Carb Airbox, Input appreciated... Options

[stepuptotheMike]

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

[aircooledtechguy]

BAS in Germany make this exact thing. I've even seen them in carbon fiber with dual air snouts before (IMG:style_emoticons/default/drooley.gif) 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??

[aircooledtechguy]

Here's the stock 912 filter assemblies I was talking about. Probably cheaper and a true Porsche product w/ factory filters. . . Just an idea (IMG:style_emoticons/default/beerchug.gif)

[r_towle]

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

[azbill]

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

[type2man]

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

[E-Man]

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

[tomeric914]

CB performance blow through turbo covers for the webers.

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.

(IMG:http://farm3.static.flickr.com/2225/3536056115_feca4a26f2.jpg)

(IMG:http://farm3.static.flickr.com/2441/3536056013_f6042d8b0a.jpg)

[azbill]

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

[r_towle]

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

[gothspeed]

BAS in Germany make this exact thing. I've even seen them in carbon fiber with dual air snouts before (IMG:style_emoticons/default/drooley.gif) 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??

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

[JmuRiz]

Not sure, but it's damn cool!

[Cap'n Krusty]

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

[gothspeed]

Not sure, but it's damn cool!

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 ......... (IMG:style_emoticons/default/smile.gif)

[Root_Werks]

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.

[URY914]

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. (IMG:style_emoticons/default/sad.gif)

[VaccaRabite]

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

[bam914]

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.

[URY914]

^^^ 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.

[VaccaRabite]

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