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> Show me your roll cage to suspension tower bracing, ..and other bracing/stiffening you've done
Chi-town
post Dec 11 2018, 09:14 AM
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@GregAmy - Thank you for the post and clarification.
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ThePaintedMan
post Dec 11 2018, 10:53 AM
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(IMG:style_emoticons/default/agree.gif) Greg nailed it. Which also makes me re-think my cage moving forward. Should have just bought the Tangerine Racing cage and been done with it from day 1. (IMG:style_emoticons/default/headbang.gif)
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Heater Guy
post Dec 11 2018, 11:40 AM
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QUOTE(GregAmy @ Dec 11 2018, 06:56 AM) *

Good morning! Just catching this thread, wanted to follow up. I am a Nationally-licensed SCCA scrutineer and a racer.

First, what the regs were when the car was built*, or what someone may have approved in the past, is not relevant. You have to meet current GCR regs to run in SCCA Club Racing. The GCR is constantly updated and can be found here:

https://www.scca.com/pages/cars-and-rules

Rollcage regs have been fairly consistent over the last decade or so; major changes in recent years include:

- Requirement for full-width main hoop bar (mid-90s, due to a cage collapse on an SSB car)
- Requirement for two door bars on drivers side (wreck circa 1999)
- Requirements for two door bars both sides (another wreck, around 2004)

Cage tubing sizes have changed over the years based on design requirements changes; anyone that compares this years book to, say, 1999 will find thicker tubing yet fewer weight brackets.

Now, there are some design elements of the rollcage that can be grandfathered in for cars that have been previously logbooked*, but generally there is a minimum-required safety standard that all cars have to meet, regardless of initial logbook issuance.

This car's requirements fall under GCR 9.4, "ROLL CAGES FOR GT AND PRODUCTION BASED CARS", page GCR 86 in the December PDF. Further, since it has the full windshield, it cannot take advantage of the "asymmetric" hoop design. Is the car going to be run with the targa top? Then it's considered an enclosed car. Without the Targa is "open top" regs.

Per the discussions above, GCR 9.4.B.2.a clearly states, "Main hoops shall incorporate a diagonal brace", which this one has.

However, GCR 9.4.B.2.b also clearly states, "Cars must incorporate a main hoop horizontal brace at the approximate level of the driver’s shoulders but not lower than the shoulder belt mounting point as described in section 9.3."

This car does not have that required horizontal brace.

GCR 9.4.C.1.c clearly states, "All open cars with a high front hoop and all closed cars except those competing in the T4, Improved Touring, Spec Miata, and B-Spec classes must incorporate a horizontal front hoop brace at the approximate level of the dashboard."

This car does not yet have that required horizontal brace.

I don't recall reading what the weight of your car is, but I'm assuming you'll fit into the 1701-2699 pound bracket. That requires 1.50x.095 or 1.625x.0080 minimum DOM mild steel. I do NOT recommend chromoly, simply because none of us generally have the ability to properly heat treat welded chromoly tubing. Stick with DOM mild steel.

It's all fine and good that someone has signed off the car, and that you have not had any grief from anyone in subsequent annual inspections and events. When I'm initially inspecting a car and issuing a logbook, I'm quite careful and detailed and ensure everything is up to spec. However, I'll freely admit that when doing subsequent annual inspections I'm less careful, trusting prior scrutineers' inspections. So it's certainly probable that this has slipped through some scrutineers' eyes. Or, we've taken it for granted that since the car has been racing for seemingly forever the design must be fine.

But just because it's been that way forever doesn't mean it meets the current regs. Maybe the regs have changed since it was initially inspected?

Bottom line, based on very little info in this thread, I do not believe the current design meets the current SCCA GCR requirements. And while you've been perfectly fine racing it that way, you run the risk of someone casually looking inside and thinking, "hey, that's not right" and they pull you off the track for not meeting minimum safety requirements. Believe me, I've done it (stick your finger around the top of some production-car-based rollcages and you may find incomplete welds (yeah, I couldn't get up there), poor welding quality (well the last guy passed it!) and I've even seen people using JB Weld or body putty to make really bad welds look good.

If I see that, I won't allow you on the track. I can't, it's not right.

Finally, I read some comments above about this cage being built to FIA specs. That's a great start! However note that unless the cage is actually "FIA Certified" for its application, it is still required to meet SCCA minimum design requirements. And, if the cage actually is "FIA Certified" then the inspector needs to have that paperwork to use as a basis for issuing the logbook, and once issued that cage cannot be subsequently modified. So I don't think we're looking at any kind of FIA certification that applies here.

