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Most E30 M3s are bought to be preserved. This one was bought to be used up, in the best possible way. The 1991 BMW M3 race car now live on Bring a Trailer has belonged to the same owner for 32 years, wears a roll cage and a closet full of fiberglass, and runs a 3.2-liter S54 inline-six in place of the original four-cylinder.
An E46 M3 Engine in an E30 M3 Shell
The S54 is the straight-six BMW built for the E46 M3, and it is one of the most loved engines the company has ever made. The E30 M3 left the factory with the high-revving 2.3-liter S14 four-cylinder, so dropping an S54 into the chassis is a significant step. The listing says the swap was done around 2010 and that the engine has since been rebuilt with coated rod bearings. It doesn't say what became of the original S14, and purists will have opinions about that.
The supporting hardware is track-minded. The engine is run by a DTA S100 standalone ECU with a custom tune and rev limiter, breathes through a custom fiberglass intake plenum with mechanical throttle linkage, and is cooled by an E36-sourced aluminum radiator, an electric fan and an oversized oil cooler. A baffled oil pan, high-volume fuel pumps and an external surge tank keep it fed in corners, and urethane mounts hold it in place. Power goes through a five-speed manual with an aluminum flywheel, a six-puck clutch and a Diffsonline limited-slip differential with 3.73:1 gearing. The listing doesn't quote a horsepower figure, but dyno results are included with the sale.
Four NASA Titles and a Track-Ready Chassis
According to the seller, the car won the NASA Midwest Regional Championship in the GTS5 class in 2009, 2011, 2012 and 2014, along with several class lap records. If the swap really happened around 2010, the 2009 title would have come with the original engine, which makes this a car with two distinct competition chapters.
The chassis has been developed to match. AST triple-adjustable dampers with remote reservoirs and Hyperco springs sit at each corner, backed by AKG Group A-style front control arms, Group N-style rear arms, double-shear pickup points, Ireland Engineering anti-roll bars and adjustable camber plates. Wilwood six-piston front and four-piston rear calipers handle braking, with a Wilwood pedal box, dual master cylinders with a bias bar, and a three-channel ABS system. The 17-inch Kosei K1 wheels wear Pirelli slicks.
The bodywork is mostly fiberglass, including an EVO-style front valance, hood, fenders and rear bumper, with Lexan windows, a front splitter, carbon-fiber dive planes and an APR carbon rear wing. Inside, the cabin is stripped to a chromoly cage with door bars, a Sparco bucket seat, a six-point harness, a fire-suppression system, a CoolShirt system and an AiM Solo lap timer. It is a race car in every sense, and it is also a clearly well-sorted one. If you like your E30 M3s with a little more attitude, our look at a race-built 1988 M3 with DTM-style attitude shows another way to go, and a 1989 M3 with an upgraded 2.5-liter stroker engine shows what keeping the original four can look like.
What's Documented and What's Seller Claim
The CARFAX report shows no accidents or damage, 11 service records and an Illinois title with an Actual Mileage notation. It also records a failed emissions inspection in April 2003, long before the car became a dedicated track machine. The odometer reads about 106,000 miles, roughly 59,000 of which were added under the current owner, while the last reported CARFAX reading is 101,890. The championship results, the swap date and the engine details come from the seller. Log books, dyno sheets and service records come with the car, so a prospective bidder can check the story against the paperwork.
The sale also includes a lot of spares: a second gearbox, four sets of wheels, a set of slicks, a set of rain tires, an alternator, brake pads, ignition coils, belts and hardware.
The Auction
The car is located in Palatine, Illinois, and is offered by a private seller. At the time of writing the high bid is $20,000 after three bids, and the listing is not marked No Reserve. The auction ends Monday, November 9, at 1:28 p.m. ET. Whether you want to chase NASA class wins or just own one of the more interesting E30 M3s anywhere, it's worth a look. To learn how the model got here, read the genesis of the legendary BMW M3 bloodline.
Photos: Bring a Trailer / seller. Listing details as published by the seller at the time of writing.
