Funnel socks for Mazda Miata MX-5

Let us explain about the funnel socks.
The funnel socks cover the funnels one by one, they are a kind of filter. They have the shape of socks that’s the reason why they are called funnel socks.

To be noted:

1. The funnel socks cover the funnels one by one, for this reason there has to be at least 8-10mm space between the funnels.
2. Even though the makers say that the funnel socks can be reused after washing, if possible we recommend their exchange.
3. If you cover the funnel too much the engine’s negative pressure concentrates on the socks’ filter’s bottom and the sponge might be destroyed. We recommend to cover the funnel lightly so that the filter can absorb enough air and so that no negative pressure concentrates on the socks filter.

In the case of the carburetor and 4-throttle injection:
The uncovered air funnel looks very cool and we can imagine the engine’s aggressive potential. However, it is very important to check the filter properly.

The intake air resistance caused by the filter is an obstacle because it makes the engine output bigger.
Now we are not talking about ignoring the longevity to be able to win a race.
That shouldn’t be important for street tuning.
Even if one recognizes the risk of high revolution combined with high output, one must understand that if there is no air filter installed the risk of an accident is high.

Intake of a foreign part

You might ask yourself: “What's wrong with not installing a filter?”
Let's take a look:
1. First, check your car’s engine room. Touch the surface of the intake manifold, the plug cord and the other surrounding parts. You will get to a part that is rough, sandy. Without a filter these parts will be absorbed by the engine.
2. When overhauling the engine, it is recommended to do it in clean environment. The parts should be properly cleaned and any dust should be removed.
3. The rough, sandy part is like sand paper and can damage the engine’s inner functions.
4. If a big part enters the situation becomes even worse and the final result might be the break-down of the engine.
5. The squish clearance between the piston and the cylinder head is very narrow. If a foreign substance enters it, engine blow might occur.

As you can see just by one foreign substance the engine might be destroyed. However, all this can be avoided by the installation of a filter.


Maruha Motors Co., Ltd.
Ushizuma 2095-6, Aoi-Ward
421- 2106 Shizuoka city, Shizuoka prefecture
TEL: 0081-54-294-0076
FAX: 0081-54-294-1312