JHR Developments has confirmed that Bart Harrison will join the team as it expands to three cars for the remaining two meetings of the GB3 Championship season.
 
The 18-year-old has been competing in the E4 and Italian F4 Championships this year, with a standout third-place finish at Monza among a series of top ten results across both campaigns. He also raced in the Formula Winter Series – with two podiums – and claimed two wins and a podium in a one-off appearance in the Formula 4 CEZ Championship
 
Bart made his single-seater debut in British F4 last year, immediately making an impression with a Rookie Cup victory in the second race of the season and going on to secure a further eight podium finishes across the campaign.
 
Prior to that, he twice finished runner-up in the British Karting Championship – in IAME X30 Junior and Senior – and became the only two-time winner of the IAME Winter Cup in Valencia, in X30 Junior. He also proudly represented Great Britain in the FIA Karting Academy Trophy.
 
The Yorkshire-based racer will join team-mates Noah Lisle and Kai Daryanani in the GB3 Championship at Donington Park on 4–5 October and at Autodromo Monza on 18–19 October for the 2025 season finale.

Career history 

2025
Formula Winter Series - seventh
Euro 4 Championship
Italian F4 Championship 
F4 Central European Zone

2024
British F4 Championship
Italian F4 Championship - selected races
Formula Winter Series

2023
IAME Winter Cup - X30 Senior

2022
British Kart Championship - X30 Senior - runner-up
Kartmasters British Grand Prix - fourth
IAME Winter Cup - X30 Senior - fourth
IAME Euro Series - X30 Senior
LGM Series - X30 Senior
IAME Warriors Final - X30 Senior

2021
IAME Winter Cup - X30 Junior - champion
British Kart Championship - X30 Junior - runner-up
IAME Warriors Final - X30 Junior - fifth
FIA Karting Academy Trophy - eighth
LGM Series - X30 Junior

2020
IAME Winter Cup - X30 Junior - champion
IAME Euro Series - X30 Junior - sixth
IAME International Games - X30 Junior 

2019
Kartmasters British Grand Prix - X30 Mini - sixth
British Kart Championship - X30 Mini - sixth 
IAME Euro Series - X30 Junior