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roll cage start open to advice (not 56k friendly)


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This is where I called it a night. Yes im aware nothing is welded yet and there is tape holding it up. lol I figure its strong enough ...just kidding

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The dash bar will be moved up and a upper bar installed but yeah

This is what im thinking of doing any changes needed?

 

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Keep in mind your height, if you are anywhere over 6 ft, You want to keep in mind your center crossbar will limit how far back your seat will go. Also, watch your head room to your top left on drivers side/passenger side where your head would be. The z has limited head room with a cage in it, especially with a helmet on.

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Keep in mind your height, if you are anywhere over 6 ft, You want to keep in mind your center crossbar will limit how far back your seat will go. Also, watch your head room to your top left on drivers side/passenger side where your head would be. The z has limited head room with a cage in it, especially with a helmet on.

 

yes im keeping the bars very close to the sides where they go back and im 6' so driving it with a cage shouldnt be too bad. How does everything else look so far?

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Looks like your on a good track. Are you having the side bars go out past the doors? In otherwords, are you going to gut the doors? There might be limited room if you do those side bars without gutting the doors, but its a good side bar design. Same as nascar, if they use it, it must be proven safe... Similar to the ones I did.

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Keep in mind your height, if you are anywhere over 6 ft, You want to keep in mind your center crossbar will limit how far back your seat will go. Also, watch your head room to your top left on drivers side/passenger side where your head would be. The z has limited head room with a cage in it, especially with a helmet on.

 

This is not an issue in an s130. I have experience in both s30 and s130 chassis and there is about 10 cm more room in the s130 chassis. His center crossbar should with a six feet guy not really matter as im 6,1 and if i go all the way back am WAY to far from every to be functional as a track car (i.e. to far from the pedals and steer even with a dished steer set up.

 

however, why the straights to the back floor? As i dont see an safety issues there, you want to have some parts of the car that actually take the blow..

If it is rule thing i would diagonal it much like in this clio

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(assuming you will weld the to the bumber supports in the back floor Is it a rule thing ?)

 

As otherwise this is basically a 'FIA' Set up;

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Note the door bars .. you tend to lean to a nascar style setup adding allot of weight. witch does not really do much .. In building a cage you have to triangle as much as you can. So on impact the forces have more than one route to divide them selfs over.

So tell me what will this car be for and what scrutenering will it be for as SCCA orso is not my cup of tea rule whise

 

Note im by no means an expert!! if it is for some class rules get a rulebook ;)

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What are your intentions with the roll cage? Autocross, road race, street, show, drag??

If its for SCCA, get a GCR and build accordingly. i.e. Main hopp cannot have more than 4 bends in it, totalling 180+/-10 degrees. Yours has more than that. Though it fits really nice. Remember, bends are really weakenig the material, and your under it.

I need to figue out how to resize pics. So I can show some pics of my cage which is built to SCCA specs. PM with email and I can send some to you. I'm 6'4" and I fit with a race seat.

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If you don't continue the diagonal bar to drivers side head, your never going to pass tech anywhere, and anyone who knows anything about safety would tell you if your cage was ever to be used, you'd probably be crushed due to lack of support for the top hoop.

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If you don't continue the diagonal bar to drivers side head, your never going to pass tech anywhere, and anyone who knows anything about safety would tell you if your cage was ever to be used, you'd probably be crushed due to lack of support for the top hoop.

 

Thats kinda what i though no biggie ill put them up is the rear x required on the two down bars that go to the back?

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If you don't continue the diagonal bar to drivers side head, your never going to pass tech anywhere, and anyone who knows anything about safety would tell you if your cage was ever to be used, you'd probably be crushed due to lack of support for the top hoop.

 

:icon13:

 

You'd be correct if he was running SCCA, but according to the post a couple up, the car is intended more for drag racing. NHRA or IHRA don't require a diagonal bar, and it's well into the single digits before any bracing accross the main hoop in a similar fashion is needed.

 

Most roll bars that are mandated in NHRA and IHRA require the lower strut bars to be different. They usually attach to the junction where the belt bar meets the main hoop, and then attaches through the floor to the frame connectors.

