Exactly What Is The Head Rest Restraint System?

[hl0m4n]

so to my knowledge the 2 things preventing bmw perf seats are the OC3 sensor and head rest restraint.

assuming you can solve the problem with the oc3 sensor by simply transfering the sensor and hooking it up, what exactly is the head rest restraint system?

is it a sensor in the headrest, is it a pad like the oc3? any ideas? help much appreciated. thanks.

[JIO]

The head restraint system for all 2009 on cars has a sort of pulley & cable system built into the lower back that when in a rear end collision, your back gets pushed into the the back of the seat causing the headrest to pop up and out to meet your head quicker, thus preventing whip lash. The harder the hit, the faster and closer of the headrest. Because of the system, the headrests are fixed from tilting but will go up and down. On BMW's, the headrest is no longer removable.

[Bob MG]

http://www.m3post.com/forums/showthr...formance+seats

I go in tomorrow to fit the wiring harness to sort all this crap out on my seats, but that's not applicable in US

[mkoesel]

Originally Posted by JIO

The head restraint system for all 2009 on cars has a sort of pulley & cable system built into the lower back that when in a rear end collision, your back gets pushed into the the back of the seat causing the headrest to pop up and out to meet your head quicker, thus preventing whip lash. The harder the hit, the faster and closer of the headrest. Because of the system, the headrests are fixed from tilting but will go up and down. On BMW's, the headrest is no longer removable.

I still question the practicality of this system.

I don't see how moving the headrest to meet your head during a collision is better than just having the headrest touching your head to begin with. If my car didn't have a tilting headrest (I have a 2008 - pre-active headrest era), I would not be able to adjust the headrest to meet my head in my normal seating position, and this would be unacceptable. Granted the fact that the headrest is free to move under pressure of my head is also not great. Ideally, it would lock in place somehow.

I've never seen a race car with a system like this, but perhaps I just haven't paid attention. And yes I realize race cars feature an entire safety system that combines a roll cage and harness. And they don't have airbags. But none of this preempts the need for a safe headrest, and yet they just have ample stationary padding there to my knowledge.

To me they should develope a seat that automatically brings the headrest toward your head as part of its normal adjustability features and then locks it there. That would be cool.

[foosh]

But, the HANS Device, or equivalent is required in most series. In a passenger car, the airbag keeps the head from snapping too far forward, and the headrest is complementary in keeping it from snapping back. The HANS Device does the same thing, but better.

[BRDHNTR]

Originally Posted by foosh

But, the HANS Device, or equivalent is required in most series. In a passenger car, the airbag keeps the head from snapping too far forward, and the headrest is complementary in keeping it from snapping back. The HANS Device does the same thing, but better.

Yeah, a bunch of people at work want to see my e46 M3 track car and without an airbag and with the 2" webbing on the shoulders, I plan on wearing my helmet and hans if I ever decide to actually bring it to work. The car is registered, insured, and inspected, but I'm sure it won't pass inspection when it comes up later this year. Oh well, I just wanted to pass tech anyway.