Audi 90 quattro IMSA GTO (1989)
The Audi 90 quattro IMSA GTO is the works silhouette car Audi of America ran in the 1989 IMSA Camel GT season. A tube-frame chassis, a 720 hp 2.2-litre five-cylinder turbo and quattro drive won seven races in one year. It is a collection and demonstration car; originals rarely change hands and works-only parts are scarce.
History
Audi arrived in North American circuit racing in 1988 with the 200 quattro Trans-Am, run by Group 44 for Audi of America. The big saloon won eight of thirteen races and both titles, with Hurley Haywood taking the drivers' crown 815. For 1989 the SCCA banned all-wheel drive and demanded American engines, so Audi could not defend its title 15. Audi of America moved to the IMSA Camel GT series instead, whose GTO rules allowed a purpose-built racer under a production-style silhouette 6.
The new car kept only the roof of a road-going Audi 90. Underneath sat a steel tube frame, double-wishbone suspension and composite bodywork over 14-inch-wide wheels 26. The engine was the last step of the Group B and Pikes Peak five-cylinder: 2,190 cc, four valves per cylinder and a large KKK turbo. Audi quotes 720 hp at 7,500 rpm and 720 Nm at 6,000 rpm 12. The gearbox had six ratios, but the rules allowed five, so one was blanked off 6. The programme started late and the car was not ready for the opener. Audi therefore skipped the Daytona 24 Hours and Sebring 12 Hours 8. Haywood later said the team also doubted the drivetrain would survive such long races 9.
Hans-Joachim Stuck drove the number 4 car and Haywood the number 5, with Walter Rohrl and Scott Goodyear sharing the two 500 km races 34. Both cars retired on debut at Miami in March 1989, one with gearbox failure and one after an accident 34. From Summit Point in May the picture changed. Stuck and Haywood finished one-two there, and Stuck won six more of the remaining rounds 67. Audi could not recover the points lost at Daytona and Sebring and finished second to the Roush Mercury Cougar in the manufacturers' standings 716.
The IMSA effort was planned for two years but was dropped after one. Audi took its budget and the quattro system to the DTM for 1990 with the V8 quattro 68. One 90 IMSA GTO went to South Africa in 1991 as the basis for the Wesbank-series Audi S4 GTO 14. The engine and six-speed gearbox of S4 GTO chassis 001 came from a 90 IMSA GTO 13. Audi Tradition keeps a 90 IMSA GTO in its fleet and still flies it to events. In 2024 it ran at an Aspen ice race and was shown at the Amelia concours 9.
Palmarès
Seven GTO class wins in 1989, all by Hans-Joachim Stuck in car number 4 357. The wins came at Summit Point, Mid-Ohio, Heartland Park (Topeka), Sears Point, Watkins Glen (shared with Walter Rohrl), Lime Rock and Laguna Seca 3. Haywood added five second places in car number 5, giving Audi five one-two finishes 47. Audi missed Daytona and Sebring and ended second to the Roush Mercury Cougar in the manufacturers' standings 7816. The car never raced again under Audi after 1989 6.
What to check before you buy
Establish which of the two 1989 race cars it is, or whether it is a spare or test chassis: Period records list number 4 as 90q-04 and number 5 as 90q-05 with the true chassis numbers unknown. Ask for Audi Sport or Audi of America build documents. Match the engine and gearbox numbers to the chassis history: The S4 GTO chassis 001 took its engine and six-speed gearbox from a 90 IMSA GTO. At least one original car has therefore lost major units. Confirm the frame is a steel tube space-frame with only the roof from a production 90: The real car keeps the production roof panel and nothing else from the road car. A converted road shell is a tribute, not a works chassis. Inspect the rear-mounted rubber fuel cell and its aluminium container: The cell sits at the rear in an aluminium box. Bladders age out and the box is bespoke; ask when it was last replaced. Ask for the race history against the 1989 entry lists: Thirteen rounds are logged per car, including retirements for gearbox, steering, engine and an accident at Road America. Repairs after those events should be documented. Verify the 1989-era Bosch Motronic management is complete and supported: The ECU, sensors and harness are works items. The 2026 Wanted request on racingcarnetwork.com lists ECUs among the parts a buyer cannot find. Check what Audi Tradition holds and whether the car was ever in its fleet: Audi Tradition still owns and demonstrates a 90 IMSA GTO, so a private car should have a paper trail showing when it left the factory.
