Piecing together a custom roll bar

[csamsh]

I didn't know Vorshlag did custom cage work though?

Don't have a drag racing shop build a road racing cage. Very different sets of rules. An NHRA certified 7 second cage will probably not pass SCCA or NASA tech.

When I say "you won't" I mean "you won't find a shop that has specific experience autocrossing and road racing the S197, and doing S197 suspension and safety equipment work."

 

[Sky Render]

Don't have a drag racing shop build a road racing cage. Very different sets of rules. An NHRA certified 7 second cage will probably not pass SCCA or NASA tech.

When I say "you won't" I mean "you won't find a shop that has specific experience autocrossing and road racing the S197, and doing S197 suspension and safety equipment work."

This. A lot of people new to the hobby just assume a cage is a cage. It's not. Drag racing and road racing cages are completely different.

For instance, a drag racing cage doesn't have to protect you from the side much, because there isn't much danger of being T-boned going down a drag strip. But on a road course, there is a very real possibility of you or someone else spinning out and hitting your car in the door. Furthermore, road-race cars need to be much stiffer than quarter-mile ones, and so the cage needs to be stiffer and more triangulated. And that doesn't even broach the topic of how NASA/SCCA cage rules are different from NHRA ones.

Can a shop specializing in NHRA cages build you a road-racing cage? I'm sure they certainly can. But wouldn't you rather take it to someone you KNOW knows how to build the cage you need, instead of finding out at tech (or, Heaven forbid, during a collision), that they didn't quite know what they were doing?

 

[SoundGuyDave]

This. A lot of people new to the hobby just assume a cage is a cage. It's not. Drag racing and road racing cages are completely different.

For instance, a drag racing cage doesn't have to protect you from the side much, because there isn't much danger of being T-boned going down a drag strip. But on a road course, there is a very real possibility of you or someone else spinning out and hitting your car in the door. Furthermore, road-race cars need to be much stiffer than quarter-mile ones, and so the cage needs to be stiffer and more triangulated. And that doesn't even broach the topic of how NASA/SCCA cage rules are different from NHRA ones.

Can a shop specializing in NHRA cages build you a road-racing cage? I'm sure they certainly can. But wouldn't you rather take it to someone you KNOW knows how to build the cage you need, instead of finding out at tech (or, Heaven forbid, during a collision), that they didn't quite know what they were doing?

Absolutely, 100%, totally correct!

If you're not going to run an off-the-shelf rollbar or cage kit that you know passes NASA or SCCA tech (and NASA is the stricter of the two), your best bet is to do what I did... Print off the appropriate rules right out of the book, look at what options you want in the cage, then contact an experienced builder. Sit down with them, go over the rule set, go over your desired options (anti-intrusion bars from the base of the A-pillar hoops to pads on the firewall come to mind immediately!), and have them do the design and fabrication.

Safety gear is no place at all to experiment with sub-par welding, design or fab skills. And yes, a cage is a LOT more complex to design than you'd initially think.

I know you're pretty much looking at "just" a rollbar setup, but as long as it's going to be a custom piece, you might as well think about how to integrate the balance of a proper cage. In other words, design the whole thing to meet full competition specs, then just build the back half of it. Pay attention to joint design, mounting plate dimensions, tube type, diameter and wall thickness. It would absolutely suck to have to rip it out because you went with too thin a wall or too small a tube...

 

[Dubstep Shep]

Don't have a drag racing shop build a road racing cage. Very different sets of rules. An NHRA certified 7 second cage will probably not pass SCCA or NASA tech.

When I say "you won't" I mean "you won't find a shop that has specific experience autocrossing and road racing the S197, and doing S197 suspension and safety equipment work."

Does Vorshlag build cages? All they have listed on their website is a harness bar. My understanding was someone else did the cage work on their car.

While I appreciate that they have extreme experience working with the S197, I would feel much more comfortable having my bar done by someone that focuses specifically on doing roll bars. If they actually have someone specifically to build cages for them, that's a different story.

This. A lot of people new to the hobby just assume a cage is a cage. It's not. Drag racing and road racing cages are completely different.

For instance, a drag racing cage doesn't have to protect you from the side much, because there isn't much danger of being T-boned going down a drag strip. But on a road course, there is a very real possibility of you or someone else spinning out and hitting your car in the door. Furthermore, road-race cars need to be much stiffer than quarter-mile ones, and so the cage needs to be stiffer and more triangulated. And that doesn't even broach the topic of how NASA/SCCA cage rules are different from NHRA ones.

Can a shop specializing in NHRA cages build you a road-racing cage? I'm sure they certainly can. But wouldn't you rather take it to someone you KNOW knows how to build the cage you need, instead of finding out at tech (or, Heaven forbid, during a collision), that they didn't quite know what they were doing?

I'm not actually getting a full cage. I'm getting a roll bar. Maybe a six point, but only maybe.

I would guess the difference between the main hoop of a drag bar and a road race bar are nearly identical.

But don't take my word for it. Feel free to call up Watson racing and ask them. The specifically called out the Cobra Jet main hoop system for my application.

