Porsche 911 Roll Cage

The latest Porsche 911 Roll Cage project is coming along nicely. We’re nearing completion of the major elements of the cage and are slowly working our way out the door. We still have some major work to do on the rear bulkhead as we rework some of the panels after adding a few of the bars in the rear.

More pictures will be up soon on www.izzyscustomcages.com/PorscheCages.html

Porsche 911 Master Cut Off Switch

We’ve been able to knock out another small project on the 911 before the cage starts going in. The Master Cut-off Switch, or Kill Switch, has been wired and mounted. In order to keep the interior as clean and uncluttered as possible, we mounted the 6 pole kill switch in the trunk of the 911. There isn’t much room in the 964’s trunk aft of the shock mounts, so we mounted the switch just forward of the shock towers on the frame rail. The switch will be actuated by 2 T Handle pull cables- one for the driver and one mounted externally along with another pull cable for the fire system for use by corner workers.

While we finish up the smaller details and the bulkhead, the main hoop and lateral bars have been bent and trial fitted. Updated pics tomorrow.

Porsche 911 side projects.

Before we start on the 8 point roll cage for the current Porsche 911 (964), we need to complete a few side projects before we have the cage in the way. These side projects include installing and wiring of a Master Cut-off Switch, removal of the factory seat brackets on the drivers side and fabricating a new seat mount, a removable rear bulkhead to make shock adjustment/removal much easier, and prep of the interior for paint.

The interior prep is underway as we are removing all of the seam sealer and melt sheet. The bulk of the mess has been cleaned away with a little residue remaining.

The new seat mount has been fabricated and installed:

Kill switch mount and rear bulkhead fabrication has started. Pics of those projects and the start of cage pad installation coming very soon.

www.izzyscustomcages.com

Cage tubing “strength”

I came across some very nice information on the Production Forum posted by Charlie Tolman.

The values below list tubing deflections at the center of a span for an applied force.

A. 1.50″ diameter, 0.095″ wall: deflection = 1.00, in arbitrary units.
B. 1.50″ diameter, 0.120″ wall; deflection = 0.83 units. ( 20% stronger than A).

C. 1.75″ diameter, 0.095″ wall: deflection = 0.61 units. ( 63% stronger than A, and 36% stronger than B).
D. 1.75″ diameter, 0.120″ wall: deflection = 0.51 units. ( 96% stronger than A, 63% stronger than B, and 20% stronger than C).

Special case E:

E. 1.75″ diameter, 0.083″ wall: deflection = 0.69 units. ( 45% stronger than A, 20% stronger than B, 13% weaker than C, and 35% weaker than D).

The deflection is inversely proportional to the fourth power of the outside diameter minus the fourth power of the inside diameter.

For tubing with a wall thickness much smaller than the diameter ( t << d ), the bending deflection is

S = Y / ( t x d^3), where S is the deflection and Y is a proportionality value.

With d – cubed, the diameter is the most important factor. *****

All of the above cases, A through E, are very close to this t << d condition.

Deflection

Charlie Tolman

3000 GT VR4 Roll Cage complete.

The Mitsubishi 3000GT VR4 roll cage is complete! The owner is converting the beast to a full on track car to run with the National Auto Sports Association (NASA) in their Time Trials program.

More pics are up on the website www.izzyscustomcages.com

Already underway is a full cage project in a beautiful Porsche 911 (964). We’ll be stripping the interior clean, adding a removable rear bulkhead, seat rails, kill switch install … not to mention the full 8 point cage and interior/cage paint.

Pics of the 911 progress coming soon here and at www.izzyscustomcages.com

NASA Time Trials 3000GT VR4 Roll Cage

Another Mitsubishi 3000GT VR4 is in the shop for a full cage. The owner is building it for the National Auto Sport Association (NASA) Time Trials program. Stay tuned for the build up.

www.izzyscustomcages.com

CHUMPCar Taurus SHO Complete!

After quite a bit of work including full roll cage, seat mount and seatback brace fabrication, battery relocation mount, harness mounts, engine mid-pipe fabrication and motor support bar, the Ford Taurus SHO is back at Eggboy Racing Headquarters for some final prep work.

Full pictures of the build are now online at Izzys Custom Cages website.

Next up, we’re going to be mocking up a skid plate for 1st Generation Nissan Sentra SE-R’s for rally/rallycross use. We’ll be using our own SE-R as a test mule for the unit.
 

Price point should be in the $215-$235 range and we’re shooting for release date somewhere in February of 2010.

Next cage is another Mitsubishi 3000GT for NASA’s Time Trials program. Stay tuned!

Taurus SHO Cage wrapping up!

The final details on the Taurus SHO cage are finished. Adjustable seat back brace is finished, lap mounts and sub strap mounts are complete and the wiring has been reconnected. Next up is building the downpipes to replace the factory configuration.

Taurus SHO CHUMPCar Roll Cage nears completion

The Taurus SHO’s 7 point roll cage is nearing competion.

After weighing the car to assure we were well below the 3K mark cutoff for .095 tubing (weight was still under 2700 lbs), we have a few more bars and gussets to finish up, harness mounts and sunroof plug to finish up. The sunroof plug was plug welded and will be finished shortly.

Parts are also on the way for a mandrel bent Y Pipe to replace the factory conglomeration.

CHUMPCar SHO progress

The Eggboy Racing Ford Taurus SHO for the CHUMPCar series is making progress. The main elements of the cage “box” are complete. The main hoop, laterals, windshield bar and its gussets, roof diagonal and temple bars have been welded and almost ready to be put back in position. The cage will ultimately be gusseted to the chassis along the A pillar as well as directly welded to the chassis in several spots along the lateral and windshield bars.

The NASCAR style doorbars will actually pass through the B pillar on the drivers side. The team driving the car have some larger drivers that require the hoop to sit about 8″ to the rear of the B pillar which creates a problem for NASCAR bar routing. We try to avoid any “S” bends in doorbars so the solution was to inset the hoop base points slightly and pass through the B pillar. Once the doorbars are in place, the B pillar will be plated and gusseted to the doorbars.

The Second Gen. SHO’s are known to be a little flexable behind the B pillar so the rear half of the cage will be heavily triangulated. There will be middle and lower X’s along with lower hoop braces. Most of the rear triangulation bars will consist of 1.5x.065″ to keep the weight down (preliminary measurements looks like we’ll save over 15 lbs over using 1.75x.095).