"Sabipa" with Bugatti wins the Italian Grand Prix

The Italian Grand Prix over 600 km at Monza was the fifth race of the 1926 World Championship, held to the international 1.5-Liter formula. It was hoped to be a Grand Finale with Bugatti, Delage and Talbot fighting it out. But this did not happen as Delage did not enter and Talbot withdrew leaving Bugatti unchallenged to secure the 1926 World Championship. Sabipa won after Costantini's Bugatti in the lead broke down two laps from the end though it was restarted after a long repair and finished second. Four other contenders retired, Alfieri Maserati and Materassi in Maseratis, Serboli (Chiribiri) and Goux (Bugatti). Simultaneously a 400 km race was held for 1100 voiturettes. It was won by the Amilcar of Morel with Duray also in an Amilcar second and De Joncy (BNC) third. The four retirements were Gubernatis (BNC), Martin (Amilcar) and the Marinos of Trevisano and Marino.

The Gran Premio d'Italia was held for the sixth time and was part of the 1926 World Championship. The Commissione Sportiva des RACI and the Società Autodromo di Monza carried out the organization under the supervision of Arturo Mercanti. It was the fourth event of the 1926 World Championship and was held at Monza over 60 laps of the 10 km circuit, a total of 600 km. Simultaneously a race for 1100 voiturettes was held over 40 laps or 400 km. The Automobile World Championship was held for the second time in 1926 and participation at the Italian Grand Prix at Monza was mandatory. After Indianapolis, France, Spain and Britain, Italy was the fifth and last event of the 1926 World Championship. Bugatti had to participate in the obligatory Italian Grand Prix if they wanted to claim the World Championship, where Bugatti held the lead with the best points score.

Entries: A total of 24 entries were received but by race day many had been withdrawn. As a result there were just 15 cars that would start, eight 1500 cars racing for the World Championship supported by seven 1100 cc cars in the Voiturette class. The 1500 cars included three Bugattis, two Maseratis and two OMs, all of them using 8-cylinder 1500 cc twin-cam engines with Roots supercharger and Bosch magneto ignition. While Bugatti and OM used Champion spark plugs, Maserati manufactured their own. The eighth 1500 car was a Chiribiri type Monza with a 4-cylinder twin-cam engine but without a supercharger. This car did not stand a chance in the race. The seven voiturettes, 1100 cc cars, were all supercharged and comprised three Amilcars, two BNCs and two Marinos. A complete list of all entries is at the beginning of this report.

Practice: During the middle of August, Maserati had carried out repeated trials at Monza with an unfinished car.       Before midday on Tuesday the red OM #5 racecar that was assigned to Minoia took to the track. After a few laps Minoia handed the car over to Morandi who punctuated his regular but not fast drive with frequent stops at the pits. Count Maggi, who was entered in one of the three OMs, made some laps with a touring car together with Balestrero. Last to go onto the track was the OM with Morandi and then with Maggi. After a few laps the car was loaded onto its truck and returned to Brescia.       On the Wednesday before the race, there was no great activity on the Monza track. The first to practice in the morning was De Joncy with his BNC. After a few laps, the driver who also had a mechanic on board was the victim of a frightening accident. At the timekeepers' stand, due to the blowout of a front tire, De Joncy lost control of the car at about 130 km/h. The BNC scrambled along a hundred yards and finally stopped against the parapet bordering the track without falling over. The damage was limited to three burst tires and a bent front axle. Neither driver nor mechanic was injured. In the OM pits Minoia acted as the manager and Foresti was with them as an observer. Balestrero, Maggi and Foresti were standing around the red # 5 OM where Morandi worked with the tiny Cavallari. After a couple of hours of serious work they started the engine. The OM was not easy to set up as the supercharger was placed upstream of the carburetor. The OM team had been there all day and left in the evening for Brescia. They intended to do the last test only on Saturday, on the eve of the race, but they did plan to be at the start.       Materassi with the Maserati practiced with Alfieri Maserati and Guido Meregalli as reserve. Shortly before 6 PM Materassi went out again to try some spark plugs, covering several laps in 3m56s and 3m54s. Goux practiced with his Bugatti and Costantini also completed a couple of laps in the afternoon, covering the oval track in 1m31s at an average of about 180 km/h, and the road circuit in 2m15s. The 3m46s lap was a respectable time but a day earlier Costantini had turned under 3m45s. In the race, if the tires would not give him trouble he could certainly reach 3m40s. With these tests Bugatti finished their setup. However it was possible that Sapiba would practice again to learn the track. Of the Amilcars only Duray practiced and drove a fast lap in 4m20s or 138 km/h.       Disappointingly, Delage had not entered and Talbot had withdrawn their Monza entries. Both teams had raced four weeks earlier at Brooklands where all their cars experienced serious mechanical defects, which possibly was the reason for not starting at Monza because the problems encountered could not be fixed in time.

