Bourdais shaded Meyer Shank Racing Acura driver Tom Blomqvist by 0.110s to secure his fourth pole from six races this year in the #01 Cadillac he shares with Renger van der Zande.
Neither the Frenchman or team-mate Alex Lynn's #02 machine left pitlane until just before the halfway mark in the Daytona Prototype international class’s 15-minute session, by which time the Acuras were already in the 1m19s zone.
Wayne Taylor Racing’s championship leader Ricky Taylor set the early pace, a tenth quicker than Blomqvist's MSR machine. Taylor had just had time to extend that margin to almost half a second when Bourdais delivered a 1m19.017s to put Cadillac on top.
Taylor’s first response drew him to within 0.033s of the Ganassi car, but couldn’t knock it off the top, even when Bourdais struck the Turn 2 wall trying to improve his time. In fact, it was Blomqvist, a first-timer on this track, who found the speed from the Acura ARX-05 to beat Bourdais and duck down under the 1m19s barrier.
But Bourdais, having checked his car wasn’t damaged from the Turn 2 wall-brush, delivered a 1m18.818s lap to shade Blomqvist and beat Lynn by half a second. Then as he tried to improve still further, Bourdais lost the rear end of his car, but somehow kept it off the wall, backed up, and then drove to the pits to celebrate.
A late improvement saw series returnee Olivier Pla - in for Tristan Nunez at Action Express Racing - pip fellow Cadillac driver Tristan Vautier’s JDC Miller MotorSports entry, but the pair were 1.5s behind the polesitter.
An equally thrilling battle for GT Daytona honours could have gone one of four ways, as the two Vasser Sullivan Racing Lexus RC Fs of Kyle Kirkwood and Frankie Montecalvo faced up to the challenge of Madison Snow in the BMW M4 of Paul Miller Racing, and Roman De Angelis in the Heart of Racing Aston Martin Vantage.
All four were chipping away tenths and then hundredths right up until the checkered flag, when newly-signed Andretti Autosport IndyCar driver Kirkwood made a final improvement to 1m29.096s that put him 0.118s beyond the reach of the opposition in the car he'll share with Ben Barnicoat.
Kirkwood is pulling double-duty this weekend with the AJ Foyt IndyCar team - replacing Jack Hawksworth after the Briton was injured in a motocross accident - and set fastest time in this afternoon’s IndyCar practice session.
De Angelis was next up, mere hundredths ahead of Snow, with Montecalvo fourth yet only 0.2s behind his Lexus team-mate.
IMSA Detroit Qualifying Results
| Cla | Driver | Class | Chassis | Laps | Time | Gap |
|---|---|---|---|---|---|---|
| 1 |
 Renger van der Zande  Sébastien Bourdais
| DPi | Cadillac DPi | 8 | 1'18.818 | |
| 2 |
 Oliver Jarvis Tom Blomqvist
| DPi | Acura DPi | 11 | 1'18.928 | 0.110 |
| 3 |
 Ricky Taylor  Filipe Albuquerque
| DPi | Acura DPi | 11 | 1'18.945 | 0.127 |
| 4 |
 Earl Bamber Alex Lynn
| DPi | Cadillac DPi | 7 | 1'19.334 | 0.516 |
| 5 |
Olivier Pla  Pipo Derani
| DPi | Cadillac DPi | 11 | 1'20.298 | 1.480 |
| 6 |
Tristan Vautier Richard Westbrook
| DPi | Cadillac DPi | 10 | 1'20.331 | 1.513 |
| 7 |
Ben Barnicoat Kyle Kirkwood
| GTD | Lexus RC F GT3 | 10 | 1'29.096 | 10.278 |
| 8 |
 Roman De Angelis Ross Gunn
| GTD | Aston Martin Vantage GT3 | 10 | 1'29.214 | 10.396 |
| 9 |
Bryan Sellers Madison Snow
| GTD | BMW M4 GT3 | 11 | 1'29.286 | 10.468 |
| 10 |
Frankie Montecalvo Aaron Telitz
| GTD | Lexus RC F GT3 | 10 | 1'29.299 | 10.481 |
| 11 |
Ryan Eversley  Aidan Read
| GTD | Acura NSX GT3 | 10 | 1'29.544 | 10.726 |
| 12 |
Robert Megennis Jeff Westphal
| GTD | Lamborghini Huracan GT3 | 10 | 1'29.781 | 10.963 |
| 13 |
Russell Ward  Philip Ellis
| GTD | Mercedes AMG GT3 | 10 | 1'29.810 | 10.992 |
| 14 |
Mike Skeen Stevan McAleer
| GTD | Mercedes AMG GT3 | 11 | 1'29.858 | 11.040 |
| 15 |
Robby Foley Bill Auberlen
| GTD | BMW M4 GT3 | 10 | 1'30.201 | 11.383 |
| 16 |
Ryan Hardwick  Jan Heylen
| GTD | Porsche 911 GT3 R | 10 | 1'30.903 | 12.085 |
| View full results | ||||||
