I didn't catch that on speed anybody record it?

Was the net top or bottom mounted - this could be part of what is driving the requirement to fix mount the bottom of the net.

I bought an Isaac. It's overall design and function provides me with the most assurance that it will in all instaces do what it is meant to do in the most efficient and effective manner available - reduce the amount of force applied to my neck from sudden changes in velocity of my body which is attached to the car while the lead weight at the other end of my neck seeks to continue its previous course and velocity. Whether via deceleration or via lateral acceleration or more likely via some exotic combination of the two.

Part of the problem is that 38.1 doesn't really care about full egress but has a release requirement that affected every product then in existence except HANS! The requirement is a single point of release (which as covered previously is a complete fallacy in production based racing from SS to Rally to NASCAR). Are you going to forget to disconnect your H&N restraint anymore so than your radio, cool shirt or window net? Egress is habitual - by the time you are in an emergency it is second nature and you will do what is necessary to exit the vehicle how ever many steps that may involve. But in a rush you can catch an extension off of the back of your head on a roll cage bar, net, wire or any number of things. Radio and cool shirt connections are much more problematic than Isaac pins which are even simpler than some window nets.

There is no other SFI standard so blatantly written with such glaring conflicts of interests.

You might find these quoted references interesting - http://www.jayski.com/pages/restraint.htm

From those sources you can put together the following:

1 - NASCAR wants a standard because drivers were pushing back on the limited options NASCAR was requiring at the time.
2 - NASCAR wants something to shove down their drivers' throats and goes to SFI (don't think NASCAR acknowledges FIA as at all valid for anything)
3 - SFI doesn't know a thing about H&N restraints
4 - SFI punts back to NASCAR saying sure write and we will make it the standard
5 - NASCAR has already been in bed with HANS for years as their own experts and consultants on the H&N topic are tied to HANS in several ways and have been whispering HANS is the only valid device in their ears for years.

And yes black helicopters were involved.

http://www.hmsmotorsport.com/docs/SFI_38.1...ecification.pdf

2.4 The Head and Neck Restraint System must be designed and manufactured to allow freedom of movement of head, torso, arms, etc., commensurate with operating a race vehicle under all race and associated conditions.
2.5 Adjustment and release mechanism(s) shall be accessible to both the user and to external personnel such that no additional motion is required, other than the release of the seat belts, to disengage the Head and Neck Restraint System during emergency situations.[/b]
It is highly questionable that any device could really pass section 2.4 of the specification, ever try to look ahead into a hairpin with a "properly" installed HANS? And section 2.5 has nothing to do with limiting forces being applied to the H&N which should be the focus of the standard and is a fallacy anyway as mentioned. And lastly if the standard wants to get into release issues then they should address full egress from the car not just releasing the belts and it needs to be a comprehensive standard across the board - egress should be covered by something simple like "from seated position as raced the driver shall be able to egress the vehicle within X seconds without assistance".

Issac would be very capable of passing all the objective tests surrounding the purpose of H&N restraint - reducing loads on the neck. 2.4 is too subjective to ever determine and arguably HANS could be the worst performer - I think Issac performs 2.4 better than any example short of air being the H&N restraint material. 2.5 was so explicitly written for HANS that it is the only product that did not require a change to comply and does not contribute to quality H&N restraint at all. We are talking sesame street here which section doesn't belong!

Lastly, I am dying to see how the HANS double belt system can be justified as passing 2.5 - the yoke (now with a retaining lip) is firmly retained between two belts! Releasing the belts does not disengage the yoke, with motion additional to releasing the belts, the belts now have to be slid off the yoke of which there is no manner to be positive that the yoke has been released even. Isaac pins are positive release - when they are released they are released.

I want to see a comparison of 5 drivers in production based race cars releasing from a HANS double belt system and Isaac and explanation how one passes 2.5 and the other doesn't.