Versions and evolutions
| Version | Years | What changed | How to identify |
|---|---|---|---|
| Audi 200 quattro Trans-Am (predecessor) | 1988 | Production-based 200 saloon shells converted for racing, 2.1-litre five-cylinder turbo, quattro drive; three chassis TA/2, TA/3 and TA/4 raced. Eight wins, drivers' and manufacturers' titles in 1988. Banned from 1989 when the SCCA outlawed all-wheel drive and required American engines. 15 | Steel production bodyshell of an Audi 200, 4.89 m long and 2.03 m wide; chassis plates in the TA/x series; numbers 14, 44 and 4 in period. |
| Audi 90 quattro IMSA GTO | 1989 | All-new steel tube-frame silhouette car with composite panels, 2,190 cc 720 hp engine, six-speed box with one gear blanked, 14-inch-wide wheels. Two cars raced: number 4 (Stuck) and number 5 (Haywood). 3 | Only the roof is a production Audi 90 part; the rest is composite over a space-frame. Period records list the two race cars as 90q-04 and 90q-05 with the real chassis numbers unknown. |
| Audi S4 GTO (South African derivative) | 1992-1994 | Two cars built by Audi Sport South Africa (Voldi) on the C4 S4 silhouette for the Wesbank Modified series, using IMSA GTO running gear. Chassis 001 carries the engine and six-speed gearbox of a 90 IMSA GTO and was raced by Stuck on its 1992 debut. 13 | C4-generation S4 body with IMSA-style wide arches; chassis 001 retains the original wide bodywork and roll cage. Offered by Collecting Cars in a sealed-bid sale in early 2026. |
Known issues
- Gearbox durability — Car number 4 retired with gearbox failure on debut at Miami in March 1989. The six-speed unit runs with one ratio blanked off and is a works-only part. 3
- Drivetrain life over long distances — Haywood said the team avoided Daytona and Sebring because the drivetrain was not expected to last. Both 500 km races in 1989 ended with a retirement or an off-pace finish for one car. 9
- Engine and oil-system failures — Number 4 retired with engine failure at Del Mar; number 5 retired with an oil leak at Mosport and two unspecified mechanical failures. A 2,190 cc engine giving 324 bhp per litre has little margin. 4
- Steering failure — Number 4 retired from the Mosport 500 km with a steering failure. The power-assisted rack is bespoke to the space-frame. 3
- Tyre consumption — Period reports say the Audi wore its tyres harder than the Nissan 300ZX and Mercury Cougar rivals. The very wide wheels and quattro traction were blamed. Budget extra Goodyear-sized rubber for demonstrations. 6
- Works-only spares — Engines, gearboxes, differentials, turbos and ECUs were never sold to customers. A Wanted request on racingcarnetwork.com from 4 November 2026 is hunting exactly these items, from single parts to team stock. on request 11
- Component migration between chassis — One 90 IMSA GTO went to South Africa in 1991. The engine and gearbox of S4 GTO chassis 001 came from a 90 IMSA GTO. Expect a car that lost or gained major units after 1989. 13
Checklist before you buy
- Establish which of the two 1989 race cars it is, or whether it is a spare or test chassis — Period records list number 4 as 90q-04 and number 5 as 90q-05 with the true chassis numbers unknown. Ask for Audi Sport or Audi of America build documents. 3
- Match the engine and gearbox numbers to the chassis history — The S4 GTO chassis 001 took its engine and six-speed gearbox from a 90 IMSA GTO. At least one original car has therefore lost major units. 13
- Confirm the frame is a steel tube space-frame with only the roof from a production 90 — The real car keeps the production roof panel and nothing else from the road car. A converted road shell is a tribute, not a works chassis. 6
- Inspect the rear-mounted rubber fuel cell and its aluminium container — The cell sits at the rear in an aluminium box. Bladders age out and the box is bespoke; ask when it was last replaced. 10
- Ask for the race history against the 1989 entry lists — Thirteen rounds are logged per car, including retirements for gearbox, steering, engine and an accident at Road America. Repairs after those events should be documented. 4
- Verify the 1989-era Bosch Motronic management is complete and supported — The ECU, sensors and harness are works items. The 2026 Wanted request on racingcarnetwork.com lists ECUs among the parts a buyer cannot find. 2
