I called ARB about a month ago, and they said they don't have their Commander bumper finished yet, but they are working on one...

 

ARB WK bumper on the XK?

Do you think this will work on the XK? Of course you will have to cut the fender flares.

 

No.
.......

 

I think what jeep5253 meant to say was.....No, because the WK has some different body lines than the XK. The headlights are slanted upward on the bottom edge compared to the flat edge on the XK. This bumper is designed to follow those lines so it would not work with the style of the XK. The basic frame components under the bumper are similar from the WK to the XK but the body is too different for this to work.

 

Yeah, that's what I meant.

 

no worries, just glad I could help

 

Okay, well I guess I'm stuck making my own.

 

Now we can boast that we have not only a Search Meister, but also a Mind Reader. Way to go Adam.........

 

Has anyone actually tried to test fit it? If the lines are the problem then perhaps a 1/2- 1 inch drop bracket could be made for the mounting points and piece of metal welded or bolted to the top to create a straight line across. Anyone?

 

I am not sure about anyone actually doing a test fit but if you talk to forum member El Cid about trying to fit the 4xguard matrix on the XK with the brush bars, the lines are very different. It is not only an issue of the upward slant but the ARB bumper also slants back toward the wheels as it gets farther from the center of the vehicle, the XK is pretty much flat straight across. My guess is that any brackets made to move the bumper out and down would totally compromise the integrity of the bumper and its ability to take an impact or winch from it safely.

 

As other folks are noting, while the under-body workings of the XK and WK are similar enough to make it absolutely worth thinking about these kinds of mods, the upper-body designs between the two vehicles WK and XK are too different to make bumper swaps possible without very significant (and costly) modifications that would reduce integrity and look, well, quite strange.

The center-to-side angle issue that adamag25 mentions, as one example, would mean that either the headlights would hang above open space (the corners of the bumper being tucked under them) or the middle section of the bumper itself would have to stick out a fair bit in front of the grill assembly. The former would be aesthetically displeasing, I think. The latter option, while it could maybe be made to look okay with enough money spent on custom-built gap covers, would weaken the assembly from a structural standpoint in addition to reducing angle of attack. Beyond that, because pushing the bumper forward would push its weight further from the axle line, it would also cause even more wear on the suspension and other related components than these bulky full bumper replacements normally do (imagine the effect on your arms of holding a bag of cement close to your chest versus holding it further away from your chest).

So, alas, this one probably won't work. But I like the way you're reaching out for possibilities. We all know we could use more options!

 

I saw an install how-to a while back regarding the ARB/hidden winch system for the WK. It involves cutting out the factory "cross member" and bolting in a new, much more substantial piece. The factory puts in what I would say is a basic C-channel made of formed sheet metal. It's not very strong, but doesn't need to be for the stock application. The piece that ARB uses is basically a box-section aluminum cross member that bolts to the factory formed frame rails. My guess is it has a boatload more shear strength than the spot-welded factory cross member. I think it would be difficult to lower it a bit to allow the WK ARB bumper to drop below the bottom of the headlight "line" of the XK. No doubt it could be done, but the time in fabrication would likely be substantial. Kudos to anyone who tries it. The ARB stuff is quality and it would be nice to have an XK application. Another thing ARB takes in to account on virtually every bumper it makes is the airbag activation. I believe ARB is the only company that addresses airbags and they claim that in a collision the airbags will function per OEM design. I guess the rest of us hope for the best!

 

Another thing ARB takes in to account on virtually every bumper it makes is the airbag activation. I believe ARB is the only company that addresses airbags and they claim that in a collision the airbags will function per OEM design. I guess the rest of us hope for the best!

Airbag sensors are no longer in the bumper, they are almost all electronic now and are part of the electronics module.

 

True. I suppose I should clarify my comment - Unless I am mistaken, ARB is the only aftermarket company that certifies that the use of their bumper systems will not adversely effect the function of the factory airbags in a front collision. I don't know how they test for their claim. Jeep (and everybody else) engineers the front crumple zone to react to a certain impact and determines whether the airbags deploy or not, based on the force of the impact. By adding a 100 pound bumper and a 100 pound winch, the way the force of an impact projects into the unibody may no longer be within the parameters the factory has 'calibrated'. Also the way the bumper mounts may change the way the impact transfers into the unibody. So if I have a head-on or near head-on with another vehicle, there's no guarantee the force parameters will be met to deploy the airbags. Likely, they would function properly, but our other-than-ARB systems have not been tested (or certified) to say they will. I guess that's the point I was trying to make.