Download the GCR, it's free. These are the minimum standards that have to be met. Always print it out and bring it to your cage builder, ensure he/she reads and understands it, and asks you if they have any questions.

*Now, THAT ALL SAID...there exists in the GCR Appendix I which exists for cars logbooked prior to 2008 (what's the initial date of your first SCCA logbook issued?) At the time of writing, "GT" cars were considered to be those of tubeframe construction, so I suggest yours would use the Production regs.

It's not a group of regs that I encourage anyone to use; after all, the latest rollcage regs have all been written in someone's blood, and these Appendix I allowance were a nod to old cars that may show up once in a while.

Despite this, within Appendix I the horizontal bracing is not explicitly called out, and the accompanying drawings indicate that the horizontal bar is "recommended."

"It is recommended that the vertical bars of the front hoop be connected by a horizontal bar at a point above the driver’s legs."

I also point out that Appendix I states, "Specific installations are subject to approval by the Technical and Safety Inspectors at each event." So you're still maintain some risk of being excluded. Better keep a copy of the GCR with you and be prepared to plead your case.

If your car has its initial logbook prior to 2008, you may choose to use a cage to either specs. However, note Appendix I was intended to grandfather legacy cars that were already built, ones that were not expected to be updated for competition. As such, the logbook goes with the cage, kinda like how the engine number goes with the chassis. If you replace and/or recreate that cage, you lose that logbook and must build your new cage to the latest requirements. Though, it's quite likely you can find a buddy locally to wink, wink, nod, nod re-stamp your new cage with the old number and pretend it's the original cage. That's up to your conscience, no one else will know except you two...

I've been doing this for a while, long enough to know exactly who these regs were written from. For example, Jay Wright at the 1993(?) Runoffs was the impetus for the horizontal bar. We used to only install a half-width horizontal bar, from the driver's side to the diagonal, to keep the seat from moving backwards in a crash and allowing the driver's head to hit the diagonal element. We also used it for shoulder harness attachments. That's what was in Jay's SSB car when it hit the tire wall along the Road Atlanta front straight coming out of Turn 12. The car went airborne and landed on the roof. The diagonal along with the horizontal half-element moved out of the plane of the main hoop, allowing the main hoop to collapse sideways and the roof came "down" on Jay's head, making him a paraplegic until the day he died. He lived a good life, and did a lot of good things for racing (technical recommendations, scrutineering, developing an affordable H&NR, the Wright Device; he was actually a NASA rocket scientist) before eventually succumbing to complications from his injuries.

As a result, we began requiring the horizontal to go all the way across and we added a diagonal within the rear hoop bracings.

Bottom line, do you want to be out there among big-bore fast cars with a outdated cage? Again, your call. After all, in the end it's your ass on the line, not mine. I sign off on your max-built cage and then you wreck your car, I go to the worker party and have some beer. I sign off your minimum-built cage and you wreck your car, I still go to the worker party and have some beer. But we'll hoist one in your honor.

I know this was a windy, heady, "harsh my mellow" post, and I apologize for those bored with it. But I do encourage well-built safety systems that exceed the minimum requirements.

Greg

Thanks for the explanation.

Ron
SFR. Pit Fire 09 T2
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sixnotfour
post Dec 11 2018, 12:16 PM
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I cut the dash so the knee bar would be higher...hopefully not being a knee bar.....with a pad its the same height as the factory dash knee pad


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GregAmy
post Dec 11 2018, 12:44 PM
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The orange historics car has a Foley cage from '98. The dash bar is right across the back of the dash cluster. That was perfect when the prior owner had installed a Stack 8130. And it was Ok when replaced that old tech and tried a leftover less-old Race Technology Dash-1. But I wanted the analog needle movement so I reinstalled the factory tach and the terminals **just** cleared the dash bar, though I had to bend them away slightly to clear.

Keep that in mind as you're planning your design.
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naro914
post Dec 12 2018, 11:29 AM
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Just met with my fabricator and he had already planned to put the dash bar in there (unbeknownst to me) and we worked out how to put the horizontal bar in so it doesn't infringe on my seat back.

he's running the dash bar behind the dash face, and right above the steering column bracket. Its pretty wide open there so it makes a nice straight shot from right to left forward cage legs. We're putting in an AIM Dash so there should be plenty of room.

Plus double row "NASCAR" style door bars.

He's worked for a few NASCAR teams and currently does the media blasting for a bunch of big name teams, so he knows a lot about the cages and structure.

