Zak O’Sullivan topped the times for Carlin in the second Friday testing session at Brands Hatch Indy ahead of the season opener on the GP circuit on Saturday.
The half-hour session took place under cloud over at 11 degrees C, with track temperatures similarly low.
Sebastian Alvarez set the fastest time of the session early, before being overtaken by Bryce Aron who immediately found two tenths in the Carlin.
Christian Mansell was the first man to lap inside 46 seconds with a 45.779s lap, but times quickly fell towards the 44-second mark.
O’Sullivan found it first, before Ayrton Simmons set a 44.649s ahead of Elite Motorsport‘s Javier Sagrera.
Mikkel Grundtvig took his time in setting a competitive lap, setting a 58- and 54s lap as his Fortec team-mate Oliver Bearman went third with a 44.780s tour of the Indy circuit.
The Dane would set a 44.912s just inside the first ten minutes of the session, putting him 16th at the time.
Simmons found half a second on his previous lap, setting a 44.176s ahead of O’Sullivan after seven minutes of the session.
Bearman went 0.010s behind Simmons before going two tenths ahead of him with a 43.621s as times began to tumble below 44 seconds.
His other Fortec team-mate Roberto Faria moved up to second with 20 minutes remaining, a tenth off Bearman and three hundredths ahead of O’Sullivan.
As most of the field ducked into the pits, Hitech GP‘s Reece Ushijima went third with a 43.726s, one hundredth behind Faria.
Positions largely remained unchanged with most runners in the garages, with the top ten laid out as follows with 13 minutes remaining: Bearman, Faria, Ushijima, Simmons, Fores, Patterson, Aron, Alvarez, O’Sullivan, Garfias.
Dexter Patterson went three thousandths ahead of Bearman just past half-distance, with a 43.575s.
Bryce Aron went third, 0.071 behind the Douglas Motorsport man in first place with ten minutes remaining.
Simmons then went fastest with a 43.438s, the CDR man the first to dip under a 43.5s lap on Friday.
It started raining at Brands Hatch inside the last ten minutes of the session, putting paid to any plans most of the drivers had to find time around the short layout for the rest of the session.
Zak O’Sullivan managed to improve though, with a 43.298s, as Reema Juffali moved up to 14th with a 44.928s lap.
He led Simmons in second, while Patterson, Bearman and Aron rounded out the top five.
Faria, Ushijima, Alvarez, Juffali and Alex Fores completed the top ten.
Alex Connor and Frederick Lubin rounded out the standings for Arden Motorsport.
2021 Brands Hatch Indy Second Test Session Results:
| Pos | No | Driver | Nat. | Team | Time | Gap | Laps |
| 1 | 51 | Zak O’Sullivan | GBR | Carlin | 43.298 | 38 | |
| 2 | 18 | Ayrton Simmons | GBR | Chris Dittman Racing | 43.438 | +0.140 | 32 |
| 3 | 21 | Christian Mansell | AUS | Carlin | 43.462 | +0.164 | 36 |
| 4 | 7 | Roberto Faria | BRA | Fortec Motorsports | 43.493 | +0.195 | 31 |
| 5 | 55 | Dexter Patterson | GBR | Douglas Motorsport | 43.575 | +0.277 | 27 |
| 6 | 87 | Oliver Bearman | GBR | Fortec Motorsports | 43.578 | +0.280 | 29 |
| 7 | 23 | Bryce Aron | USA | Carlin | 43.646 | +0.348 | 39 |
| 8 | 13 | Reece Ushijima | JPN | Hitech GP | 43.726 | +0.428 | 30 |
| 9 | 12 | Sebastian Alvarez | MEX | Hitech GP | 43.752 | +0.454 | 29 |
| 10 | 10 | Reema Juffali | SAU | Douglas Motorsport | 43.817 | +0.519 | 37 |
| 11 | 34 | Tom Lebbon | GBR | Elite Motorsport | 43.839 | +0.541 | 20 |
| 12 | 90 | Alex Fores | GBR | Chris Dittmann Racing | 43.844 | +0.546 | 31 |
| 13 | 81 | Max Marzorati | GBR | Chris Dittmann Racing | 43.883 | +0.585 | 32 |
| 14 | 43 | Mikkel Grundtvig | DEN | Fortec Motorsports | 43.926 | +0.628 | 33 |
| 15 | 99 | Jose Garfias | MEX | Elite Motorsport | 43.946 | +0.648 | 32 |
| 16 | 3 | Javier Sagrera | ESP | Elite Motorsport | 44.205 | +0.907 | 10 |
| 17 | 27 | Alex Connor | GBR | Arden Motorsport | 44.349 | +1.051 | 26 |
| 18 | 78 | Frederick Lubin | GBR | Arden Motorsport | 44.359 | +1.061 | 25 |
