By Lori Vizza

3:40 pm : Day 1 Goodnight - That will do it for today's coverage from the track. Join us again tomorrow when the Xfinity Series teams will join us for this weekend's festivities.

The track goes green at 10:30 am with practice for the Kobalt 400. Practice for the Boyd Gaming 300 takes place from 12:30 pm until 3:55 pm with one hour break for lunch starting at 1:55.

At 4:45 pm we'll set the grid for Sunday's Cup race.

3:00 pm : Test Day Done - Aric Almirola saved his best for last and jumped to the head of the class for this afternoon's test session with a 192.940 mph in the No 43 Ford. Almirola toured the track just 0.008-second slower than Johnson's fastest lap during this morning's session.

2nd through 5th after the afternoon session were Austin Dillon, rookie driver Ryan Blaney, Kurt Busch and Greg Biffle.

Denny Hamlin's backup car made it through the session unscathed. Hamlin logged 41 laps and was 10th fastest with a 189.387 mph lapm, which was more than 3 mph slower than his quickest lap this morning. 

2:30 pm : Test Session Update - With approximately 30 minutes to go in this final test session, Austin Dillon jumps to the top of the speed chart with a 191.993 mph lap. Aric Almirola is second fastest at 191.428 mph. Biffle falls from 1st to 3rd, while Matt Kenseth and Kasey Kahne round out the top five.

1:15 pm : Hamlin Crashes - Daytona 500 champ Denny Hamlin is the first driver to run into trouble here in Sin City after crashing the No 11 Toyota in Turn 2. Even though he is able to creep back to the garage without help from the safety crew, the team will have to unload another car. He was second fastest before that incident.

Greg Biffle continues to lead the way. Jimmy Johnson, Kurt Busch and Ricky Stenhouse Jr are 3rd through 5th with a little over 90 minutes to go in the session.

12:30 pm : Biffle Early Leader in Second Test Session - Today's second and final test session is underway and Greg Biffle is fastest so far at 189.800. Biffle is followed by Jimmie Johnson, Denny Hamlin, Kurt Busch and Ricky Stenhouse Jr.

Biffle has a dozen Cup starts at LVMS but is still seeking his first series victory here.

And for the record, today's activity is categorized as a technical test session. This means teams are not required to go through tech, they can run telemitry if they choose to and they can run a different car and/or engine for the rest of the weekend if they decide to.

11:00 am : Johnson Fastest in First Test Session - The first test session is in the books and, Johnson holds onto the top spot with that 192.981 mph lap. In fact, there were no changes among the top with Hamlin, Kenseth, Vickers and Patrick, 2nd-5th on the time sheet.

The teams will have an hour to work on their cars and another three hours on the track this afternoon to dial them in.

10:20 am : Pearn Back on the Box for Truex, For Now - Cole Pearn, the crew chief for Furniture Row Racing and river Martin Truex, Jr has received a temporary reprieve on the one-race suspension handed down by NASCAR officials for an issue with the roof flaps on the No 78 Toyota at Atlanta Motor Speedway last week.

The suspension has been deferred until after NASCAR hears the team's appeal on a date still to be determined.

10:00 am : Johnson Leads the Way - We're halfway through today's first test session and Jimmie Johnson is fastest so far with a lap speed of 192.981 mph. Johnson has completed just 8 laps in this session.

Jeff Gordon set the single-lap track record in 2015 in his final Cup Series start at LVMS with a lap of 194.679 mph.

Rounding out the top five are Denny Hamlin, Matt Kenseth, Brian Vickers and Danica Patrick.

Kyle Larson and Denny Hamlin have completed 18 laps each, more than any other driver so far.

If you are wondering about Sin city's own Busch brothers, Kyle and Kurt are listed 7th and 10th fastest, respectively.

9:20 am : Breaking Down the Cup Competition - We have 39 cars representing 20 teams entered for Sunday's Kobalt 400. Of those 20 teams, 10 are single-car operations. The good news for the less well funded teams is everyone will earn a starting position for the race so nobody is in danger of making the long haul out west for nothing.

9:00 am : First Test Session Underway - Kyle Larson and Danica Patrick are the first two drivers on the track for today's first test session. 

8:15 am : Good morning from the Speedway. We're getting ready for Day 1 of the Boyd Gaming 300/Kobalt 400 weekend. 

The Sprint Cup teams will have the track to themselves for five hours of practice. The first session runs from 9:00-11:00 am and the afternoon session starts at noon and ends at 3:00 pm.

Stayed tuned for all the action as it happens....or better yet, come on out to the track and join us live!