Race: After the rainy days during practice, there was beautiful weather on Sunday, the day of the race. Spectator attendance was estimated at about 30,000. Disappointingly OM withdrew their cars on Saturday and were actually wise to do so, because the cars from Brescia were so poorly prepared, they would not have lasted many laps. OM was perhaps the last company one would have had hoped to withdraw but setting up a racecar cannot be done in a few days or hastily. Materassi with the red Maserati was for most spectators Italy's hope of the day while Costantini in the blue Bugatti was the clear favorite to win.       At 10:30 AM the race cars were being pushed from the pits to the start area. Materassi was leading with his faithful red Maserati - number 3. Alfieri Maserati followed a few meters behind with his car and mechanic, ahead of the two blue Amilcars of Duray and Martin, which were followed by Serboli, the only Chiribiri driver, who was loudly cheered. Next the blue Bugatti of Costantini emerged from the pits and he was highly favored. There was new applause as Goux headed towards the start. The Bugatti drivers were preparing for the last round of the World Championship. The most coveted title was theirs for the taking in the absence of Talbot and Delage, they only had to start.

7 Goux Bugatti 4 Serboli Chiribiri 3 Materassi Maserati 16 Sabipa Bugatti 12 Costantini Bugatti 9 Maserati Maserati 23 Morel Amilcar 22 Gubernatis BNC 21 Marinp Marino 27 De Joncy BNC 26 Martin Amilcar 24 Trevisani Marino 28 Duray Amilcar

