the GPZ airbox is not pressurized. There is no "ram-
air" effect. Air is not fed in, it must be pulled in by the engine, so 
basically, your engine sucks!

----- Original Message -----
From: scapco at ecentral.com
Date: Tuesday, May 15, 2007 1:41 pm
Subject: Re: k&n air filter
To: Kawasaki GPZ1100 discussion <gpzlist at micapeak.com>

> Jerry,
> I think Steve might be able to explain this better than I, 
> but the GPZ really does have an undersized air box for an 
> 1100 cc motor.  That's why the really big HP gains are all 
> with the airbox off.
> If you prefer to keep the airbox on, you can always open it 
> up a little by removing the intake baffle on the airbox.  
> The California models don't have this because of the 
> canister emmissions crap.  The difference might only be one 
> extra HP, but it will breath better.  Then do the stage one 
> or two mods with a nice pipe and you will definitely feel 
> the difference.
> Charles S.
> > Now can someone explain how a pod works better than
> > an air box?
> > If the box or air filter surface area is not under sized,
> > there should be higher pressure in the box when the bike
> > is in motion.  Heck, just open your helmet over 70mph and 
> > it's more difficult to breathe ..
> > I'd really rather not go through a whole jetting 
> > procedure.
> > 

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