Debate about bumpers

[svc]

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.

That there is some very good information as most of us in the aftermarket accessory biz don't have the resources to pay for crash testing of all our parts and accessories. Nor should we ever speak in absolute truths without 100% of the data behind our statements, and I was guilty as charged last night when I posted there won't be any impact on airbag deployment.

So what I'm really curious to know as you have a very keen understanding of the subject, is whats your opinion on aftermarket bumpers in general? More to the point of direct bolt on bumpers that protrude well beyond the front valence of the vehicle. I ask because I'm sure down the road we would like to develop a second line of bumpers that may or may not be totally flush with the front valance like our current Baja bumper that is a direct bolt on with no frame cutting. I would like to get your take on how you feel the airbags might be effected, if at all by a bumper that is very large and clearly adding a different dynamic to the original crash testing that Ford performed with the Factory bumper? Also, would the addition of a winch have any negative impact or no impact on airbag deployment and function in the scenario of a head on collision?

Obviously anytime you modify anything on these trucks you are changing the dynamic of the OE vehicle in some way. How large is the question? To my knowledge no one has stepped up in the aftermarket industry to crash test a truck with their bumper, regardless if it was direct bolt on or not so we really don't know the full impact of any aftermarket bumper from what I can gather until such a test is performed on each individual bumper. Would my assumption be correct in your opinion?

Having been hit in the face with my current Raptors airbag a few years ago it did hurt, but no more than when my big brother used to deck me as kid

Anyway, thanks for such an in-depth explanation of how a modern day airbag system works. I think most of us on here just got a wee bit more educated on the subject based off your response.

Jarrett

 

[HAYNES OFFROAD]

my other question for collision damage is- by taking the horns off so many inches, is that leaving my engine bay and front only protected by the strength of the bolt? Does it move the point of true impact/not the bumper back to where it could cause more damage? If that makes sense.

and wreckless, the bumper i was going with is yours. I want the angle but i want it flush. I dont have many options if i keep it flush.

As far as damage goes to your own truck, I firmly believe (my opinion, not fact) that bumpers such as the SVC Baja, with the attack angle it provides, would help deflect a lot of the impact to under the truck, like a wedge. You would prolly end up half way climbing over whatever car you may happen to hit. Good for you, not for them.

And as far as where the true impact is, yes, it may or may not shear the two ¾" (?) Mounting bolts off, but being that the SVC bumper is fully boxed around the frame horns, it wouldn't move too much farther back, if any, being that its also mounted down lower on the power steering rack bolts. So there's 4 strong mounting points. I firmly believe you would suffer LESS damage than the OEM bumper. But that's theoretical as well.

There's definitely not many options as far as low profile, with a good angle. But I firmly believe the SVC bumper is your best bet even though the frame needs cut.

To cut or not to cut, that is the question....

Once you decide, if you need a shop to install it, shoot me a pm.

 

[bstoner59]

I forgot to mention the accident my second truck was involved in. Someone ran it into 3 parked cars and totaled all of them then drove away. The frame seemed tweaked just a tad from the impact. It was never checked for sure. Still drove straight. I bet if the stock bumpers were on there would be a lot more damage than there was. No airbag deployment either. The truck drove away and was found 15 miles away out of gas.

Remember all bumpers from aftermarket companies are bolt on. Some just require a little massaging to get them on. Any aftermarket bumper is going to protect the truck/do more damage to the other vehicles in an accident.

 

[svc]

I forgot to mention the accident my second truck was involved in. Someone ran it into 3 parked cars and totaled all of them then drove away. The frame seemed tweaked just a tad from the impact. It was never checked for sure. Still drove straight. I bet if the stock bumpers were on there would be a lot more damage than there was. No airbag deployment either. The truck drove away and was found 15 miles away out of gas.

Remember all bumpers from aftermarket companies are bolt on. Some just require a little massaging to get them on. Any aftermarket bumper is going to protect the truck/do more damage to the other vehicles in an accident.

