Kyle Busch will drop to the rear of the field for the start of Sundayâs Bojanglesâ Southern 500 after his No. 18 team changed the engine on his Joe Gibbs Racing Toyota following a subpar qualifying run.
Busch was slated to start 33rd out of 39 cars after his qualifying lap at Darlington Raceway of 167.351 mph â significantly behind the Busch Pole Award-winning speed of William Byronâs No. 24 Hendrick Motorsports Chevrolet at 172.487 mph.
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âSomething is wrong,â Busch said after his qualifying run for Sundayâs 6 p.m. ET race (on NBCSN/NBC Sports App). âI donât know whatâs wrong. Iâm not that slow. Thatâs a second off of what it should have been. âŚ
âEverything was fine until about halfway down the back. It started to lay down. It started to shake and vibrate. When I got out of the gas in (Turns) 3 and 4 and got back to throttle, it got worse. So, I donât know. It fired up and ran fine here on idle, but if you plug your computer in order to check it and look at anything, you go to the back (of the field).â
Buschâs previous worst starting slot this season was 31st â at both the August Bristol Motor Speedway race and at the Daytona 500.
NASCAR.comâs Terrin Waack contributed to this report.