So....everyone can calm down now! (IMG:style_emoticons/default/beerchug.gif)

But to respond to a few assumptions being made:

The car was SCCA Club Race Log Booked in 2014 and PCA Club race log booked in 2006. The cage was inspected and stamped by both entities. I have NEVER been questioned and since I've won a few entire groups and always in top 3 overall , I am always in SCCA impound. (every race). Again...never questioned.

But...as someone that owns a business dedicated to selling safety equipment for race and track...safety has to be the driving force on how we do things.

Thank everyone for derailing this thread!! LOL...all I had asked about was the shock tower bracing!! But some very good information here.... (IMG:style_emoticons/default/smile.gif)
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Heater Guy
post Dec 12 2018, 12:28 PM
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QUOTE(naro914 @ Dec 12 2018, 09:29 AM) *

Just met with my fabricator and he had already planned to put the dash bar in there (unbeknownst to me) and we worked out how to put the horizontal bar in so it doesn't infringe on my seat back.

he's running the dash bar behind the dash face, and right above the steering column bracket. Its pretty wide open there so it makes a nice straight shot from right to left forward cage legs. We're putting in an AIM Dash so there should be plenty of room.

Plus double row "NASCAR" style door bars.

He's worked for a few NASCAR teams and currently does the media blasting for a bunch of big name teams, so he knows a lot about the cages and structure.

So....everyone can calm down now! (IMG:style_emoticons/default/beerchug.gif)

But to respond to a few assumptions being made:

The car was SCCA Club Race Log Booked in 2014 and PCA Club race log booked in 2006. The cage was inspected and stamped by both entities. I have NEVER been questioned and since I've won a few entire groups and always in top 3 overall , I am always in SCCA impound. (every race). Again...never questioned.

But...as someone that owns a business dedicated to selling safety equipment for race and track...safety has to be the driving force on how we do things.

Thank everyone for derailing this thread!! LOL...all I had asked about was the shock tower bracing!! But some very good information here.... (IMG:style_emoticons/default/smile.gif)


It must be realized that, for one reason or another, there is no one
Cage requirement in the SCCA GCR's. Interpretation of the rules is
Always an issue. Unfortunely there isn't a cookie cutter solution which all. Example, if tubes tie into suspension points, in compliance
with the GCR's in cage design, it may be in violation in the GCR's under chassis strengthing prohibition. This why one scrutiner
may see the rules one way and another will see them another. They are all trying to help keep us safe and in compliance.





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naro914
post Dec 12 2018, 01:00 PM
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QUOTE(Heater Guy @ Dec 12 2018, 02:28 PM) *

It must be realized that, for one reason or another, there is no one
Cage requirement in the SCCA GCR's. Interpretation of the rules is
Always an issue. Unfortunely there isn't a cookie cutter solution which all. Example, if tubes tie into suspension points, in compliance
with the GCR's in cage design, it may be in violation in the GCR's under chassis strengthing prohibition. This why one scrutiner
may see the rules one way and another will see them another. They are all trying to help keep us safe and in compliance.

Yes and no...as Greg pointed out, there are clear cage requirements for GT class cars, which Papa Smurf is (GT2). It was NOT SCCA log booked before 2008, so it has to conform to the requirements as he noted.

To be honest...I think one of the biggest issues that all volunteer organizations face (and even some pro ones), is the ever changing rules that are admitedly put there for a good reason, but for a volunteer scrutineer to be able to keep up with them is not always possible. My wife was a PCA scrutineer for a pretty long time, and she just couldn't always keep up with all the changes.
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Heater Guy
post Dec 12 2018, 01:14 PM
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QUOTE(naro914 @ Dec 12 2018, 11:00 AM) *

QUOTE(Heater Guy @ Dec 12 2018, 02:28 PM) *

It must be realized that, for one reason or another, there is no one
Cage requirement in the SCCA GCR's. Interpretation of the rules is
Always an issue. Unfortunely there isn't a cookie cutter solution which all. Example, if tubes tie into suspension points, in compliance
with the GCR's in cage design, it may be in violation in the GCR's under chassis strengthing prohibition. This why one scrutiner
may see the rules one way and another will see them another. They are all trying to help keep us safe and in compliance.

Yes and no...as Greg pointed out, there are clear cage requirements for GT class cars, which Papa Smurf is (GT2). It was NOT SCCA log booked before 2008, so it has to conform to the requirements as he noted.

