Aluminum Airbox Ideas Needed

[BigGreenMachine]

Looking to make an nice airbox for my Tecate to sit where the shock/airbox once sat.

Will be a basic short rectangle shape with a sloped up bottom. Material will be 1/16th or 1/8th sheet. The inake tube and filter selection is what I'm having trouble with.

For the outlet from the box I'd like to have a velocity stack with a filter for the end but do not know where to find one in aluminum. The connection from the carb to the box will be through the kind of hose you find on a aftermarket car intake.

The filter needs to be BIG for the air demands from the 500 motor. Also has to be a foam clamp on for simplicity.

What has more surface area, a cone style filter or a cylinder type?


Heres a stock KX500 airbox from ebay.



Here is sort of what I'm going for except the opening will be on the side.




James

[3Razors]

I would use the stock airbox setup from the original 500. It has all the engineering (flow/size,ect.) built right in from Kawasaki. Plus it looks to be an easy fit with minimal mods.

[firefirefire90]

Why not something like this?



but with a piece that would cover the exhaust so you don't get hot air?

[BigGreenMachine]

Why not something like this?



but with a piece that would cover the exhaust so you don't get hot air?

I ride far too wet/muddy conditions for that to work for me.

3Razors, I'd rather fabricate my own simply to have things the way I'd like. Besides, the opening for the KX500 box is on top and I'd have a hard time getting to the filter for cleaning. Wish Kawi made the seat and rear fender easily removable.

If any of you haven't noticed, the 84/85 Tecate uses the backbone of the frame as a snorkel that flows air from just behind the steering neck. I plan on using this on my new box as well.

[Somekindofjerk]

Use a coffe can

[Billy Golightly]

I'd use the stock airbox as sort of a template and make it larger where ever possible. Might run you a few bucks but I bet if you take the stocker to a sheet metal shop they could hook you up.

[BigGreenMachine]

I'd like to Billy but this is somewhat of a budget build at this time.

Twostrokes love velocity stacks correct? Would I be hurting performance if I simply welded in a 1 1/2 inch piece of aluminum pipe to act as a mounting flange for the filter and tube to the carb? What I mean is holesaw the correct diameter hole, put the tube through and weld it solid so it leaves a flange on teh inside and outside.

What I'm afraid of is that the motor won't have the velocity stack to speed up the air and really force it through the carb.

[Louis Mielke]

my buddy works in a sheet metal shop. Made a really sweet box out of aluminum for my 500. I'm trying to find a picture right now but having trouble finding one.

[Billy Golightly]

If you want to get really technical (over my head too, haha) theres a formula for a "Helmholtz resonator" that pretty much in principle works the same as the exhaust pipe on a 2 stroke except this works with vacumes (intake) instead of pressure (exhaust). Here is a thread I made on Planet sand a while back asking about it: http://www.planetsand.com/ubbthreads...ge=3&fpart=all

Evidently when you get this "right" you will get a pretty big pickup in HP. Dave Moore, a really well known builder claims to have picked up 6hp from one alone.

This tool is also mentioned in the PS thread: http://www.bgsoflex.com/intakeln.html Which is geared towards 4 strokes but I think it would work the same for a pinger with the reeds working as an intake valve. I plugged in 19inches as the length and got a 10 percent pulse strength in the 6183 to 7503 range which is about where my CR500 makes optimal HP.

[moose 53]

Wish Kawi made the seat and rear fender easily removable.

Kawasaki doesn`t but you can.

[BigGreenMachine]

Very cool! Moose, your a very good source of info!!

[Louis Mielke]

Well I don't know about all the performance stuff as I'm not looking to make the biggest bang, but if you're just out to keep the mud off your air filter one like this works pretty well. my buddy bent it all up after we made a cardboard prototype, and then my machinist Cart welded it all up. Turned out pretty nice. If I had to do it all over I'd use thicker material.

[BigGreenMachine]

NIce one Louis! What thickness aluminum is that? 1/16th? Looks thin.

I'm thinking I need the tubing section that goes from the box to the carb. Thats there to hold a reserve of air so the engine isn't sucking and not getting all the air it needs.

Think if I get that part I'll be alright.