So I have Weber 44s on my car. When the installation was done by a previous, previous owner, there were some aspects that were less than detail oriented. Items such as the following:

-Fuel Vapor lines from the front (car is a 73) just dump into the engine compartment. Assuming this contributes to fuel smell in car.
-Crank vent is basically a hose with a tiny air filter on it, suspended over the engine case... this leads to oil film all over.
- No head breather ports. Heads were never drilled/tapped for them, but I don't think my venting is adequate and it's causing oil leaks.
- Carbs in general are just loud. I want to hear some throat when I get on it, but don't need it all the time.

So in reading through various threads (especially the ones on the breather setups folks have posted recently) I started thinking about how I could solve all of these problems in 1. Creating a legal setup that would pull the fuel vapors and case/vents into the carb intakes..... and quieting things down a little bit.

So I thought about creating a single airbox that would install over the combined carb setup. Ideally, I would think plastic would be the medium of choice, but I have no clue where I would start.... so then I started thinking about fiberglass. Granted, I've never really built anything with glass, but it's fairly cheap and if it doesn't work I figure I'm only out my time and a few bucks. Plus I learn something in the process. I figure I could use techniques similar to those that the custom speaker box guys use to form shapes and build the box. This would just be thinner.

So I came up with the following crude drawing to illustrate kind of what I'm talking about. I would appreciate thoughts on this concept. Shoot holes in it as you see fit. Been down this road before? Know somebody that tried something similar?

Thanks in advance.... Mike

Click to view attachment

BAS in Germany make this exact thing. I've even seen them in carbon fiber with dual air snouts before A set-up like this would quiet down the noise and keep rain out too. What about just using 912 filter assemblies from a set of Solex PII's??

Here's the stock 912 filter assemblies I was talking about. Probably cheaper and a true Porsche product w/ factory filters. . . Just an idea

I have thought about this also.
I have looked at the German ones...quite a few are really nice, but very expensive.

The one that got me thinking is attached.
Here are the basic parts that I would use.

CB performance blow through turbo covers for the webers.
Get two.
Super beetle airbox...that is what is pictured (could just be any beetle)
Then get silocone hoses from a boat supply place..

Rich

I got sick of hearing air going into the throttle bodies - to much noise for nothing. I came up with "Quite Air Induction" I will be selling the system in teh near future. Here is a picture of the proto-type.


Bill Shaffer

Wow, that looks awesome. I am guessing part of the kit would also be a bellcrank linkage. What's the estimated price on it?

That looks good Bill. Any way to route it to get colder air?

I was thinking of boxing in the vents on either side of the engine lid, making rain hats for the filters, and put drain lines on the boxes.

-Mike

Those are 2" diameter connections IIRC which are ok if you are pressurizing with a turbo, but are flat out restrictive for airflow.

I had some made with 3" connections for my T4 setup on my Baja using a centrifugal air filter. It was quieter for certain but clearly restrictive probably because of the Donaldson air cleaner I was using. I'm tempted to use them on the 914 now.

I am using 3" tubing and have found that the Quite Air is somewhat restricted. When I get the production model done I will dyno the car again and state what the difference. The price has not been determined.

Yes it is designed to complement the Sidewinder throttle control. But, I am selling them as separate units.

Bill Shaffer

Back of the napkin math makes me think about the tubing size.
A single 40mm barrel on a dual weber is close to the 2 inch tubing size of 50mm
So it makes me think that for a system to work properly and have no restriction, you would need at least a 3 inch intak tube from each carb (80mm is 3.14 inches) and then at your merge portion you would need 6 inches.

None of my math factors in the timing of each intake pulse, but I think if you step up to 3 inch tubing, you will probably be alot better off.

Rich

Does anyone know if this BAS Airbox is available here in the states? ........... or ............ does anyone make something similar?

Not sure, but it's damn cool!

You need only one port on the air cleaner housing for the EVAP. The other hose goes to the fan shroud. There has to be a flow through the system in order for it to work.

The Cap'n

Indeed!! I will try to find the BAS version ........ if I cannot find anything ....... I will probably have to make something similar to the 6 cylinder weber airbox .......... I am not a big fan of noisy intakes or exhausts .........

The 912 units don't work. Well, they work 50%.

I purchased a set of 912 air cleaners that fit with the 914 rain tray still on. From 1967 912 I think?

The pass side fit fine using an adapter plate.

The drivers side ran into the firewall by about 3/4 of in inch.

So I pulled them off. My solution was going back to FI.

I'm in the process of making a fiberglass shroud (for lack of a better term) that would connect both of my carbs and have a center section that my air scoop would sit on. It's a slow process with having to make the buck then the mold then the actual piece. The mold is in two pieces that I'll have to join together. I have to do this on each side. The center section is next and finally the scoop which will go up over the targa bar. I should wrap it up in 2012 if I hurry.

