Roll bar/roll cage design

[Ludachris]

For anyone planning on getting a roll bar or roll cage installed I wanted to start a thread about it so we can discuss the options and how they relate to NASA (and other racing org) rules.

I'm planning on getting a custom roll bar welded in. It will probably be a 4-point rear cage since I don't plan to do wheel to wheel racing, only Time Trials, and I know Time Trials doesn't require a cage but it's a good idea anyway. I want to have the rear bars mount to the shock towers with an X brace between them. The main hoop will have a diagonal bar and a harness bar. I figured that if I end up doing wheel to wheel racing I can always go in and add on the forward bars later. I'm reading through the NASA CCR now so that I can make sure that the cage will be legal for wheel to wheel just in case.

The cage will be 1.75x.095" mandrel bent DOM tubing. The main hoop will have no more than 4 bends and will be one continuous piece of tubing. The rear bars will have no bends. The mounting plates will be at least 3/16" thick. Etc, etc, all based on NASA's CCR.

Anyone else already do a bunch of research on this?

 

[MIdsm]

http://e30m3performance.com/tech_articles/cage_symposium/cage_symposium.htm

 

[Bob 95 Talon]

I'm actually sending the demensions of my Talon to Jegs. They have quite a few different sizes for different cars that are pre bent already. They will take your specs and mix and match their inventory for a very reasonable price. And for 75.00 more they will custom bend one to your requirements. I do have it easier then most of you guys because my car is gutted. I oval track race. I am presently ordering 3 or 4 cages at once. The shipping is way cheaper. I have 5 2GNT's and one empty body. As soon as I hear back, I'll update on this. Bob

 

[4G63FLA]

You could aslo get one of these cages http://www.dsmparts.com/customer/product.php?productid=660&cat=&page=1 and just add the door bars etc. that you wanted on the cage. I believe this is something similar to what Greg used in his Laser. It is also constructed of 1.75" x .134" steel tubing. Just something different for people to consider.

~Eddie

 

[eclipse2via]

Greg's car has a modified Autopower 6pt. bolt in cage. That Comp Engineering cage is a drag race cage.

 

[RusherRacing]

Make it to meet SCCA and NASA rules.

From what I have seen and read if you cover these two organizations you should be covered for all the others. Also be careful if your thinking about passing the cage through the firewall. This can really effect classing etc again read the rules which it sounds like you already have. From your first post it sounds like your pretty much ontop of what needs to be done. but here is some input.

I would also recommend having the cage built specifically for your car so it fallows as close to the body as possible, helping to increase the rigidity of the car. You will definitly want to tie together your rear strut towers but you already know that. Have a reputable local race car fabrication shop build it for you. It may cost a little more up front but you will see the difference in quality. I would have wolf weld (doug wolfgang ex outlaw sprint car driver) do the work on my car because he is local. Find someone in your area that is well respected frame/cage builder.

 

[4G63FLA]

Greg's car has a modified Autopower 6pt. bolt in cage. That Comp Engineering cage is a drag race cage.

Oh yeah. I remember reading that it was an Autopower cage thank you. But even if the other one is a "drag" cage. It is made from the same material as the other cages. Why would that make a difference? If it is made from the same thickness of tubes and has more points as well as more point attachments, should that not be a suitable cage? Just curious is all.

~Eddie

 

[awnmotorsports]

I'm building 2 different roll cages for both my DSMs. the 2G will have a much stronger roll cage than my 1G, because I will be doing road coarse with it. and i'm doing it myself. a couple of things to know, I'm pretty sure NASA is the sam, but SCCA requires a 3/8" hole drilled in several areas of the cage for inspection purposes, also you have to build the cage as close to the roof of the vehicle. and states must be 2" above drivers helmet. and there are many of rules like that. I've seen a little about NASA and it seems their rules are not as strict as SCCA so if you build it on their regulation i'm sure it will pass NASA. you can get the regulation off their site www.SCCA.com click on any event like solo and then on rules.

 

[4G63FLA]

Good luck on your design there. Post some pics for us when you get it done. I would like to see it.

