CN regulations help.

[fausto cedros]

To all of you tuned.

I am trying to think to some modifications to a Norma M20 CN2 prototype, and i have bbeen trough some difficulties reading the regulations.The article 259.3.7.4 of J annex, states that the bottom from the vertical plane tangent the aft front wheels to the end of the bodywork must be FLAT. How can they lift it behind the rear axle to make the diffuser? Where am i getting the rule misread?Please, any ideas welcome.

[dumrick]

Hi,

I was unable to find the FIA regulations for the CN class but, while searching, I learned that many national FIA affiliates and championship promoters seem to take some liberties regarding what is written in the J Annex.

Two examples: UK's Speed Sports Prototype Series regulations have a section of "Additions & Amendments" to the Article 259 of the J Annex (allowing a diffuser, among other things). Another popular series is french VdeV that allows entries only to FFSA-approved CN vehicles (see Article 4.2.3.7.1.). This regulations (see Article 3.7.4) define that the flat bottom must be only between the rear of the front wheels and the front of the rears.

Therefore, I advise you to start by reading the specific regulations of the championship the car's going to race in, and only mind the general FIA regulations where no particular national regulation exists (like usually in safety fields). Maybe you're interpreting the rule ok, but it doesn't affect you.

Edit: if you desire to work the aero of the Norma, Racecar Engineering magazine had a Aerobytes section with a CN car (I believe it may have been the Ligier JS49). It's always a good starting point to check what they've tried at the MIRA's windtunnel and the results they got, it may help you on your particular work.

[Scuderia_Russ]

I ran a Norma M20 for a few seasons a couple of years ago in European V de V and the U.K. version, now called Speed Series but I'm afraid I'm struggling to understand your question. P.M. me and I might have some photos that could help you out.