Bolt in/Weld in Roll bars

[JimIII@JDM]

What 4 point bar setup are you running, likes or dislikes? Any input would be grateful , looking at a set for a few customers and just trying to get some experienced opinions. Also what are the requirements for having a 4 point bar versus a complete cage? I know about the specifics for drag racing but a bit of a novice when it comes to Corner Carving!

JimIII

 

[jayel579]

Role cage installs tend to be club and class dependent. Whether you are tying into any pillars or shock towers or not. It really comes down to the rule book.

4 points are pretty much for harness mounting and roll over protection. I have seen some pretty scary drag race cage installs (bad welds, bad tie ins or wrong positioning of bars, etc) so I'd hope your work is better then that.

 

[JimIII@JDM]

Role cage installs tend to be club and class dependent. Whether you are tying into any pillars or shock towers or not. It really comes down to the rule book.

4 points are pretty much for harness mounting and roll over protection. I have seen some pretty scary drag race cage installs (bad welds, bad tie ins or wrong positioning of bars, etc) so I'd hope your work is better then that.

We don't do any cage work here, and we are very particular when working with other shops on building a cage in our drag cars. We have used Carroll's Rod and Racecraft, Rhodes Custom, and Joe Gambino. All top names in the drag racing world.

I was looking into the Watson Racing 4 point bolt in cage as the customer is most likely just doing some track event days and not anything competitive.

http://shop.watsonracing.com/ROLL-BAR-MUSTANG-2005-14-p/wr-boltincage.htm

Then they also have this bad boy...Full Road Coarse cage they put in the Boss 302R and road race cars.

 

[jayel579]

Well I am putting that exact same bar into my car in the next few weeks. It is bolt-in but we will weld it in as well. I will let you know how it comes out.

 

[JimIII@JDM]

Well I am putting that exact same bar into my car in the next few weeks. It is bolt-in but we will weld it in as well. I will let you know how it comes out.

Yes share some pics or install detail, Thanks!

 

[GreenTerror]

I've been looking at putting a 4 point in my 'vert for safety and do be able to take to some track days. For HPDE, track days and autocross everything I've found says that a 4 point roll over protection is all that is needed. Drag race rules vary widely and I've not been able to find a definitive answer on what is or is not needed there, it seems to be more track dependent.

This is the one I have been thinking of getting.
http://www.maximummotorsports.com/S...-no-harness-mount-2005-convertible-P1385.aspx

 

[Roadracer350]

I may get flamed but I just ordered a Jegs 10pt weld in cage and 40' of 1.75" tube to add the bars I want. I am going to mimic the cage out of my FR into my street car then take it off the street. The Jegs cages are NHRA and IHRA certified so it should be more than enough for SCCA and NASA. I really don't want to mess with a bolt in bar or cage especially after I watched a little blue mustang flip at Hallett and the bolt in cage punch thru the floor. Not going to name the shop that installed it....

 

[jayel579]

I may get flamed but I just ordered a Jegs 10pt weld in cage and 40' of 1.75" tube to add the bars I want. I am going to mimic the cage out of my FR into my street car then take it off the street. The Jegs cages are NHRA and IHRA certified so it should be more than enough for SCCA and NASA. I really don't want to mess with a bolt in bar or cage especially after I watched a little blue mustang flip at Hallett and the bolt in cage punch thru the floor. Not going to name the shop that installed it....

Do not assume NHRA and IHRA standards equivalent to SCCA or NASA, I doubt they are close. All NASA and SCCA classes require yearly inspection certifications on cages, I have yet to see someone's 9 sec quarter mile car go through that.

We have all seen that Mustang at Hallett. Though I have the exact feelings as you towards bolt in cages (hence why I am welding mine in), that failure was not due to the bolt in design but the foot plate size and placement. Foot places should be a minimum of 4x4 inches and that cage had maybe half of that. And should be mounted to structure not the floorboards. Think poking someone in the side with your finger versus your entire palm, finger sinks in more palm won't.

 

[jayel579]

I've been looking at putting a 4 point in my 'vert for safety and do be able to take to some track days. For HPDE, track days and autocross everything I've found says that a 4 point roll over protection is all that is needed. Drag race rules vary widely and I've not been able to find a definitive answer on what is or is not needed there, it seems to be more track dependent.

Biggest problem with convertibles is passing the broom stick test, hence why many clubs won't even allow miatas to run unless they have the hard top installed. They want the roll bar or roof to hit the grown first before your head in a roll over.

 

[modernbeat]

We looked at what was available when we put a rollbar in the Vorshlag car and debated making our own. But the mounting foot of the Maximum Motorsports bar won us over. We could make it, but ours would end up an exact copy of theirs - so we buy theirs. We've installed a number of them in customer cars and it's nice to be able to configure them exactly like you want.

 

[GreenTerror]

I thought that the maximum 4 point for the 'vert passed the broomstick test.... maybe someone can chime in if that is true of not? I know there are a few guys with 'verts and cages and functional tops.