~Eddie

 

[awnmotorsports]

also you can get roll cage accessories like gussets, 4 bolt tubing flanges and tubing end spindles. oh and if you plan on doing a bolt in cage and are going to sleeve the tubes together, the sleeves must be at least 8" long and have at least 2 grade A 5/8" bolts. but you can get all of that @ www.chassisengineering.com

 

[awnmotorsports]

Oh ya BIG thing! if you are doing it yourself..........NO MIG WELDING....... must be ARC or TIG. mig is not strong enough, and the inspectors will check the welds. I really recommend going to SCCA and printing out the rules & regulations on roll cages. its only about 10 pages long, and really good info.

 

[Bob 95 Talon]

I got a call back from Jegs. It seems that the Mustang up to 02 is a very close size to the dimensions I gave the tech. It was an inch narrower then my measurements. Keep in mind my cars are gutted, no interior. I will take some photos after the install. I ordered three cages and the total was under 600.00 with shipping for all three 8 point cages. One of my cars will only get a 4 point with door bars on drivers side only. As per track requirements. I think it's dumb that you can't have more points but rules are rules. Oh and all tubing is 1.75".
As soon as one is installed I'll try to post some photos.

Oh and 4G63FLA, I just looked at the link you posted after my response, Hence the edit of this post. The Jegs bar looks and is the same as the DSM cage but is less expensive.

Bob

 

[4G63FLA]

I got a call back from Jegs. It seems that the Mustang up to 02 is a very close size to the dimensions I gave the tech. It was an inch narrower then my measurements. Keep in mind my cars are gutted, no interior. I will take some photos after the install. I ordered three cages and the total was under 600.00 with shipping for all three 8 point cages. One of my cars will only get a 4 point with door bars on drivers side only. As per track requirements. I think it's dumb that you can't have more points but rules are rules. Oh and all tubing is 1.75".
As soon as one is installed I'll try to post some photos.

Oh and 4G63FLA, I just looked at the link you posted after my response, Hence the edit of this post. The Jegs bar looks and is the same as the DSM cage but is less expensive.

Bob

Sounds good Bob. So you are actually putting in a Mustang 02 & up cage in there? Thats great man. I would Love to see how that turns out. My car is also 3/4 gutted so I would have similar conditions to yours. So when you can man, post some pics up. Thanks for the info.

~Eddie

 

[eclipse2via]

Oh yeah. I remember reading that it was an Autopower cage thank you. But even if the other one is a "drag" cage. It is made from the same material as the other cages. Why would that make a difference? If it is made from the same thickness of tubes and has more points as well as more point attachments, should that not be a suitable cage? Just curious is all.

~Eddie

I'm not up to speed on NHRA reg but from what I remember talking to drag guys the sub 11 second cage is designed to protect a cat that goes over once or onto it's side and skids down the track. With no provision for side impact from another car. The road race cage is designed for going over more than one time. And has driver door bars for added protection in case you were to get t-boned plus that strengthens the somewhat outrigger frontposts.

 

[4G63FLA]

I'm not up to speed on NHRA reg but from what I remember talking to drag guys the sub 11 second cage is designed to protect a cat that goes over once or onto it's side and skids down the track. With no provision for side impact from another car. The road race cage is designed for going over more than one time. And has driver door bars for added protection in case you were to get t-boned plus that strengthens the somewhat outrigger frontposts.

Oh ok. Thanks for that info on the cages. I thought maybe there would be a difference, just was not sure. I will wait and see hwo those Jeg cages come out for him. Thanks.

~Eddie

 

[pnishr]

Subscribed

Bob, let us know about that cage when it gets in. I've been looking for alternatives for an 8-pt cage. Mine will be mostly gutted, and you can always make stuff fit.

As for that one on dsmparts... it's been "out of stock" for about a year now. I think they made them, sold them all out, and then decided that the 2g market wasn't big enough yet.... I dunno.

 

[4G63FLA]

Subscribed

Bob, let us know about that cage when it gets in. I've been looking for alternatives for an 8-pt cage. Mine will be mostly gutted, and you can always make stuff fit.

As for that one on dsmparts... it's been "out of stock" for about a year now. I think they made them, sold them all out, and then decided that the 2g market wasn't big enough yet.... I dunno.

