There Are So Many Ways To Lose At Phoenix Raceway: A NASCAR Engineer Explains It All

Track limits? What track limits. There are a number of things that make racing at Phoenix Raceway unique, but the one that most people immediately think of is the restarts. A

t Phoenix Raceway there is what’s known as a “dog leg” front straightaway, where there is sort of a 45-degree kink that is taken wide open. Think 130R at Suzuka in a modern open-wheel car. What makes this racetrack so special is that the entire apron is paved and NASCAR could not care one bit about track limits in this section, effectively turning part of the infield into a Mario Kart-style shortcut. You will often see some great photos of the cars going 6 and 7 wide on the restart.

[Ed note: As an experiment, we’ve been watching this season’s NASCAR Xfinity Series races together in our Discord. We had Bozi around the first week and Alanis last week. During the conversation a new name appeared: Aeden McHugh.

He’s not just one of Alanis’s many friends, he’s also the engineer for the #1 JR Motorsports car driven by Sam Mayer. Not only did Aeden provide race updates, he provided them from his pit box as the race was happening! Now he’s providing us with weekly track guides when he can. Join our Discord and come back later today at 4:30 PM to talk about the race.]

It’s A Tough Place For Spotters

One thing to note about this is the location of the spotter’s stand. At Phoenix Raceway, the spotter’s stand is located at the top of the grandstands in Turns 3 and 4. This means that the cars are moving away from the spotters as they fan out and then all funnel into the first corner.

You can see the start/finish line in the middle right of the photo. Drivers will begin fanning out after that line and then way off in the distance is the entrance to Turn 1.

Because of the vantage point, it’s very hard for the spotters to give a definitive “clear” over the radio, if you’re listening to a scanner you’ll hear a lot of “your call” which means it’s up to the driver to make the final decision on whether or not they are clear.

Some teams do it everywhere, but at tracks like Phoenix and Pocono, or superspeedways like Daytona, Talladega and Atlanta, teams will often put a little piece of tape on the mirrors as can be seen here on Denny Hamlin’s helmet cam from the 2018 Cup Series race at Kentucky.

Denny can use this piece of tape on his A-Post mirror as a visual reference to clear himself in situations where his spotter might not have the best vantage point. When looking in the mirror, that orange line represents the plane of his bumper. If a car is above this line, then they are ahead of his bumper, below the line the opposite is true and he is clear to make a move.

You Can Kill Your Day On A Restart

Phoenix is also a track where you will usually see several drivers get caught with a restart violation over the course of the weekend. Per the rule book, you cannot change lanes and you must stay on the racing surface until crossing the start/finish line. Drivers will be eager to take a hard left and begin cutting the dog leg on these restarts to try and take the shortest possible route to Turn 1. In the below photo from the 2021 Xfinity Series Championship race you can see Justin Allgaier committing a restart violation and was therefore given a black flag despite being the leader of the race on this restart.

Ditto here for John Hunter Nemechek in the 2023 spring Xfinity race:

It’s also fairly easy for the drivers who are second and third in line to get baited into the penalty. When the cars are bunched up on a restart there are very few visual references on the inside line. You have cars on three sides and the inside pit wall is far enough away that it’s hard to accurately get a reference point. If you’re following in the tire tracks of the car in front of you, or shading a hair lower it’s very easy to accidentally end up below the line too early.

The advantage to cutting the dog leg is obviously to take the shortest possible path from the start/finish line to Turn 1, but the disadvantage is that it severely compromises a driver’s corner entry. As Turn 1 approaches the driver will be trying to get back onto the racing surface to enter the corner from somewhat of a normal position on track, but in doing so the trajectory of the car will be headed to the outside of the track, effectively making the corner entry sharper.

There is also a risk of getting to the corner with multiple cars still on their outside. This creates two problems. First, they will be entering the corner on a tighter radius and second, they will likely be forced to run down on the apron which is completely flat. The flat apron on a tighter radius will be able to handle a much lower speed than that of the regular racing line. Often drivers who cut the dog leg from the inside line will gain a bunch of spots on the initial launch and then give some of them back from Turn 1 to the backstretch. 

You Can End Your Day Just Driving Into The Pits

I wonder if pit lane speed limiters would reduce incidents like this and also help get rid of most speeding penalties. pic.twitter.com/4AQ3ZRitfp

— Bozi Tatarevic (@BoziTatarevic) February 27, 2024

There’s been a lot of discourse on social media lately about pit road speed limiters and NASCAR. Unlike most other racing series, NASCAR does not utilize any pit road speed limiters. At normal tracks, this is fairly straightforward. Teams can calculate based off of gear ratios and tire rollouts what RPM to run on pit road to not get a penalty. Lights are then set based on RPM and the driver is told which ones to run down pit road “flash 2 red” etc.

