Custom airbox?

mik_str · Post by **mik_str** » Sat Mar 17, 2007 5:13 am

Further to some snooping around on the Speedzilla RC51 (SP-1/SP-2 for you folks on the other side of the Pond, lol) section, I came across info relating to a chap who makes a custom airbox for RC's (http://speedzilla.com/forums/showthr...hlight=airbox). It has a larger volume and allows the engine to breathe better thus generating more power. This, of course, got me wondering if this basic premise (larger volume airbox) would help the Firestorm/Superhawk breathe better (and, you guessed it, generate more torque and hp).

So, I think I will attempt to build a larger volume box (using all available area under the gas tank) out of fiberglass to test the theory. By doing the work myself, it shouldn't cost too much and as I won't be making any permanent changes I can simply throw it out if it doesn't work. Also, as I have a Flo-Commander, I'll be able to play with the mixture without taking the carbs apart. I am also looking at making some sort of ram-air system (by opening the "phony vents" located in the front of the fairing and feeding them into the airbox). I realize that doing so could potentially create issues with air pressure differences compared to using the stock air inlet but I hope to get around this by borrowing a practice from the snowmobile industry. That is, I will join the fuel bowl vents together with a T and feed it into the airbox directly through a grommet (thereby making the fuel bowls sense the same pressure as the airbox/carbs and thus keeping the equilibrium between the two). Not sure how any of this will work but it should be fun and hey, I may even uncover some hidden hp in the process (not to mention learn something too).

If all of this works, I may then look at fitting a BMC "race" air filter to capitalize on the better breathing. BTW, doesn anyone know what the difference is between the street and race BMC filters?

cheers

LotusSevenMan · Post by **LotusSevenMan** » Sat Mar 17, 2007 7:24 am

Well I have been looking to modify a stock one (bought off of eBay) after seeing these postings here

http://www.vtr1000.org/phpBB2/viewtopic ... ht=air+box

Let us all know how it goes please!!!!!

LotusSevenMan · Post by **LotusSevenMan** » Sat Mar 17, 2007 7:25 am

Well I have been looking to modify a stock one (bought off of eBay) after seeing these postings here

http://www.vtr1000.org/phpBB2/viewtopic ... ht=air+box

Let us all know how it goes please!!!!!

alan · Post by **alan** » Sat Mar 17, 2007 9:22 am

LSM your repeating yourself again its time for the old peeps home

LotusSevenMan · Post by **LotusSevenMan** » Sat Mar 17, 2007 2:00 pm

Alan.
Weird (no, not you)
It didn't send so repeated it. Only one showed so thought OK etc.
Umm. Slow server I guess!!!!!!!!

LSM, Sunny Mead OAP's home, Eastbourne!!!

Stormin Ben · Post by **Stormin Ben** » Sat Mar 17, 2007 11:38 pm

Mik,
I bought a second hand airbox to test this very concept.

My intention is to remove teh top and build the sides up til they contact teh bottom of the tank.
Putting a rubber seal round the top of the wall should then seal it

BTW the float bowls idea should work fine -its how most RAM air bikes are setup

If you do decide to try making a complete airbox, one method is to put a binn liner under the tank and then fill it with expanding filler.
Should give you a pretty true representation of the area under the tank

Ben

mik_str · Post by **mik_str** » Sun Mar 18, 2007 5:09 am

Hi Ben, great minds think alike, lol I am toying with two options: make an entire fully enclosed airbox cover, or the sides only and seal it agaisnt the tank as the other chap (RC forum) does and you are proposing. In terms of creating the "mold", I will use expanding caulking foam in a plastic bag/membrane (so it doesn't make a mess and stick to everything). It will give me an exact imprint, I can then simply lay the fiberglass on that and presto, perfect match up (should be quite easy and inexpensive to do). I am looking for something to use to seal things up though and not sure what to use (it has to be resistant to gasoline, was thinking weatherstripping/door frame foam but it's likely affected by fuel fumes). Any suggestions welcome...

I may also add filter area to my stock filter (my opening it a hole in the plastic backing and gluing a portion of car (foam) filter in place. I will also see what can be done in terms of force-feeding air to the box. Should be fun, lol Ah, the curse of an inquisitive mind....

Zer0Zer0 · Post by **Zer0Zer0** » Sun Mar 18, 2007 9:53 am

i seem to remember a pic of one with two chrome trumpets set into the top
from germany i believe? looked cool

LotusSevenMan · Post by **LotusSevenMan** » Sun Mar 18, 2007 10:33 am

Check my link above Zer0Zer0. You can view it again there!!!

mik_str · Post by **mik_str** » Sun Mar 18, 2007 5:22 pm

Hi,

the set-up shown above, while incrsing airflow (in theory anyhow) does nothing to increase airbox volume, a critical component (or so I would think).

Crazy schemes, part XX:

was wondering about fitting a small high-flow fan motor atop the airbox, with air scoops drawing air from the openings between the tank and frame (mid-tank), resulting in force-fed air into the carbs. Could hook up the motor to a rheostat linked up with the thrpttle so as to vary the motor speed with throttle opening (a poor man's supercharger, lol). Think of it as a way to get mechanical ram-air. The filtration could be set-up at the air entry point, thereby eliminating the present filter and shelf, really opening up the airbox for better volumetric efficiency.

Crazy or what?

Forgive me but I have an overactive mind (really should have been an engineer).....

cheers

Bondy · Post by **Bondy** » Sun Mar 18, 2007 6:25 pm

Are you using the 17 litre tank or the 19 litre as i remember someone saying recently that as standard the 17 litre tank has a bigger airbox to start with.

Lsm hows the airbox comin on.

LotusSevenMan · Post by **LotusSevenMan** » Sun Mar 18, 2007 6:31 pm

Hi Bondy.
Project on back burner at the moment as I try and sort a problem with handling (see my head shake thread!!), and get the Caterham Se7en ready for the good (:!:) weather to come...................... I hope