Yeah, I noticed that myself. I'm looking forward to see how that Jeg's cage works out actually.

~Eddie

 

[Bob 95 Talon]

The guy to talk to at Jegs is Larry Nelson. Hey Tell him you spoke to Bob, The guy that bought 3 cages. Larry is the frame guy there. He's a little dry but knoledgable and helpful. Boy, I hope he doesn't read this forum. The dimensions I came up with for the main hoop were as follows,

Total Height- 39"

Width at top- 36"

Drop to straight part of leg- 16"

Width at lowest point of upper angle- 52"

Width of bottom by floor- 52"

JEGS BAR MEASUREMENTS as follows

Total height- over sized cut to fit

Width at top- 36"

Drop to straight part of leg- 13"

Width at lowest point of upper angle- 51"

Width of bottom by floor- 51"

All other bars are longer then needed and to be cut to length. Includes 3/16" plates as needed. This should work out just fine. It's cheaper then having a custom cage built and fun to do yourself.

I should have these early next week. They had two in stock and are building the third right away. But until then I'm working on my trailer. Just installed a microwave and coffee pot cabinet with room for the crock pot too. Hey gotta keep the pit crew fed and alert.

 

[stealthTT]

The dimensions I came up with for the main hoop were as follows......

I'm surprised you found a cage with such close dimensions. Thanks for sharing the info with us and kudos to Jegs for working with you on the order.

........ Just installed a microwave and coffee pot cabinet with room for the crock pot too. Hey gotta keep the pit crew fed and alert.

Oh man, warm cups of Joe in the morning and a slow-cooked barbecue beef sandwich for lunch. That'd be a lot better than most on-site concession stands. These are the best reasons I've heard for an enclosed trailer yet.

 

[pnishr]

The dimensions I came up with for the main hoop were as follows...

So, excuse my crappy Paint doc, but let's assume the red lines are the actual dimensions of what you ordered, and the black are what you measured. Are you certain that with the higher drop, it won't interfere with the b-pillar of the car? I know it's also an inch narrower, but with the drop 3 inches higher, it seems that the curvature of the car would be more rapid. You seem competent enough, that I'm sure you measured, but just wanted to check, especially since you said your car is totally stripped. Clearance may be an issue for anybody with any interior. How much will their be between the bar and car?

Thanks much.

Jeff

 

[pnishr]

Bob,

Any word on fitment yet?

Thanks,

Jeff

 

[Flash]

http://www.swracecars.com/shopping/shopdisplayproducts.asp?id=104&cat=Mitsubisi
I hope this is a helpful link. You have to weld it together yourself or have a shop do it.

 

[Jake30]

I get all my stuff from S&W Racecars. Very good fit with the weld in cages.

Here is just a quick pic of my 10pt cage with funny car style conversion, doors are x braced and so is the rear.

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Here is a link to the gallery if you would like to see more...

http://www.mitsustyle.com/photopost/showgallery.php?cat=516&ppuser=

 

[terefic181]

Just a note, so you don't possibly spend money on something you can't use.

If your going to be racing with NASA make sure, the tubing your cage is made from is DOM (drawn over mandrel) as Chris mentioned above, and not ERW (electric resistant welded).

I'm sure there are a number of cages produced out there, that are not DOM, that may be accepted in drag racing, but will not be accepted in NASA or SCCA, for racing purposes.

There are a lot of regulations for cages. You might want to take a look, it starts at section 15.6.

http://www.nasaproracing.com/rules/ccr.pdf

 

[Jake30]

"15.6.18:

2201 - 3000 lbs.
1.500" x 0.120" Chrome-moly / Seamless mild steel (DOM)
1.750" x 0.095" Chrome-moly / Seamless mild steel (DOM)
1.750" x 0.120" ERW* (No issuance of log books for cars with ERW cages 04/30/03)
*Note- Specifications listed for reference for inspection of grandfathered vehicles.
"

I'm guessing what that means is for cars that have ERW cages before 4/30/03 installed then they are grandfathered in? What happens if you've been building the car for the last 3 years to compete, is it still grandfathered in?