I am currently welding in my roll cage and i want to weld a 1-3/4" Chrome moly Tube between the two rear shock towers. The rules is to use 6"x6" plates..but on the integras (dc) they have this OEM peiece sticking out of it on each side. What are some best options to do here? I could cut the peice out, but i do not know what function it serves, so im hesitant on that. I could build a box around it, but duno the best way of doing it.

I do have a couple ideas in mind, but wanted to see what you guys think would be the best option here to approach this. The two bars coming off the main hoop will not be welded onto there, it will be welded into the floor of the trunk on 6"x6" plates.

Any suggestions would be great! thanks

 

Would this be safe or pass specs if i tig it to the bracket and tig weld the seams in red?

In essence it would act like the 6x6 plates...or not ha

 

i doubt another bar between the towers will have any affect with a properly designed cage.

 

Its not really part of the cage, its for chassis stiffning...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by racintweek2 &raquo;</TD></TR><TR><TD CLASS="quote">i doubt another bar between the towers will have any affect with a properly designed cage.</TD></TR></TABLE>

Sure it will. Look at all well designed cages!

 

just get a strut bar.. then when you relize it does nothing you can take it out.

 

That does have a fuction it provides rigity for the tower encasement to what extent I do not know. I would just get the cage in then consider this the cage isn't stiff enough.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iBrandon &raquo;</TD></TR><TR><TD CLASS="quote">Would this be safe or pass specs if i tig it to the bracket and tig weld the seams in red?

In essence it would act like the 6x6 plates...or not ha


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I would cut out the peice in red and replace it with a flat 1/8 cromoly peice that wraps around the towers a bit and than weld the cross bar to the plates.

 

I myself would make a box around that that piece. Like this, I took this pic from another members thread

 

look at these posts lol, show me a cage with no rear crossbar

 

I already started on how i want to do it, ill show pics after im done.

by the way, whos ever cage that is, the rear bars coming off the main hoop should not be welded there, its incorrect i believe. Im sure many of you guys already know haha..

 

Oh, one quick question! How are you guys shaping and bending 1/8 steel plates? Took me forever to shape one plate around that shock tower.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iBrandon &raquo;</TD></TR><TR><TD CLASS="quote">
by the way, whos ever cage that is, the rear bars coming off the main hoop should not be welded there, its incorrect i believe. Im sure many of you guys already know haha..</TD></TR></TABLE>

why is it incorrect? i dont see anything wrong with it.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iBrandon &raquo;</TD></TR><TR><TD CLASS="quote">Oh, one quick question! How are you guys shaping and bending 1/8 steel plates? Took me forever to shape one plate around that shock tower.</TD></TR></TABLE>

they prolly have a brake. u could achieve a bend by starting your plate in a vice and hitting it at the point where the vice is gripping the plate. u could continue doing that until u got the desired bend.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mikey3000 &raquo;</TD></TR><TR><TD CLASS="quote">

why is it incorrect? i dont see anything wrong with it.
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Correct me if im wrong but i thought the bars had to be welded onto the chassis itself, whether it be directly on the strut towers or on the trunk floor and not on a bar going across.

The load wouldnt be spread out as much in my opinion if the car was to flip. All the load in the rear would be put on those two plates on the strut towers and the bar going across itself. Putting alot of stress on the welds of those two plates as oppose to having 4 plates that would spread the load more eqaully...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iBrandon &raquo;</TD></TR><TR><TD CLASS="quote">

Correct me if im wrong but i thought the bars had to be welded onto the chassis itself, whether it be directly on the strut towers or on the trunk floor and not on a bar going across.

The load wouldnt be spread out as much in my opinion if the car was to flip. All the stress in the rear would be put on those two plates on the strut towers and the bar going across itself. Putting alot of stress on the welds as oppose to having 4 plates that would spread the load more eqaully...</TD></TR></TABLE>

I have seen the guys at nrg do it like that as well, thats what I first thought of.

 

Yeh, i seen it done like that too...I was just remembering a little while back on a thread they were debating over on this type of setup.

Ah who knows! haha... Do know if that design passes inspection?? Im sure if NRG designed them, it should, correct? hehe

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iBrandon &raquo;</TD></TR><TR><TD CLASS="quote">Yeh, i seen it done like that too...I was just remembering a little while back on a thread they were debating over on this type of setup.

Ah who knows! haha... Do know if that design passes inspection?? Im sure if NRG designed them, it should, correct? hehe</TD></TR></TABLE>

If it was the topic that I think it was, that wasn't about those rear bars, it was about the main hoop, but it might not of been that one.

Yes NRG knows there stuff.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RCautoworks &raquo;</TD></TR><TR><TD CLASS="quote">

If it was the topic that I think it was, that wasn't about those rear bars, it was about the main hoop, but it might not of been that one.

Yes NRG knows there stuff.</TD></TR></TABLE>

well i think they do too for the most part, but if they designed the rearend of that cage they didnt think it through too well

but ive seen some "top notch" teams do some stupid things when it comes to engineering...so its not impossible

 

If you mount the bars like that the cross bar will just shear off the plates. If you run the bars down to the towers they will load into the tower plates. Now the only thing holding the hoop up is those 2 welds.

 

The reason why you dont bisect a tube like that is it puts the horizontal bar in bending...which is a BIG no no. It should attach at a node (the strut tower point as well)

If you've taken statics this is very apparent.

to the OP...BOX that ****. I would also...stitch weld the seam that will be hidden and paint the welded section

 

maybe you could continue the diagonal bar on the other side of the horizontal bar to brace that.

&lt;took statics

 

To reiterate, you definetly do not want to put that tube in bending. They should terminate at the same place...at the strut tower. And better yet...if you do diagonal bars going back from the roll hoop to the strut tower you end up triangulating the whole piece...where as if you do as its done above you end up with a rectangle. (triangles rock...squares suck)

Carrol Smith speaks of this in Engineered to Win as well.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by essex &raquo;</TD></TR><TR><TD CLASS="quote">If you mount the bars like that the cross bar will just shear off the plates. If you run the bars down to the towers they will load into the tower plates. Now the only thing holding the hoop up is those 2 welds.</TD></TR></TABLE>

Where would you suggest mounting the bars on the tower though ? Not a lot of room anywhere over there.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RCautoworks &raquo;</TD></TR><TR><TD CLASS="quote">Where would you suggest mounting the bars on the tower though ? Not a lot of room anywhere over there.</TD></TR></TABLE>

To the floor in the trunk and construct your triangular structure there. I am only welding the strut across the towers to help stiffn the chassis, unless you have room to put the other bars at the towers, which is very limited.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iBrandon &raquo;</TD></TR><TR><TD CLASS="quote">

To the floor in the trunk and construct your triangular structure there. I am only welding the strut across the towers to help stiffn the chassis, unless you have room to put the other bars at the towers, which is very limited.</TD></TR></TABLE>

Well I know the floor can be done, the other guy acted though as if they could be placed on the strut towers.