 

I don't believe you'd have a problem in NHRA or IHRA with that main hoop, but maybe not as just a roll bar. My uncle built a tube frame Fiat Topolino "replica" with a multipoint cage, that also had peaked main hoop and winsheild bar to gain more head room. It is or was an NHRA certified chassis. The only reason I say "was" is because the guy that recently bought it is planning to change the door bars to swing out which won't pass cert, in this car. As a roll bar the peak may cause you problems. Most tracks don't check the roll bar much unless you are into the single digits. Most tracks that I've been to, or I have read about just make sure you have a bar below 12.99.

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check your rule books. not for scca, but not sure about drag race cages, if your using it as a drag car, you might want to look into it. For nasa, scca, and other organizations I don't believe requires it.

 

Want to double check though, don't take my word for it.

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here is what i have right now. Keep in mind I'm an electrician not a welder i know the welds are stout and have good penetration. Also they are welded all the way around what a pain in the ars. here is the start going to go through and put gussets in still. The middle bar is just sitting in place its not crooked

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you can kinda see here i went through the firewall and attached to the struts(not welded in yet

 

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hopefully it will be close to done tomorrow if no work comes in. Hows it looking. Im kinda thinking (with the x that still needs to go in the rear) getting a flat steel peice and busting the plasma out and carving zx or s130 or something any suggestions?

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I would remove that bar beteen the main hoop "X" and the rear floor. It doesn't really go anywhere, what I mean by that is there is no corresponding cage member on the other side of the X to transer load through the chassis. It also looks a lot like a spear, in the event of a crash. Yes the rest of the cage should transfer the impact through the car, but where it is attached at the floor is really pretty weak, yes it strong under normal circumstances, such as what you want to do with the car, like driving, cornerering, braking, etc, but under forces where other objects are making contact with the car, can force that area to move in ways it's not intended to.

 

A roll cage can sometimes make a crash more dangerous for the occupants than not having one. This has been seen over the years, where a cage that was built without a plan from the beginning and seemingly random bars were added, caused inuries or fatalities, because they were positioned poorly, or welded poorly (even a well planned cage with poor weldingis dangerous).

 

If you're planning to add another bar from that X to the front of the cage, such as the dash bar, or on a diaginal to the base of the passenger side door bar/windsheild hoop, then that would help transfer the load from the bar in question, and has been done on many cars. I've even seen two bars ran from that point to the dash crossbar in a triangular shape.

 

I will make one more suggestion about that bar, and a bar for the other side if you plan to add one there, and that is attach the bar directly to the other bars, not to the plate welded to the bars. The reason I say this is to get maximum strength. The plate is most likely not able to completly transfer the force from that rear diagonal link to the X in the main hoop, due to there being a little space between the plate and the X. Even just a very little space less than 1/16" is far too much space and will compress under impact curcumstances, or worse yet, pull apart making those links useless, and now becoming dangerous, as they can move in thier own pathes, possibly becoming objects that will come in contact with the occupant(s).

 

If you still want a plate there, you can cut a hole in the middle, slide it over the tube, weld the tube to the other tubes in the X, then slide the plate back up to the X and weld around the rear diagonal link, and then to the other bars. This is a very strong joint, much like a miter joint in wood working, where there are 2 or 3 planes to the joint, instead of just 1.

I'm also not sure you're really gaining any strength with the plates such as they are, I would think properly fitted gussets between the bars would be just as strong, if not stronger.

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you got me worried how can i tell if my weld is good? it isnt pretty but hitting a 2x4 on each beam with a dead blow it doesnt budge good enough? they are all welded all the way around

 

I didn't mean to get you worried about your actual welds, since well I can't really inspect them and pictures can be misleading when trying to evaluate the look of a weld.

 

I also thought you would have cut the rear bars, the ones that run from the main hoop to the rear floor and have them notched to fit around the strut brace. What you have is better than nothing, but would tie the chassis together better for it to be fitted with the bars intersecting on the same plane. At this point, it would take a bit of work to change, and unless you start building 4 digit HP and running deep single digits, or serious road racing/auto-x, I would just leave it as is.

 

Add a bar accross the bottom of the X brace, in the rear bars. This will triangulate the bracing much better. If you had made the connection pint of the bottom of the X at or very near the floor, then the extra bar would not be needed.

 

I also think it's time to start concentrating more on the front than the rear. You sit in the front, not the rear. ;)

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