At 11:00 AM the polar aviator General Umberto Nobile gave the starting signal by raising the blue flag and at a nod by Cavaliere Marley lowering it. Costantini immediately took the lead by completing the street circuit in 2m31s, followed after 7 seconds by Materassi, Sabipa and Maserati. At the end of the first lap the order was as follows: 1. Costantini (Bugatti) 4m08.0s 2. Materassi (Maserati) 4m21.6s 3. Sabipa (Bugatti) 4m25.0s 4. Maserati (Maserati) 4m26.4s 5. Goux (Bugatti) 4m26.6s 6. Morel (Amilcar) 7. Duray (Amilcar) 8. Martin (BNC) 9. De Joncy (BNC) 10. Serboli (Chiribiri) 11. Gubernatis (BNC) 12. Marino (Marino) 13. Trevisani (Marino) On the second lap Costantini increased his lead by lapping in 3m57s only slightly faster than Materassi's 3m58.8s. He was followed by Goux just ahead of Maserati who had both passed Sabipa. The beginning was electrifying and the spectators applauded Materassi and Maserati who bravely battled each other. At the end of lap two Costantini was 15 seconds ahead of Materassi, 26s ahead of Sabipa and 30s ahead of Goux. Gubernatis in the 1100 BNC was the first retirement on the second lap.       On the third lap Costantini still led the field, followed by Materassi 27 seconds behind. Martin's Amilcar retired on lap four with a seized supercharger. Materassi finished the fourth lap in 16m17.8s, but did not reappear since he retired with piston failure on the straight after passing the stands. Costantini led at an average of 150.5 km/h with the following times after 5 laps: 1. Costantini (Bugatti) 19m56s 2. Maserati (Maserati) 20m32s 3. Sabipa (Bugatti) 20m39s 4. Goux (Bugatti) 20m41s 5. Morel (Amilcar) 23m10s 6. De Joncy (BNC) 23m26s At the end of lap five Maserati arrived at reduced speed. The engine of his car was not working properly, but he passed his pit without stopping. However shortly afterwards he came to a halt at the end of the straight. Both Maseratis, which had formed the crowd's main hope for a win, were now out of action with engine problems. Broken pistons, supercharger and bearing damage were quoted as the reasons for the retirement of the two Masertis. Goux and Sabipa now automatically advanced behind Costantini who lapped in 3m56s to 3m57s. Morel was the first of the voiturettes and kept his lead to the end. De Joncy in second place was unable to threaten him. Marino stopped at the pits to change spark plugs but retired on the seventh lap.       On the ninth lap Sabipa arrived with a flat rear tire, stopped at the pits, changed the wheel and rejoined the race. On the next lap Goux also stopped to change a tire. Duray's Amilcar fell behind because its engine was running irregularly. The fastest of the first 10 laps was driven by Costantini in 3m55s at an average of 153.191 km/h but his race average was 151.100 km/h after 100 km when the positions were as follows: 1. Costantini (Bugatti) 39m42.4s 2. Sabipa (Bugatti) 42m45.6s 3. Morel (Amilcar) 45m32.6s 4. Goux (Bugatti) 45m56.4s 5. De Joncy (BNC) 46m30.2s 6. Duray (Amilcar) 48m16.2s 7. Serboli (Chiribiri) ----- On lap 11 Trevisani retired the Marino with engine problems. On the following lap De Joncy stopped the BNC to change a spark plug and Serboli stopped to replace the fuel tank cap. Costantini improved his time on lap 15 with a lap in 3m51.6s at 155.440 km/h average speed. Morel, driving regularly, lapped the Amilcar of his teammate Duray on lap 16 when he also made the fastest lap of the voiturettes in 4m19.2s at 138.907 km/h average speed. Sabipa changed another tire on the nineteenth lap. The positions were as follows after 20 laps: 1. Costantini (Bugatti) 1h18m55.8s 2. Goux (Bugatti) 1h21m49.2s 3. Sabipa (Bugatti) 1h26m03.0s 4. Morel (Amilcar) 1h29m35.0s 5. Duray (Amilcar) 1h34m54.8s 6. De Joncy (BNC) 1h39m20.0s 7. Serboli (Chiribiri) 1h49m24.6s Refueling took place between lap 22 and 25. Costantini was first of the Bugatti team to stop at the pits and was passed by Goux, but on the 29th lap he took his lead back. On the 28th lap there was an incident that broke the monotony of the race. The Chiribiri of Serboli caught fire in the turn before the finish straight, when fuel spilled out from the open fuel tank after the fuel cap had fallen out. The fuel splashed onto the hot exhaust pipe and ignited the rear of the car. It passed in front of the stands with the exhaust pipe completely in flames, but Serboli was not aware of the serious danger. Only shouts from the crowd made him look around to see the flames that grew larger from one moment to the next. Serboli did not lose his calm, he turned off the engine, braked slightly, stood up, holding the steering wheel with one hand, and climbed out of the seat, which was being lapped by flames, putting his feet on the edge of the chassis. In this position he drove the car, which had lost most of its speed, in front of the pits. Unfortunately the car came to a halt at a fuel station. The moment was dramatic. The flames continued leaping at the bodywork. It was feared that the fuel tank would explode any moment, but firefighters rushed with extinguishers and in short time the fire was doused. The car was retired with damage to the rear bodywork. After 300 km, halfway, the times were as follows after 30 laps: 1. Costantini (Bugatti) 2h02m00.6s 2. Goux (Bugatti) 2h06m13.2s 3. Sabipa (Bugatti) 2h08m50.6s 4. Morel (Amilcar) 2h16m56.8s 5. Duray (Amilcar) 2h25m43.4s 6. De Joncy (BNC) 2h29m29.0s On the 37th lap Goux arrived at the grandstands with the engine backfiring. He stopped at the pits and started again, but came to halt at the end of the straight where he parked the Bugatti on the grass next to the track with oil pump trouble. Goux walked along the track back to the pits. Meanwhile Morel in the 1100 Amilcar was on his last lap, and ended his race to the applause of the spectators. Duray and De Joncy finished next. Costantini kept leading the Grand Prix with the order of the field after 40 laps: 1. Costantini (Bugatti) 2h46m10.0s 2. Sabipa (Bugatti) 2h49m00.2s 3. Morel (Amilcar) 3h03m22.8s 4 laps behind 4. Duray (Amilcar) 3h09m26.4s 5 laps behind 5. De Joncy (BNC) 3h16m52.0s 7 laps behind Once the voiturettes had completed their 40 laps, there were only two cars left circulating the track, the Bugattis of Constantini and Sabipa. After 45 laps Costantini led in 3h06m12s at 144.997 km/h average speed. Sabipa changed tires on the 47th lap. On lap 50 Sabipa stopped once again in the pits and refueled. After the 50th lap the times were: Costantini 3h26m06.6s at an average of 145.532 km/h followed by Sabipa in 3h35m20s. On lap 58 Costantini passed the stands at a reduced pace with a loud rattle under the car's hood and stopped at the pits. His mechanic worked for a long time on the engine as the valves had been damaged. His Bugatti was no longer able to compete, or so it seemed. Costantini lost 12½ minutes so Sabipa who had been more than nine minutes behind passed Constantini while he was in the pits. Costantini restarted slowly, driving with three cylinders running at a speed of about 50 km/h to complete the last two laps of the boring race. Meanwhile Sabipa had completed the 60 laps to become the winner of the Italian Grand Prix. Nobody had expected Louis Charavel with the pseudonym "Sabipa" to be the victor but during the entire race he had proved to be a careful and reliable driver. When Costantini finally arrived the spectators received him with enthusiastic applause. But having led for all but the last two laps, it was of little solace to him.