In fact, the only difference between what I'm trying to do, and what the MM bar would do, is that I want an x brace to the shock towers.

Sky, I asked you once to leave. I'll ask again. Leave this thread. Whatever advice you think you may give me, I'm ignoring it simply because I think you're a doushbag. I'd hate to ignore you, but that's the next step.

Absolutely, 100%, totally correct!

If you're not going to run an off-the-shelf rollbar or cage kit that you know passes NASA or SCCA tech (and NASA is the stricter of the two), your best bet is to do what I did... Print off the appropriate rules right out of the book, look at what options you want in the cage, then contact an experienced builder. Sit down with them, go over the rule set, go over your desired options (anti-intrusion bars from the base of the A-pillar hoops to pads on the firewall come to mind immediately!), and have them do the design and fabrication.

Safety gear is no place at all to experiment with sub-par welding, design or fab skills. And yes, a cage is a LOT more complex to design than you'd initially think.

I know you're pretty much looking at "just" a rollbar setup, but as long as it's going to be a custom piece, you might as well think about how to integrate the balance of a proper cage. In other words, design the whole thing to meet full competition specs, then just build the back half of it. Pay attention to joint design, mounting plate dimensions, tube type, diameter and wall thickness. It would absolutely suck to have to rip it out because you went with too thin a wall or too small a tube...

Likely I'll go back with an entirely different setup when I convert to a full cage. I don't want to reuse my roll bar as part of whatever cage I get. That's a whole different animal at that stage.

I agree though. Whoever I take it to, I'll be taking a rule book with me and consulting them fully beforehand.

 

[csamsh]

If it were me...it's not...but if it were, I'd ditch the idea of a true rear coilover and just get the Maximum Motorsports 4-pt bar and run coilover springs with weight jackers in stock spring locations, for a variety of reasons. Chief among them being that I don't see the advantage of a true rear coilover, other than with motion ratio. Also...as far as I can tell from their website (they don't explicitly say one way or another) the Griggs coilovers are just Koni twin-tube inserts. I don't want to pay that amount of money for such a thing, same with Cortex.

If you want to know more about Vorshlag fabrication capabilities, call them up and ask. Jason/Terry would be more than happy to go over all that stuff with you.

Why wouldn't you want to reuse a main hoop from a 4-pt bar in a whole cage??? That seems somewhat logical to me.

 

[Sky Render]

Sky, I asked you once to leave. I'll ask again. Leave this thread. Whatever advice you think you may give me, I'm ignoring it simply because I think you're a doushbag. I'd hate to ignore you, but that's the next step.

Want to know why all your threads get derailed? It's your attitude. And I'm the one who needs to grow up?

I just gave you some good advice, which SoundGuyDave (an experienced road racer) said was "Absolutely, 100%, totally correct," and that's still your attitude. Once again, you create a thread asking for advice, then ignore and/or belittle those who give it to you.

Good luck in the professional engineering world, little boy. You'll need it.

 

[Roadracer350]

Guys... Come on let's get back on track here. Your starting to sound like me n Gmitch! LOL! Ok if it were me (and this is what I'm doing) you want a cage that meets NASA and SCCA rules. Download and print off the section about the cages and compare. Then get every pic (in my case I have a tub to measure) you can of the roll cage of the FR500S/C and Boss 302S/R and just mimic in 1.750DI x .134wall tube. Now with that being sad IMHO their is absolutely nothing wrong with starting with a pre bent cage/roll bar kit. I was going to do one of Jegs pre bent cages but their to small BUT their 4/8points are the correct OD and wall thickness. I just purchased at Harbor Freight a small home tube bender. I'm going with their prebent 4pt weld in bar and I am going to order the 20' extra sticks I need local and build my own using the FR500S cage as a template. As long as you take your time it will go smooth. Of course you need to know how to weld.

 

[ford20]

Come on guys, please don't fuck up tech with trivial bullshit.

 

[DILYSI Dave]

Guys... Come on let's get back on track here. Your starting to sound like me n Gmitch! LOL! Ok if it were me (and this is what I'm doing) you want a cage that meets NASA and SCCA rules. Download and print off the section about the cages and compare. Then get every pic (in my case I have a tub to measure) you can of the roll cage of the FR500S/C and Boss 302S/R and just mimic in 1.750DI x .134wall tube. Now with that being sad IMHO their is absolutely nothing wrong with starting with a pre bent cage/roll bar kit. I was going to do one of Jegs pre bent cages but their to small BUT their 4/8points are the correct OD and wall thickness. I just purchased at Harbor Freight a small home tube bender. I'm going with their prebent 4pt weld in bar and I am going to order the 20' extra sticks I need local and build my own using the FR500S cage as a template. As long as you take your time it will go smooth. Of course you need to know how to weld.

Be careful with the HF bender. Some people have gotten "sorta-OK-ish" bends by packing the tube with sand and welding caps on the end before using it, but most people kink a few pieces of expensive DOM and then throw it in the trash where it belongs.

