Private League Derivative for TTM at THR
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Engine:
- Type: Alfa Romeo 061.58
- Configuration: 1.76L inline-4 DOHC 8V with EFI
- Aspiration: modified Garrett T3 turbocharger (2.2 bar)
- Fun Fact: Campionato Italiano Superturismo Class S1 allowed upgraded Group A cars

Pros:
- low weight
- strong brakes
- strong acceleration
- optional 6-speed
- tons of final ratios
- weight balance, thanks to transaxle gearbox

Cons:
- significant turbo lag
- boost comes on like a light switch
- only 5 gears for top speeds over 270 km/h
- live axle in the rear (AC does not support De Dion natively)
- low downforce (not adjustable)
- prone to flatspotting while braking
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Model: SimBin RACE 07, edit rFactor TCL, conversion AC unknown (v1.1)
Model Damage & Dirt textures: Valentin K
Authentic 1991 CIS liveries: Unknown
Authentic 1990 CIS liveries: Valentin K (except Windscreen & Hood stripes)
CSP Config: Valentin K
collider.kn5: Kunos (M3), adapted by Valentin K (adjusted position & nose/tail geometry)

Physics baseline: unknown, edited by AC Racer (v1.1)
- TTM Edits by Valentin K: Engine, Tyres, Aero, Tank, Weight, CIS Race 2 gearbox
- TTM Edits by JackCY: Suspension, Engine inertia, Group A gearboxes & final ratios
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The story behind the Alfa Romeo 75 Turbo Evoluzione S1 is a long and somewhat troubled one. Sit back and keep reading to find out how a failed Group A car evolved to become an important stepping stone on the way to international dominance.

The Alfa Romeo 75 1.8 I.E. Turbo Evoluzione was Alfa Romeo's Group A homologation evolution model, based on the promising transaxle midsize sedan that was the 75. Derived from the normal 75 Turbo, the Evoluzione was propelled by a slightly destroked and turbocharged aluminium inline-4 engine with a displacement of 1.762cc with an 8-valve DOHC head. A 5-speed transaxle gearbox by Brena transported the power to the rear wheels, which were on a De Dion Axle. Unfortunately, the Turbo Evoluzione turned out to be a competitive disaster. Its participation in the 1987 WTCC became a calamity due to an overly restrictive exhaust setup that choked the engine. Alfa Romeo was not willing to fund another evolution homologation to fix that issue, and pulled out of the WTCC before the overseas rounds (such as the Bathurst 1000) to skip the logistics costs of contesting these. The car fared no better in the DTM that year, where defending champion Kurt Thiim (coming from a Rover SD1) finished the 1987 season in an utterly disappointing 21st place with only two top-10 results.

The car got a new chance to shine in the spotlights back at home, though, when the Giro automobilistico d'Italia was revived in 1988. This event consisted of a mixture of rally stages and circuit races across Italy, and in contast to the previous 1973-1980 editions, it put a far greater emphasis on rally stages now. Interestingly, alongside Group A and Group N cars, the organizers allowed cars built according to IMSA regulations from North America to compete as well. Alfa Romeo made full use of that and built IMSA versions of the 75 Turbo Evoluzione.

The 1988 edition was won by a trio of 335 hp IMSA-spec factory Alfa Romeos. Top honours went to the crew formed between Formula 1 driver Riccardo Patrese and WRC aces Miki Biasion & Tiziano Siviero. Their team mates Nicola Larini, Dario Cerrato & Giuseppe Cerri (2nd place) and Alessandro Nannini, Yves Loubet & Jean Marc Andrié (3rd) completed the podium. Further domestic success in 1988 was provided by Gianfranco Brancatelli, who won the inaugural season of the Italian Touring Car Championship in a 75 Turbo Evoluzione.

For the 1989 edition of the Giro automobilistico d'Italia, Alfa Romeo installed a larger Garrett turbocharger (probably the T5, as the T3 had been the standard type) and cranked the boost up to 2.0 bar, harvesting 400 hp at 7100 rpm. The trio of boosted featherweights (976 kg) was good for a top speed of 300 km/h now. Without any serious competitors in their class, Alfa Romeo's IMSA cars dominated once again. Giorgio Francia, Dario Cerrato and Giuseppe Cerri emerged victorious ahead of their team mates Nicola Larini, Miki Biasion & Tiziano Siviero. However, 3rd place went to the privateer trio of Federico D'Amore, Gabriele Noberasco & Daniele Cianci in the Group A model of the 75 Turbo Evoluzione. The third of the factory IMSA Alfa Romeo piloted by Roberto Guerrero, Yves Loubet, and Jean Marc Andrié took 4th place after an accident in a night race had taken out its headlights and forced Guerrero into the pits. Due to lack of interest from other manufacturers, the Giro automobilistico d'Italia was abandoned after the 1989 edition, and the IMSA cars became museum pieces.