 

I emailed ARB. Their response was, "No bloody way mate!" Ok, well they didn't use those EXACT words but that was the gist of it. I also asked about a future bumper for the XK and they said maybe but it was FAR down on the list as the Commander is only popular in the U.S.A.

 

Also the way the bumper mounts may change the way the impact transfers into the unibody. So if I have a head-on or near head-on with another vehicle, there's no guarantee the force parameters will be met to deploy the airbags. Likely, they would function properly, but our other-than-ARB systems have not been tested (or certified) to say they will. I guess that's the point I was trying to make.

I'm not certain but I think the concern with having a more solid bumper would be premature deployment of the airbags is low speed collisions. You lose any sort of 'cushion' that the plastic bumper creates and the force of the impact is directly transferred to the frame. This would cause the vehicle to decelerate more quickly than OEM system. This greater deceleration would be registered as an impact of greater force, result --> premature detonation of the airbags.

At least that's my hypothesis.

 

Good point. That is entirely possible. Either way, once we've modified the fronts of our XK's with a different bumper system, the factory parameters are likely compromised in one direction or the other. ARB certifies their bumpers are "airbag compliant", whatever that means. Maybe its just a selling point. I have hijacked this thread with comment to an unlikely situation that has ballooned a bit. Though ARB makes terrific stuff, they don't make anything for us and a WK system would, in my opinion, look odd on an XK anyway.

 

Premature detonation is not good !

 

Premature detonation is not good !

I was wondering who was going to be the first to comment on that.

 

The airbag sensors are supposedly 200g accelerometers according to an associate of mine in the engineering dept of TRW. He said the commander's SRS system is actually a Bosch, but the g parameter should be the about the same. A g-sensor would probably be more sensitive with a stronger front bumper/sub frame because it would transfer force more efficiently as opposed to soaking it up by crumpling, but it would still take quite a whack to trip it. Odds are pretty good if you meet the 200g threshold, you most likely are going to need the airbags to deploy.

Long story short, in the Commander, I wouldn't worry about a bumper messing with the system.

 

I don't want to beat a dead horse here, but I was just thinking. I saw one website where a gentleman in Australia (close to the ARB factory) took a bumper from a Landrover and cut it shorter to fit his XJ. He also cut off the light/grill guard so it fit the style better.
This got me thinking of buying a KJ ARB bumper (because I like the style best for the XK) and having it widened to fit the XK. But the big problem is the custom mounting system. So going back to the WK ARB bumper..... if the mounting brackets were the same on the WK and the XK, why couldn't the bumper be modified? Cut the top of the bumper where it would interfere with the XK and keep all the other lines the same. This might mean filling in the XK turn signals and using the ones on the bumper. Or cut off the light/grill guard, make it flat where it angles up towards the lights, and possibly mount a tube light/grill guard that fit the XK lines better. Just a thought.
I realize that these bumpers are very expensive and would need some more modding costing even more money, but all the valid points of having a well engineered bumper would hold true.

 

I think it's probably true that with enough time, money, and curse words, anything can be made to fit pretty much any vehicle, iTom:

It really boils down to a cost/benefit issue. It's not just an issue of matching lines: the body shapes are totally different. If you looked at an XK and a WK side-by-side from above, you'd see that the WK slopes backward from centerline far more dramatically than the "boxy" XK. So fitting the WK bumper to the XK would essentially require you to go Dr. Frankenstein with a total rebuild of either the bumper or the vehicle, multiplying the already high cost of the ARB bumper by, oh, I'd guess at least 3.

At which point, well, you're better off either forgetting the metal front end on your XK or just buying a WK.

Me? I'd just forget the steel noggin', 'cause the XK beats the WK, baby!

 

Mike - where did you find a picture of a49er's Smart?

 

I agree about preferring the XK. That is why I bought one (although I have seen some very nice lifted WK's out there). I am going to be drawing up a 3D model of the front bumper that I would want. I recently met a gentleman (sold him some baby Jeep items) that is starting up a local fabrication shop.
We had a little talk and I may be trading him service for service. I build him a website and he builds me a front bumper. Sounds like a good deal to me. But I am sure I am a year away from install.

 

That sure does sound like a good deal, iTom. I do wonder why you'd want to add all that weight up front, but you're not the only one who will have done so. And to each his (or her) own!

 

I don't have it yet, but I do plan on installing the Old Man Emu lift. If I end up with the front bumper with a winch, then I will make sure to get the heavy duty springs. It may add 150 lbs to the front after the factory bumper/bracing is removed. That would be my goal anyways.

 

This is a serious bumper ! http://www.kenmtnac.com/Commander.html