Boxing the frame or not
 

I was wondering if it would be better to completely box the frame, or just over the front ifs and rear axle. I see in all the magazines they only partially box the frame. Does the frame need to flex? Is it too stiff if fully boxed? :)

The general consensus is to box a frame where an independent suspension can do it's job. So if you have an IFS, then boxing the front makes sense, as the IFS will do the work the frame originally did with leafs. Leafs are an up and down only movement. The frame allows one side to move up and down more or less than the other side, thus frame flex. So unless you have an IRS, then boxing the rear will only make for a harsher ride, since it won't allow the frame to flex.

I agree by boxing the frame it causes the suspension to do all the work. On these old trucks the frame was part of that suspension. On my 51 I am boxing the frame front to back and building a tubular center section but I am also doing IFS and IRS so I do not want any chassie flex. This will allow me to tune the suspension and not need to factor in the chassie flex.

Kevin
LFD Inc.

I boxed my the frame on my 55 F-100 and did the same thing with a tubular crossmember. Here is a pic of my setup :). The tubular crossmember was original designed to prevent chasis flex, however it helpded beef everything up enough that I can put whatever kind of horsepower down I want.

(hopefully)


ben

http://www.achievethought.com/galler...2/100_2384.JPG

Where do you guys get the tubular crossmembers?

I made mine with a tube bender and a tube notcher.

Thanks guys. I'm planning on a IFS and a solid rear axle with air bags. Wasn't sure how much to box. A bit less welding I guess.

Please, box that thing in, boxing in sections just transfers the stress, frames that flex are doing work that the suspension should be doihttp://images.ford-trucks.com/forums...cons/icon7.gifng

Yep that is along the same idea I will be doing. I have been building tube chassies for a few years now both for the street and offroad. Here is one of my tube toys!

http://i16.photobucket.com/albums/b20/rokcrln/nate1.jpg

http://i16.photobucket.com/albums/b20/rokcrln/eb10.jpg

http://i16.photobucket.com/albums/b20/rokcrln/pc91.jpg

And a future 500hp street tube toy waiting for it's turn in the fab shop!
http://i16.photobucket.com/albums/b2...ln/futura1.jpg


Kevin
LFD Inc.

Looks like an easy way to change the oil;)

I boxed mine completely. just made sense to me:confused:?? Runnin heidts superride II and heidts 4-bar ride is great!!:-drink

The more I think about it. I think I want an air suspension. I was checking out No Limit this evening. I'm thinking it looks very good. Wondering how it will work the Flathead I'm using.

remember that you need the associated parts for the suspension too.
compressor, air tank, hoses, valves. switches (or other control)..

I am having a devil of a time finding places for mine (and its only for the rear).

Tank under the pass door (where the battery used to be)
compressor (I think) under the rear fender next to the gas tank (outboard of the frame).
valves.. need 2 per air bag (1 up and 1 down).

Sam

sdetwell, couldnt the compressor and solinoids fit under the bed along the frame on a bracket between frame and drive shaft?

well, I have my exhaust partially up in there.. and the triangulated rear suspension parts.. amazing how much side effect (collateral damage!) one decision can have.
(and how little room there really is!)

I am constantly rethinking the triangulated rear.. as the mechanics are in the way constantly..

The long tube headers had to be high enough to get the tailpipe sections over the tranny cross member, else they would drag on speed bumps. (as I worry about my running boards).
the long lower trailing arms of the custom rear eat up a lot of frame rail space but provide good anti wheel hop/axle twist.

the triangulation provides good lateral stability, but take up a bunch of upper inner frame rail space.. and may block out the ability to take the exhaust up and over the axle.
(where the fuel line runs!) but I can't go out the side cause the trailing arms are in the way..
I can unbolt this thing in a heartbeat and go 4 link.. but wanted something different.. and its been an 8 yr journey.

had to raise the bed 3/4in to account for the drop when the bags are down and the c-notch. and am rethinking how I did that.. added a spacer on top of the cross members, which forces longer, non-standard bolts from the bed strips... adding a different spacer at the chassis would make things more normal..

anyhow, its more a complex puzzle than I had anticpated..

Sam