To be honest...I think one of the biggest issues that all volunteer organizations face (and even some pro ones), is the ever changing rules that are admitedly put there for a good reason, but for a volunteer scrutineer to be able to keep up with them is not always possible. My wife was a PCA scrutineer for a pretty long time, and she just couldn't always keep up with all the changes.


Agree. Monthly SCCA Fast Tracks can sometimes drive me nuts.
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GregAmy
post Dec 12 2018, 01:24 PM
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QUOTE(Heater Guy @ Dec 12 2018, 02:14 PM) *
Agree. Monthly SCCA Fast Tracks can sometimes drive me nuts.

(IMG:style_emoticons/default/biggrin.gif)

I'm weird: I actually look forward to them! I used to be on the Super Touring Advisory Committee to the CRB, so I'm a bit of a rules nerd...nerdly enough to where I actually wrote regs (helped create the category)...

The Court Of Appeals is my favorite section of Fastrack...so much drama...I appeared in it earlier this year...

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Brett W
post Dec 13 2018, 07:30 AM
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QUOTE(naro914 @ Dec 12 2018, 11:29 AM) *

Plus double row "NASCAR" style door bars.

He's worked for a few NASCAR teams and currently does the media blasting for a bunch of big name teams, so he knows a lot about the cages and structure.



Apparently not, because he chose the second worse door bar arrangement for any uni-body car. The design of a NASCAR chassis is significantly different than any uni-body design. The NASCAR chassis is designed for the "nascar door bars". Most production cars are in no way designed to accommodate the NASCAR door bars and most are at best a compromise and at worst an overweight tragedy.

If your fabricator is considering using the current mess in the car, find another fabricator.
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Chi-town
post Dec 13 2018, 09:02 AM
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QUOTE(Brett W @ Dec 13 2018, 05:30 AM) *

Apparently not, because he chose the second worse door bar arrangement for any uni-body car. The design of a NASCAR chassis is significantly different than any uni-body design. The NASCAR chassis is designed for the "nascar door bars". Most production cars are in no way designed to accommodate the NASCAR door bars and most are at best a compromise and at worst an overweight tragedy.

If your fabricator is considering using the current mess in the car, find another fabricator.


There are a lot of different designs that people use the term "Nascar doorbars" for.

A prime example would be the guys in the Pro Drift series.

I think most use the term when talking about a double row door bar configuration extending to the outer door skin but not specifically the design used by Nascar.
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Brett W
post Dec 13 2018, 09:20 AM
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I understand what he is talking about. In order for them to work the way they work with a Cup chassis, they have to be plated and tied into the chassis properly. Looking at the current structure within Bob's car, there is little to no structure to support those bars. Its doubtful the builder understands what needs to be done to make those work.

Of course my comments apply to most average roll cage builders who would put door bars on the existing structure. Guarantee they walk over to the bender, bend a couple of tubes and stick them to current a-pillar down bars and main hoop.

They put no thought into the way the loads from an impact will feed into those two completely unsupported nodes and thus cause them to collapse inward. To properly utilize the "NASCAR" bars, you would need to build what amounts to a square box around the driver and then out to both shock towers.

I have build dozens of cages and refuse to install NASCAR bars because they are not the right solution. IF NASCAR bars were the end all be all, Porsche, Ferrari, Ford, Chrysler, BMW, etc would install them on their factory engineered race cars. They don't, because they aren't the best solution.

Don't get me started on the drifty kids. They don't build cars for anything beyond show and sliding.
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GregAmy
post Dec 13 2018, 10:24 AM
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QUOTE(Chi-town @ Dec 13 2018, 10:02 AM) *
There are a lot of different designs that people use the term "Nascar doorbars" for.

SCCA uses the term "NASCAR bars" not as a design term but as a descriptor for the need for two (minimum) horizontal bars:

NASCAR-Style Door Bars – If installed, shall consist of one or more sidebars that intrude into the door cavity and connect the main hoop to the front hoop.


Fabricators should absolutely consider load paths and attachments when building these, with the goal of stopping a car from intruding into the cockpit and injuring the driver.

I do not build cages (though I do have a BSMechE) so I'll defer to fabricators like Brett, but my general mindset is that the bars should be sufficiently stout not so much to stop a car from coming in, but to assist in moving the caged car out of the way of a collision, based on weight and tires used.

Toward that, SCCA is allowing and encouraging fabricators to attach the seats directly to the cage, not to the car's structure. That way, when the cage moves, the driver moves within that protective structure. That can also give fabricators some flexibility in cage-point-restricted classes (e.g., Touring, B-Spec, Improved Touring) by attaching to cage on both sides of the driver, making a mini-cell-within-the-cell.

