For those wit SFBD frame size Q's

[ConnecticutX]

id be down but the truck is put away...

[NCHEVYHEVN]

Quote: Originally Posted by CDEEZY

Taking my weak ass little frame to Florida for Spring Fling if anyone wants to go dragging.

Dragging is gay

[ohsolow1]

I was wondering if i built a double rail frame like you see alot of the street rod guys use out of 3x2x.25 if that would be sufficient for my x-cab? I was planning on using the stock front frame section and replacing everything from the firewall back. I attached a drawing of what i would like to do.

The black represents stock frame, blue is the 3x2x.25 and the green is round tube 1 5/8 .118 wall thickness.

[ohsolow1]

Well, since my pic didn't attach could you tell me if this sounds right? On the chart it says the the deflection on a piece of 3x2x.25 is like .94in. so for two frame rails that would be .47in per 1000 pounds? So basically if i ran 4 sections of the 3x2x.25 under the cab the deflection would only be .235in per 1000 lbs. This should be plenty strong, right?

[Dragginbody]

Quote: Originally Posted by ConnecticutX

mkay...i quick made this up to stop all the rumors about what size box tubing to go with for frame rails.....its kinda self explanitory, ignore the stuff in the middle, just pay attn to the hieght, width, thickness, deflection and weight. The deflection is in inches and the weight is in lbs.

BTW...this is assuming stock dimensions, a 5 foot length, and 1000lbs of force on the beam....

avteckk brought up a good point about your chart..

a stock frame is all 1/8th metal not 3/16th.

and the height and width varies from the firewall back.

[Dragginbody]

Quote: Originally Posted by NCHEVYHEVN3

Dragging is gay

you are gay!

[ConnecticutX]

im sick of defending this thread....i quit.

[AVTekk]

uh ok..but the chart isnt correct for stock rail size and people are trying to compare their choices to it..

[Bdydrp02s10]

Quote: Originally Posted by ConnecticutX

im sick of defending this thread....i quit.

Really. I never thought you would give up that easily. And only after this being 4 pages.

[ConnecticutX]

lol, the only way to make it 100% correct to the stock frame is to call up gm and have them send you a solid model of the frame, then stick it into a finite elament analysis program. I seriously doubt gm would ever let a drawing leave the doors, so until then i give you the estimate that is in the chart. Merry Christmas. IMO a 3/16" thick simple beam is a good estimation considering that the stock frame is much more complex then a simple 1/8" rail. Things like the overlaps, the gussets and geometry changes all make the frame stronger. Av, I know you know about those pain in the ass gussets.....And yes its 4 pages.......of nuthin but doubt.....Change my user name to AVTekk, nuthin personal Dave, and all you would read in this thread is a bunch of ass kissing about how great the chart is....but what do I know, I just build helicopters.....I vent

[whitedime]

Quote: Originally Posted by ConnecticutX

Change my user name to AVTekk, nuthin personal Dave, and all you would read in this thread is a bunch of ass kissing about how great the chart is....but what do I know, I just build helicopters.....I vent

oh, billy...
jon call me about starting on your truck.

[Phag96]

Quote: Originally Posted by NCHEVYHEVN3

Dragging is gay

no shit, it gets old quick, well dragging body does

[Lucky Dime]

haha ill kiss your ass jon....call me back brotha

[KCJester07]

I'm 6'6'', I guess I'm not a real man.

Quote: Originally Posted by clean n low

real men raise the floor and take it like a man.

[Lucky Dime]

Quote: Originally Posted by KCJester07

I'm 6'6'', I guess I'm not a real man.

Unless your 6'6" 150 lbs

[cain]

Quote: Originally Posted by ConnecticutX

Change my user name to AVTekk, nuthin personal Dave, and all you would read in this thread is a bunch of ass kissing about how great the chart is....but what do I know, I just build helicopters.....I vent

its funny none responded to this...

[Phag96]

Quote: Originally Posted by absolutcain

its funny none responded to this...

if they do they risk the consequences

[Lucky Dime]

Quote: Originally Posted by absolutcain

its funny none responded to this...

no one*

[ConnecticutX]

Quote:

no one*

Richard.

[Blazinlow15]

Hey connecticutx, i have a ? what is the dimensions of ur radiator and where did u get it, i like how u put it inside the core support is there a certain reason u did that?

