History of 1988 Corvette ZR-1 Prototype EX5023

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1988 Corvette ZR-1 Prototype


This is a running history of 1988 Corvette ZR-1 Prototype #EX5023 VIN 1G1YY218XJ5100048 finished in Medium Blue Metallic with a blue leather interior.

December 10, 2020:

Below is a sale listing on the Cars and Bids website for 1988 Corvette ZR-1 Prototype #EX5023. The car is listed for sale there by Brett Henderson - the owner of Blue Flame Restorations.

Highlights

  • This Corvette is currently located at the Lingenfelter Collection in Brighton, Michigan where it is available for in-person viewing.
  • The true mileage of this Corvette is unknown and the odometer currently displays approximately 59,200 miles.
  • According to Mecum Auctions, this is one of just two surviving King of the Hill prototypes.
  • The attached AutoCheck history report only dates back to 2018, but shows no accidents in this ZR-1's past.
  • This Corvette was a prototype used by Lotus in Hethel, England, as a test mule for the calibration of the LT5 engine that was in development at the time. It comes with thorough documentation including a project report, engine assembly instructions, the factory build sheet, and more.
  • The original Corvette ZR-1 based on the C4 was codenamed "King of the Hill" while it was in development. Developed with Lotus under GM's ownership, the ZR-1 was positioned to compete with more expensive supercars from the likes of Ferrari and Lamborghini. It was a successful experiment with unanimous praise from the automotive press at the time as one of the best American sports cars to date.
  • Power for this Corvette comes from an experimental LT5 Phase 2 5.7-liter DOHC 32-valve V8 engine with an aluminum block and aluminum heads. The production version of the C4 ZR-1 produces 380 horsepower and 370 lb-ft of torque. It powers the rear wheels via a 6-speed manual transmission.

1988 Corvette ZR-1 Prototype #EX5023 - Phase II LT5 Engine

Recent Service History

This car was recently restored and serviced by the seller, who is the owner of Blue Flame Restorations.

Ownership History

The seller bought this car from a Lotus engineer in 2010.

Seller Notes

  • This car is currently located at the Lingenfelter Collection in Brighton, Michigan where it is available for in-person viewing.
  • The seller is offering a spare experimental motor with the sale at an additional cost; it is LT5 Phase 1 motor number 26.
  • This is 1 of 2 running King of the Hill prototypes according to the seller.
  • The seller notes that this was 1 of 25 prototypes built in July 1987.
  • According to the seller, this car was rescued in the early 1990s from a U.K. junkyard by a Lotus Engineer who drove the car daily during the development of the LT5 engine. The seller bought the car from that engineer in 2010.
  • The seller is the owner of Blue Flame Restorations in Pendleton, Indiana, which specializes in restoring early C1 Corvette models. He restored and serviced this ZR-1 prototype himself.
  • The rear Goodyear tires were experimental and have "Not For Sale" molded into the sidewalls.
  • Several of the parts on this car are hand-dated 7/87.

January 2018:

Below is the Mecum Auction Listing for 1988 Corvette ZR-1 Prototype EX5023 from January 2018:

Lot S165 Kissimmee 2018 Jan 5-14

Estimate:  $190,000 - $225,000

Highlights

  • 1 of 2 existing 1988 King of the Hill Prototypes
  • Vehicle built before the name ZR1 was decided upon
  • 1 of 25 Built in July 1987
  • Engineering data tag EX5023
  • Used by Lotus in Hethel, England for development
  • Utilized for engine calibration and emissions certifications
  • Tested at the Milford Proving grounds
  • Ordered scrapped by General Motors in 1990
  • At time of restoration, the original suspension, frame and most of the body tub were intact
  • Fiberglass body panels and portion of rear upper surround sourced from a 1989 pre-production Corvette
  • Lotus-designed, Mercury Marine-built Phase II LT5 engine, the 43rd one built
  • ZF 6-speed transmission
  • Medium Blue Metallic with Bright Blue interior
  • New interior in 2017 with exception of original console plate with power key
  • 8,000 RPM tachometer not available on production cars
  • ZR1 prototype wheels, 11 inch width
  • Experimental Goodyear Gatorback tires with 'not for sale' molded on the inside
  • Featured in Anthony Young's "Heart of the Beast: History of the LT5 V-8 and ZR1 Corvette"
  • Shown at the 2010 C4 Gathering at the National Corvette Museum
  • Handwritten engine book from Lotus
  • Build sheet

This 1988 Chevrolet Corvette occupies a special place in the Corvette community as one of only two surviving factory “King of the Hill” ZR1 prototypes. It is one of 25 built in July 1987, before the Corvette team decided to resurrect the ZR1 moniker first used on its race-ready 1970 namesake. Bearing engineering data-tag EX5023, the car was used as a development mule at Lotus Cars’ Hethel works in England for engine calibration and emissions certifications, and it was later tested at General Motors’ Milford Proving Grounds. Following standard practice for prototypes, General Motors ordered the car scrapped in 1990; instead, somehow, it was abandoned in an auto-recycling yard, where it remained for years before it was discovered and identified by the man who would undertake its painstaking restoration. At the time that began, the original frame, suspension and most of the body tub were intact, but the roof needed repair. Fiberglass body panels and a portion of the rear upper surround were sourced from a 1989 pre-production Corvette to complete the essential structure. The heart of the second-generation ZR1 was its LT5 engine, a 5.7L 32-valve DOHC all-aluminum V-8 designed by Lotus Engineering and built in the U.S. by Mercury Marine, and in this case, a refined Phase II version, the 43rd LT5 built. Like all production ZR1s from 1990 to 1995, this prototype is fitted with the CAGS-controlled ZF 6-speed manual transmission. Finished as original in Medium Blue Metallic, the car received an all-new bright blue leather interior in 2017, the only exceptions being the original console plate, power key and a special original detail: an 8,000 RPM tachometer that was not available on production cars. Featured in Anthony Young's “Heart of the Beast: History of the LT5 V-8 and ZR1 Corvette,” the car wears 17x9.5-inch front and 17x11-inch rear aluminum ZR1 prototype wheels fitted with insanely rare experimental Goodyear Gatorback tires with the words “Not For Sale” molded on the inner sidewalls. Shown at the 2010 C4 Gathering at the National Corvette Museum, this historically significant ZR1 prototype comes with the factory build sheet and handwritten engine book from Lotus.

Click on the images below for a larger view:

1988 Corvette ZR-1 Prototype EX5023 1988 Corvette ZR-1 Prototype EX5023
1988 Corvette ZR-1 Prototype EX5023 1988 Corvette ZR-1 Prototype EX5023
1988 Corvette ZR-1 Prototype EX5023 1988 Corvette ZR-1 Prototype EX5023
1988 Corvette ZR-1 Prototype EX5023 1988 Corvette ZR-1 Prototype EX5023
1988 Corvette ZR-1 Prototype EX5023 1988 Corvette ZR-1 Prototype EX5023
1988 Corvette ZR-1 Prototype EX5023 1988 Corvette ZR-1 Prototype EX5023
1988 Corvette ZR-1 Prototype EX5023 1988 Corvette ZR-1 Prototype EX5023
1988 Corvette ZR-1 Prototype EX5023 1988 Corvette ZR-1 Prototype EX5023