We don't have a lot of engineers in the scrutineering pool, so a lot of the design falls on the fabricator; if it has two horizontal bars, it's a "NASCAR Bar" and will get signed off. So, choose your fabricators carefully...
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mlindner
post Dec 16 2018, 05:50 AM
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Here's mine, I'm six foot, never a problem with the knee bar. MarkAttached Image
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Beechhousegarage
post Apr 20 2019, 01:48 PM
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Working on a T45 cage by Custom Cages UK,
Attachments from rear main hoop to trailing arm, and another to shock tower, then triangulations.


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Beechhousegarage
post Apr 20 2019, 01:50 PM
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another view


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GregAmy
post Apr 20 2019, 07:34 PM
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Is that cage above being built to a specific sanctioning body's regs? May want to review those regs. It would not be acceptable for SCCA Club Racing:

"Braces must be attached as near as possible to the top of the main hoop (not more
than 6 inches below the top), and at an included angle of at least 30 degrees."
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Beechhousegarage
post Apr 21 2019, 10:56 AM
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QUOTE(GregAmy @ Apr 20 2019, 07:34 PM) *

Is that cage above being built to a specific sanctioning body's regs? May want to review those regs. It would not be acceptable for SCCA Club Racing:

"Braces must be attached as near as possible to the top of the main hoop (not more
than 6 inches below the top), and at an included angle of at least 30 degrees."


?From your quote:
9 C. Roll Cage Bracing
1. The main hoop must have 2 forward braces extending from the hoop and attached to the frame, monocoque, or front hoop. Braces must be attached as near as possible to the top of the hoop but must not be more than 6 inches below the top and at an included angle of at least 30 degrees.

or 9.4.B1c
c. Cars must have 2 braces extending to the rear from the main hoop and attaching to the frame or chassis. Braces must be attached as near as possible to the top of the main hoop (not more than 6 inches below the top), and at an included angle of at least 30 degrees.

In a 914, Is a short rear brace to the inner frame at the top of hoop inside the cabin acceptable?

such as in:

9.4.c.2.e. On cars where the rear window/bulkhead prohibits the installation of rear braces (e.g. Honda del Sol), the main hoop shall be attached to the body by plates welded to the cage and bolted to the stock shoulder harness mounting points. This installation design must incorporate a diagonal bar connecting the top of the main hoop to the lower front passenger side mounting point (Petty Bar).


Hi, still building the cage, not building for SCCA club racing, rather tarmac rally. Will be adding braces high on the main hoop to above the seatbelt anchor bolt frame. Main hoop diagonal, harness cross brace and roof diagonal. The cage is FIA spec kit, but I've modified it so the upper main hoop stays don't travel through the rear window.

options to modify further, always good to build it for as many venues as possible, (ie the next owner)

Any suggestions appreciated, and thanks for the nudge to check roll cage rules again.

Cheers
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GregAmy
post Apr 21 2019, 02:15 PM
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For reference, I'm an SCCA scrutineer.

What caught my eye on this was that the rear braces do not appear to go up to within 6" of the top of the main hoop. The purpose of those rear bars is to ensure the integrity of the main hoop in case the world turns upside down on you. The braces you have there will support the bottom half of the main hoop, but that leaves the top half vulnerable to collapse.

There are two ways to resolve this:

- Run rear tubes that start within 6" of the top of the main hoop, and run the tubes through a polycarbonate rear window; see second part of GCR 9.4.c.2.e, quoted below.

- If you don't want to run a poly rear windows, then follow first half of GCR 9.4.c.2.e that you quoted above, by adding plates to attach the cage to shoulder harness mounting points and adding a Petty Bar, from the top of the cage just to the right side of the driver's head (with sufficient clearance) down to the mounting plate for the right front leg.

The first option is the more common and traditional method for "real" race cars, and allows you to continue that tube to strategic rear points on the chassis; that's the way my race car was built by Chris Foley. See attached.

But maybe it's a dual-mission car and you don't want to run poly rear glass and/or cut into the car? Then you can use a Petty bar and the additional tab mounts as required. That Bar can also be sleeved to make it removable for the dual-mission, just ensure you make some kind of padded cap to go over the studs for safety in a road accident.

GA


QUOTE
Alternatively, the rear window may be removed and a clear, lexan replacement
installed. The rear cage braces may pass through this replacement window and through the engine cover or bodywork to allow connection to the frame or unibody. Such allowances shall be noted on the car’s specification line.


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