SPARTA, Ky. - Seventeen-year-old Venturini Motorsports' No. 55 driver William Byron launched his ARCA Racing Series (ARS) superspeedway debut week by leading a 25-driver contingent visiting Kentucky Speedway to test Friday's Crosley Brands 150 with a 175.342 mph lap. 

The current NASCAR K&N Pro Series East (KNPSE) championship leader set to make his second ARS start and first on Kentucky Speedway's rough 1.5-mile tri-oval in a little more than 72 hours, started strong leading the series morning session with 171.456 mph effort.

"It was my first time on a mile-and-a-half, and I learned a ton," Byron said. "I was a little timid at the beginning. I didn't know where the edge was, so I kept my guard up.

"We worked on my comfort level and then we worked more on the car. I feel like we're in a good place. It's definitely a lot of fun. The sensation of speed is incredible and there are so many moving parts to superspeedway racing.

"We got some long runs in today so I feel like we came out with a good feel of what it's going to be like in the race. Looking at what was here today, there's going to be so much competition."

He holds a 13-point KNSPE lead on the second-place Scott Heckert through 13 events this season with only an Oct. 2 Dover International Speedway tilt remaining to decide the championship.  

Byron's teammate Brandon Jones turned the second-fastest lap of the day with at 173.863 mph. 

Jones, 18, will make his ARS Bluegrass State debut just two months after starting ninth and placing 10th in his first Kentucky Speedway competition with Gallagher Motorsports in the NASCAR Camping World Truck Series (NCWTS) UNOH 225.

"We unloaded really good," Jones said. "We tweaked on it all day, made very small changes. Whenever you can get through on making small changes and get where you need to be, it's a good day.

"My biggest takeaway from today's test was the consistent lap times we were able to put down. I feel really good about the race. It'll be nice to get some laps in the ARCA race for the race on Saturday." 

He'll wheel the No. 33 Richard Childress Racing (RCR) ride in his first NASCAR XFINITY Series (NXS) event at the track in this weekend's 300.

The two-time 2014 ARS race winner has knocked out five top-five and seven top-10 finishes through eight series starts this season. He earned his season-best second-place finish on the paved half-mile Mobile (Ala.) International Speedway March 14.  Jones had reeled in two top-five, including a June 19 second-place Iowa Speedway finish, and a combined four top-10 finishes through 11 NCWTS appearances this season. He also charted his NXS season-best eighth-place finish at Iowa Speedway May 17 in his first of four starts to date.

ARS championship leader Grant Enfinger rounded out the top-three in the test with a 172.811 mph lap.

"That was definitely a mock qualifying run there at the end, but we'll take it," said Enfinger, who has won three of the last four ARCA races, including last Saturday at Salem Speedway.

"We weren't exactly where we needed to be but we made good, solid gains on it all day. Jeff (Stankiewicz/crew chief) made some great calls and got us more speed, more comfort out of it.

"Kentucky's all about the bumps. We fought it at the beginning but got better at it. The bumps are always a big deal here. Today was no different."

The 26-year-old wheelman will make his fifth Kentucky Speedway start in the series owning two top-five finishes at the track through four starts. He delivered his series track-best second-place result July 18, 2009. 

He's raked in six victories, 11 top-five and 14 top-10 finishes this season through 18 of a scheduled 20 races this season. He'll take the Crosley 150 green flag holding a 225-point advantage on the second-place Josh Williams.

Race tickets, campsites and infield Fan Zone passes for the Crosley 150 and can be purchased through the Tickets and Camping pages of this website, by calling (859) 578-2300, with a visit to the Kentucky Speedway ticket office off of Interstate 71 Exit 57 and Ky. Hwy. 35 N as well as the speedway gates on race days.

Full Crosley 150 test results follow. Jones, Roush Fenway Racing's Ryan Reed and Joe Gibbs Racing's Daniel Suarez are scheduled to compete in both Kentucky Speedway weekend events. 

1 55 William Byron Toyota 30.797 175.342
2 25 Brandon Jones Toyota 31.059 173.863
3 23 Grant Enfinger Chevrolet 31.248 172.811
4 43 Scott Heckert Chevrolet 31.269 172.695
5 01 Travis Braden Chevrolet 31.369 172.144
6 99 Austin Cindric Chevrolet 31.458 171.657
7 69 Will Kimmel Ford 31.603 170.870
8 15 Daniel Suarez Toyota 31.798 169.822
9 52 Ross Kenseth Chevrolet 31.897 169.295
10 38 Ryan Reed Ford 32.096 168.245
11 78 Noah Gragson Ford 32.166 167.879
12 6 Josh Williams Chevrolet 32.174 167.837
13 77 Tom Hessert Dodge 32.191 167.749
14 22 Kyle Weatherman Dodge 32.238 167.504
15 59 David Levine Ford 32.404 166.646
16 78 Mason Mitchell Ford 32.438 166.471
17 2 Sarah Cornett-Ching Chevrolet 32.546 165.919
18 68 Nick Higdon Ford 32.547 165.914
19 58 Brandon Lynn Ford 32.558 165.858
20 36 Kyle Benjamin Ford 32.763 164.820
21 98 Austin Wayne Self Ford 32.904 164.114
22 42 Bo LeMastus Dodge 33.108 163.103
23 5 Bobby Gerhart Chevrolet 33.108 163.103
24 58 Michael Lira Ford 33.180 162.749
25 10 Rick Clifton Ford 34.541 156.336

 - Kentucky Speedway -