However, there are certain tracks on the schedule like Phoenix, Bristol and Martinsville where the pit lane has a corner in it and is not straight the entire way. Pit road speed in NASCAR is calculated based simply on a time-over-distance formula, not instantaneous speed. The pit lane is divided up by a series of timing lines and driver’s rolling time is measured via the transponder in each section. At each track there is a declared pit road speed and drivers are given a 5mph buffer above that before receiving a penalty. So if the pit road speed limit is 45mph, everyone will try to run 49.9mph down the pit lane. For the sake of simplicity let’s just call it 50mph and assume that the timing lines are 100 feet apart. Under these conditions, it would take 1.36 seconds or longer to cross this section legally. Anything under that time would result in a penalty.

This calculation becomes a lot more interesting when the pit lane is not straight the whole way. NASCAR places the timing loops on the pit wall. If the pit road is curved then the cars will travel along a path longer than the one between the timing loops because they are on the outside of the pit lane, meaning that even if the car is still traveling at 50 mph the pit road timing system would show it running several miles per hour slower. Teams will gather data on how much further this radius is in the path of travel vs the distance between timing loops and bump up the RPM to match the further distance.

The math is fairly straight forward but the execution can be a bit tricky. If the driver accelerates too early before the curved section begins they will likely receive a penalty. Ditto for not slowing down quickly enough when the pit lane straightens out. The driver must also be careful to keep the vehicle on the path along which this higher RPM was calculated. Teams will give their driver a visual reference for where to place the car to maintain this path.

Looking at Phoenix Raceway from Google Earth you can see that there are white hash lines towards the outside of the pit lane. If the team calculated the higher RPM for the car to have its left side tires on the hash marks, the driver could easily earn a penalty if they take the corner too sharply and run with the left side tires say two feet inside of the hash lines.

You can watch Ty Gibbs pre-race pit road run from 2022 here at 12:40 and hear how the RPMs pick up in the curved sections:

This sounds like a fairly straightforward process for a driver to manage, but when you add in the other vehicles on pit road it can become very easy to mess up. This is especially true when closely following another driver down pit road, it can be difficult for drivers to spot the references for the line they are supposed to run. Watch Chase Elliott here in 2020 as he follows Denny Hamlin and Joey Logano down pit road at 45:05:

It’s Hell On Crews As Well

A curved pit road can also create challenges for the pit crew as well. Per the NASCAR rule book “Crew member’s feet and/or pit equipment must not touch the pit road surface before the vehicle is one pit box away from its assigned pit box or the equivalent marked distance.” When a car is coming around a corner it can be difficult for the pit crew to time their jump off the wall.

This penalty can be negated by the crew member getting back onto the pit wall before beginning service on the vehicle. While this will avoid a penalty it will slow the stop down significantly and result in lost track position. Chase Elliott’s jackman TJ Semke famously avoided this penalty at Martinsville in 2020, ultimately saving their race and their season as Elliott was able to advance to the Final 4 where he won the championship. 

Clearly, it pays to know the rules.

Drivers Have To Give A Shift Here

While the NASCAR Cup series cars shift at most oval race tracks these days, this is rare for the Xfinity Series cars and Craftsman trucks. Phoenix Raceway is one of the few places where you will see these series shifting during green flag runs. As the lap time falls off over the course of a run, some drivers will begin shifting down to 3rd gear in Turns 3 and 4. This downshift provides extra deceleration from engine braking and gives the driver extra torque to launch the car out of the corner. 

It is unlikely that you’ll see any drivers try shifting in Turns 1 and 2 as they are usually fighting for right rear grip and drive off of this corner already – even in 4th gear. You will however see drivers playing around with different racing lines at this end of the track.

NASCAR used to apply PJ1 resin to the upper grooves at Phoenix, and there is still some residual compound left in these grooves. Drivers that are struggling with an oversteer condition will often times take a higher entry into Turn 1 in the previously treated area which allows them to turn down across the track earlier in the corner and take a straight exit.

You can imagine this line as similar to how F1 drivers approach a hairpin corner with maximum straight-line braking, late turn-in and apex followed by a straight launch up and off. Drivers that are struggling with understeer will likely take a standard entry into Turn 1 and wrap low around the corner. This might seem counterintuitive at first, but putting the left front tire below the yellow and onto the apron actually helps rotate the car and effectively pulls it around the corner. In circle track racing we call this “de-wedging” the car as loading the left front wheel on the apron lowers the cars wedge (also known as “cross weight” which is the percentage of load on the right front and left rear wheels) which helps it corner.

Top Photo: Big Machine Racing/Barr Visuals