Schroth's Harness Safety Guide - Wear a HANS with a harness

Below is the link to Schroth's Competition Instructions, which contains critically important information on installation guidelines for harness & related items.  This is an absolute MUST READ for anyone who already has harnesses installed, or will have harnesses installed in the near future.

http://www.schrothracing.com/sdocs/2009_Competition_Instructions.pdf

Some key takeaways from this doc:

• To quote the doc, "5-point racing harnesses are less safe, proven by computer simulation, sled testing and in real world accidents. Therefore SCHROTH strongly recommends the use of 6-point racing harnesses only"
  
• Always wear a HANS or equivalent with a harness.   Refer to the following crash test video which shows what happens without a HANS; there is additional information in the doc.
  
  
  
• Maintain proper routing angles of both shoulder & lap belts.  If the angles of either are incorrect, you will likely cause yourself some injury.  As an aside, the lap belt angles can also apply to a 3-pt lap belt setup.
  
  
  
  • Spoiler alert: For the shoulder belts, downward angles larger than 20 degrees should be avoided at all costs.
    
  
   
  
• Anti-submarine belt routing differs greatly between 5 & 6 pt harness
  
• Take note of Schroth's statement on proper seats below.
  
  
  

Very good point.  I would hope everyone on here goes on track with a good helmet and a HANS or similar device.   However, driving on the street (with no helmet) is a conundrum.  

Since we are nothing but a floppy rag doll in a violent crash, not wearing shoulder belts present several terrible possibilities including bouncing your head off the ground in  a rollover.  So, you'd like to stay upright in the seat using the shoulder harness but then your head could fly off your shoulders (well technically a basal skull fracture which is about as bad) in a high G head on crash.  You could argue you'd crush your chest/hear on the steering wheel without the shoulder belts, so there's no good solution:  pick your poison.  

Me?  I've got a short thick neck and would take my chances using shoulder belts with no helmet/HANS on the street.  But that's the way I'll roll the dice.  YMMV.