Caging / Roll Bar for the LS - Discussion

DeviLSh

DeviLSh

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Only know of a few people that have ran cages, who might even still be around. But wanted to toss this out there for anyone who was had a custom one built before, know some of the do's & donts, and maybe has some LS/DEW98 knowledge that would be useful as I begin to look into building something for my LS.

My primary needs are safety, harness support (shoulder bar), rigidity, and to some extent looks/aesthetic. My car will be used for primarily drag strip visits, maybe the occasional track day/fun laps, an otherwise car shows/cruises. Looking to do a Half cage for the rear only Something like a main hoop, harness bar, pair of rear downward bars, and likely a X-brace or diagonal brace across the main hoop.

Some of the questions I have are:
1) Best places to mount the hoop, down bars, and any cross bars
2) Bolt in or weld in, pros/& cons based on LS body structure or material?
3) What size dia tubing for the LS?
4) estimated weight add-on for the setup.
5) Basis or reasoning to add anything forward of the B-pillar?

Thanks in advance for any insights.
 
Quick question: are you planning to run in a particular series or at at particular track? Whatever you end up doing just make sure you're up to their regs/specs. Might be best to have it done by a shop with experience, 'cause it'll cost you more to have them make it right later
 
DeviLSh said:
Only know of a few people that have ran cages, who might even still be around. But wanted to toss this out there for anyone who was had a custom one built before, know some of the do's & donts, and maybe has some LS/DEW98 knowledge that would be useful as I begin to look into building something for my LS.

My primary needs are safety, harness support (shoulder bar), rigidity, and to some extent looks/aesthetic. My car will be used for primarily drag strip visits, maybe the occasional track day/fun laps, an otherwise car shows/cruises. Looking to do a Half cage for the rear only Something like a main hoop, harness bar, pair of rear downward bars, and likely a X-brace or diagonal brace across the main hoop.

Some of the questions I have are:
1) Best places to mount the hoop, down bars, and any cross bars
2) Bolt in or weld in, pros/& cons based on LS body structure or material?
3) What size dia tubing for the LS?
4) estimated weight add-on for the setup.
5) Basis or reasoning to add anything forward of the B-pillar?

Thanks in advance for any insights.
Click to expand...
I can't agree more with HRL ....I am a Motortrend Channel junkie...yes I have a problem lol ...anyway after watching Texas Metal, Junkyard Empire, Fantomworks, and many many more full custome garages do this kind of work I had no idea everything that was involved to do it not only the right way but like HRL said what is regulation at many tracks
 
Yup noted - it all makes sense. I am not really building this car for any particular "class" or competition. I take it to the local drag-strip, who references IHRA tech sheets on their website, and I have also been referencing the NHRA rule book. But most of these go by a type of car class which my hodge-podge build doesn't fit into. I can see myself going to a couple club days or laps at a road course, but never really to compete. (No drifting either, sorry Alz & Stu, haha). So all that being said I am still a bit lost on which "class" this fits into, and therefore what cage I would need. Obviously I am tryin to see how fast I can get the LS on its stock motor/trans. (a high 12 at best?) but eventually, I want to look into a Jag swap, supercharger, nitrous, etc. Some sort of power adder once I get the rest of the car ready for it and squared away.

I am leaning towards a 5 or 6 pt cage. And am just learning some of the basics so far. These two links have been especially helpful in getting me started.

https://24hoursoflemons.com/wp-content/uploads/2017/06/How-To-Not-Fail-Lemons-Tech_v3.5_040419.pdf

https://blvckflagd.com/tech/roll-cage-101-first-time-fabrication-part-1/?v=7516fd43adaa

I get that every class will have rules, but there has to be some sort of happy medium where I can "overbuild" the setup so that its good for what ill be doing I would think. Maybe its not that easy to just back into though.
 
What tracks are you most likely going to go to? Try to find out what class they're going to put you in. That's what you gotta worry about
 
04_Sport_LS said:
Devl,

Did you ever get that snapped off rear suspension cradle bolt out of the frame?

I took a small Va-Ca from here around that time.
Click to expand...

Yes - check my build thread - Ended up welding in a threaded coupler. Remote welder/fabricator came to the house and did it on site. Subframe bolted up nice and snug.

HRLNKN said:
What tracks are you most likely going to go to? Try to find out what class they're going to put you in. That's what you gotta worry about
Click to expand...

Great Lakes Dragaway and Autobahn Country Club most likely. Will dig in there, thanks for the guidance.
 
