Havoc explain which was first. I alway considered it as a limited edition bike sold thru the dealer network. A Yenko, I am thinking was only available at Yenko, not all Chevy dealers..
They were sold thru dealers here, I KnOW of at least one person that had one. Another bike showed up here and a drag racer used the Turbo and parted out the rest... 
By 1978 Kawasaki's legendary Z1 -- saw its prior performance supremacy eclipsed by the competition, mainly Suzuki's GS1000, Honda's CBX, and even Yamaha's XS1100. A bold stroke was needed. Hence the Z1RTC Turbo. Though not a true "factory" product, the Z Turbo nonetheless was the harbinger of future factory Turbo efforts to follow.
The Z1RTC was built by the Turbo Cycle Corporation (the TC in Z1RTC) utilizing American Turbo-Pak (ATP) turbocharging kits. TC Corp., headed by former Kawasaki marketing director Alan Masek, essentially bought the turbocharger units from ATP, bolted them up to existing Kawasaki Z1Rs and sold them through "select" Kawasaki dealerships, without warranty (you're on your own, kid). The kits were essentially basic Z1 kits sold over the counter, however they featured an improved (No. 370F40) Rayjay turbocharger which utilized a thicker heat shield separating the turbine and compressor housings and a new center-bearing that offered improved lubrication. The turbocharger's wastegate came pre-set to operate at 6-8 lbs. of boost, but could easily be insanely increased via an adjusting screw on the bottom of the wastegate. But since the Z1RTC's crank pins were inexplicably not welded -- a common Z1 performance modification -- your $5,000 investment wouldn't last very long if you got the urge to "boost up." And you'd undoubtedly need to run racing fuel to keep the engine from grenading.
In '78 silver-blue trim the Z1RTC was not exactly a sales success. So TCC painted the remaining warehoused Turbos jet black and added racy red/orange/yellow Molly graphics in an effort to make the bikes more appealing. The marketing ploy worked, but some of the credit had to go to the bike's growing reputation as a two-wheeled hellraiser. TCC even added an improved "spider"-type header to replace the ugly "log"-type unit and the Z1RTCs sold out quickly in '79. But the euphoria over the bike's new-found showroom success was short lived as a new law in California made it illegal for dealers to sell any motorcycles with a modified exhaust system (and a turbocharger is about as modified as you can get). So there were no Z1RTCs in 1980 and the "experiment" was dead.
The Z1RTC performs like you would expect any overly-modified, hinged-framed, skinny-tired, inadequately-braked motorcycle to perform.
If you like being scared this is the Turbo for you.
There were some aftermarket frames that helped but.... It was almost as bad as the H models in terms of handling. Especially at speed.
I paraphrased but.... you get the idea. I believe Honda was the first "factory" turbo but Yamaha might have beat them to it. Both were offered in 82 (?)
