Practice pacesetter Castroneves looked to be in a strong position to put the #7 Penske Acura ARX-05 on pole, vaulting to the top of the timesheets with a 1m36.607s and then pulling clear of the opposition with a 1m36.090s.

But van der Zande was able to beat Castroneves' benchmark in the dying stages of the session by a scant 0.007s on his final flying lap, giving defending race-winners WTR and the #10 Cadillac DPi the top spot.

Filipe Albuquerque made it two Cadillacs in the top three by taking third in the #5 Action Express car, just 0.111s slower than van der Zande, while Pato O'Ward was the best of the LMP2 runners in fourth aboard the #38 Performance Tech Motorsports Oreca.

The Mexican's 1m36.318s just edged out Tristan Vautier in the Spirit of Daytona Cadillac to take a place on the second row.

Robin Frijns ended up sixth in the best of the Jota-run Jackie Chan DC Racing Orecas, while Felipe Nasr took seventh in the second Action Express entry.

Jonathan Bomarito claimed ninth place in the only one of the Joest-run Mazdas to take part in qualifying after the sister car that had topped first practice was hit by an undisclosed technical problem.

Fernando Alonso qualified 13th in the #23 United Autosports Ligier JS P217, 0.925s off the pace but around 1.2s faster than teammate Bruno Senna in the #32 car.

Neither of the ESM Nissan DPis set a representative time - Nicolas Lapierre went off on his first hot lap in the #18 entry and damaged the left-front suspension, while the #2 car didn't take part in qualifying because it was undergoing an engine change.

Corvette on GTLM pole

Corvette shaded Ford for honors in the GT Le Mans class, as Jan Magnussen grabbed pole with a 1m42.779s in the #3 C7.R.

That was enough to beat Joey Hand in the #66 Ford GT by a mere 0.019s, while Porsche locked out the second row in class as Laurens Vanthoor beat Patrick Pilet to third late on.

The second of the Ganassi Fords ended up fourth in Richard Westbrook's hands. The sole Ferrari in class, the #62 Risi 488 GTE, took seventh ahead of the two new BMW M8 GTEs.

In GT Daytona, Daniel Serra clinched pole for the #51 Spirit of Race Ferrari squad with a best time of 1m46.049s, four tenths clear of Miguel Molina in the #82 Risi 488 GT3.

The Grasser Racing Lamborghini Huracan that had been qualified third by Mirko Bortolotti, has been sent to the back of the grid after failing the stall test in post-qualifying tech inspection.

Qualifying results (top 10):

Pos.	No.	Driver	Chassis	Time	Gap
1	10	Jordan Taylor Ryan Hunter-Reay Renger van der Zande	Cadillac DPi	1'36.083
2	7	Helio Castroneves Graham Rahal Ricky Taylor	Acura DPi	1'36.090	0.007
3	5	Christian Fittipaldi Filipe Albuquerque Joao Barbosa	Cadillac DPi	1'36.194	0.111
4	38	Joel Miller James French Kyle Masson Pato O'Ward	ORECA LMP2	1'36.318	0.235
5	90	Matt McMurry Tristan Vautier Eddie Cheever III	Cadillac DPi	1'36.472	0.389
6	37	Robin Frijns Daniel Juncadella Felix Rosenqvist Lance Stroll	ORECA LMP2	1'36.492	0.409
7	31	Mike Conway Eric Curran Felipe Nasr Stuart Middleton	Cadillac DPi	1'36.508	0.425
8	54	Loic Duval Romain Dumas Jon Bennett Colin Braun	ORECA LMP2	1'36.567	0.484
9	55	Harry Tincknell Spencer Pigot Jonathan Bomarito	Mazda DPi	1'36.633	0.550
10	6	Juan Pablo Montoya Simon Pagenaud Dane Cameron	Acura DPi	1'36.931	0.848