Aluminum Armour???

kerryp said:

In an attempt to get some technical discussions started and a topic on Jeeps I have a question?

I am all about reducing weight on my Jeep and most of the armor that you buy for Jeeps is really heavy steel. These jeeps have a hard enough time pulling their own weight without having 1000lbs of additional weight added in bumpers, shids, rockers, etc.

I have often wondered why there aren't more light weight materials used for some of these items.

I understand that aluminum is not as strong as steel and will not take the abuse steel will (i.e. skid plates).

With that being said, I would think that items such as bumpers could be made from aluminum if steel inserts were used for specific parts such as steel winch plates, and steel inserts that would be used as tow points. IF these pieces were reinforced and attached to the frame, would they be strong enough?

There are obvious areas of concern such as tire carrier mounting, shackle mounts, winch, etc.. I would think these could be worked around with the right design and the weight saved could be in the hundreds of pounds.

Unfortunately items such as skids would probably not be a candidate, since the skids on JK's span such a large area and would not withstand the forces applied if they were aluminum.

But rockers could theoretically be made from aluminum with replaceable steel skins that could take the abuse and when the steel skin was beat up bad enough, take it off and replace it?

This may all be pipe dream based on the cost of engineering and producing something out of aluminum (i.e. the cost would likely be very high), but like I said at the beginning, I just wanted to talk Jeeps and this is something I have been kicking around in my head for years....

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Its more a cost and durability thing.

You CAN make aluminum harder, and so forth, and use steel inserts, etc...but, the more TIME it takes to make something, the higher the labor costs...and, as the MATERIAL is more expensive, the material costs also go up.

Machining and other procedures would make aluminum parts cost prohibitive.

If we had a cheap source of titanium, that would be an alternative perhaps.



I think the only way to get people to consider buying something that expensive, especially considering the doubts they'll have about its durability, etc...would be if it were SO MUCH lighter that the armor didn't sag the suspension, reduced the COG off camber, and increased their mpg ENOUGH over what a steel armor alternative would.

IE: What's the payback period?

Example: If the Al version cost another grand...but you saved 1 mpg due to weight savings.

If I got 16 mpg with steel, and 17 mpg with Al...at $2/gallon to make the math easier...so I'd need to save ~ 500 gallons to break even.

So (x/16) - (x/17) = 500 gallons....with x being the number of miles you have to drive to break even.



That's roughly 136,000 miles to break even...not that compelling.

To get the payback down to a year...let's say at an average of 18,000 miles/year...I'd need to get way too many more mpg out of the mod than is feasible.

So the market would be "cost is no object weight reduction fiends"...a limited niche.

TeraFlex sells aluminum sliders...I haven't seen them in action. I've HEARD they hold up...but the sample size is very limited...so I don't have a context for how hard that is to do, etc.

I've SEEN Al skids, and, they gouged and were damaged like crazy...so I was not impressed...but, I don't know what grade, etc, of Al was used, etc.

T-6 alloy, etc...is pretty good stuff...if anyone used it for skids, they should pipe up.

In my opinion I think that it is not quite as soft as people are afraid it is. I would be really curious what a aluminum underbelly skid looked like after the full weight of a vehicle was dragged across a sharp rock.

It reminds me of what some XJ guys where doing for some armour. They where using plastic!! Yes, plastic (well, not exactly plastic but I forget tghe actual material name it was being made from). They found it was like butter. It actually wouldn't gouge as deep as you would think becuse it slid so well. Then when it was beat up they would just replace it. They were mostly using it on Quarters though.

I have been thinking of that for a skid. Not sure what the weight or cost differences are though


Here is an interesting thread on nylon and VHMW skids, they start talking about it on about post #960
http://www.pirate4x4.com/forum/showthread.php?t=375081&page=39

I think companies could do a lot mroe to save weight. Some of these companies have such a high margin anyway, why not put a little effort in and stand out from the crowd.


If you look at desert trucks for example there are holes drilled everywhere and all sorts of other materials used without drastic increases in cost.

Keeping a Jeep light would save more than just fuel costs. It would climb better, side hill better, save brakes, and breaks. Repair costs would be lower.

Bumpers for the JK would be easy. An aluminum bumper would simply surround the steel winch plate and factory tow hooks that all bolt to the frame. With a stubby bumper it would never really contact any rocks anyway.

rear bumpers could by made high clearance and light. Ditch the heavy swing aways and concentrate on reinforcing the tailgate with an extra hinge and some plate to add stiffness.

There are all kinds of ways to keep the weight down on these things, its just easier to build it with heavy steel and call it "hardcore"

Xtremjeepn said:

The amount that I see aluminum used for other uses and other motorsports without prices being outrageous I don't see why it can't be done here.

Even if you use KerryP's wheel example. Each wheel is not outrageously expensive. That same amount of material could be cast/forged or assembled to make bumpers, etc.


Once problem I see is that there are so many other things made for Jeeps from steel that have no real reason for it. (like CB racks, light tabs, etc )

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It is kinda funny to me...I come from more of a auto racing back ground, I had an XJ to play in but it was not my main focus. Anyway, everything was about saving weight. I mean, even switches and knobs where made out of light weight material or drilled out.

Jeeps are the opposite, it is all about adding weight and "strength". like you said, even the cb mounts are made from steel, lol

In motorsports they are able to design surprisingly strong parts from lighter weight material such as aluminum. Not sure why it can't be true with Jeeps. In the end I don't think the cost is that big of deal, I think it is th eknowledge of Jeep parts buiolders in general but mostly the buying publics reservations on non steel items. I think there is a lot of "no replacment for displacment" types driving Jeeps if you catch my drift.





MAn, wouldn't it be nice to have a Jeep lighter then stock AND stronger then stock as opposed to a beast that weighs in at a couple grand over stock design out on the trail?