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Discussion Starter · #1 ·
Just need a quick clarification.

Building a cage in a 99 impreza coupe, intended to be logged with Rally America.

Using 1.75 x .095 dom.

I need a total of 3 door bars correct?
One along the sill.
Then two bent in a v shape with the points of the v touching each other so they look like an X viewed from the side(with gussets of course).
Does the one along the sill have to be completely straight? or can it bend out towards the door?

I'm fairly certain this exceeds the current regs, but want to confirm before we start bending that section.

My apologies for another door bar question, I have searched, but there are so many topics covering it here, I've had a tough time discovering which have fact(and current facts) and which are opinion.

Thanks
 

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ITURNRT
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You only need one door bar, one sill bar, and one a-pillar bar (or as called the "FIA BAR"). Only the Sill bar needs to be 1.75" x .095" minimum. The FIA and door bar can be 1.5" x .095" minimum. But you should send an email to [email protected] as he is the final word on viewing of the cage design rules.

http://www.rally-america.com/info/2008_Rollcage.pdf Here is the RA diagram.


The red bar that is parallel to the sill bar can be at angled, but you should refer to FIA Article 253 for more details on cage design door bars in ARTICLE 8 : SAFETY CAGES. More specific 8.3.2.1.2 Doorbars and Drawings 253-9, 253-10, 253-11 show door bar configurations (253-8 is not legal for new logbooked cars per FIA rules).

You can add an additional bar to make an X and you can have one solid bar with another intersecting it, or the two bend V to make an X like you describe.
 

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Discussion Starter · #3 ·
Thanks Billy,

Some of my confusion is from reading the fia regs and looking at the drawing on the rally america site. The RA drawing shows the one straight door bar, then if you look at 253-49 of the fia regs You see the x, but not a sill bar(which could be out of site I suppose). Bottom line I wanted to make sure one bar didn't need to be perfectly straight from pillar to pillar as that would cut down on driver space.
It will have the fia/flemke bar. It will appear from the side nearly identical to 253-49, with the exception being the X will be formed as two bent V's rather having a traditional x as in the diagram. We'll have the sill bar as well. It'll all be 1.75 because it just made sense in terms of purchasing the dom, and I'd prefer the extra protection there.
 

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Sounds like your plan is pretty much exactly what I did for my cage. I built to the FIA specs. Some example pics here:



You can kinda see in this pic that the sill bar is bent out slightly to take it closer to the door, and IMO it stages the side impact and puts the sill bar in expansion and when it starts to buckle then you're putting the door bars into tension.



 

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ITURNRT
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Like I said though... the RA spec is BASED off of the FIA. So I'm not 100% sure if you're required to have a sill bar. You can get away with no sill bar in FIA cages if you have a door X or that odd triangle thing.

Email Hurst @ [email protected] just to clarify. I'd hate for you to put an X in the door and then still need the requirement for the door sill.
 

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You only need 2 door bars, no sill bar per se. One bar needs to be continous 1.75x.095. So just an X is acceptable. Most people do add a ssill bar then an X above it.

Gene McCullough
RA Western Tech Supervisor
 

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While you probably don't NEED a sill bar for the rules, I have seen a rolling rally car hit a tree floor pan first and bend up to the door bars, not a good thing since your seats are mounted to the floor.......

Even before door bars were manditory, after seeing that crash, my cars had sill bars.

Mike
Rallywest Tech director
 

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Sill bars are so easy to put in, to me, it was a no brainer. In my GC, the bottom of the half-lateral coming down the a-pillar in the front, and the bottom of the main hoop are in the same plane, therefore it was only a straight bar, with easy fish-mouths cut straight through on each end. I like it as it adds some hip protection in a side impact with a stump. I'll probably add a piece of punch/flared steel to weld it to the rocker at some point too.





*note: cage was not finished at this point, hence no gussets etc.
 

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Discussion Starter · #9 ·
I intend to do almost exactly what Ryan H has posted. However, I'm hoping to bow the x bars out a touch as well and intend to not have the fia/flemke bar intersect the door bars and be just inboard of them. I suppose we'll see when we get there. Got a lot of work done on the cage today. Unfortunately the passenger side A pillar bar was not quite right, so we decided to scrap it. That meant we are short of DOM until we can get more on Monday.
Rear half of the cage is done.
My buddy that is helping me(OK he's really doing the lion's share of the work) is pretty anal about the fit of everything. It can mean some slow progress, but the results are usually quite nice.
 

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If ever there is a time to be anal and fit things well, it's in the cage - you REALLY don't want to find a problem the first time you use it ....Not that you will of course, but ....
 

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Discussion Starter · #11 ·
If ever there is a time to be anal and fit things well, it's in the cage - you REALLY don't want to find a problem the first time you use it ....Not that you will of course, but ....
agreed 100%

His commentary was along the lines that if I ever need to use it, he wants to be able to look at my wife and child and KNOW he did it correctly.
 

