Air Box, what's that all about?

[The Gorilla]

Hi,

As Alexk has posted, Ram Air is important.

The CSL Airbox [Plenum] has an
achilles heal though, in that the Air Filtre
is located to close to the Intake runners.

This acts almost like a second flap
that can not be opened.

The Ram Air [ velocity] is reduced when
passing through the filtre.

Filtre further away from the TB's mouth with
a good Intake path would give a better velocity
into the TB's.

The Intake Runner length and its form is also critcal to the engine.

Leave those shiny Chinese Carbon Airboxes well alone !!

On the E30 M3 DTM cars [S14 ENGINE] they had several Intake
runner lengths to their Carbon Airboxes pending
if they required more Power or Torque from the
Engine.

15cms intake runner was used on the more shorter
Sprint races for Torque and then they would fit the
longer 17cms + for the more endurance type
Races where they needed to improve power Gains.

This was on either 48mm TB's or 49.5mm Slides.

I have a set of E30 M3 BTCC Zytek slides here which
were fitted to an S14 in an E36 Compact.

The Intake runner lengths were increased by about 30/40mm
something you can do with the S14 in the E36 Shell,
and the engine Power increased by around 18/20 BHP..

So proper Carbon Airbox tuning is a real science not
just noisey bling.

Regards,

The Gorilla.