I found this air intake system for Weber carbs from Thoro-Tec Thoro-Ted web site
They also have other 914 related items.

Click to view attachment
Click to view attachment

"Looks" nice from an elegant visual design standpoint but I'm wondering how it flows and whether or not it accomodates velocity stacks.

It looks constricted to me forcing a 90 degree airflow change and potential for turbulence just before the venturi. However, I've seen CFD on other designs that I thought didn't look optimal and they performed well both in CFD and later on during validation testing.

This is the sort of stuff that I think the company needs to provide CFD and/or dyno proof before I'd shell out $1000 for what is esentially a pretty air filter.

I'd be interested in flow specs.
Looks better for forced induction.

Agree with the above comments. Look like far less filter surface area. In addition to the flow specs what are the filtration properties?
I guess one benefit would be less likely to catch fire if the car backfires.

Does it matter? Filter is red. Surely adds 15 HP.

Would be better with an MSDS filter. I like the clean look.

As much as I like the filter hats on a /6 engine I'll probably run the modified stock airbox i got from Britain Smith.

They also have three rain hat type covers

Not enough volume.
It needs something like a /4 version of a /6 intake, large central plenum, large runners and as much height over the velocity stacks as possible.

M96 has two 4"(-ish) tubes but they're attached to two large plenums, total volume of several liters.

overpriced "Dreck"

@Superhawk996

Wouldn't the long runners double as velocity stacks? Seems like they should ...

@SirAndy

I think you are right they might serve to boost flow velocity initially but then that 90 degree turn without much height above the venturi would mess it up as it then decelerates flow into the tiny "plenum" over the 2 barrels of the carb.

Velocity stacks might help restablish a linear flow down into the venturi but those little plenums above each carb would seem to constrict flow downward into a velocity stack for each venturi.

All purely speculation on my part. At a bare minimum I'd want to see a dyno plot that shows HP is at least equal to standard IDF style filters.

I really do like how clean it looks. Just not convinced it won't cost HP.

Looking at it makes me feel like I'm breathing through a straw.

Was wondering what the advantage of this setup is given the air filter is still exposed to the elements. It looks very similar to the various CB performance setups for forced induction.

https://www.cbperformance.com/product-p/7312t.htm

If doing non forced induction and want to join both stacks to a single air filter, i think this is the better way to go as it actually protects from the rain.

https://www.ahnendorp.com/VW-Type-4---Porsc...tml?language=en

People drive a 914 in the rain?


Fluid mechanics sometimes has surprising results. I can't imagine anybody making something like this without modeling it.

My quess is that is is quieter more than anything else.

Adding oil just got a little more time consuming.

I can. Happens all the time. Sort of looks like they might be 3D printed as an on demand business model. Can't imagine them selling more than 1 or 2 at that price point. 914/4 owners not exactly known for rollling in cash and spending big $ on parts.

Long ago I had a conversation over beer with a buddy. We discussed going into the aftermarket business, making "hop-up" parts, and how we might market them based on what goes on in the industry.

We both eventually arrived at the postion that unless we were going to be willing to make absurd claims about added horsepower, improved fuel economy, etc., we might be giving up lots of money to those that do. We both decided to focus on our day jobs.

My hat goes off to the suppliers we have supporting this community and providing honest products and standing behind them. It ain't easy!

True...but usually aftermarket stuff like this isn't modeled well. Most really falls in the ColorfulFluidDynamics realm where people assume presentation==validity. Generally intake simulations kinda suck to do by their cyclic nature and aren't really for the faint of heart.

That said, it does look really nicely made! I am curious to know what the base at the carb looks like. Seems like their might be enough room for a nice partial bellmouth which would be OK. I'd agree with that, you're damping a lot of the noise of the butterflies which can be nice.