Published in the January 2022 issue of “Die Porsche Kassette”

Ⓒ2022 Technolab /

For more information about the Porsche 959 and more, please visit my website:  


Happy Porsche'ing,

In a previous issue we discussed the beginnings of the 959 as well as its technical advances and immediate racing successes.

Now we’ll tell you the rest of the story.

The 959 was never meant to be a street car and certainly not a California car to be driven on normal city roads.

Two years after the Gruppe B appeared at the Frankfurt Auto Show (1983), Porsche announced the introduction of the 959 with a production of 200 cars to homologate the model for competition. 

Even at the price of $250,000 all of the cars were quickly spoken for.

When the U.S. Department of Transportation requested 4 cars to crash-test, Porsche said no.   Without approval from the National Highway Traffic Safety Administration (NHTSA) the 959 could not be sold nor driven on US soil.

Two of the first buyers of the 959 were Microsoft co-founders Bill Gates and Paul Allen. News of the banning of the 959 in America was not well accepted by the pair who decided to ship their cars to the West Coast anyway.  Their contraband was soon discovered and impounded and reportedly confined to a California warehouse for more than a decade.

With no way to lawfully enjoy their 959s at home, some wealthy US owners decided that changing the law was what they’d do. 

In 1990 a Seattle-based company called Vehicle Technologies, Inc. launched an attempt to import the 959 and have it approved for the USA, an effort that was quickly thwarted.

Several year later, a group called The Special Vehicle Coalition engaged discussions regarding proposed new legislation that would allow cars of note that were never sold new in the USA to be imported as individually owned show exhibits.

This costly and lengthy campaign finally paid off in 1998 with the arrival of the “Show and Display” (S&D) Law which permits significant cars such as the 959 to be driven on US roads for up to 2,500 miles per year.

S&D however did not exempt the cars from having to be emissions compliant.  The Environmental Protection Agency (EPA) requires that vehicles less than 21 years old used on US roads need to meet air emissions standards for the year of manufacture.

So, making a 959 compliant was not going to be easy, especially in California.

For starters, the 959 never had catalytic converters nor was its Motronic’s brain programmed to recognize an oxygen sensor (although the car was built with the wiring harness and bung for a sensor). Reportedly a few factory retrofit kits were made available but it’s difficult to know if that’s true or not.

The first company to gain NHTSA and EPA approval for a Porsche 959 under the S&D legislation was G&K in Santa Ana, CA.  They partnered with GIAC, a developer of vehicle software and the first 959 was certified on September 2001.  It took almost $50,000 of work to do it.

But because the 959 had its engine derived from the 935/76 racecar which later also powered the 956 and 962C to victories at the 24 Hours of Le Mans, there were those who hoped for more from the newly certified 959 than just clean/green performance.  Enter Bruce Canepa, a California racer who became a Porsche fanatic.  In 1988 he purchased a 959, which he thinks to this day, is one of the best – if not the best – all-around sports car ever made.  He also believed that the 959 had some additional potential performance built-in.  He figured that it was good for 600 hp so he set out to modify the 959 to make 600 hp while still hitting the EPA emissions targets.

Based in Scotts Valley, CA, Canepa Design changed their 959s from a sequential-turbo setup to a twin-turbo operation using Garrett turbochargers.  They installed new engine management systems and new exhausts which included catalytic converters.  Two versions were prepared: A Phase 1 making 575 hp and a Phase 2 making 640 hp.  They also offered a suspension package with tuned dampers and titanium coil springs plus a new clutch and pedal assembly to improve feel.  The original wheels were modified to accommodate 245/45R17 front and 275/40R17 rear Michelin Pilot Sport2 rubber.

Nowadays though, the 959 can be used in the USA with no certification other than the S&D Certificate.  This is because the EPA requirements expired once the 959 turned 21 years old.  A total of 337 cars were built before production shut down in 2009.

Most of the 959s in America were modified to comply with the existing regulations, but after 2010 a few factory-original 959s have come to America.

Photos of a freshly imported 959 getting a new clutch.