1987 - 1990 Corvette ZR-1 Prototypes

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The following notes regarding ZR-1 prototype history and production were compiled by Tyler Townsley. The Corvette Action Center would like to thank Tyler for compiling this information and allowing us to include it here.

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• All of the prototypes sent overseas had to be registered with real paperwork and registration plates before they could be used on the road. The European prototypes could actually be titled. The prototypes built for testing in the United States had to have manufacturer plates only.
• GM started the ZR1 prototype numbering system with the 1988 MY even though some were clearly assembled on the 1987 production line as evidenced by the comment on the build sheet of EX5014, ie kick in behind 126565. Atch 1
• GM engineering kept track of the cars using the P numbers, The earliest known survivor is P8Y087(See # written on the inside of the hood and on key fob). P8Y088 is in England and was one of the famous Lotus junkyard cars that were modified using a backhoe and sledge. P8Y090 was used in drag tests and turned a 12.89 2 run average. Atch 5
• Vins 10034-57 were to be used for prototypes built as 1988 models. Additional information is available at the NCM on any of the others that were built. Items that were special for the ZR1s were tagged with CPC stickers to help in assembly line work. Some of which are displayed. Atch 3-4.
• The EX numbers appear on Challenge cars as well as the ZR1 prototypes. The highest number I have record of is EX5236 which was on a Challenge race car.
• The P2 motors were built in England and sent to the US with a spec sheet. Items on the build sheet that have a # sign were included as part of the engine assembly. Word has it that the first frame/engine assembly Tofor (The frame dolly that the frame/engine rode on before being mated to the body.) had to be tilted 17/18 degree angle to get into the engine compartment. There were over 150 engineering changes done on the P2 motors alone, the most significant of which was the change in timing chain design to a duplex chain. P8Y087 and 88 had simplex chains. There were at least 2 P2 motors with the duplex chains one of which was used in the famous 400 hr endurance test. A side note on the P8Y088 car is that it had a prototype 4 bolt block in it and 87,000 miles on it when it was rescued.
• In my quest to complete my 88 prototype I had Geoff Jeal build me a correct phase 2 motor from items he found in the Graveyard. To my supprise the block he used had been built in England (expected) shipped to the states and installed in a prototype. I know this because I have the engine build book that was shipped with the motor to BG. Engine sn is 42, according to Geoff and HOB 60 phase 1 and 2 motors were built with 59&60 being the 400 hr test motors. I decided to ask Geoff how the motor ended up back in England. His reply:
  

  "The sequence of events for the proto cars was as follows, all the engines were built at Lotus from parts procured by Lotus usually from the eventual production supplier. Around 36 of the engines were shipped to BG for fitting into the proto cars another 8 or 10 engines went to the likes of Sealed Power in MI, Bay City cams, Rochester Products, etc for component testing. A further batch of engines, not sure how many, were built for dyno testing at Lotus. The only engines that had the type of log book you have were the vehicle engines.

  As the cars were built at BG they were allocated to various engineering groups within GM and to suppliers to the programme. You will see on most of the build sheets that the cars were allocated to the engineering group at Warren this is because they had the ultimate sign off responsibility for the cars, in other words they were all shipped to Warren prepped for delivery and shipped to there final destination from there.

  Not sure how many but several of the P2 cars were shipped to the UK for emissions, drivability and performance work. During their life in the UK the cars would have had their engines and other chassis components updated as the later level parts/engines became available. It was not unusual to have changed the engine in a particular vehicle 5 or 6 times, especially the calibration cars. My car (His car was next after mine and is one of the squashed graveyard cars) was shipped to the UK and back twice. It was used for the hot environment test in 88 then emissions certification and then shipped to the UK, shipped back for some work in 90 and eventually was used for oil consumption tests in the UK in 91 fitted with a production level engine. It met its end at the beginning of 92.

  All of the proto and production test/dyno engines that were removed went to the scrap. That's what makes your car so remarkable, it is as BG built it. I don't know of any other P2 mule as they were called that has survived let alone as original as yours.

  Geoff