Well Said Stoner, A crappy situation for you gives us all a little more knowledge on the subject. Any aftermarket bumper considered strong or more durable will seem to have an effect on air bag deployment. Aftermarket bumpers may allow you to plow through stuff and come out with minor personal damage where as the stock bumper will crumple and cause more damage to the truck and possibly your self. The cutting of frame horns requires a commitment with knowledge of the possible outcomes in the future.
-Jeff

 

[SilentShooter]

Since my truck is register/insured under my company I just sent my insurance agent a message asking about installing a bumper that modified the frame. Before I do this I am making sure it will be OK should I get into an accident. We have a huge umbrella policy to cover our selves but would not want to void that with a modification. To big of a risk if it will void coverage as then it would not leave just me open to liability but our business and my family.

 

[MajorAR]

Silent....def playing it smart. Bottom line....there is risk involved.


Sent from my iPhone using Tapatalk

 

[HAYNES OFFROAD]

I agree, smart on silentshooters part, for his situation.

Bottom bottom line?? Theres risk in everything you do. The severity of that risk is different for each individual. And honestly, my bumper is the last thing I'm worried about when I'm bombing dirt roads in those triple digits. THAT is the risk in MY situation, not the legalities of a aftermarket bumper. But everyone is different.

 

[SilentShooter]

The truth is the majority of the driving time behind the wheel of my raptor is on the streets. Wish it was more off road but it is what it is. So I need to make sure my ass is covered. But I do want the SVC bumper for offroading purposes. Now lets hope they can both co-exist.

 

[Deleted member 12951]

Our bumpers are 100% bolt on and do not require you to cut the frame horns at all!

You'll get that aftermarket look without cutting the frame, and if you wanted to, just bolt it off and swap it for the stock one again if you decide to sell or whatever.

Link: Exterior : Baja Raptor Front Bumper | LGE*CTS Motorsports home of L&G Enterprises and Custom Truck Shop
Some pics of out bumper:

Liking your bumper, sent you a PM

 

[BAJASVT]

So what I'm really curious to know as you have a very keen understanding of the subject, is whats your opinion on aftermarket bumpers in general? More to the point of direct bolt on bumpers that protrude well beyond the front valence of the vehicle. I ask because I'm sure down the road we would like to develop a second line of bumpers that may or may not be totally flush with the front valance like our current Baja bumper that is a direct bolt on with no frame cutting. I would like to get your take on how you feel the airbags might be effected, if at all by a bumper that is very large and clearly adding a different dynamic to the original crash testing that Ford performed with the Factory bumper? Also, would the addition of a winch have any negative impact or no impact on airbag deployment and function in the scenario of a head on collision?

Jarrett

I don't believe there have been any crash tests performed with aftermarket bumpers, or any aftermarket accessory, because there are so many different crash tests and they are very expensive to run. The price of the truck aside, you still need to pay for the facility time, testing, and instrumentation. The most popular front vehicle crash test would be the 35 mph 90 degree rigid barrier test; this test simulates a direct head on collision of two vehicles traveling both at 35 mph. In all frontal test modes, a bolt-on bumper should alter the results much less than cutting off a portion of the frame horns and crumple zones. Especially in the 35 mph 90 degree frontal, the less amount of bumper material you have directly in front of the frame horns should also minimize differences in test results against the stock bumper. I'm not trying to pick on anyone, but the d-rings and front hoop that extend to the front of the LGE/CTS bumper would probably have a much larger effect on 35/90 test results than a more flush bumper that doesn't have anything protruding out of the front.

Once you get into offset, angular, pole, and other test modes, it's really anyones guess what effect the bumper would have on things. Frontal 40% offset tests were some of the most severe tests until recently and even those pick up one of the frame horns. There's a fairly new test called SORB (Small Offset Rigid Barrier) that is similar to the frontal 40% offset, but only picks up 25% of the vehicles front end - that means that only the front end of the vehicle outboard of the frame horn is contacted, so the cantilevered section of the OE bumper, sheetmetal, and tire are what take the brunt of the impact... very violent test.

NOTE: Even the "bumperettes" on the front of the OE bumper act as a decelerant as the frame crumple zones do.

Again, I'm not trying to pick on any company or bumper... just helping to explain how it could change things in the event of a crash. I personally am strongly considering a SVC bumper for my personal daily driver Raptor.