I have a box of parts - namely 912 air cleaners, which I have been trying to find the time to work on to my car. I am very slow....

One of these days I'll get it done. the induction is REALLY loud.

Zach

Here is my idea. Just need to lay fiber glass over it. I have already talked with someone about making a mold. But I did not think there would be much interest. If there is I can look into the cost.
Click to view attachment
Click to view attachment

^^^ That looks good and is sorta like what I'm doing but mine is using seperate pieces for each carb running into a center section.

I'd be interested. The 912 cleaners are heavy.

BAM, where does the filter go? K&Ns on each side, or a panel filter somewhere?

Zach

That is totally where I was looking to go with my initial question, but have had absolutely no time to fiddle with it. Glad to see that some of you guys have been doing some thought/work on this concept.

I see in your shape that you have a bit of a "V" cut into the back side. Can you expand on the reasoning there? My initial thought had been to leave it more square in the hopes of using a more standard rectangular air filter that pulls air from the under side..... negating the need for a conical style filter out the front or side of the housing (and the fitment issues that would require).

I would definitely be interested in a group buy depending on cost/fitment, etc.

Mike

Here are some alloy versions, kinda crude with the design ....... and it looks like it will not accommodate a rain gutter.

http://www.chircoestore.com/catalog/produc...roducts_id=4937

http://www.advancedaircleanersystems.com/airboxes.htm

Checking in to cost right now.

Here is a shot of mine...


Click to view attachment

Huh, feel free to doublecheck me, but I think 2 inch to the carbs and 3 inch at the join would be fine.

This is how I figured it:
Area of a circle = Pi*r^2.
If we assume that the carb in question has a 32mm main vent (which would be as big as most of our cars would ever have), that means each barrel has an area of 803mm^2.
Both barrels would then be 1608mm^2
And all four barrels would be 3216mm^2

A two inch circle has an area of 1994mm^2
Therefore, a 2 inch tube should be plenty for 1 bank of carbs.

A three inch circle has an area of 4415mm^2, which should be fine for both banks.

So, not taking into consideration drag from going through the air filter, a 2 inch tube to each carb bank and a 3 inch inlet should not cause restriction.

Obviously this would not work for a 6, just a 4.

Zach

My guess is that if you make these, you will have several buyers. I'll be one of them. Especially if it means I can use a box type filter and get rid of the K&N filters I have to use currently.

Zach

One of the problems to overcome is how to attach this thing to the carbs. You need to have some type of base plate on the carbs and you need a tight fit and have a gasket or seal.

Mine is going to have a top and bottom. The bottom will bolt the normal way a filter does. The top will Dzus on with a seal around it. Mine will require the short manifolds and no rain tray. I plan on using a Formula Ford style cone air filter.

Click to view attachment

I can tell you that a 2" tube to each carb is not enough.

I'd be a buyer of a setup that is quieter and that allows using high quality air filters
that do not decompose and clog up your idle jets!

I have thought along the same lines as you all. I was looking at the turbo covers
for IDFs with the idea of a box in between with a large, paper filter in it.

I'd think you need to use the size of the top lip of your intake stack for calculating
restriction then add something for bends or direction changes the air has to make.

John

Correct, you'd need at least 2.25" to equal the twin 40mm area. Might as well go for 2.5" to have some comfortable overage.

Blake... No horse in this race as I'm all sixes but, why not a 911 filter? This way people who mistakenly want to use a K&N could but, those who want better protection could use the factory paper.

Your concept looks excellent... When I first saw it I thought you were going for the factory filter in that plug.

I am basically building this for my race car. Never intended to use it for the street. I will go over to my dads and get the carb housing for his 914-6 and see what it would take to use the air filter from it.

Seems logical.

If you're just doing it for your own use, you could then use the snorkle and seal from the 911 piece and make a negative of the inside back where the filter rests. Mold a couple studs into it to fit the snorkle ala factory.

I'm sure there's enough scrap 911's out there that snorkles would be abundant for any others you might make to re-coup costs.

Here are some more dual weber air boxes ..........

http://www.csp-shop.com/cgi-bin/cshop2/fro...mp;artnr=19931a

these have awesome baseplates!!

http://kaefer.motor-sport-service.de/html/...eranlagen1.html


on the samba

http://www.thesamba.com/vw/forum/viewtopic...asc&start=0

The 911 air box filter does not have a large enough ID for what I want to do for mine. So I will be continuing with my original plan.

Just for more thought, what about using the original filter holder and making an insert to fit where the filters do out of light guage steel or aluminum. Then run flex hose from each carb to a filter box out of a toyota or simular?