 

[Dubstep Shep]

Why wouldn't you want to reuse a main hoop from a 4-pt bar in a whole cage??? That seems somewhat logical to me.

Simply because you're building for two different purposes.

With a cage, you have to consider all the additional members and how they operate.

With a bar, there are less members to consider.

But with each, they're designed for a purpose and built specific to that.

Want to know why all your threads get derailed? It's your attitude. And I'm the one who needs to grow up?

I just gave you some good advice, which SoundGuyDave (an experienced road racer) said was "Absolutely, 100%, totally correct," and that's still your attitude. Once again, you create a thread asking for advice, then ignore and/or belittle those who give it to you.

Good luck in the professional engineering world, little boy. You'll need it.

My threads get detailed because of petty little people like you who can't stand the idea of being wrong.

It's good you aren't an engineer, because as soon as someone tells you that you're wrong, you turn into a six year old throwing a tantrum. Pathetic.

You ignore previous points made by the other person, ignore sources of information far more reliable than your own, and you're basically just a doushbag about it the whole time.

Goodbye.

Come on guys, please don't fuck up tech with trivial bullshit.

Well sky will be ignored from now on, so that will certainly help.

 

[modernbeat]

I didn't know Vorshlag did custom cage work though?

We do custom cage work. And we would have done the rollbar in the Mustang if the Maximum Motorsport part wasn't so well done and relatively economical.

Here's a full cage we did for a C4 roadrace car.

 

[Dubstep Shep]

We do custom cage work. And we would have done the rollbar in the Mustang if the Maximum Motorsport part wasn't so well done and relatively economical.

Here's a full cage we did for a C4 roadrace car.

Interesting... I may be hitting you up here soon.

 

[Roadracer350]

We do custom cage work. And we would have done the rollbar in the Mustang if the Maximum Motorsport part wasn't so well done and relatively economical.

Here's a full cage we did for a C4 roadrace car.

Sweet!!!!

 

[DILYSI Dave]

Simply because you're building for two different purposes.

With a cage, you have to consider all the additional members and how they operate.

With a bar, there are less members to consider.

But with each, they're designed for a purpose and built specific to that.

Not really.

Now, there is order-of-operations to consider. It would be a pain to build a cage off of a pre-installed bar simply because the LAST thing you do when installing a cage is to weld the hoop to the car and add in the rear stays, because once you do that you no longer have access to get to the tops of the tube junctions without cutting the roof. For that reason, if I were adding a cage to a preinstalled bar, I'd at a minimum plan on cutting it where the 4 points hit the floor just so that I could get the halo welds right. That said, the design and construction of the main hoop is identical in either case.

 

[stkjock]

Come on guys, please don't fuck up tech with trivial bullshit.

thread cleaned up

as everyone I'm sure has realized Shep needs to try and reinvent the wheel in nearly every thread he starts. Sometimes good comes from it. Some times not


Back on topic - no one should reply to my comments

carry on

 

[Dubstep Shep]

Not really.

Now, there is order-of-operations to consider. It would be a pain to build a cage off of a pre-installed bar simply because the LAST thing you do when installing a cage is to weld the hoop to the car and add in the rear stays, because once you do that you no longer have access to get to the tops of the tube junctions without cutting the roof. For that reason, if I were adding a cage to a preinstalled bar, I'd at a minimum plan on cutting it where the 4 points hit the floor just so that I could get the halo welds right. That said, the design and construction of the main hoop is identical in either case.

My point exactly.

Why try and salvage the bar and "make it work" so to speak when starting from scratch is just as easy.

But this is getting WAY ahead of ourselves. I won't be doing a full cage for years.

 

[Roadracer350]

Be careful with the HF bender. Some people have gotten "sorta-OK-ish" bends by packing the tube with sand and welding caps on the end before using it, but most people kink a few pieces of expensive DOM and then throw it in the trash where it belongs.

Did not know that! Haven't opened the box yet doin will look at some other benders and see if I can take this one back. Thanks for the heads up!

 

[2008 V6]

Did not know that! Haven't opened the box yet doin will look at some other benders and see if I can take this one back. Thanks for the heads up!

Sand is compressible - Too much air - Bad idea - Use water @10-20PSIG -NO AIR

 

[DILYSI Dave]

Did not know that! Haven't opened the box yet doin will look at some other benders and see if I can take this one back. Thanks for the heads up!

No problem. For what it's worth I've been really pleased with my JD2 bender. https://www.jd2.com/c-12-tubepipe-benders.aspx.

Mine is a Model 32 that I converted to hydraulic operation - https://www.youtube.com/watch?v=THSFWnf5B6Y. I've done several 1.5" cages and just bought a 1.75" die for a couple of heavier projects that are coming up.

You can get into a bare bones model 3 for ~$600. I'm a bit more than double that for the M32 with the framework I welded up and the cylinder I snagged from another piece of equipment.

 

[Dubstep Shep]

Sand is compressible - Too much air - Bad idea - Use water @10-20PSIG -NO AIR

What about using oil or hydraulic fluid? It's even less compressible than water.

Or I suppose at that stage it really doesn't even matter.