Ram air katana

[BRAUNSTEIN82]

I have seen in the past a newer 750 kat with his front turn signals turned into air intakes with pipes running straight to the air bow and the box was sealed up. It seems restrictive to me in low run but im not sure about higher speeds. What do you all think.

" THIS SOUNDS LIKE A JOB FOR CYBERPOETE, when there is a tech issue that you dont understand, CALL CYBERPOET, CYBERPOET. "

Ha Ha think of underdog theme song when reading that.

[Crackshot]

I was interested in doing that too.

[Anonymous]

ram air works not sure about on a kat but it does work and usally at speeds over 80mph it takes quit a bit of air being forced into the airbox to actually create a ram air effect and its good for a few hp on top end as far as low end having the air box sealed up with ram tubes wont effect the bottom end it will run normal the old fzr600;s dif sp did the srad gixxers

[Spedee]

Like this:

[SweetLou]

Looks Fugly with them Blinkers sticking out like that. I don't really see a need for it though, if you want more power, go to a stage 3 jet kit with pods IMO.

You are going to be having to go pretty fast to get any use outa the ram-air.

[The CyberPoet]

RAM air definitely works -- if the passage is big enough and there aren't too many turns (figure each hard 90 degree turn robs 50% of the ram-air effect, and like an exhaust, the more surface area, the more resistance to airflow there will be -- but too small a passage is power-robbing).

A poor man's turbo-charger in essence...

The effective compression ratio of an engine is a the work of a few basic pieces of input:
The ambient pressure of the air about the bike (obviously higher at sea level than at 4000 feet)...
The design compression ratio (11.2:1 on a 98+ Kat 600 for example)...
The amount of valve overlap (how much time the exhaust valve is still open after the intake valve starts to open)...
and the speed of the air coming into the intake valves (which varies with RPM and vacuum levels and valve-overlap; the best speed or highest cylinder loading happens at torque peak by definition).

RAM-Air systems work by increasing the ambient pressure at the airbox (kind of like getting free changes in altitude -- downwards), thus increasing the speed of the air going into the intake valves when the bike is moving forwards by shoving air into the airbox under pressure. Depending on the ram-air pathway design, this can be a serious benefit (especially if you are sucking that same air out from just in front of the bike, so the bike doesn't have to push it aside to move forward). Advanced designs, like those in the ZX14 with it's huge intake, also design in the location of the pressure zone of the bow-wave from the bike cutting the air, so even more pressure is applied that would be solely by the speed of the bike. Note that these bikes also have specially designed systems to filter greater air pressures without fail, and to dump rain water and other contaminants that get slammed into them without making the engine ingest it...

The problem for the Kat is the engine/frame layout -- where do you take the air from to pressurize up the airbox without making it turn too much, without restricting the passage too heavily and still making sure the air in the airbox is fairly even in pressurization across all four cylinders? In an ideal world, you'd route through the underside of the tank, right over the engine, and hit an airbox that is designed to very smoothly spin the air 180 degrees into the velocity stacks while separating out the water/debris before the filter. Unless you're into redesigning the gas tank and airbox, this isn't real feasible... Thus the picture example of it being faired into the side-fairings above...

The problem is that at low speeds with that size/location/placement (the one shown in the pic at least), the extra drag on the engine to suck air in through those tubes will actually negatively affect the power of the engine. Thus you're talking about a top-end benefit with a low-end price (as is the case for many mods). Given the open size and routing distance/path, it may not have any appreciable benefit at double-digit speeds at all. And you'll have to rejet to compensate, at minimum in the idle circuits, more likely everywhere. We're talking for peak benefit, paying someone like Ivan to jet it properly, including new needle designs that take the change in air pressure at varying speeds into account...

But it looks cool. Personally, I would have used a wider opening (cone shaped) to put more air pressure at the opening, then narrowed down the passage some on the way back to increase the velocity of the inbound air... some serious airbox changes would also be involved in my design if I was ever to consider such an undertaking (can't imagine doing so for a standard Kat for traditional road-riding purposes).

Cheers,
=-= The CyberPoet

[BRAUNSTEIN82]

The one i seen was silver and the turn signals were removed and replace with screens and the bulb was removed and a hose about 1 inch run from that hole to the aitbox and the airbox was sealed.

[md86]

Well , I read a tech article in one of the bike mags about ram air a while back , and it showed that while there WERE gains to be had (in SOME cases anyway ) , they weren't always that great . SO I wouldn't bother experimenting on my own with it .

[illinoiskat]

Why not buy an electric fan and put that over the air box to help boost air intake/ Box pressure. Put a switch on the handle bar, so not to drain the battery when not needed. I thought of this, but then you will using some engine power to turn fan. hmmmmm

[SweetLou]

Why not buy an electric fan and put that over the air box to help boost air intake/ Box pressure. Put a switch on the handle bar, so not to drain the battery when not needed. I thought of this, but then you will using some engine power to turn fan. hmmmmm

You would need a big fan to move enough air to make a difference I do beleive.

[bobs]

Why not buy an electric fan and put that over the air box to help boost air intake/ Box pressure. Put a switch on the handle bar, so not to drain the battery when not needed. I thought of this, but then you will using some engine power to turn fan. hmmmmm

You've described a low-boost electric supercharger. Someone's selling a product like that in the car world. It's snake oil. It draws more electrical power than the difference in horsepower generated.

Here's an example: http://motors.search.ebay.com/_W0QQs...f2Q5fmuchQ5fhp