Air Filter / Box mod question...

[ruxpin76]

For those that have torn out the old airbox and put a Unipro or K&N on, what did you do with all the stuff that connect to the airbox (fuses, relays, etc.) on the right side? I'm considering just cutting away part of the airbox (bottom, left side except for bracketry, front) and putting the new filter in the "inside" of the old airbox area...

Yes, I know I'll have to rejet if I change the airflow characteristics...

Advice appreciated. Cheers,
~Ted

[Easy Rider]

Originally Posted by ruxpin76

I'm considering just cutting away part of the airbox (bottom, left side except for bracketry, front) and putting the new filter in the "inside" of the old airbox area...

You may already be aware of this but you need to consider air box changes real carefully BECAUSE the entire air box on a GZ is "downstream" from the stock filter. That is, unless you put in a filter that is radically different, any holes you make in the air box will let in UNFILTERED air; not good.

AND I consider a K&N filter to be only slightly better than a piece of screen wire when it comes to filtering out dirt from the air.

[ruxpin76]

I am replacing the airbox with a "conventional" outside-->in filter, either a uni-pro or similar. The best filters are made of cotton fibers with a correct, light application of filter oil. I race high performance 2-stroke karts, and know about filtration. In short, I'll be using part of the shell of the original airbox to hold the accessories it currently holds, and by removing the front/left/bottom it will create access for the replacement filter. I just wondered what the people who completely scrapped the airbox did to mount their accessories. Thanks for the input! ~Ted

[Sarris]

Do a little reading on site (via the search engine) and you'll notice that very few have had a good experience removing the air box without other very substantial modifications. Our collective experiences will tell you that the GeeZer runs like shit without the air box. Muffler mods are just about as worthless (unless you just want louder).

If in fact you pick up 10% extra horsepower (which I kind of doubt) you'll go from 18 hp to about 20 hp. You are going to spend a lot of time and money to get maybe 1.8 hp.
That's just our collective experiences. You may know better that us, but I think you'll find that a 16 tooth front sprocket and a needle shim is the easiest way to mod the GZ for slightly better performance.

You can do what you want, but I doubt your experience will differ from ours. The GeeZer is what it is.

Good luck.

[ruxpin76]

Thanks for the tips....
My change is mostly for appearance and ease of replacement (the OEM and even HiFlo are a pain to have to order). I'm going for a retro/cafe appearance, and want to get rid of the sidecovers and relocate the battery to the tooltray area. At least that's my current thinking.

FWIW, those of you interested in performance gains are looking in the wrong areas, IMO.
If I wanted more power, I'd do these things, in this order:
* raise compression
* different cam grind
* bigger intake/exhaust valves
* port and polish

Compression is the holy grail, and beyond that, the more you can get it to breath, the better.
Of course the price is paid in reliability too...

[Easy Rider]

Originally Posted by ruxpin76

Of course the price is paid in reliability too...

In addition to the price you would pay for all the machine shop work.......if you could even find anybody to do it.......which would exceed the value of the bike.

That situation is not unique to the GZ however. All the things that an amatuer can do to a bike to increse the power are largely a matter of perception more than actual gain.

Regardless of what bike you ride, the best (and only practical) way to get more power out of your bike is: Use it as a trade-in on a more powerful model.

[Sarris]

One word. Parts. There are no hi-po parts available, so..... you'll have to make your own or find something similar to work.

We really do know what to do, it's just prohibitively expensive to do for the very minor gains you are going to get. Even with a 25% gain (highly unlikely) you're going to make 23 hp maybe???

Why not just get a bigger bike that those type of parts are available for? You'll spend less and get more in the long run.

But...... I guess you know better than the 300 or 400 of us who've been there and done that.

I's your money and time. Have at, I'm done.

:??: :whistle:

[ruxpin76]

I'm a certified machinist, and contemplating getting my own lathe and mill and cylinder hone soon, mostly for starting a karting engine business. So, the labor's "free", anyhow. There's some karting cam companies that will do custom grinds, but I don't know if they'd work with the GZ's original as a core or not.

I am not saying I know better, and really for a bike I paid $1100 for and put $500 in a new tires and head gasket/milling, you're right -- it's not so economically feasible. But I can reach 80mph with my GZ now (well, once I get another air filter and solve a bog in the rpm range). The engineering is part of the fun for me.

I have a welder too, so I was thinking about making a frame similar to the Sachs MadAss and putting the GZ motor on it. I want a sportbike or cafe tail with a naked front, and the GZ's simplicity appeals to me. In my ideal build I'd have:

MadAss style frame with gastank integral in main tube
Ninja 250 race wheels (front/rear, easier to buy new rubber for)
Ninja 250 fork assembly
Custom fabbed rear swingarm to a monoshock on frame
clip ons w/ bar-end mirrors

But this is getting off the main topic...

[RamAir]

Any progress on your project buddy?