[Xaos.]

well after all like he sead the man does build helicopters. shit my hats off to you.wow that takes some brains there. um whats the lbs. difrence of a factory frame / a frame made of 3x3 1/4 from the fire wall back .standard cab. im runing a 2.2 afterall.

and would i use the 3x3 1/4 all the way back ? or could i go to a smaller size after my link im runing a sd s10 4link now but want to run the 5link. and iff i do i dont want shit ever bending.

[556mm]

damn workin the graveyard shift i see

[WolfeCustoms]

Quote: Originally Posted by ConnecticutX

IMO a 3/16" thick simple beam is a good estimation considering that the stock frame is much more complex then a simple 1/8" rail. Things like the overlaps, the gussets and geometry changes all make the frame stronger.

Isn't a stock frame tempered? The densities and strengths are going to be different between stock and new tube steel... right?

[wizard_polo]

just adding some links to the topic might be helpfull

http://metalgeek.com/static/deflection.php

[miniblazinbmx]

I know several people with bodydropped trucks that used 2x3x.25 tall and never had any problems... and it's been fine for years. I think if you use enough gussets and crossmembers it's just as strong or stronger than the stock frame. And yes the stock frame is meant to crush or "flex" during major impacts. Think of it this way, if you get into a wreck THAT bad, your truck is ****ed anyway. Most trucks don't weigh shit in the back anyway, and I don't know too many minitruckers carrying loads in their bed, so I think 2x3 is a safe bet, as long as it is done right and gusseted where need be. 3x3x.25 is overkill and way too expensive for the project, plus most of these guys want to lay rocker. Not to mention the weight difference, but how much more pressure would it take to lift the truck with 3x3 than 2x3?? Don't harass me because I'm just posting what I know, and what I've seen work WITHOUT any problems. I understand everything from the engineering point of perspective, but like was said, 'real-world' applications are different sometimes. Something calculated on paper vs. something that is actually built is not always the same. I like the chart though, it's very interesting, but I just don't think there is enough weight to induce that type of stress on the frame(assuming it is built correctly).

[DROP DEAD]

i think my brain just blew up reading all that.

[DROP DEAD]

im runnin 2x3 3/16" square tube on my f-150 thats stock floored and i havent had any problems. standard cab longbed.

[93blazer4dr]

ok im going to build a frame from firewall back i was going to use 2x3 is that big enough its on a 93 blazer 4dr

[undy]

huge problem i think, just brought my cab back from work, i got rid of the pinchweld and built 1/8th rockers, and got rid of all cab mounts, my frame at home i put 2x3 rails for the drop. so my frame is 2 inches high and my mounts are all gone on the cab and it still dont lay flush with the frame. i heard on here 2 inch rails would easily work. kinda bumed out. havnt looked into to much yet, been drinkin too so it might just be me being the error, but i think i have to redo the cab floor again. ****. hopefully i figure something out or if someone has good knowledge on this lend some info to me please.

[whitedime]

some of you guys think way too much

[BlackEnvyDubz]

AVTekk What did you use on the 4Dr ?

[EndlessAuto]

just to throw something out there for you to think about my buddy builds 40 ft transit buses and all they are built from is 1 1/2 by 3 1/8 inch wall box tube with enough bracing in the right places anything is possible

[AVTekk]

3x3x1/4 and 2x3x3/16 for the backhalf

[s10sixteynine]

ok i have a simple ? cause i tried to find it in here if i use 3x3 can i lay rocker

[sdimeon22s]

before i read this ad i had already used 2x4 .25 w/ the 4 x2 so i figured that wouldnt be strong enough so i used 2x2 .25 beside that i was just wanting some comformation if this would be strong enough?

[ConnecticutX]

Quote: Originally Posted by s10sixteynine

ok i have a simple ? cause i tried to find it in here if i use 3x3 can i lay rocker

I lay door with 3x3x1/4 and the seats are at stock height........

[ConnecticutX]

Quote: Originally Posted by sdimeon22s

before i read this ad i had already used 2x4 .25 w/ the 4 x2 so i figured that wouldnt be strong enough so i used 2x2 .25 beside that i was just wanting some comformation if this would be strong enough?

huh? I dont understand what you did...

