Performance parts for road and track

Home > 911 Rgruppe Project  > -150 Days

Rgruppe Monterey or Bust!    

Impossible schedule '73 911 Outlaw

January 31, 150 days post deadline

Roll Cage

The car has been progressing, however web updates have fallen a bit behind.  Rolling since August 2003 the car debuted in a raw form at German Autofest 2003, then with more refinements at Dunkel Brothers 2004.  

Because the car will see both street and track duty, we decided to forgo a full two-hoop cage. Front hoops can be dangerous to drivers not wearing a helmet. Further, traditional door bars make for difficult entry/exit.  

Despite the limited cage, we wanted to make the chassis very rigid and provide the driver a high level of protection.  We also wanted the cage to be removable, and as light as practical.

A custom partial cage was fabricated to fill the bill. The cage consists of a traditional main hoop and removable door bars.  Bolt plates are used at all connection points, making the entire assembly removable.  The bolt plates are welded to the uni-body box sections for maximum strength and rigidity.   Main hoop is attached to the B pillers, providing triangulation to the door openings and imparting a great deal of rigidity to the chassis.

All tubes are 4130 chromoly, providing for light weight.  Without door bars, the assembly weighs only 25 lbs.  With door bars, the entire partial cage is about 33 lbs!

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	Main hoop with diagonal and harness bar.  All tubing is 4130 Chromoly.
	Detail through rear window.
	All tie points have bolt plates to allow removal.  Bolt plates are welded to uni-body box sections.  Welding to the box section is stronger and more rigid than traditional bolt-in solutions that attached to flimsy floor sheet metal.  4 bolts at each point.
	Front and rear tie points are welded to the box section.
	Detail showing B piller attachment.  This is key to triangulating the door frames and increasing chassis rigidity. Door bar (not installed) slips over the spud and is bolted into place.
	Door bar protects driver and triangulates door.  Front of bar has a bolt plate welded to the rocker box section, 4 bolts to secure the front.  With B piller attachment, door bars really stiffen the chassis and protect the driver.
	Interior shot of door bars.  They hug the RS door panels and are not too hard to climb over.  No need for a quick release steering wheel.
	Picture of driver seat / door area with the door bar removed.  All set for street duty.

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