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  #11  
Old 08-23-2017, 09:58 PM
JRas JRas is offline
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Originally Posted by Joe D View Post
I did my car a lot like the cup car design, but I had the X meet with bends welded around where they meet and then boxed in. The X can provide a stiffer chassis. Boxing in around the X is very strong

The thing I don't like about NASCAR bars is you generally have a long distance that is unsupported. I did a lemons Sentra with NASCAR bars but plated the rocker panel and added 3 braces from the NASCAR bars. It's also really hard to avoid the S bend without going through the B pillar with either type of door bar.

Also, make sure all tubes terminate so the load path goes into another tube or the chassis. You don't want tubes welded more than 3" away from each other.

Another thing to consider is adding FIA rollover tube. It triangulates the A pillar and prevents it from collapsing in a rollover.
When would a tube not be into another or the chassis? Just trying to understand in instances where that isn't true.

Quote:
Originally Posted by gills View Post
If you're only going to have one rear strut member it needs to be high on the main hoop, just like Def stated.

Things move in a proper crash. Give yourself SPACE, again, like Def stated. Get the bars as far away from you as possible into the door. If you have S-bends, they can be supported by having verticals like in a NASCAR style cage and then ultimately tie it into the rocker panel or rocker cage member if you have one.

With Joe D's cage description you could fortify it even more by having a vertical running to the vertex from the rocker panel. If I were to build a new cage right now, I would do this method.


The biggest benefit of NASCAR bars is protrusion potential. They are usually skinned and provide a ton of space. And correctly done, they don't have S-bends and tie into a straight lower member that runs along the rocker.

Don't be scared of going through the unibody B-pillars. They are pathetic on an S-chassis anyway. Take a good look here from my old car/cage (where I would now change quite a few things):

Guys are spitting knowledge at me, trying to understand. What is a vertex?

Seems like every NASCAR "style" door bar I've seen has an S bend.

Is there any issues with NASA/SCCA and going through the B pillar? seems smart to me, likely more labor intensive as well.

Fabricator I planned on going through told me he didn't feel comfortable not doing a halo bar. I'm guessing a lot of these guys are doing standard 4 and 6 points intended for drifting only.

Would it be worth doing an 8-point? One fabricator asked forward of the A pillar at the firewall.
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  #12  
Old 08-24-2017, 04:37 AM
Joe D Joe D is offline
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Sorry to confuse you. I'm not sure how to write it so it makes sense. You want to look at the load path. I'm not saying its not connecting to a tube. I mean it needs to have another tube on the other side to distribute the load.

The vertex is the middle of the X. I actually have another straight tube that has the tube from the vertex to the middle of it. The car was originally built for SCCA IT and NASA PT and it's not allowed to have an extra attachment point to the rocker.

Mine is similar to this with a vertical tube in the middle and it bends out into the door:

Then I plated it in with taco gussets similar to this:

I did a halo in the sentra. It is a little easier in some ways. I do like the look of one continuous a pillar bar from the main hoop forward and it isn't all that big of a deal to make.

You need to understand the rules for any class you may want to run in. In general most classes don't want you going through the B pillar or cutting it up. If you have a fairly well prepped car with some higher horsepower it won't matter because you'll be in a more open class anyways.

You do have to do some pretty extensive surgery to the door if you go through the B pillar though. It becomes pretty flimsy but we made it work with some extra bracing.

Go on google and look at pics of cages. Make sure you understand the rules for whatever organization is inspecting your cage and make sure the builder understands them.

Eventually I'll build another one because you always learn what you would do different when you finish one.
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  #13  
Old 08-24-2017, 04:55 PM
a250gpguy a250gpguy is offline
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https://www.youtube.com/channel/UCcx...rjTVSSUkzZ2Jlg

This is not a terrible place to start either. This guy has a whole play list doing a time attack cage.

Ch

Sent from my SM-G955U using Tapatalk
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  #14  
Old 08-24-2017, 08:52 PM
JRas JRas is offline
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Quote:
Originally Posted by Joe D View Post
Sorry to confuse you. I'm not sure how to write it so it makes sense. You want to look at the load path. I'm not saying its not connecting to a tube. I mean it needs to have another tube on the other side to distribute the load.

The vertex is the middle of the X. I actually have another straight tube that has the tube from the vertex to the middle of it. The car was originally built for SCCA IT and NASA PT and it's not allowed to have an extra attachment point to the rocker.

