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ITG Megaflow Air Filter Base Plates, how to measure for the correct size

Here we explain how to measure and order the correct base plate for your ITG Megaflow air filter. “Megaflow” air filters are the red banded single or multiple carburettor and throttle body filters. As below:



To fit these filters to your vehicle, you need both the filter element, as above, and the base plate, as below. The base plate is fastened to the front of your carburettor or throttle body(ies) and then the filter element clips on to the base plate with quick release fasteners.



ITG produce a range of pre-drilled base plates to suit a wide range of carburettor/throttle body applications. In some instances though, there may not be a pre-drilled base plate available for your application. If this is the case, we sell blank base plates for you to drill or cut yourself.

On applications where there are twin carburettor or individual throttle bodies fitted you will need to measure the centre to centres of the chokes to establish the spacing between the two carburettors (because not every application or engine is identical and even different inlet manifolds on the same engine could be different). We then may be able to supply a pre-drilled base plate with your spacing.

On applications which use twin Weber DCOE/DCO’SP, Dellorto DHLA, twin SU, and individual throttle bodies, you will need to measure the centre to centre spacing of choke 2 and 3. Finding the exact centre of the chokes is quite tricky, so it is easier to measure the furthest left of choke 2 to the furthest left of choke 3. This will give you the same measurement. It is advised to remove any ram pipes before measuring. Example below:



Another thing to bare in mind is that, due to space restrictions, you may require the filter to sit “off set” on the carburettors. This means that the filter sits slightly more to the left or the right. This is useful if you are restricted by a bulkhead, inner wing, strut tower, brake servo etc and need to move the filter away from this.

Below shows a standard symmetrical base plate (top) and a left hand off set base plate (bottom). As you can see, the left hand off set base plate has its holes further to the right. When mounted to the carburettors, this will push the filter and base plate more to the left. Ideal for inlet manifolds on the right side of the engine. A right hand off set base plate is required for inlet manifolds on the left side of the engine. 



Photos below of a proper job done by a customer of ours from Japan last year. An ITG JC40 blank base plate cut by himself to fit his immaculate Toyota Corolla AE60. Thanks again for your photos Tomohide!










Archived in: ITG | Base Plates

18th April 2023