Once its Giro d'Italia commitments were over, Alfa Corse decided to put a greater emphasis on the Italian Touring Car Championship for the 1990 season, which was renamed to Campionato Italiano Superturismo (CIS) and introduced a new class called S1. While the IMSA cars were not permitted to drive there, it allowed a variety of upgrades without having to build another 500 road cars for homologation. Alfa Romeo saw an opportunity, and went for it. The bodywork, ultra-reinforced and lightened according to S1 specifications – therefore without the IMSA widenings, but retaining the width of the Group A 75 Turbo Evoluzione with the exception of the rear spoiler – was prepared to take on the fierce BMW squad that had put Roberto Ravaglia, Johnny Cecotto, Gabriele Tarquini, and Emanuele Pirro behind the wheel of the effective M3s.

Rather than competing with a full factory team, Alfa Romeo entrusted Jolly Club with the management of its efforts in the CIS. Jolly Club also backed CiBiEmme Sport as a quasi works team. Star driver Nicola Larini (#5) won four races but only contested 8 of 20 races due to his parallel Ligier F1 commitments. Despite that, he took home 3rd place in the drivers championship as the best Alfa Romeo driver with less than half the score of Ravaglia (BMW). In Larini's absence, Gianni Morbidelli flew the flag for the number 5 Alfa 75, winning at Misano and finishing second at Imola. Marco Brand in the #21 secured two podium finishes with a flamboyant driving style but his championship score was nothing to write home about. It is interesting to note that, despite the extreme mechanicsal setup (the cylinder head has no gasket because no gasket could withstand such stress), the problems encountered in the race that led to the retirements were due to the tires or driver errors, but the S1 car itself always proved to be a winner. At the end of 1990, CiBiEmme Sport sold its two 75 Turbo Evoluzione S1 cars and became Alfa Romeo's fiercest rival by becoming the official BMW Italia team for 1991 and 1992, campaigning the mighty M3.

In 1991, Alfa Romeo homologated a new 6-speed transmission and another 51 (!) different new final ratios as an extension to the Group A homologation of the aging car. Giorgio Francia missed out on the drivers title but delivered a runner-up finish in Super Turismo Divisione S1 after a strong season in the 75 Turbo Evoluzione S1 of the Jolly Club Totip team. One of the CiBiEmme chassis from the previous season (CBM005) carried Ernesto Vita to 6th place as the best privateer. But even in the S1 class of the Campionato Italiano Superturismo, the writing was on the wall for the aging transaxle design now, to make way for its successor.

The new Alfa Romeo 155 GTA S1 (Abarth Project SE051) debuted in 1992, and that car was a whole different animal. Derived from the 2.0 liter turbocharged 155 Q4 with 4-wheel-drive, Alfa Romeo's engineers pushed 2.5 bar of boost from a Garrett T3 into the powerplant and converted its rear suspension geometry to a MacPherson layout with the blessing of the championship organizers. That proved to be a mistake, because the SE051 dominated the S1 class of the 1992 Campionato Italiano Superturismo class to such an extent that it was discontinued after that year: it locked out the top 4 of the drivers championships with 17 wins in 20 races. In addition to that, the crushing dominance of the 155 GTA laid the groundwork for its far better-known younger brother: SE052 was the code name behind the Alfa Romeo 155 2.5 V6 Ti that Alfa Romeo developed to the new Class 1 regulations for the 1993 DTM season. Alfa Romeo dominated that in similar fashion, because none of their competitors brought a full-blown Class 1 car to the grid. The Italians bagged the manufacturers title, and Nicola Larini's points margin over runner-up Roland Asch (190E) was more than 25%.

Neither of these dominant 4-wheel-drive beasts would have seen the light of day without the late successes of the little-known domestic IMSA and S1 evolutions of what had started its competitive career as a very disappointing Group A touring car.