Originally Posted by Trier Germany
If you Track in the U.S. you have to have an SA-2005 rating or above!
The SA2005 refers to the year that that spec of protection was defined by the Snell Foundation (http://www.smf.org/
). I believe they specs are updated every 5 years, and a helmets certification lasts for 7 years. Whether organizations/clubs allow 7 years or 5 years differs, some people think the certificate only lasts until the next certification is published. Anyway, a Snell SA2005 helmet will have its certificate expire in 2012 and will no longer be accepted by a (reputable) organization after that. If you are buying a helmet now, you need an SA2010 certified helmet - this you will be able to use at any event, whereas a cheaper M2010 helmet might be rejected.
What the Snell certification does is set a minimum safety standard for helmet protection. SA helmets have a degree of fire resistance that motorcycle helmets don't. If the helmet passes this spec, it is considered safe, whether it cost $50, $500 or $1000. In most cases, the extra cost is for materials used, finish and the brand of helmet - a $700 helmet will offer little more protection than a $250 helmet, but it will have a lighter shell, better lining, better ventilation and better visor material/mechanism. The weight will make a difference in a 3 hour endurance race where you are pulling high-g's in corners, but unless you have a pencil neck, not much in a 20-25 track session in a stock/lightly modded M3 without a harness where your whole body is essentially moving about. In a harness, your body is strapped in, so there is no "compensation" to reduce the amount your head moves about, so weight becomes more important. It is all about you wallet and your comfort and your acceptable ratio between the two.