Project Nissan 300ZXTT Part One

As we continued work on the roll cage, we added more tubes to triangulate the structure; breaking the cage down to a series of small triangles. The triangle is strong, stiff and minimalist, the most so of all structures. This makes the triangle an elegant form to use for a race car chassis giving the most strength for the least amount of weight. To help keep the weight down, the additional tubes are smaller in diameter and of thinner wall than the mandated by the rules main tubes.

Louie adds additional tubes and dimple die plates to the cages main structure. The cage relies heavily on triangulation for efficient stiffening.

The uninterrupted X door bar is very strong. These fully boxed dimple die gussets strengthen the siamesed juncture in the tubes

We made extensive use of thin dimpled gussets to spread the load and stiffen things without having to resort to thicker tubes and adding a lot of weight.

Our cage is almost completely tied into the unibody

Almost every major tube is literally now a part of the body

Some more of the triangulation in the back of the cage

We should not have any problem with torsional twist here

We also added a unique feature to the cage, an impact absorbing structure behind both door skins. The main part of the cage behind the doors uses an uninterrupted X design which is where the two door bars are formed with a shallow V and welded together to make an X, the center of which is reinforced with gussets. This is one of the strongest forms of door bars and makes a nearly impenetrable wall before the driver. In front of the uninterrupted X is a structure we call an impact attenuator. This structure is made of lighter gauge tubing and is designed to crush inward in a severe side impact, taking up a lot of the side loads that can injure or even kill a driver even if the cage withstands the blow.

We looked to cars from the German Touring Car series for inspiration on our cage design. DTM cars are the most sophisticated racing unibody sedans ever built.

Some of Louie’s detail work is evident even in the footwell of our cage

The gusseting extends up to the roof

The roof is completely sealed to the cage. This bar helps reinforce the cages huge span across the Z’s curving roofline.

We were worried that the Z’s long unsupported roofline would fair poorly in a rollover so we added a vertical tube to shore it up. Then we reinforced it with this beautiful swooping gusseted area.

To save weight we decided to make extensive use of composite parts. We replaced the hood, doors and rear hatch with fiberglass pieces from Escort. Escort is a well known Japanese tuning shop which had the quickest Import Drag 300ZX many years ago with their tube framed car which won a few Wally’s. Escorts parts in the typical JDM fashion fit perfectly. The doors themselves weigh only 11 lbs and save about 70 lbs apiece alone. To mount the rear hatch and save weight, Louie mounted the Escort hatch directly on the cage using specially fabricated hollow tabs. Interestingly enough, the Escort parts all use the stock latches and mounting hardware so they can easily bolt onto any Z32 although we don’t recommend using the doors without a cage.

In our next segment of Project Z we continue work on the body fabrication and get ready for some really trick suspension parts.

Sources

L-CON Fabrication

The best damn fabricator in town

www.L-CONracecars.com

(714) 572-4130

Performance Auto Body

Roof clip

1826 Oak St.

Torrance, Ca 90501

(310) 618-9617

Escort Racing