The lower chin is NOT a "crash bar". It's primary purpose is to provide a point for the air dam to be mounted on to. Far from being a part of the frame and on 2007-10 JK's it was barely attached with what looked like tack welds.
looking to change front bumper again.. better approach angle
- Thread starter RoadRageJKU
- Start date
The lower chin is NOT a "crash bar". It's primary purpose is to provide a point for the air dam to be mounted on to. Far from being a part of the frame and on 2007-10 JK's it was barely attached with what looked like tack welds.
10frank9
Web Wheeler
Arizona
New member
I think it took me less than 2 minutes to cut off.... Hardly attached
I haven't crawled under to look at it yet. I was assuming it was a normal crossmember which does provide integrity for the engine bay. Regardless i plan on cutting it out for install of a 1/4 pounder
All the "cross members" on the frame are boxed in and made out of the same thickness of steel as the rest of the frame or is a tube like what you find on the forward most cross member. The chin is only a C-channel and one that is made of much thinner steel. Again, on 2007-10 JK's, it literally was only held on by 2 thin tabs on either end. This chin offers ZERO structural support for the engine bay and is literally there so that the air dam can be mounted to it.
NevadaZielmeister
Caught the Bug
This is all great information. Thank you guys.
When I look at the first two photos of this thread ( http://wayalife.com/showthread.php?29973-Got-in-an-accident ) I can see that the lifted Jeep (striking vehicle) and the bumper both worked in harmony to completely destroy the struck vehicle. The apparent force of the impact directed the energy over the rear bumper of the struck vehicle. I do not see how cutting 2 inches off the end of the frame member would change the outcome in this scenario. I am sure there are others where having those two inches of extra frame member would help. I just do not see how much worse the injuries would be to the occupants. I personally would not be concerned with any extra liability.
But back to wheeling. Question: Is it better to strike the obstacle with your bumper? Is there some positive benefit from having a bumper that would strike as opposed to a bumper that would not? Is there any kind of feedback that is helpful to the driver?
When I look at the first two photos of this thread ( http://wayalife.com/showthread.php?29973-Got-in-an-accident ) I can see that the lifted Jeep (striking vehicle) and the bumper both worked in harmony to completely destroy the struck vehicle. The apparent force of the impact directed the energy over the rear bumper of the struck vehicle. I do not see how cutting 2 inches off the end of the frame member would change the outcome in this scenario. I am sure there are others where having those two inches of extra frame member would help. I just do not see how much worse the injuries would be to the occupants. I personally would not be concerned with any extra liability.
But back to wheeling. Question: Is it better to strike the obstacle with your bumper? Is there some positive benefit from having a bumper that would strike as opposed to a bumper that would not? Is there any kind of feedback that is helpful to the driver?
I have personally seen what the frame of a JK looks like after you REMOVE a heavy duty bumper that has been in a serious accident. Of course, you're more than welcome to have faith in what you choose to believe. :yup:
LOL!! Don't get me wrong but, what in the hell are you talking about?
NevadaZielmeister
Caught the Bug
:cheesy: No, seriously, I'm not trying to put you off but I seriously didn't understand what you were asking. I mean, if you really are the kind of badass who feels the need to hack off 2" off your frame rails just to give you a bit more approach angle, I can guarantee you that you will STILL hit your bumper because of the kind of terrain you're playing on. If you don't, you're just all talk or have an over inflated idea of how hard you really wheel. Mel has completely cut off his frame rails and flush mounted his bumper to the face of EVO 1's grill and STILL hits it. Of course, EVO 1 is an Ultra 4 race rig now and the trails he has to tackle are about as tough as they get.
I should also note that there are real benefits to mounting a winch IN BETWEEN your frame rails instead of putting it up on top. Also, all the approach angle won't do shit for you if you don't have the kind of BREAK OVER ANGLES to get you up and over the obstacle.
NevadaZielmeister
Caught the Bug
No worries. I do not feel put off at all. I guess if anyone wanted to look on the internet for stupid questions, they would arrive at this thread. :yup:
I am super thankful for the input Eddie. In thinking about geometry and the dynamics of off-roading and rock crawling, there comes a point where you are just going to hit your vehicle with something. That will take come getting used to for me, since I have no experience.
I hate to say it.. again…but it appears I am heading towards EVO 1/4 pounder for the front bumper. I really like how the winch sits inside that thing. I was just being stupid regarding approach angles. Sometimes us new guys get too wrapped up in the "numbers" without actually seeing it in person and understanding the bigger picture. Thank you Eddie for everything.
To be fair, there are a LOT of great bumpers out there other than the 1/4 pounder that will get the job done. One of my favorites is also one of the cheapest you can get and that's the PUREJEEP Bare Bonez bumper. The problem with "numbers" is that they, for the most part are just sales pitches - marketing tools that manufactures and vendors use to sell guys like you on the idea that you should buy their stuff. And really, there's nothing wrong with that - kudos to anyone who can make a buck off of their marketing skills. Of course, I think it's great that people just buy stuff because they think it looks really cool. My only purpose in commenting on a thread like this at all is to keep it real and keep the facts straight.
I thought this for the longest time too, but after a discussion with one of the structural engineers for Chrysler, I learned that beyond holding the air-dam this bar is officially there to prevent a Jeep from shooting over a low vehicle in a collision. I was told this bar's official name is "Crash Bar". The reason the upright pieces are now fully welded to the frame was to make improvements after crash data showed it was not doing it's job properly.
I agree the horizontal bar is fairly weak and I even find it hard to believe it makes that much of a change. But according to the guy I talked to it is a federal safety requirement to have it there.
Now, does it make a hill-a-beans difference once you lift the Jeep anyway? Doubtful. But I thought I would share what I learned
Edit... after reading just a bit more (sorry) I see some of this has already been addressed.
UncensoredAggression
New member
I need to cut mine off. It hangs low and looks silly. Where should I cut it and what tool should I use?
It's not the 16 gauge steel that is the important part for the crash as I understand it. It is the verticals. But remember thinner metal will absorb energy where thicker will deflect it. The whole point of this bar is to stop the deflection. ...at least that is what I was told. I didn't design it and don't know enough about crash testing or ratings. All of my info is third-hand.
Jk909
New member
I'm not arguing with what you have been told. I'm also not an engineer. I've just seen how metal reacts under certain circumstances. I hope you don't think that was directed at you.
LOL, not at all... and even if you were I have pretty thick skin. :yup:
The one thing that bothers me a bit about the bar and makes me believe the dude is the fact that if it were only there to hold the air-dam it could actually be done with far less material. Also, the fact that they later beefed the welds calls its full purpose into question. :thinking:
But who knows? All the manufacturers seem to make some odd calls and changes that seem to be for no logical reason. Perhaps this was one and I was being fed a line a bull. Big auto engineers often have a small penis problem and feel they need to flex their knowledge, even when it is false. :crazyeyes:
Jk909
New member
I spent 30 hours this weekend fixing an engineers mistake that I had already warned him about. Not all engineers are created equal. I always take what they say with a grain of salt
Jk909
New member
If you moved your vacuum pump cut it off from right under the frame with a cutting wheel or sawzall
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