Meo Costantini with Bugatti wins the Milan Grand Prix

An assortment of 20 racecars appeared at the start of the 400 km Milan Grand Prix at Monza. Bugatti started with nine cars and their success was corresponding with Costantini, Goux, Farinotti and Chiron finishing in the first four positions and Stefanelli in sixth place. Bugatti's competition consisted of Segrave with a 12-cylinder Sunbeam, which led the first 12 laps before retiring and Brilli Peri in the 5.8-Liter Itala Special who lost considerable time with problems restarting and finished fifth. On lap 13 Costantini (2000 Bugatti) inherited first place which he held unchallenged until the end. The 1500 class was led by Ernesto Maserati (Maserati) until three laps from the end when he retired and Stefanelli won the class. De Joncy (BNC) won the 1100 category. Materassi (Maserati) retired after 11 laps.

The Gran Premio Milano was organized by the Commissione Sportiva des RACI and the Società Autodromo di Monza who carried out the organization under the supervision of Arturo Mercanti, the Director of the Society who was also President of the Milan AC. The race was held at Monza over 40 laps of the 10 km circuit, a total of 400 km, and was run to formula libre regulations. As a result the organizer received a large entry of 32 cars which were divided into four categories, 1100 cc, 1500 cc, 2000 cc and over 2000 cc. The Automobile Club had a total prize fund of 200,000 lire of which the overall winner received 80,000.

