Open airbox for VAZ carburettor

(Szerző: z. (Houdek Zoltán), utoljára módosítva: 2007.01.19.)

IMPORTANT! This modification may not be street legal in all countries.
Thanks to Szivar for some comments.

Comment: in cold winter you better switch back to the original airbox. Therefore it is advised to get a second air filter box before you start to modify one.

Comment: airbox has a function regarding the perfect airflow. When Lada (and Fiat-124) was desgined, this effect had not been taken into consideration that much... although do not be surprised if you loose some low-RPM torque.

Comment: most of the effect of this modification is mental only, because of the cool sound.

Comment: this modification is not street legal in most of the countries.

After these precautions, lets do it :-)

The top of the airbox should be cut to a diameter equal to the air filter diameter. Don't use low-quality cheap filters. Those with a metal net or perforated alimineum sheet around the paper filter are better. These filters keep their height while you tighten the 3 screws on the airbox. If the filter loses height, its working surface is decreasing in size.

Try and keep it as nice circular as possible. The lower part of the box should be cut to the air-filter diameter, or at least to the diameter where it is thicker than at the rim. At the center it is built of two sheets welded together. Don't cut into this enforced part. The crankcase breather is tied to a pipe there. This pipe must not be cut off. You can leave it there, cut it around. The fumes won't go outside, this pipe leads to the inside:

You can paint the airbox (top and bottom part), it looks nice in the engine bay.


The engine is much louder at idle speed, and at full throttle also produces gives a nice sound. Acceleration is better over 3500RPM.

More air needs more fuel:
2105 carburettor jetting:
primary barrel: fuel 120, air 170.
secondary barrel: fuel 162, air 150.
float level: 6.5mm +/- 0.25mm

Fuel consumption:
this is a very slight modification, you just cannot measure the real fuel consumption changes, since your driving style counts more than this airbox cut or jet swap/drill.

Top cover: nice cut

Top cover: cut at larger diameter

This is how pros do it at K&N...