- Check what Audi Tradition holds and whether the car was ever in its fleet — Audi Tradition still owns and demonstrates a 90 IMSA GTO, so a private car should have a paper trail showing when it left the factory. 9
Running costs 11
| Rebuild interval | Not published. The works ran sprint rounds of one to two hours. It avoided the 24-hour and 12-hour races because the drivetrain was not expected to last 9. |
|---|---|
| Typical rebuild cost | Not published; no specialist quotes found. Treat engine and gearbox work as bespoke one-off engineering. |
| Consumables | Tyres for 14-inch-wide 17-inch rims, worn faster than rivals in period 610; fuel-cell bladder; turbo and brake discs are works items. |
| Spares availability | No customer parts supply ever existed. A November 2026 Wanted request on racingcarnetwork.com seeks engines, gearboxes, differentials, turbos, ECUs, suspension, brakes, wheels and bodywork for this car 11. |
Where it races today
- Demonstration events · Manufacturer and invited displays — Audi Tradition ran its car at the F.A.T. International Ice Race in Aspen and showed it at the Amelia concours in 2024, and used it for filming in 2022 9. Audi displayed one at Jarama in 2016 17. The S4 GTO sibling ran the Goodwood Festival of Speed hill in 2017 18. 9
- Historic racing series · Not established — No sanctioned historic series with a class for a 720 hp all-wheel-drive silhouette car was found. Assume demonstration use only until an organiser confirms otherwise. 6
Market prices
- Audi S4 GTO chassis 001 (carries a 90 IMSA GTO engine and gearbox), Collecting Cars sealed-bid sale: not published; result not found GBP (2026-03) 13
- Audi 200 quattro Trans-Am chassis TA/4 (1988 predecessor), offered by Canepa with spares: not published USD (2016-05) 15
- Wanted request on racingcarnetwork.com for Audi Sport IMSA GTO parts, budget on request: on request EUR (2026-11) 11
As of November 2026 no public auction of an original Audi 90 IMSA GTO was found. The only related sale is the S4 GTO derivative, offered by sealed bid in February-March 2026 13. Demand for works parts is active, as the November 2026 Wanted request on racingcarnetwork.com shows 11.
Reference prices are dated and sourced; live asking prices are in the listings above.
Frequently asked questions
How many Audi 90 IMSA GTOs were built and where are they?
One reference work says six were built, but Audi has not published a figure. Two cars raced in 1989. Audi Tradition keeps one in its fleet and still demonstrates it. One car went to South Africa in 1991 and donated its engine and gearbox to the S4 GTO chassis 001. The rest are unaccounted for in public sources.
Can I race one in a historic series?
No organiser with a class for this car was found. The works used it only in 1989 sprint rounds. Today it appears at demonstrations: Audi Tradition took its car to an Aspen ice race and the Amelia concours in 2024. Plan for hill runs and parade laps, not wheel-to-wheel racing.
What parts will I struggle to find?
Everything mechanical. The 2,190 cc engine, the six-speed gearbox, differentials, KKK turbo and Bosch Motronic ECU were works items never sold to customers. A November 2026 Wanted request on racingcarnetwork.com lists exactly these parts, which shows how thin the supply is.
How do I tell an original from a tribute?
An original is a steel tube space-frame with composite panels; only the roof comes from a production Audi 90. A tribute is usually a road 90 shell with wide arches added. Ask for Audi Sport or Audi of America build records and compare the car against the 1989 entry numbers 4 and 5.
Why did Audi skip Daytona and Sebring in 1989?
Audi says the late start meant the car was not ready for the season opener. Haywood added that the team did not expect the drivetrain to survive a 24-hour or 12-hour race. Missing those two rounds cost Audi the manufacturers' title, which went to the Roush Mercury Cougar.
What is the Audi S4 GTO and is it the same car?
No. The S4 GTO is a South African derivative built by Audi Sport South Africa for the 1992-1994 Wesbank Modified series on a C4 S4 silhouette. Two were built. Chassis 001 uses the engine and six-speed gearbox of a 90 IMSA GTO and was raced by Stuck on its debut.