Entries: Although there were 32 entries, only twenty starters appeared on race day. Segrave entered the 4-Liter 12-cylinder Sunbeam, which was famous for holding the Kilometer land world speed record of 245.114 km/h, set on March 16, 1926 at Southport. The green Sunbeam had a reinforced front axle which had been fitted after their disastrous experience at the Spanish Grand Prix. Brilli Peri appeared with the red 5.8- Liter Itala Special apparently on loan from Emilio Materassi. The 2000 category comprised seven 2-liter race cars, the 80 hp touring type Bignan of French Pierre Clause and a variety of six 8-cylinder Bugattis. The two factory entries were the fastest Bugattis, now equipped for the first time with superchargers, producing 130 hp. The car of Jules Goux was blue while Meo Costantini's was red in respect of his nationality. He had wire wheels to fit Dunlop tires. The other Bugatti entries came from France with Chiron, Tunisia with Eyserman and Italy with Farinotti and Montanari.       The 1500 category also comprised seven starters. The two red supercharged 8-cylinder Maseratis for Materassi and Ernesto Maserati were the favorites. Stefanelli and Varzi were in 4-cylinder Bugattis while the two 4-cylinder Chiribiris were driven by Roberto Serboli and the Swiss H. Jenter from Zürich. The last car was the French 6-cylinder Jean Graf for Maleterre, a lesser known driver.       The four cyclecar entries comprised the two BNCs of de Joncy and Gubernatis, the Salmson of Clerici and the Jean Graf driven by Graf himself. A list of all entries is at the beginning of this report.

Practice: On Wednesday Segrave practiced with the 4-liter 12-cylinder Sunbeam and was timed on three consecutive laps at 3m33, 3m33s and 3m34.4s. The lap times obtained on the road circuit were 2m08s, 2m08s; those on the track 1m25s; 1m25s. On the 4500 meters of the oval track, the Sunbeam achieved an average of 191 km/h and on the complete circuit 169 km/h, which was faster than the official record of Antonio Ascari with the 2-Liter Alfa Romeo. At the same time, Costantini with the two-liter Bugatti lapped in 3m36s over the whole circuit. Goux practiced without forcing his car. Achille Varzi who was to debut on Sunday in an automobile race with his 1500 Bugatti drove his first test laps. Before the evening the Frenchman Chiron went out for practice as did Jenter in the Chiribiri, who had arrived directly from Zurich. Alfieri Maserati who was at Monza, announced that his two cars would not start in the Milan Grand Prix.       On Thursday Segrave was practicing again, also Clerici with the Salmson, Ciriaci in the Fiat 503 and Clause in the Bignan. From the Bugatti team only Goux practiced, driving some very fast laps. Achille Varzi with the 1500 Bugatti also did some fast laps and Farinotti completed various laps in the 3m56s - 3m58s range. Montanari, Chiron and Eyserman also practiced in their Bugattis.       Contrary to what had been said by Alfieri Maserati one day earlier, two Maseratis would be driven by Materassi and Ernesto Maserati to compete in another demonstration of their reliability. Participation, especially that of Materassi was important, since he for the last two years had been the driver who collected the most victories in Italy. One Maserati did several laps without forcing. A Jean Graf and Gubernatis with the BNC also took part in the practice.       The entries included two daring young ladies, Signorina Gilda Colli and Signorina Pina Conti, who were not expected to be sufficiently fast and would jeopardize the much faster cars. For that reason Race Director Arturo Mercanti established an eliminating test run of three consecutive laps at the minimum average speed of 120 km/h to qualify for the race. The two young ladies who drove standard Amilcars had to take part in this test, which included Guido Ciriaci in a Fiat 503 with touring car chassis and the Jenter with his Chiribiri. Only Jenter was admitted to the race.

