I've got a Simpson open face race helmet like some of the old time NASCAR drivers used to wear before they mostly switched over to the full face models. the NHRA rulebook says helmets must meet the Snell or SFI specifications to be legal. Snell SA or Snell M for both open and full face helmets meet the specs. The SFI specs are 31.1A, 31.2A, 41.1A or 41.2A Snell K-98 is acceptable in place of any Snell M rated helmet. Snell 90, 95, K-98 are also acceptable for ET bracket cars running quicker than 13.99 secs in the 1/4 mile.

 

Mine's a full face helmet as well... not sure if its Snell rated never looked but I assume so since its a sportbike helmet

 

peel back the lining at the back of the inside of the helmet and there should be a manufacturer's sticker there telling you what spec it was made to as this is what the really sharp tech officials do to see if it is a legal helmet. I think mine's a Snell 95 but not real sure!

 

what is water injection and how does it work, ive head u can run really advanced timing with it too???

 

water injection is just a band-aid for not building the engine correctly for the application IMO. it does just what it says, it injects a water/alcohol mixture into the intake to prevent detonation by cooling off the intake charge some but like I say, it's a band-aid for not fixing the real problem. besides, to use it a lot you need a big tank of water which weighs 8.34 lbs./gallon, so it can be really heavy too.