Mine is similar to this with a vertical tube in the middle and it bends out into the door:

Then I plated it in with taco gussets similar to this:

I did a halo in the sentra. It is a little easier in some ways. I do like the look of one continuous a pillar bar from the main hoop forward and it isn't all that big of a deal to make.

You need to understand the rules for any class you may want to run in. In general most classes don't want you going through the B pillar or cutting it up. If you have a fairly well prepped car with some higher horsepower it won't matter because you'll be in a more open class anyways.

You do have to do some pretty extensive surgery to the door if you go through the B pillar though. It becomes pretty flimsy but we made it work with some extra bracing.

Go on google and look at pics of cages. Make sure you understand the rules for whatever organization is inspecting your cage and make sure the builder understands them.

Eventually I'll build another one because you always learn what you would do different when you finish one.
Thanks for clarification

Quote:
Originally Posted by a250gpguy View Post
https://www.youtube.com/channel/UCcx...rjTVSSUkzZ2Jlg

This is not a terrible place to start either. This guy has a whole play list doing a time attack cage.

Ch

Sent from my SM-G955U using Tapatalk
Watched a few episodes, seems helpful for those guys building their own cage.
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  #15  
Old 08-28-2017, 04:52 PM
JRas JRas is offline
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crazy the price gap between quotes but sounding like I'm a week out

What is your opinion, on the design of this cage?
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  #16  
Old 08-28-2017, 05:53 PM
Def Def is offline
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Btw, welds on that motoiq gusset plate are absolute garbage. A bunch of cold tack welds with a big stop hole in the middle of every one. Ugh... just freaking weld the thing...
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  #17  
Old 09-01-2017, 05:21 PM
Joe D Joe D is offline
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Quote:
Originally Posted by Def View Post
Btw, welds on that motoiq gusset plate are absolute garbage. A bunch of cold tack welds with a big stop hole in the middle of every one. Ugh... just freaking weld the thing...
Yeah, they're pretty horrible. I almost didn't want to post that picture because of that, but I'm lazy and did feel like look for another one.
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  #18  
Old 09-04-2017, 08:33 PM
JRas JRas is offline
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Prepped the car good this week, dropped the car off today.

Planned on having him do the cage welded to the floor, builder recommends at least boxes for the front for tighter fit.

ideal spot to terminate on rear strut tower?

Are gussets worth it, planned on A and B pillars?

Not really sure what the weight of the car will be, NASA weighs without fuel and driver. If I was under 2500lb I could go with 1.500” x 0.095” DOM

Last edited by JRas; 09-05-2017 at 05:01 PM..
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  #19  
Old 09-07-2017, 07:35 AM
gills gills is offline
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Quote:
Originally Posted by JRas View Post
Prepped the car good this week, dropped the car off today.

Planned on having him do the cage welded to the floor, builder recommends at least boxes for the front for tighter fit.

ideal spot to terminate on rear strut tower?

Are gussets worth it, planned on A and B pillars?

Not really sure what the weight of the car will be, NASA weighs without fuel and driver. If I was under 2500lb I could go with 1.500 x 0.095 DOM
Boxes tying into the rocker panel for the A-pillars is a good idea.

Ideal spot to terminate is on the strut tower up high. You can create a box of sorts around the tower to make it so it's easy to cut the tube to fit and weld.

Gussets where exactly? If you're going to run an "FIA bar," probably overkill on the a-pillar.

S13 or S14? My S14 VQ35DE is 2470lbs with 1/3 tank of gas and no aero, lexan rear windows, etc. Gutted pretty well.

My old S13 KA24DE was 2420lbs with 3/4 tank of gas and no aero.
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  #20  
Old 09-09-2017, 04:44 PM
JRas JRas is offline
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Quote:
Originally Posted by gills View Post
Boxes tying into the rocker panel for the A-pillars is a good idea.

Ideal spot to terminate is on the strut tower up high. You can create a box of sorts around the tower to make it so it's easy to cut the tube to fit and weld.

Gussets where exactly? If you're going to run an "FIA bar," probably overkill on the a-pillar.

S13 or S14? My S14 VQ35DE is 2470lbs with 1/3 tank of gas and no aero, lexan rear windows, etc. Gutted pretty well.

My old S13 KA24DE was 2420lbs with 3/4 tank of gas and no aero.
Doing boxes in the front, and having the fabricator do the main hoop on the rear shelf (based on recommendations)

Gussets will be on A and B pillars

S14, 2420lb sounds nice and light to me
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