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ITURNRT
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I intend to do almost exactly what Ryan H has posted. However, I'm hoping to bow the x bars out a touch as well and intend to not have the fia/flemke bar intersect the door bars and be just inboard of them. I suppose we'll see when we get there. Got a lot of work done on the cage today. Unfortunately the passenger side A pillar bar was not quite right, so we decided to scrap it. That meant we are short of DOM until we can get more on Monday.
Rear half of the cage is done.
My buddy that is helping me(OK he's really doing the lion's share of the work) is pretty anal about the fit of everything. It can mean some slow progress, but the results are usually quite nice.
Take note though... with my car, I would have liked to have the FIA bar be solid. However, positioning the bar with no bend it would have made contact (or been real close) to the steering wheel. I'm a bit better now, since I've went to floor mounted pedals which shifts me back about 5" and I had to get an 80mm wheel spacer to push the steering wheel back.


See my cage below showing with the position before wheel spacer.

 

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Take note though... with my car, I would have liked to have the FIA bar be solid. However, positioning the bar with no bend it would have made contact (or been real close) to the steering wheel. I'm a bit better now, since I've went to floor mounted pedals which shifts me back about 5" and I had to get an 80mm wheel spacer to push the steering wheel back.

Like Billy, I too. I had the same issue with the steering wheel. I also replaced the dash bar with DOM like Billy. This gave me the opportunity to remount the steering wheel in towards the center of the car a bit more, that gave me clearance I was comfortable with. Despite the fact that the wheel is slightly off center of the seat, it is not noticeable at all. People have driven my car and then i told them and it was a "no $hit" moment for them. Two different ways to accomplish the same thing.
 

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Discussion Starter · #14 ·
It appears that there isn't a bend on your fia bar, perhaps it's the camera angle. Rules allow for a bend in that bar provided it appears straight from the side view. Do you think that bend would allow enough room on the wheel?
Camera angles can sometimes deceive the eye, but it looks like Billy's A pillar is further rearward than mine. Mine comes down behind the stock dash bar. It hits the floor right where it slopes up. It also looks like the fia bar is completely straight from the door bar up.
Hadn't thought of moving the steering wheel over either, which could be a solution if I have a clearance problem.
Billy and Abington is your fia bar 1.5 or 1.75?
Also out of curiosity are either of you running a steering wheel that is a different size than stock?
 

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It appears that there isn't a bend on your fia bar, perhaps it's the camera angle. Rules allow for a bend in that bar provided it appears straight from the side view. Do you think that bend would allow enough room on the wheel?
Camera angles can sometimes deceive the eye, but it looks like Billy's A pillar is further rearward than mine. Mine comes down behind the stock dash bar. It hits the floor right where it slopes up. It also looks like the fia bar is completely straight from the door bar up.
Hadn't thought of moving the steering wheel over either, which could be a solution if I have a clearance problem.
Billy and Abington is your fia bar 1.5 or 1.75?
Also out of curiosity are either of you running a steering wheel that is a different size than stock?
my bar is 1.75 and it is straight. I wanted to keep it straight, if possible, to make it as strong as possible. My steering wheel is 350mm and there is about 5'' of clearance to the fia bar. A bend will def. get you more clearance.
 

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ITURNRT
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Same with mine, Mine is approx same size wheel as stock and I have a straight bar. To me, if the bar isn't straight it is a weak point in the cage. While it is legal to put up to a 20° bend in the bar, I wanted it straight. Mine is 1.5" tubing.

But again, all of that has been overcome by events since I went to my pedal assembly. I added a 3-1/8" wheel spacer so I don't have any clearance issues. However, with my wheel being so far out, I need to re-adjust the angle of the steering wheel. It was slightly pointing to the door of the car and not straight on, adding another 3+ inches made it a bit more to the left than I'd like. Could I drive with it how it is? Probably... Will it bug the hell out of me if I don't fix it? Probably. :)
 

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Discussion Starter · #17 ·
another quick question.
in the picture below

You have the split V door bars. If there was an x there, it would HAVE to be taco gusseted. Since it's not an intersection, does it have to be taco gusseted?, or am I within the rules to cover that area with 1/8th inch plate on the outside?
I've sent an email to RA about it, but curious to hear the opinions of those here.

Thanks,
 

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I don't know that we have an actual rule about this one..yet. I would plate both sides. When a bar is bent like these it turns into a hinge on impact. It will both bend in the middle or wherever impact is centered and the whole bar will try to twist inward also. If you just weld along the surface joint that might tear. If you plate the outside the bars will still try to hinge as the plate is on the wrong side more or less. With a plate on the inside the plate will have to stretch because it is more in tension under impact.

Take a couple of straws or anything round and put a piece of tape on one side in the middle. You will be able to twist the straws inward but not outward ( depending which way you hold the straws).
 
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