Roll Cage

[ddewhurst]

***My response? The fish have been silenced...........***

Jake, you trying to slip out the back door?

Come on, play nice & me asking for a response from you was that I requested a sensible response to my question to you about the head rest rule. Some things are HOT, but as cool as your handle the response. While you don't respond I'll need to presume that you'll lose points for potentially talking against the house.

[rsportvolvo]

Any thoughts on the required tubing sizes in Section 9.4.F.2? The 2007 GCR stated the Improved Touring cars were to use the ITCS listed weight minus 180 lbm for required tubing size. Is this still valid? Or is the omission of this statement my answer?

I'm builidng an ITB Volvo 240 and the ITCS listed curb weight is 2780 lbm. Minus the 180 lbm for driver puts the car curb weight at 2600 lbm. I'm getting ready to begin roll cage construction and I want to make sure I understand the new rules. Using the incorrect main tubing size would be a rather large mistake.

As for the rear roll cage down tube bends not being straight... That is typical in V8 Supercar and is currently the case in the SPEED World-Challenge TC Tindol Mazda 6's. If the design is a 2nd main hoop (first seen on the 1991 BMW E30 M3 Touring cars) and includes the bracing traditional of this design, then the strength is more than adequate and preferable to the straight down tubes of traditional SCCA roll cages. This setup is definately the way to go on flexy flyer chassis' like the BMW E30 & E36 (I own M3's of both). Albeit at an increase in weight even using smaller tubing for the optional reinforcements. For those unfamiliar with this setup please see the following links:

BMW E36 Super Touring car
http://e30m3performance.com/tech_articles/...36_mclaren1.htm

Team Kiwi Racing wrecked Holden Commodore
http://www.tkrfan.com/tkrbathurstcar/index.html

Personally the roll cage regulations should be pretty much standard across the board for production based cars. I particularly don't care for the firewall rule as tubing ahead of the firewall will better protect the driver's feet. Some argue that the cage stiffens the uni-body more as a performance advantage, but what new production car doesn't have a stiffer uni-body to better protect the occupants? Case and point: The E90 BMW 3-series shell is stiffer than the E30 M3 Motorsport caged shell. Safer too.

[Speed Raycer]

If you've got anything bigger than a miata, just go with 1.75x.095. We're only talking about 30 lbs differnce in 100 feet over 1.5x.095.

LOL, I like the whole upgrade by 1/4" and you can run .080 wall... apparently SCCA rulemakers haven't tried to find .... and pay for.... .080 tubing

[Marcus Miller]

I'd rather go up on wall thickness than lose the 1/4 inch space; I'm a big guy driving a small car.

[Z3_GoCar]

I'd rather go up on wall thickness than lose the 1/4 inch space; I'm a big guy driving a small car.

[/b]

And they took away our option for 1.5x0.120 for <2600lb production car cage&#39;s althought it&#39;s still allowed for formula/sports racers. My car&#39;s not much larger than a Miata and if I didn&#39;t already have a log book it&#39;s cage would be illegal. I guess they assume that all the <2600lb cars have room in them like a f-body/Mustang.

James

Edit: looked at it again and realized they shifted the weights up 200 lbs which explains the removal of the 180 lb from the spec weight, still I agree with Marcus as I&#39;m not exactly petite myself.

[mtownneon]

Here&#39;s the cage rule I&#39;m trying to wrap my head around:

In American Sedan, Improved Touring, Showroom
Stock, Spec Miata, and Touring the door window glass, window operating mechanism, inner door trim panel, armrest, map pockets, and inside door latch/lock operating mechanism may be removed and the inner door structural panel may be modified, but not removed only if the door bars extend into the door cavity.[/b]

So am I or aren&#39;t I allowed to remove the inner structure of the door panels to make room for NASCAR style door bars?

Dave

[dickita15]

Yes Dave, if your door bars intrude into the front doors you can modify the door panels as much as you want as long as you do not completely remove them. Make sure you do not remove the factory anti intrusion bar that is attached to the outside skin of the door.

[ddewhurst]

Dave, adding to what Dick stated a NASCAR bar may within the SCCA be one (1) tube bent & traveling deeper into the door than the metal door panel. Please always use the SCCA GCR Glossary.

[DBurke]

Isn&#39;t/wasn&#39;t there wording in the GCR to the effect of required tubes that terminate at a mounting plate must be welded a complete 360 degrees. I can&#39;t seem to locate it, I&#39;ve been reading the General Sporting regs and I&#39;ve got nothing.

[ddewhurst]

Please see GCR-98, Rule 9.4.G.4. Basically "all joints of the roll cage be welded". A tubular roll cage joint is the total distance around at the joint which is 360*.

[mtownneon]

Yes Dave, if your door bars intrude into the front doors you can modify the door panels as much as you want as long as you do not completely remove them. Make sure you do not remove the factory anti intrusion bar that is attached to the outside skin of the door.
[/b]

Thanks for the advice. The question was more of retorical one as the way it is worded it contradicts itself. That&#39;s what I love about the GCR, it&#39;s as clear as mud, or a southern short track&#39;s rule book.

Dave

[cjb25hs]

Please see GCR-98, Rule 9.4.G.4. Basically "all joints of the roll cage be welded". A tubular roll cage joint is the total distance around at the joint which is 360*.
[/b]

You are correct if you are using a weld in cage, but bolt in cages are still legal for IT, Touring and Showroom Stock. That rules actually reads "It is recommended that all joints of the roll cage be welded."