DeviLSh said:
Some of the questions I have are:
1) Best places to mount the hoop, down bars, and any cross bars
2) Bolt in or weld in, pros/& cons based on LS body structure or material?
3) What size dia tubing for the LS?
4) estimated weight add-on for the setup.
5) Basis or reasoning to add anything forward of the B-pillar?

Thanks in advance for any insights.
Click to expand...

The main problem is you need a someone to build and install the cage. Find that person and let them do whatever they're willing to do and you're willing to pay for. Note that things like keeping the interior intact, and especially integrating the cage into the interior, will dramatically increase the price.

1) Close behind the seats for the belt bar, down bars wherever they land, cross bars wherever they land. The B pillar is pretty far forward on this car, so the hoop will be blocking the rear seat entry. Unless you're really short and keep your seat really far forward.
2) whatever the builder wants to do. There's lots of aluminum on this car, so that can make life tough. There's no frame to tie into, so will just have to use large base plates. But, the floor pans aren't really flat anywhere, so it'll be a PITA.
3) Whatever is required by class, or whatever the builder wants to use, or whatever you can afford
4) depends on how much you spend (exotic lightweight stuff is expensive), but probably 100 lbs
5) the front part of the cage is what saves you in everything except a plain rollover. Bars out past the firewall dramatically increase the stiffness of the overall car.

Now, the kicker is that it's unlikely you'll be in a class that requires a cage. The LS just isn't quick enough. NHRA (IHRA is very very similar) starts to require a cage at 9.99 seconds (in the quarter!) and faster. Beginner road course classes run folks spaced out or just a few at a time and they're not going to require a cage because it costs so much. Autocross doesn't require a cage either because you never really build up speed. So you can mess around, see what you like, and if you get serious in one type of competition then you can work your way up the ladder and, maybe, eventually, need a cage.

24 hours of lemons has a lot of junkers, there's a lot of cars on the field, most of the drivers are amateur, and there's a lot of contact, so they pay more attention to safety than is justified by the cars themselves. And no one cares about looks, so you rip out the interior and work from scratch.
 
You would need just a roll bar - 4 point. No need for anything forward of the main hoop running close to your helmetless head on the street. Some groups recommend main hoop no more than 6in behind the helmet bit not over the helmet. IMHO a 1.75x0.120 DOM tubing should be used based on weight. No ERW nonsense. I would locate the main hoop on the rear seat shelf. The rear down bars either at the main rails in the trunk (think shock tower area), possibly at the hardened seat belt points or at the rear wheel wells like many bolt-in cages. Check the allowed angles in GCR. Main hoop driver diagonal mandatory, X nice but mandatory if there is a passenger. The harness bar should be at or above the shoulder height. Check GCR - about a 20deg range, from memory. Also, the seat back harness slots HAVE to be at or above the shoulder level. If the slots are below the shoulder level a frontal impact will cause the belts to compress the spine with very unfortunate consequences. Rear down bars need a diagonal or X as well. No bends in down bars. Do not have a rear shock tower cross brace and then have down bars welded to that. Down bars should go from the hoop to the weight spreader plates on the chassis in a straight shot. Look at NASA or SCCA GCR or general FIA cage rules. The drag racing cage rules are at least forty years out of date as they still cater to body on frame vehicles hence the requirement for diagonal tubes from the harness bar area to the middle of the floor on each side - that was so the frame kept the rollbars from punching through paper thin car body floors of the era. Expect at least a 60lb weight hit. Worth it in case of a rollover.

There are DOT legal 4 point harnesses that are made to rotate the body like a 3 point harness to prevent submarining under the belt in case of front impact on the street. If you can use the stock 3 pointer on the street that's great. You shouldn't use a racing harness on the street with a fixed back seat especially without a rollbar.

Have the tubes go as close to the body as possible.

On the other hand you also have the Blachawk Farms raceway on WI border on I90 and Gingerman and Grattan in MI close by. And Road America and Putnam Park and Gateway raceway and so on.
 
Thank you very much - super helpful! I agree the weight add on is worth the safety.
 
LSontheloose said:
Worth it in case of a rollover.
Click to expand...

Most definitely. Years ago when visiting family in Cali... my brother-in-law, son, and myself went to Barona Dragway, (1/8 mile track), on a "test and tune" day.

A guy from the U.K. was there with a '63 Super Beetle. Whatever engine he had in it... was not stock... and stuck out the back far enough the lid wouldn't close.

Last run of the night, (dusk), he gave it all he had. When he grabbed 2nd... he pulled the front wheels. When he grabbed 3rd... shit went wrong fast. The Bug went sideways... and tumbled through the trap at over 100mph... and went another 150 YARDS before it stopped.

He was banged up a little... but ok. 8 of us ended up picking the car up by hand... and setting it on his trailer.
 
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