View Full Version : Intake mod

11-11-2006, 09:27 PM
I've got my '94 stripped down for a valve adjustment, and I've been looking a lot at the airbox. It looks like there could be a lot to be gained in the breathability department, and I was wondering if anyone has done anything really clever. If not, maybe I can find something clever to do. It's a shame there isn't any room to run some ducts through the frame. :stupidagree:

11-11-2006, 10:20 PM
You mean make some ram air :-s ? It HAS been discussed before , actually .
You CAN just get K&N pods . Some like them , some have no end of trouble with them (I'm in the second camp :smt011 ) .

11-12-2006, 04:53 AM
The stock airbox looks very non-performance, but it actually flows quite a bit of air through it.

Keep this in mind. If you increase the flow of air, you will have to increase the amount of fuel flowing also. Then, to make sure it all flows right, you will need to up the flow on your exhaust. Unless you already have an aftermarket 4 into 1 full system on it.

PS... where in Arkansas are you??

The CyberPoet
11-12-2006, 08:04 AM
The airbox's function isn't just to filter air, but also to make sure that the pressure at each carb is approximately identical, so each cylinder makes about the same amount of power, for a smoothly running engine (same reason you sync carbs after a valve adjustment and after any carb work).

The primary restriction in the breathing is the collector and the exhaust header pipe diameters. Changing the intake without changing the exhaust and fueling (as Court said) is a formula recipe for ruining the bike's reliability and giving yourself headaches.

=-= The CyberPoet

11-12-2006, 08:31 PM
Hmmmmmm. Fuel injection, anyone? Oh well, don't have days on end right now to spend in the shop fabbing parts, so I guess I'll leave the darn thing the way is. Bad thing about these two-wheelers is you can't really go overboard on mods without seriously considering the very-readily availble product sitting down the road on the showroom floor.

I'm in Springdale.

11-13-2006, 05:30 AM
There is a recent thread covering converting to fuel injection too. Not really a viable option for the Kats. You would spend more time and money on it than the bike's worth, and still possibly not have it run right.

Springdale? Cool, born and raised in Benton/Bryant myself.

11-13-2006, 09:16 PM
Hence the comment about picking up the latest technology for $8500 more. Good idea to move. The area is buckling under the growth. I'm ready to head back to my mountains...

11-14-2006, 04:39 AM
Well, I joined the Army after High School. Didn't have much choice on the moving part. :lol: I go wherever Uncle Sam tells me to go. Parents still live there though.

11-14-2006, 09:47 AM
The intake is not the bottleneck on a katana. A good, quality full exhaust and proper jetting will get some small gains, mostly in driveability and some top end increase. Offset that with slightly lower gear ratios and you will have some additional performance.

On a stock katana, you are looking at about $100 per hp gained for minor mods.

The real gains to be had on these motors are not practical for what it is - namely overboring to increase displacement, regrind or change cams to increase duration and lift, and change carburetors to increase fuel flow and mixture. Sure, with $4000 in custom motor work you can get 120hp from a katana motor, but driveability and reliability will be shot. You will have a twitchy drag racer that doesn't want to idle and needs 100 octane gas to run and overheats.

Turbo and nitro are poor choices for an oil cooled motor.

The real gains on these bikes are in gearing, brakes and suspension - otherwise, go with the aluminum framed, FI, water cooled 600 down the road as mentioned above.