|
|
12-16-2008, 02:10 AM | #1 |
Major General
152
Rep 5,124
Posts |
Crash Protection- '08 vs. 09' w/Active Head Restraint
Well, the M3 headrests have long since been an important topic on here, but when the 09 models were first released there was some talk about the loss of tilt functionality due to BMW's Active Head Restraint (AHR) system. Nobody has really said anything about AHR since.
Some results were just published by the Insurance Institute for Highway Safety on the 3 series' AHR headrests and how they compare to the non-AHR headrests. The first link below has some fairly detailed data on backset (how far the headrest is from your head), head contact time, max shear neck force, max neck tension, and a few other categories. The bottomline is that the non-AHR headrests receive an Acceptable rating (2nd best), while the AHR headrests receive a Good rating (best). I was most surprised that the AHR system eliminates the 90N max shear force and almost cuts the max neck tension that is seen with the non-AHR rests in half, despite a greater backset and top of the head distance. I still have yet to see a demonstration of these head restraints in a crash, but I would like to see a video after seeing this data. The test doesn't say anything specific to the M3, but I thought that some of you might take interest in the general data and test results. The second link shows more detailed and scientific information about how the tests are conducted for all nerds and naysayers. I should also mention that these particular tests were done by striking the vehicle from the rear with a vehicle of similar weight at 20 mph. http://www.iihs.org/ratings/head_res...spx?bmw#tested http://www.iihs.org/ratings/head_res...aint_info.html Enjoy. |
12-16-2008, 03:05 AM | #3 |
Major General
152
Rep 5,124
Posts |
|
Appreciate
0
|
12-16-2008, 03:12 AM | #4 |
Captain
48
Rep 636
Posts |
And they also can't be removed. They will adjust up and down. The rear ones can be removed and so they are not AHR's...only the front two.
|
Appreciate
0
|
12-16-2008, 06:41 AM | #5 |
Moderator
7512
Rep 19,368
Posts |
IIHS site appears to be down right now.
I stilll love my tilt headrests, even if they aren't as good as the new ones in an accident. It will be interesting selecting my next BMW when the time comes, without tilt headrests. Seems like they could still allow tilt if it relied on something more than friction to keep its position. Maybe they'll have that figured out by the time the F30 3 series debuts |
Appreciate
0
|
12-16-2008, 10:22 AM | #6 |
NASA SpecE30 Racer
82
Rep 1,307
Posts |
I have an 09 with the AHR, and I have no issues with them. I don't normally rest my head on the head rest when driving, but I like knowing it is in a fixed position and close to the back of my head. Even when I do lean my head back it feels comfortable.
__________________
King Tut
2012 BMW M3 Individual: Sold lsb.ridedomain.com 1987 BMW 325is SpecE30: spece30.ridedomain.com 2009 BMW M3 Coupe: Sold e92.ridedomain.com |
Appreciate
0
|
12-16-2008, 05:03 PM | #8 |
Moderator
7512
Rep 19,368
Posts |
|
Appreciate
0
|
12-16-2008, 06:38 PM | #10 | |
Major General
892
Rep 9,032
Posts |
Quote:
I just wonder if BMW used the mechanical mechanism or some pyrotechnical one that needs to be replaced once it's activated.
__________________
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."
|
|
Appreciate
1
Flying Ace4984.50 |
12-16-2008, 06:47 PM | #11 |
Second Lieutenant
7
Rep 247
Posts |
__________________
2009 E90 M3 - Silverstone/Fox Red - M-DCT, CW, PP, TP, 19", Moonroof, Sunshades, PDC, Enhanced Prem Sound, HD Radio, Sat, iPod, Smartphone Integration
|
Appreciate
0
|
12-16-2008, 07:09 PM | #12 |
Lieutenant Colonel
205
Rep 1,864
Posts
Drives: F80 M3
Join Date: Jun 2007
Location: Texas
iTrader: (2)
Garage List 2016 Porsche GT4 [0.00]
1999 Porsche Spec B ... [0.00] 2014 Ram 1500 Laram ... [0.00] 2007 Porsche GT3 RS [10.00] 2013 Tesla Model S 85 [0.00] |
Good post. I recall a thread bemoaning the new requirements, seems that they are surely worth losing the tilt feature of the 2008 death traps.
|
Appreciate
0
|
12-16-2008, 07:18 PM | #13 | |
Moderator
7512
Rep 19,368
Posts |
Quote:
But if this is good, then why isn't it similarly good to have the seat back itself normally a set distance from your back, and then only "shoot forward" in a crash? What is so special about the head/neck that it would make more sense for the safety system to operate this way, instead of just cradling your head to begin with? You know, like it would in racecar? |
|
Appreciate
0
|
12-17-2008, 01:02 AM | #15 | |
Major General
152
Rep 5,124
Posts |
Quote:
Okay, now I'm confused Anybody want to videotape themselves getting rear ended? |
|
Appreciate
0
|
12-17-2008, 02:00 AM | #16 | |
Moderator
7512
Rep 19,368
Posts |
Quote:
"The backset, or distance behind the head, should be as small as possible." Ok, well how bout zero? That's as small as you can get. But, by not having tilting head rests, you make the liklihood of the backset being zero less. So why is that good? To me the best way to do it would be allow the headrest to adjust and then lock into place, like I said earlier. But hey, I am certainly no safety engineer. Also, since the headrests still move up and down (right?) then the "height" measurement on the IIHS site can also be changed. So why allow that to change still, if its also safety concern? |
|
Appreciate
0
|
12-17-2008, 02:37 AM | #17 |
Major General
152
Rep 5,124
Posts |
|
Appreciate
0
|
12-17-2008, 10:40 AM | #18 |
First Lieutenant
13
Rep 376
Posts |
Hey BW, I volunteer mkoesel
__________________
M3 ...the ultimate driving machine
2008 M3 6MT Cabrio, Jerez Black w/ Bamboo Beige interior, Tech/Preimum Packages, I-Pod, SAT/HD Radio, 19" MWheels 2008 535i tt, 6MT, Monaco Blue w/ Cream Beige interior, Preimim/Cold Weather/Sport Packages, HUD, HD Radio, etc. |
Appreciate
0
|
12-17-2008, 10:43 AM | #19 |
NASA SpecE30 Racer
82
Rep 1,307
Posts |
I thought the metal shafts still allow you to move the headrests up and down. I know the active headrests in my Nissan Frontier allow the headrests to move up and down on the metal shafts.
__________________
King Tut
2012 BMW M3 Individual: Sold lsb.ridedomain.com 1987 BMW 325is SpecE30: spece30.ridedomain.com 2009 BMW M3 Coupe: Sold e92.ridedomain.com |
Appreciate
0
|
12-17-2008, 11:30 AM | #20 | |
Moderator
7512
Rep 19,368
Posts |
Wow, that's surprising. I rely on both the tilt and elevation controls for comfortable head position. I would be lost without those.
Quote:
j/k guys |
|
Appreciate
0
|
12-17-2008, 11:31 AM | #21 |
Major General
152
Rep 5,124
Posts |
hahahahaha, i totally didn't even see that.
|
Appreciate
0
|
12-17-2008, 10:49 PM | #22 |
NASA SpecE30 Racer
82
Rep 1,307
Posts |
You mean the 2009 E93 headrests. Mine look just like the 2008s do.
__________________
King Tut
2012 BMW M3 Individual: Sold lsb.ridedomain.com 1987 BMW 325is SpecE30: spece30.ridedomain.com 2009 BMW M3 Coupe: Sold e92.ridedomain.com |
Appreciate
0
|
Post Reply |
Bookmarks |
|
|