BAJASVT
FRF Addict
As a person who's worked in crash safety development for nearly 20 years, I must somewhat disagree with these statements for a few reasons.
It's true that "crash sensors" do use accelerometers that measure the rate at which a vehicle decelerates to determine whether or not to deploy the airbags, but the entire dynamic event of a crash/collision is a little more complicated. Acceleration/deceleration is measured in distance/time^2. The time part of the equation is key and is why the frame crumple zones are important; the crumple zones are designed to reduce the rate at which a vehicle decelerates during a collision. Additionally, the crumple zones are designed to absorb the energy of the impact so it's not transferred to the rest of the vehicle, and most importantly, the occupants. Air bag deployment timing, the amount of energy to be absorbed by crumple zones, and the size/shape and speed at which airbags deploy are something that auto manufacturers spend millions of dollars on every year. Mess with any one of those items and the entire occupant protection equation is out the window.
Additionally, modern multi-stage deployment airbags, OCS (occupant classification systems) installed in vehicle seats, seat belt and seat belt buckle pretensioners, collapsible steering colums and steering shafts (deigned to stroke and eventually break), and timed duration crash sensors all play into the "crash pulse" and exactly how the airbags are fired... they don't just go BOOM like they did 20 years ago.
With all that said, it goes without a doubt that most of the prerunner bumpers are stronger than the stock bumper. They're going to hold up to offroad abuse tremendously better and the same can be said for minor vehicle collisions where the airbags don't deploy. The severe collisions where airbags deploy to save your life are where we get into the unknown in regard to frame-cut prerunner bumpers because there's been no testing done. As mentioned, a large amount of data is processed essentially in an instant to determine airbag deployment. You can read this and think that a little change in timing input to the crash pulse from cutting your frame horns may not make a big difference, but keep in mind that lethal portion of a severe car accident occurs in approximately 300 milliseconds which is approximately the same amount of time it takes for a human to blink an eye. A little change to the crash pulse is huge when it has affect on an airbag moving at your face at over 200 mph.
NOTE: Someone said that airbags will deploy if crash sensor wires are cut. This is not true, but I don't recommend ever cutting crash sensor wires. All connectors for all automotive pyrotechnic devices (i.e. airbags, pretensioners, air curtains, etc.) are equipped with a shorting bar on the module side of the electrical connector. When you disconnect your airbag wire harness connector, a shorting bar instantly shorts the pins to the device to prevent any stray potential difference (voltage) from deploying the module.
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