Airbox chop (instead of pods)

Hello,

I've been reading out the troubles with CV carbs and pod filters.
there seems to be a problem with either air turbulence or the kidney hole in the top of the carb throat.

The pod filter either partially blocks the kidney shape and/or the air trajectory is so short and twisted and unpredictable.

Well I want more air on my engine and I like the naked look.
I have a theory for you to kick around.

Cut the airbox in half at the line where it meets the frame.
Get rid of the part that sits next to the battery and modify the part that sits in front of that rising frame bit.

Cut a square hole in the back of it large enough to fit a flat car air filter and fabricate whatever bits you need to secure it in place.

I've drawn some pics of the idea:



By using the same boots to connect the filter to the carbs, we can be pretty confident that the final air approach will be appropriate for the kidney shaped hole and there may be enough length to the system to smooth the air out (better than pods anyhow) and we have a very large filter/air source to draw from.

Don't worry about aesthetics at the moment, but I'd love your opinions on the physics/engineering of it.

 

Your design solves one issue - the intake boot "velocity stack" is retained and airflow is straight, rather than turbulent.

The second issue - the stock airbox is a ported, restricted volume that may actually resonate at operating speeds, or full throttle.
With an auto filter from, say a 1.8 litre car, your design is essentially "open" and *might* run lean at higher RPM's

But don't let my opinion stop you!

 

Enticing Idea, wish I had more to contribute.

 

Enticing Idea, wish I had more to contribute.

 

i love the idea. this is very unique. please make it and sell it, or dont. this has amazing potential.

 

Go for it.

 

other members on here have run pods by retaining the carb to airbox boots and have had sucess in tuning them...

just another option. I saw mention of it in the "simple mod may solve pod tuning hardships" thread a bit further down the forum. I believe it was mentioned around the 21st page of the thread

 

hi , all
ive allready decided on this exact same thing, though i have to say mines not yet up and running, because i'm in the process of cafe'ing mine, it will be interesting to see if i can get enough air through the smaller filter.
though i have some wriggle room if not.
see what you think.


fitted a small circular air filter in there


made a alluminium plate to mount the outer funnel on






one other advantage is the airbox can be removed without removing engine

 

Nice one!
Send thru a pic of the finished product when you get it installed
Curious to know if theres any resulting difference in leanness between the inner and outer carbs

Anyone have a diy way of measuring airflow?

 

Anymore DYI is not cheaper than storebought for most things.

http://www.amazon.com/s/ref=nb_sb_ss_sc_0_11?url=search-alias%3Daps&field-keywords=airflow+meter&sprefix=air+flow+me%2Caps%2C265

Be happy that you live in an amazing time. What used to be thousands of dollars worth of test equipment can be had for next to nothing.

 

Nice, but I'm sure you could rig something with an old hot wire MAF, car battery, length of hoover tube & a multimeter that would do effectively the same job if you really were as tight-azz as me Especially if you were less concerned about actual airflow than difference between cylinders.

 

Sorry for the lengthy delay,
Voila - the airbox chop


(Thank god for thermoplastics that can be welded together with a soldering iron)

 

thanks guys.you have given me some ideas.have cut up airbox and will hopefully attatch two pods.plan on controlling the air flow into box to replicate factory cheers scruff

 

That looks really good. Now I'm just trying to picture what the stock airbox looked like. :?

I've always contemplated building a breadbox filter like this using the stock intake boots, but just haven't gotten around to it.
Breadbox filter

 

So how do they perform? I'm not wanting to put my airbox back in my frame and I also don't want pods. So this looks like an option, or a modded breadbox. Someone make a breadbox fit a maxim!

 

So how do they perform? I'm not wanting to put my airbox back in my frame and I also don't want pods. So this looks like an option, or a modded breadbox. Someone make a breadbox fit a maxim!

 

Be prepared to jet it just like you put pods on it. As free flowing as that looks you wont stand a chance with stock jetting.

 

sry for slow feedback, I think I have an intake leak, so I cant yet comment on how well it works. I have gone up a size with the jets, but its possible I'll need more.
Also, there is an argument that CV carbs just dont like unrestricted air. When I've got it running nice, I'll let you know what was required.