[s10sixteynine]

awesome do u have a thread on that? sorry im kinda new to the site

[ConnecticutX]

Quote: Originally Posted by s10sixteynine

awesome do u have a thread on that? sorry im kinda new to the site

I had one on here a long time ago..........If you want to check it out it is on DropNDrag.com under members projects........I dont feel like puting it in two spots.

[2separate]

What if your ride will be a daily driver and you use 3x2-1/4 inside the frame rails. I mean, can't you run the tubing inside the rails and keep the outer and under part of the factory frame for strength? Cut it down to meet the tubing, weld it, (difficult if the body is still on ofcourse) and cut it off just behind the cab, where the frame starts to curve up. That part of the frame on the outside will act as a fish plate for the first butt joint of the new rear frame clip. I've seen all of the stock frame cut up and scraped and as a result, when you look at a frame built from tubing it doesn't butt up to the stock frame (firewall cutoff) it is inside, leaving a not flush obvious gap where the two connect like an exhaust. Woudln't the result be a SLIGHT taper in the body to frame? I could be crazy, but this double vision I tell ya!!

[2separate]

Quote: Originally Posted by 2separate

What if your ride will be a daily driver and you use 3x2-1/4 inside the frame rails. I mean, can't you run the tubing inside the rails and keep the outer and under part of the factory frame for strength? Cut it down to meet the tubing, weld it, (difficult if the body is still on ofcourse) and cut it off just behind the cab, where the frame starts to curve up. That part of the frame on the outside will act as a fish plate for the first butt joint of the new rear frame clip. I've seen all of the stock frame cut up and scraped and as a result, when you look at a frame built from tubing it doesn't butt up to the stock frame (firewall cutoff) it is inside, leaving a not flush obvious gap where the two connect like an exhaust. Woudln't the result be a SLIGHT taper in the body to frame? I could be crazy, but this double vision I tell ya!!

I mean't to say 2x3 Not 3x2

[TUCNRIM88]

Ok

Thanks For Posting That


So I Get 3x3 1/4 Inch

Tie That Into The Front Section

Im Doing Underslung I Think Its Cleaner And Easier

Im Assuming That You Put A Crossmemeber Where Ever Factory Crossmembers Are

And Maybe One More Fro The Four Link Lower Bars


Any Help Would Be Apreciated

[dv8customs]

I realize this thread is old but since it is a sticky I thought I would mention the chart is wrong. You used the wrong equation to begin with (WL^3/3EI). That equation assumes that the tubing is fixed at one end and just cantileavered out at the other end with a 1000 pounds sitting on the end. The equation you should have used was indeed mentioned earlier and it is (WL^3/48EI). This equation assumes that the beam is supported at each end which it is in a truck frame. The load in this case is directly in the center of the beam which gives you the worst case scenario. This changes the numbers in your chart considerably.

[AndrewH]

I generaly dont rip peoples ideas and thoughts when they make sense, but saying that 3x3" .250 tubing should replace the stock frame rails is IDIOTIC!!!

who cares about deflection if you dont know aceptable tolerances!!!

the stock frame would be off the charts, and your worried about these little baby penis sized numbers?! you've got to be kidding me!!!

[slam]

Quote: Originally Posted by ConnecticutX

mkay...i quick made this up to stop all the rumors about what size box tubing to go with for frame rails.....its kinda self explanitory, ignore the stuff in the middle, just pay attn to the hieght, width, thickness, deflection and weight. The deflection is in inches and the weight is in lbs.

BTW...this is assuming stock dimensions, a 5 foot length, and 1000lbs of force on the beam....

Does any one know how 2.5x2.5/-1/4 would compare to this chart?
(not using for a frame, just wanted to know its properties)

[1st-timebodydrop]

hey guys,my advice on this subject is go out to a steel dist. and look at the material because i was blown away when i saw mine when i ordered mine and picked it up yesterday i got 3x3 3/16 and at home when i was planning my project i grabbed a ruler and was like eh this tubing isnt that big or thick so i was debating on goin 1/4 '' wall but when i ordered it and saw it i was like whoa thissawesome lol it was way beefer than i anticipated it to be so im not saying not to go aginst the physics in this but to get out there and take a look at what ur using before dropping a ton of money in steel ...im glad i didnt go with 1/4' wall lol