Velocity stacks, hight? diameter? Filter? Options

[Alphaogre]

I have dual carbs (webber) on my 70 914-4 and I am looking to run velocity stacks and having some trouble finding options for not only the stack but also some means of the filters as well.

It also seems that there are augments on both sides for tall vs short on the stacks hight...? any recommendations?

I would really like to have something like below.

[SirAndy]

It also seems that there are augments on both sides for tall vs short on the stacks hight...? any recommendations?

I would really like to have something like below.

Two things:

1 - The stacks pictured above do *not* have filters. Do not mistake that mesh on top for a filter.

2 - The height of the stacks depends on what you want from your engine:
a - If you want high rpm HP, get short stacks
b - If you want low end torque, get tall stacks


(IMG:style_emoticons/default/driving.gif)

[ww914]

Velocity stacks are important in directing the air into the carbs. I am certainly not an expert, but it depends on the size carbs you are running, the size of engine and many others things. Go to www.cbperformance.com and read up on what they say.

[Alphaogre]

I know the above is just a mesh but I have seen close to the same thing but with a filter as well as a mesh.

CB performance is where I have been reading up on most this stuff along with the samba, I just wanted to be sure that the general bug and VW applications in this matter are applicable to the 914 engins with out any variables or anything like that.

Im thinking of going long (6 in) with the boots they have for them at CB Performance.

I wasn't sure if there were any other sites that had them or other options.

[URY914]

Save your money. The stacks don't do much and those cheap ass covers are mesh with a thin layer of foam between them. I had a set and sold them years ago.

[ThePaintedMan]

Save your money. The stacks don't do much and those cheap ass covers are mesh with a thin layer of foam between them. I had a set and sold them years ago.

Just adds more weight, right Paul? (IMG:style_emoticons/default/smile.gif)

[euro911]

I'm running short stacks on dual 40 IDFs, 32mm vents, 9:1CR 2056 with K&N style filters.

[rhodyguy]

they come in dif diameter sizes too. top of throttle bore specific, not venturi size. ones for 40mm, 44mm, etc. the height of 2 3/4ish" seems to be a happy medium. there should be a stamping on the bottom carb flange. 40, 44...

k

[zig-n-zag]

Take a look at www.bbrfilters.com for stack filters.

[McMark]

Get any of the above. Unless you're planning on dyno tuning you engine, it's just for looks. (IMG:style_emoticons/default/wink.gif)

[Alphaogre]

Thanks for all the impute...We have been trying to see what has been with the motor so far.

The guy I bought it from wasn't really sure all the stuff and it turned out that some of what he thought was a little off, but in a good way. The carbs are turing out to be 44's and it looked like some one has gone through the motor with the initial inspection of the intake and exhaust portion of the motor, it looks as though some one has done through the motor.

So now the question is what should I look for to try and gather what has been done to the heads, also would any one ever put 44's on a motor that has not had work done to it? Would there be any benefit to just bolt the carbs? If there is some head work and the carbs then what would be the best intake/ filter set up to make it all as effective as possible?

[ChrisFoley]

The pictured velocity stacks belong on a race car, not on a street car!
V-stacks are of little value below 5000 rpm.
The stock engine redline is only 5700 rpm.
Regardless of any upgrades the engine has had, those cool intake horns will seriously shorten your engine's lifespan.
Forget about individual tall velocity stacks, each with their own filter.
Get some short (1 1/2" to 2") stacks that fit under a set of really good air cleaners.

As far as carburetor size goes,
You need to find out what camshaft was installed in the engine.
If its a stock cam, the 44s may be too big, depending on displacement.
The stock engine displacement in 1970 was 1.7L.
That was 90mm bore x 66mm stroke.
The best way to measure the bore and stroke is to remove a cylinder head and measure them directly.

How about some pictures of the port work?

[brant]

44's sound big to me for anything but full redline

I had a souped up 2.0 street car with a web cam once upon a time
the 44's on it were never as good as the 40's
(I even choked them down)

brant

[rhodyguy]

engine OFF...take one of the filter tops off and look down into one of the venturis. you should see a number stamped on the top edge of the choke. for stock 44s it'll prob be 36. REAL crappy low air speed response and you might have tuning difficulties. best for a stockish 2.0 streeter would be 28s imho.

k

[Alphaogre]

Awesome thanks for the input. It's always fun to try and figure out all the "great" ideas that have been applied to the car by the previous owners over the years.