Race: By 2:00 PM the Autodrome had filled with spectators. The grandstands and the other viewing areas contained a fair number of spectators but certainly not as many as seen at the boring Grand Prix one week earlier. Many enthusiasts were scattered around the circuit, especially at the famous Lesmo curve. Eventually the 20 cars were brought from the pits to the finish line to be arranged on the grid as follows

12 Clause Bignan 11 Eysermann Bugatti 3 Brilli Peri Itala Spl 1 Segrave Sunbeam 19 Costantini Bugatti 18 Goux Bugatti 15 Chiron Bugatti 14 Farinotti Bugatti 27 E. Maserati Maserati 24 Maleterre Jean Graf 23 Materassi Maserati 22 Montanari Bugatti 31 Gubernatis BNC 30 Varzi Bugatti 29 Stefanelli Bugatti 28 Serboli Chiribiri 25 Jenter Chiribiri 36 de Joncy BNC 33 Graf Jean Graf 32 Clerici Salmson

The engines were started one minute before take-off and screamed angrily awaiting the start. The Race Director Arturo Mercanti started the cars at 2:30 PM in a superb show as Segrave shot away ahead of Brilli Peri and Costantini with the two Jean Grafs of Malterre and Graf at the tail of the field.       After the first lap Segrave led in 3m54.2s ahead of Costantini in 4m02.8s, Goux in 4m12.6s and Brilli Peri in 4m13.8s. After a gap, Chiron, Eyserman, Farinotti, Materassi and Montanari were next. Maserati was leading the 1500 category and De Jony was first of the 1100 class. The 1100 Jean Graf of Graf passed by slowly with the engine running irregularly and would soon be out of the race.       After the 2nd lap Segrave led in 7m41s ahead of Costantini in 7m50s. Goux in 8m10s and Brilli Peri also in 8m10s had a close battle with identical times; they must have crossed the line virtually side by side. They were followed by Materassi in 8m44s and Eyserman in 8m54s.       Lap by lap Segrave and Costantini distanced themselves from the other drivers. Goux and Brilli Peri formed a second duo, followed after a 30 seconds gap by Materassi, Eyserman, Chiron and Farinotti. The 1500 group was composed of Ernesto Maserati, Stefanelli and Varzi, Serboli was already far behind the leaders. Segrave did not seem to force the pace, lapping between 3m47s and 3m50s, ahead of Costantini who did not lose sight of the leader, driving in 3m47s and 3m55s. Brilli Peri and Goux drove in the four minutes range and Materassi in 4m02s. Clause had stopped his standard chassis Bignan in the pits on the 2nd lap and resumed, but only after a very long stop. Since the car was no longer recorded by official timing, his position in relation to the other cars is not known. The Jean Graf of Maleterre stopped on lap four at the pits. Goux and Brilli Peri had been having a wheel to wheel race separated by only a second or so. Chiron and Materassi were only a few seconds behind them. After the fifth lap the order was as follows: 1. Segrave (Sunbeam)   19m13.2s 2. Costantini (Bugatti 19m30.6s 3. Goux (Bugatti) 19m48.2s 4. Brilli Peri (Itala Spl)) 19m49.0s 5. Chiron (Bugatti) 20m50.6s 6. Materassi (Maserati) 20m52.2s 7. Farinotti (Bugatti) 21m26s    8. Eyserman (Bugatti) 21m49s    9. E. Maserati (Maserati) 23m22s    1 lap behind 10. Montanari (Bugatti) 23m23s    1 lap behind On the sixth lap the Bugatti of Chiron stopped at the pits for 48 seconds to change a rear wheel. The Chiribiri of Serboli also stopped for one minute at the pits. After the 7th lap Segrave led in 26m49s, ahead of Costantini in 27m22s, Goux in 27m27s, Brilli Peri in 27m34s and Materassi in 28m02s. After lap eight Segrave's time was 