The 'Stealth' Z - Part One...continued

One day, I happened upon Corky Bell's number (owner of Cartech). In speaking with him, I asked if he knew how to get 250HP out of a Z engine. He laughed and told me he could easily get over 350HP out of a turbo engine for the same price as a built up 250HP engine, and perfect driveability to boot. After talking with Corky at length and then getting a ride in a Miata with one of their turbo kits, I was sold. Corky, who pioneered the art of turbocharging Datsun Z-Cars 15 years ago, decided to do a custom experimental kit for my car to meet my particular needs: low end torque so I could autocross, yet enough power to run a low 12 sec. quarter mile with street tires and street gas. Just for reference, a real quick Mustang or Camaro will run in the mid or low 13's - like I said, I hate to lose. Plus, I wanted to be able to beat the V8 powered Z's with the 'stock' factory inline 6.

Without getting too detailed, the kit consisted of a new Nissan Turbo long block (although new blocks are no longer available, Nissan has reman. engines that are literally as good), a Mitsubishi turbo and custom plumbing to and from an oversized intercooler. Under Corky's direction, I pulled the head and milled it .075". Yes, that is a bunch. But it raised compression from the stock turbo's 7.4 to a more modern estimated 8.5. I had to use 5 'headsaver' shims under the cam towers to bring everything back into alignment. While the head was off, I radiused all sharp edges and polished the combustion chamber. I didn't do any porting or make any changes to the combustion chamber or intake ports as Nissan did a lot of research in promoting mixture swirl and reducing detonation (in the turbo head), and I'm not bold enough to even imagine that I could out-think and out-design a full staff of Nissan engineers.

The fuel management system consists of the now very popular ACCELL DFI Digital Fuel Injection system. The system consists of the black box controller, wiring harness and all related sensors. The beauty of this system is it is flexible enough to run anything from a lawn mower to a top fuel dragster. The system can be completely programmed from start up - to warm up - to full throttle.

Ignition is handled by a 280ZX distributor and module that sends a signal to a J&S Safeguard Knock Sensor. The J&S unit is microprocessor-based knock sensor that can retard the timing on individual cylinders. The advantage is that many times it is only one cylinder that has a hot spot or lean mixture, etc., and the J&S can retard the timing only on that cylinder and not lose power on the other five. This also allows more initial advance, which can give you more power and better (off-boost) response. I have the optional display that will show the amount of retard and the air/fuel ratio. Estimated horsepower is 375HP. Estimated performance: 0-60 4.1 sec., quarter mile 12.2 sec., top speed 165MPH. I had reason to believe these numbers as I rode in a 260Z customer car they just finished that did a Vericom timed 4.5 sec 0-60 with 195/70/14 street tires and my setup was going to be one or two steps farther than that car!

With most of the technical stuff out of the way, the fun starts next month!

Go to the Stealth Z - Part 1.5: