Hi I’m new to the forum and have owned my mx5 (or miata) for about four months now.

I’m trying to find out some technical information on my ’99 NB miata, if anyone knows the following, it would be very appreciated:

The volume of the intake plenum, which I understands changes at a certain rpm due to the VCIS

The intake runner lengths.

The intake and exhaust port dimensions.

I have tried searching on the plenum volume size but have not had much luck.

Many thanks