30m39s, Costantini 31m10s, Goux 31m20s, Brilli Peri 31m22s and Materassi 33m22s. The Jean Graf of Maleterre was stranded in the pits with carburetor failure and required new spark plugs as did the car of Graf prior to his retirement. Varzi also stopped at the pits to change spark plugs. On lap ten Segrave drove a fast lap in 3m43.2s at 161.434 km/h and led after 100 km at 154.841 km/h with the times as follows: 1. Segrave (Sunbeam) 28m14.0s 2. Costantini (Bugatti) 38m59.6s 3. Goux (Bugatti) 39m03.4s 4. Brilli Peri (Itala Spl) 39m06.4s 5. Materassi (Maserati) 41m51.4s 6. Farinotti (Bugatti) 42m44.0s 1 lap behind 7. Chiron (Bugatti) 43m04.4s 1 lap behind 8. Eyserman (Bugatti) 43m16.6s 1 lap behind 9. E. Maserati (Maserati) 46m12.4s 2 laps behind 10. Montanari (Bugatti) 46m43.4s 2 laps behind 11. Stefanelli (Bugatti) 47m26.8s 2 laps behind 12. De Joncy (BNC) 47m57.4s 2 laps behind Segrave drove the tenth lap in 3m43.2s at 161.434 km/h average speed. On lap 12 Materassi who was leading the 1500 category in his Maserati retired at the pits with the fuel tank broken. Farinotti stopped at the pits on lap 12 to change rear tires. On the same lap Eyserman broke his oil sump and damaged his engine bearings, which ended his race. Since he was one lap behind, he had completed only ten laps. On lap 13 the red Bugatti of Costantini appeared in first place, followed slowly by Segrave who stopped at his pit where he retired with a broken gearbox. From then on Costantini had an easy time because his opponents were far behind and could not threaten him. Brilli Peri stopped to change the left rear tire. The change was made quickly, but the heavy car refused to start and had to be pushed for a hundred meters. Only after several attempts, lasting 15 minutes, was Brilli Peri able to start again. Varzi retired on the 13th lap due to bearing damage. Since he was more than two laps behind, he had completed only ten laps.       After 15 laps Costantini held the lead in 58m19 s followed by Goux in 59m42s, Chiron in 1h06m36s, Farinotti 1h09m16s, Maserati 1h09m32s, Montanari 1h10m23s, Stefanelli 1h10m40s, De Joncy 1h11m37s, Jenter 1h12m24s and Serboli 1h12m59s in tenth place. Maserati was forced to make frequent stops in an attempt to solve his carburetion problem. After lap 15 Costantini stopped at the pits where he refueled in exactly 30 seconds. On lap 17 Costantini drove the fastest lap of the race in 3m41.2s at 162.016 km/h average speed. The Bignan of Clause reappeared after its 'rest' on the first lap but it had to stop again. The BNC of Gubernatis stopped to refuel, and the Bugatti of Chiron, stopped at the pits to change spark plugs leaving immediately. On the 20th lap Goux refueled and changed the two rear wheels losing three minutes. Costantini led after 20 laps at 155.520 km/h km average speed, with the field in the following order after 20 laps: 1. Costantini (Bugatti) 1h17m19.6s 2. Goux (Bugatti) 1h21m02.4s 3. Farinotti (Bugatti) 1h30m14.4s 3 laps behind 4. E. Maserati (Maserati) 1h32m41.6s 3 laps behind 5. Chiron (Bugatti) 1h32m58.0s 3 laps behind 6. Stefanelli (Bugatti) 1h33m44.6s 4 laps behind 7. Montanari (Bugatti) 1h33m45.0s 4 laps behind 8. Brilli Peri (Itala Spl) 1h34m21.2s 4 laps behind 9. Jenter (Chiribiri) 1h36m45.6s 4 laps behind 10. Serboli (Chiribiri) 1h38m21.2s 5 laps behind 11. De Joncy (BNC) 1h40m26.6s 5 laps behind 12. Clerici (Salmson) 1h40m26.6s 5 laps behind Costantini who was on his 21st lap, refueled and enjoyed mineral water, leaving after a stop of only 50 seconds without spinning the tires. On the 22nd lap Costantini led in 1h25m48s, followed by Goux in 1h28m42s. Maserati stopped to refuel and check his engine problems. The BNC of Gubernatis retired on lap 23 and since he was at least 6 laps behind, he had completed only 17 laps.       