3/16" plate steel too thick for stiffening?

[raf2379]

what is your opinion on thickness of material to use for plating the unibody of an XJ? I have some 3/16" plate steel and the plan is to plate all sides of the unibody (inside, bottom and outside) boxing it in i guess you could say. 

some concern i have is that it will add quite a bit of weight, but it sure would make it nice and stiff especially if i plan on running D60 and 36" IROK's
the stiffening i see on the net only really stiffens the middle section on the outside and bottom only which in my opinion doesent do much more than 2 good built cross-members in the middle of your chassis.

what are you opinions on 3/16" or should I go down to 1/8" if I'm boxing the whole unibody frame?

[mike s]

Well... Weight is the enemy, more to lift up over things. YJ frames are made of 1/8" steel so adding than to existing "frame" should be plenty. I've seen guys cut out crossmembers for more flex. Kinda depends what your building for as a final result. A soft flexy frame can compensate for lack of suspension, but high speed is out of the question. I didn't think Cherokees suffered from unibody flex, just lack of wheel openings for bigger tires. Have to have a beer and think about it...

[w squared]

Something tells me that Raf will not be suffering from lack of suspension

[esi]

Just my opinion, but 1/8 should be strong enough since essentially you're making a piece of channel and adding it to your existing frame. which should make it at least 3/16" thick.  If you use the 3/16" plate you're adding 50% more weight and making the frame 1/4" thick. That's what allot of 1 1/2 ton and heavier frames use.
Nice work on the crossmember for your long armkit as well.

[tubby]

There are a few companies that sell unibody-stiffeners  that are 3/16" ( TMR Customs and TNT) that cover the middle section of the "unirail" but I've come across some builds with  guys plating front to rear. They all said that it added a lot of weight. It's a good idea anyways  Rafal. I don't think I've ever come across a build that had 2 extra crossmembers added in.

I've got the unibody stiffeners from Ruffstuff Specialties that I believe are 10 guage steel(0.134"?) with rosette holes built in. You can borrow them if you want to take a closer look.

[apeman]

i copied the set from Noel...they are pretty cool in thier application..and dont think they need to be any thicker...

[raf2379]

thanks for the input guys, 1/8" would make it a bit easier to bend around the unirail. i've found that 1/8 is about 2.5lb lighter per sq/ft than 3/16. i might just have to go the 1/8 route since i am boxing the whole uirail in, instead off just stiffening one side like TNT as you mentioned Tubby.

if my calculations are correct, i need about 35 sq/ft of plate for each unirail. with 1/8" steel i'd be adding roughly 366lbs of weight and with 3/16" i would be adding 534lbs. bahh why is metal so heavy haha.

[cLAY]

Plating front to back is overkill. The only place I needed to reinforce on my XJ was around the steering box and where the crossmemeber bolted on for the long arms. I would suggest doing the "mid" rails as they dent easily if landed on and then you'll have a good spot to mount the long arm mounts to.. The only place I saw an XJ frame crack was on one that had a rear coil conversion and it cracked in the wheel well where the upper coil sat. The frame wasn' t designed for weight to be placed up there and cracked as a result.

[hps4evr]

http://pirate4x4.com/forum/showthread.php?t=920130

this guys building a zj. doin a good job beefing up the uni-body on it.

[WhiteOut]

^That is HOT!

[raf2379]

thatslooks awesome. that is what i had in mind as far as plating/boxing in the unibody rails. i didn't see in his post what thickness of plate he used, looks like 1/8th.

[Immortal]

"Started plating the inner frame horn. I did the inside with 1/8 and the out side and main rails will be 3/16."

About 1/3 the way done between the pictures.

[raf2379]

i see it now. thats definetly some good work.