 

[NoTicket]

It may pass the broomstick test for somebody that is 6' tall, but it may not for someone that is 6'5". The broomstick test is whether the broom clears your helmeted head when you are sitting in the driver seat and the broom is resting on the header (top of the windshield) and the roll bar. It has as much to do with your height and leg/torso ratio as it does the car.

edited for clarity

 

[GreenTerror]

I apologize for de-railing this thread. But if your head doesn't hit the top when its up and the roll bar goes all the way to just touching the top when closed I would imagine it should clear. I agree if your 7 feet tall you may have additional complications but I'm only 5' 10".

 

[Roadracer350]

Do not assume NHRA and IHRA standards equivalent to SCCA or NASA, I doubt they are close. All NASA and SCCA classes require yearly inspection certifications on cages, I have yet to see someone's 9 sec quarter mile car go through that.

We have all seen that Mustang at Hallett. Though I have the exact feelings as you towards bolt in cages (hence why I am welding mine in), that failure was not due to the bolt in design but the foot plate size and placement. Foot places should be a minimum of 4x4 inches and that cage had maybe half of that. And should be mounted to structure not the floorboards. Think poking someone in the side with your finger versus your entire palm, finger sinks in more palm won't.

Yea I need to look at that Insted of just building it. The cage I bought is 1-5/8 x .134 wall. I'm going to build the bracing and door bars just like the FR. basically it will be a copy of the FR cage

 

[SoundGuyDave]

Potential major fail... If all you want is a "cool cage" for HPDE days, that'll be fine, since no cage is actually required. If, OTOH, you plan on getting into a race group at a later date, you'd have to cut it all out and start over again. Decision is yours to make, but I know which way I would lean.

Basic NASA cage specs, as applicable to a "standard" S197 build:

1.75" x 0.120" wall mild steel DOM or seamless tubing for all required tubes, no ERW allowed. Optional tubes may be any size desired... Only the required are listed below.
No bend may be tighter than 4x the cage tubing diameter, all welds must be 360* with full penetration. No gaps, no skips, period. And yes, they check.
Main hoop: Max 4 bends, 180* +/-10*, full width of the interior, and as close to the roof line as is practicable. Must have diagonal and harness bars in plane of the hoop
Rear stays: No bends, attach as close as possible to the top of the main hoop, 75-105* included angle in plan view (from the top: perpendicular to the main hoop +/-15*), may land on shock towers or suspension pickup points.
Forward hoops: Extend from the main hoop and follow the contour of the roof and A-pillar, extending down to the floor, max 4 bends. A windshield bar must connect the two as close to the roofline as is practicable. Dash bar is optional, but I would recommend it. Good place to hang the column from, also great place to mount the center net attachment point.
Door bars: At least two bars on the driver's side, one tube on the passenger. If you do NASCAR door bars (which I recommend!), you may then gut the doors completely. Otherwise you must retain all the stock sheetmetal.
Mounting pads: Min 2", max 12" on a side, 100 in(sq) max, 9 in(sq) min, 0.080" thick minimum, and they may extend onto vertical surfaces.

I think you can see that most NHRA/IHRA cages will not pass tech. Your tubing, for example, while plenty thick, is too small in diameter, and is probably ERW tubing. IIRC, the NHRA/IHRA growth path for cages creates a cocoon around the driver's seat, where as the road-race cages try to bullet-proof the entire greenhouse. Also, IIRC, NHRA/IHRA specifically dis-allow the diagonal in the main hoop.

If you want to cage the car, do it right. If you want to sell it, it'll be a lot tougher when it's not legal for NASA (and I think SCCA is the same basic spec) competition. As I said, do what you want, but personally, I would start with a clean sheet of paper and have the NASA CCR section 15.6 sitting right in front of me the whole time. When I did my cage, I worked with the builders on the design, CCR in hand, and it passed tech first time through, with no problem but compliments on the workmanship.

 

[GreenTerror]

Potential major fail... If all you want is a "cool cage" for HPDE days, that'll be fine, since no cage is actually required.

Just to clarify, this is true if you have a coupe. If you have a convertible at least the HPDE rules I found say roll over protection, minimum 4 point, is required.

 

[jayel579]

Thank you for clarifying all of that Dave!

Just to clarify, this is true if you have a coupe. If you have a convertible at least the HPDE rules I found say roll over protection, minimum 4 point, is required.

Again, it is all club and region dependent. I know Northern NJ NASA (aka Motorsports NE) allows convertibles but then NJ BMWCCA doesn't. My mustang will only ever be a DE car. I am in the process of building another race car that will go wheel to wheel so a correct cage is being put into that car.

 

[csamsh]

Good post Dave...I'm not caging my car any time soon but it's a good read nonetheless!

 

[pcdrj]

Please read Dave's post carefully. I've seen numerous BMW's and 911's who were competing in PCA or BMW Club but failed NASA tech. I had a very reputable drag race shop ready to build me a cage. I supplied them with SCCA and NASA regs but after investigating further found their cage would not have passed.

Tube diameter, wall thickness, construction, welds, and workmanship will all be evaluated. Your final car weight will also impact the requirements.

 

[Roadracer350]

Ok I just read all the same on the SCCA website. I called and talked to Jegs and canceled the order. While plenty thick as you said the tube size is smaller. The material was DOM also. What I will do is look for another prebent cage and add the door and extra bars I need. As far as quality and craftsmanship I'm not worried about that as I will TIG everything myself plus I have a tubing notcher.