On lap 24 Costantini led in 1h34m12s. Brilli Peri stopped at the pits to replace tires and lost about 10 minutes before his car restarted. The Jean Graf of Maleterre retired from the race after many pit stops due to spark plug problems and may have completed only 10 laps.       After 25 laps, Costantini held the lead in 1h38m00s followed by Goux in 1h40m07s, Chiron in 1h53m56s, Farinotti 1h54m15s, Montanari 1h56m46s and Stefanelli 1h56m46s in a close battle, Maserati 1h58m13s, Jenter 2h00m22s, Brilli Peri 2h00m56s, Serboli 2h05m59s, De Joncy 2h03m13s and Clerici 2h08m01s in twelfth place. On the 28th lap Costantini led in 1h49m22s ahead of Goux in 1h52m10s. On his 29th lap Goux was forced to drive half a lap on a wheel rim at a reduced pace. He stopped at the pits at the end of the lap to replace the left rear wheel and had fallen two laps behind the leader. Montanari and Stefanelli still had a close battle with less than one second between them. The order of the 12 car field was as follows after 30 laps: 1. Costantini (Bugatti) 1h57m05.4s 2. Goux (Bugatti) 2h05m39.4s 2 laps behind 3. Chiron (Bugatti) 2h14m44.4s 4 laps behind 4. Farinotti (Bugatti) 2h15m02.4s 4 laps behind 5. Montanari (Bugatti) 2h19m40.2s 5 laps behind 6. Stefanelli (Bugatti) 2h19m40.6s 5 laps behind 7. E. Maserati (Maserati) 2h19m58.8s 5 laps behind 8. Brilli Peri (Itala Spl) 2h20m41.2s 5 laps behind 9. Jenter (Chiribiri) 2h23m42.4s 6 laps behind 10. De Joncy (BNC) 2h26m50.2s 7 laps behind 11. Serboli (Chiribiri) ----- 12. Clerici (Salmson) ----- On the 31st lap Montanari stopped for five minutes in the pits to change spark plugs and Goux stopped again to have one spark plug replaced. Costantini at that time had an advantage of eight minutes and was leading at an average speed of 153.815 km/h. On lap 33 Costantini's time in the lead was 2h08m39s. On lap 34 Montanari retired because of irregularities in the engine. He changed spark plugs, but it was probably a matter of broken valve springs. Montanari was 5 laps behind, so he had completed just 28 laps. On lap 35 Costantini was leading in 2h16m12s. On lap 36 the Swiss H. Jenter left the track at the Lesmo curve and overturned his Chiribiri which then was on fire but the driver was unharmed. Jenter was six laps behind and he had completed only 29 laps.       On the 37th lap and just 30 km from the end, Maserati's magnificent race came to an end when he retired with a broken fuel tank; first he stopped at the pits and then he retired along the track. He was 5 laps behind, so he retired on his 32nd lap. (To avoid bad feelings with outside firms, it was said that the fuel tanks had given way. It was a pretext that would be used frequently as an official reason by the factory to justify their retirements.) Stefanelli inherited first place in the 1500 category. During the following laps up to the end of the 40th lap the Bugatti of Costantini always passed in the lead. He crossed the finishing line greeted by the notes of the Marcia Reale followed by the Giovinezza, and received great applause and cheering. He completed the 400 km race in 2h36m18.4s at an average of 153.444 km/h, eleven minutes ahead of the second finisher and after having made the fastest lap at an average of 162.016 km/h.