Z06 Stereo install, part 2

In last week’s blog, I promised more about the stereo installation that William Fonseca and 1Off Rides did in my Z06. William and his crew did a fabulous job meeting my requirements, but he also worked very hard to make the whole install look like a factory installation. So there aren’t big bunches of wire connection barrels, or wire nuts. Instead, all the connections are done in-line with soldered connections and automotive grade OEM style wrapping. corvette pics 162.jpg

All the wiring is tidy: easy for maintenance and any enhancements.

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Here’s one view of the wiring behind the head unit. The nylon mesh along with shrink wrap tubing is a quality of keeping wire harnesses together.

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Here’s another view. You can see the original and the additional wiring.

Corvette Z06 Stereo install

Late last year, after buying a new-to-me 2007 C6 Z06, I took the car over to William Fonseca at 1Off Rides. William has done several installs for me, and wanted to show off his new brand of gear: Hertz. He took detailed photos of his whole install process, so I’ll show off some of his work across a few blog entries over the next couple of weeks.

I gave William two requirements:

  1. The system couldn’t cut any wires to install. I wanted to be able to return it completely to stock for resale.
  2. The sub and amp had to be removable for track use.

William did that, and added one of his own: when the sub and amp are removed, the system still plays! He put audiophile relays in all the speakers and connected both to the big Hertz amp and to the head unit: a Pioneer AVIC Z110BT. The sub and amp are removable with two mil-spec connectors and two nuts. They float in the back of the car: that is to say: they don’t touch the carpet. So when you remove them, there’s no matted down carpet.

All in all, William and his shop did a fantastic job with the install. Here’s a few pics for now:

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The Hertz speaker is mounted to an aluminum adapter.

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Here it is mounted to the door.

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The GM LAN interface module and main power relay, along with the splice harness.

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The mil-spec connector for the amp. It’s a simple pull to disconnect.

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Just a few of the relays needed to allow the dual mode system to work seamlessly.

Unfair’s Interior Fabrication

We are using a very interesting new material for Unfair’s interior. It’s called Airex C70.

AIREX® C70 is a lightweight, closed cell foam for universal use in sandwich constructions. Its excellent stiffness and strength to weight ratio and high toughness make it suitable for a large variety of applications. The foam is ideally suited for statically and dynamically loaded structures and is compatible to all resin systems.

Our friend and collaborator Guillermo (William) Fonseca of 1Off Rides is working on the interior panels using this awesome material. It can be fabricated as though it were MDF (the standard material for speaker boxes). It cuts fine with woodworking tools, and can be glued or screwed together to make complex shapes. Once the shapes are glued/screwed together and all the panels sanded/finished to fit, you can use ordinary fiberglass mesh and resin to make the shapes permanent.


Unfair Rear suspension and Spohn’s Del-Spheres

When Art Morrison first approached us with the idea of the transforming / combination 3 and 4 link rear suspension, we loved the idea. And after I thought about it a bit longer, I called Matt Jones (their suspension engineer) at Morrison and told him to be sure and design the brackets of the new suspension to use Del-Spheres. Matt took some measurements and they were able to accommodate us.

As a result, Steve Spohn’s Del-Spheres are all over the rear suspension on Project Unfair, and for good reason. I first used Del-Spheres on my previous project (II Much) when the original rod ends started to wear (after a few hundred miles) and started to transmit NVH (noise, vibration, and harshness) into the car. I swapped the rod-ends to Del-Spheres and it greatly reduced the NVH, with no loss of accuracy or articulation.

Strictly speaking, the Del-Spheres don’t have quite as much misalignment capability as a rod-end, but for rear suspension linkage arms like Unfair’s combination 3 / 4 link, it offers plenty with no loss of strength. The main body of the Del-Sphere is forged steel, with a forged ball. The body and ball are separated by Delrin rings, and the body incorporates a rebuildable and grease-able design that allows for the quiet of rubber and the accuracy of steel.

We’re confident the car will have excellent handling and ride characteristics, as well as handle the 1200 hp the engine will put when we put the hammer down!


Here’s the whole rear suspension in what Frank and I call “5-link” mode. 🙂 Note how the Del-Spheres are used on all the control arms except the Watts link.


This is the road racing setup with a 3 link. For drag racing, the upper control arm in the middle is removed and replaced with two control arms on the side. The Del-Spheres provide the misalignment we need for turning the car on the 3 link setup, and the strength for 1200 hp launches on the 4 link setup.


Here’s a closeup of the Del-Sphere, screwed into one of Unfair’s 4 link upper control arms.


Taking off the pre-load adjuster shows the Delrin inserts and how they isolate the ball from housing.


Here’s a complete disassembly. The forging line in the housing is visible.