Sources
- Audi 90 quattro IMSA GTO, model year 1989: most powerful five-cylinder works engine in motorsport, AUDI AG (2024) — Power 530 kW (720 hp) at 7,500 rpm, 720 Nm at 6,000 rpm, seven wins in 1989
- Audi 90 Quattro IMSA GTO specifications, Ultimatecarpage.com (2013) — Displacement 2,190 cc, bore and stroke, Motronic, KKK turbo, steel tubular frame, suspension, brakes, weight 1,207 kg, dimensions, six built, 324 bhp per litre
- Complete archive of chassis 90q-04#, RacingSportsCars.com (2024) — Car number 4 race-by-race results, retirements (gearbox Miami, steering Mosport, accident Road America, engine Del Mar), unknown real chassis number
- Complete archive of chassis 90q-05#, RacingSportsCars.com (2024) — Car number 5 race-by-race results, co-driver Scott Goodyear, retirements (accident Miami, oil leak Mosport, mechanical Portland and Del Mar), Goodyear tyres
- 1989 IMSA GT Championship, Wikipedia (2025) — GTO class winners by round, Audi absent from Daytona and Sebring
- #TheUnfairAdvantage: the Audi 90 IMSA GTO, Historic Motorsport Consulting (2015-07) — Silhouette rules, roof retained, steel space-frame, composites, six-speed with five used, late development, missed Daytona and Sebring, Miami debut DNFs, tyre wear versus Nissan and Mercury, two-year plan cut to one, move to DTM
- Audi 90 GTO poised to repeat history on iRacing, iRacing.com (2016-09) — List of the seven 1989 wins, five one-two finishes, second in drivers' and manufacturers' standings behind Halsmer and the Mercury Cougar
- quattro auf der Rennstrecke, AUDI AG (2020) — Tube-frame construction, 720 PS, seven wins, late entry and skipped Daytona and Sebring, 200 Trans-Am eight wins and titles, dimensions of the 200, return to DTM in 1990
- Audi Tradition fleet cars visiting America, Audi Club North America (2024-02) — Audi Tradition owns a 90 IMSA GTO, appearances at F.A.T. Ice Race Aspen and Amelia 2024, 2022 Electrikhana filming, Haywood on skipping long races
- Audi 90 IMSA GTO, ableitet.no (cites Meredith and Pollard quattro books) (2018-12) — Weight 1,206 kg, 14x17 wheels, rear rubber fuel cell in aluminium box, six-speed gearbox, Haywood and Stuck championship positions
- WANTED: Audi Sport & Gumpert Apollo parts - TransAm, IMSA GTO, Sport quattro S1, LMP, STW, V8 DTM, racingcarnetwork.com (2026-11) — Wanted request of 4 November 2026 for 90 IMSA GTO engines, gearboxes, differentials, turbos, ECUs, suspension, brakes, wheels, bodywork; budget on request
- SA-made Wesbank Modified Audi racer on auction, Business Day (2026-03) — S4 GTO chassis 001 on Collecting Cars 6 March 2026, first of two built, 2.2-litre engine from the IMSA GTO, 537 kW and 720 Nm, Stuck debut wins
- Ex-Hans-Joachim Stuck Audi S4 GTO silhouette racer is up for grabs, Octane (2026-02) — Sealed-bid sale by Collecting Cars, price undisclosed, engine and six-speed gearbox from a 90 IMSA GTO, chassis 001 provenance, Goodwood appearances
- The Audi 90 IMSA GTO's twin: the Audi S4 GTO, Audi Motorsport Blog (quoting a South African magazine) (2012-09) — One 90 IMSA GTO sent to South Africa in 1991 as the study base, two S4 GTOs built by Voldi, later owners
- For sale: 1988 Audi 200 quattro Trans-Am, Motorsport Retro (2016-05) — Chassis TA/2, TA/3, TA/4; eight wins of thirteen; SCCA ban on all-wheel drive and foreign engines for 1989; Canepa offer with spares, no price
- Stuck in the middle: IMSA GTO Audi 90, Jalopnik (2007-04) — Two cars entered, Rohrl and Goodyear as co-drivers for long races, second in GTO manufacturers' standings, budget moved to DTM
- Pic of the week: Audi 90 IMSA GTO, PistonHeads (2016-09) — Static display by Audi at Jarama in 2016
- This Audi S4 GTO is a legendary five-pot's last hurrah, Goodwood Road & Racing (2017-07) — S4 GTO one of two built, demonstrated on the Festival of Speed hill in 2017
- File:Audi90QuattroHH5a-89mia.jpg, Wikimedia Commons (1989-03) — Image licence and author
Did you know
- The 2,190 cc engine gave 324 bhp per litre, one of the highest specific outputs of any Audi works engine 2.
- The gearbox had six ratios but the rulebook allowed five, so Audi blanked one off rather than build a new box 6.
- Audi Tradition flew its 90 IMSA GTO to the United States in 2022 to film Electrikhana. It returned in 2024 for an Aspen ice race 9.
- The predecessor Audi 200 Trans-Am was 4.89 m long and 2.03 m wide, the largest race car Audi has built 8.
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