Tech Talk: Trent Owens On PJ1 & Heavy Vertical Loads at Bristol

The No. 37 team, driven by Chris Buescher, and crew chief Trent Owens are coming off two strong finishes for its small organization. Watkins Glen International was an 11^th-place run, and Michigan International Speedway was sixth, the best finish of 2017 for JTG Daugherty Racing. Strategy, fuel mileage, caution timing and a little luck all played into the result.

This weekend the team heads to another track at which Buescher is confident — Bristol Motor Speedway — after scoring a top-five finish last season.

In this week’s Tech Talk, Owens discusses vertical loads and the need to anticipate the stresses the cars will put on suspension parts. He also touches on tires, PJ1 and practice versus race lines.

Mike Neff – Coming off a couple of great weekends, your team’s confidence has to be sky high. You took advantage of some chaos at the end of Michigan and wrangled a sixth-place finish. How did you feel about your results up in Michigan?

Trent Owens – It has been two really good weekends in a row, to grab an 11th-place finish at Watkins Glen and then come out of Michigan with a sixth-place finish. Sixth was probably better than where we ran most of the day. We played good strategy, we played the fuel game properly and we caught the caution at the end. We definitely were in the preferred line at the end. I’m not going to take anything away from that; Chris did a great job making some aggressive moves on the final two restarts making some passes. I think that is our best finish of the year, and I’m very happy. It is a little morale boost heading into Bristol, which is another good track for Chris. All indications are that we should have another good run up there.

Neff – We hear about preferred lines from time to time with Atlanta Motor Speedway, Martinsville Speedway and Michigan, and we’ll hear about it again this weekend at Bristol. Is there anything that the crew chief can do to help a driver when they find themselves in the less-preferred line, which will inevitably happen?

Owens – It isn’t the same at every racetrack. When I spoke of the preferred line at Michigan, when you restart on the outside at Michigan you can stay tighter to the guy on the inside and make him a little looser, especially with this aero package. The [No.] 20 [Matt Kenseth] also had an issue on that final restart that kind of stopped the whole inside line, but that was another issue. Not all tracks are like that. Some tracks it is the inside line. That can happen just because the outside line isn’t working and the inside line is an advantage. We started in the 10th position, which was on the outside, and the outside is where you want to be at Michigan. There is really nothing you can do. There are times when we’ll try and stagger ourselves as we exit pit road if there is a real distinct advantage to get an even or odd number, but it is really just luck of the draw.

Neff – Would you be in favor of doing a choose cone before restarts like they do at local short tracks?

Owens – I don’t think so. The guys at our level of racing, I don’t think you need to throw too many tricks at them. I think it would cause more chaos than it is worth, in most cases, with everything else that is going on. I would steer clear of that.

Neff – Bristol officials have already put down the sticky stuff and intend to keep applying it throughout the weekend. You’ve dealt with this three or four times. Is there anything that you do differently knowing that you’re going to be dealing with the track prep on the surface this weekend?

Owens – It is kind of difficult, because you know going up there that you’re going to have to practice on the bottom, because that is where the compound is applied. One thing I don’t like [is that] the last time and I believe this time, they put on the PJ1 too wide. It was nice when you could just put your left sides around the bottom. For us in the Cup Series, the race is so long that we know the top side is eventually going to come in good. Unfortunately, our practice sessions are going to be committed to the bottom, so we probably won’t know how our car will drive up top. I’m not really in favor of that. I am in favor of putting additional grip in the racetrack, I just think they may have it too wide compared to the first time they tried it.

Neff – Do you have to do anything different with suspension components like bump stops and springs because of the intensity of the vertical loads at Bristol?

Owens – We have to prepare, for sure. Some of the suspension has to be more rigid. Some of our spring seats have to be steel instead of aluminum. It is probably one of the more high-loaded, especially spike-loaded, tracks that we see. You’ll see the cars roll off of pit road a little higher, especially compared to Michigan. We have to prepare for a lot more suspension travel at Bristol. If you try to put your car too low you have to make the suspension so stiff that the car just won’t grip. You’ll see a lot of up-and-down movement that you don’t see at most racetracks anymore. The place is just really hard on the torsional stiffness of the chassis and the suspension components. All of that stuff takes a real beating.

Neff – On the straightaways, you still have a decent bit of banking. Does the vertical load on the straights have an influence on your cars and setup as well?

Owens – We prepare for so much corner travel that we have plenty of clearance when we go down the straights. It can make the left front ride a little low and cause your front sway bar to get neutralized. That can cause a loose in condition. That is probably one of the biggest things we fight at Bristol, especially into Turn 3, and the straightaway banking causes a lot of that by neutralizing the sway bar.

Neff – We’ve seen some people being busted for pit lane violations multiple times during the same race this year. Some readers have asked how that can happen multiple times in one race. It would seem that a calculation is made for what RPM will give maximum speed on pit lane. If that is wrong and a violation occurs, the driver will back it down 100-or-so RPM the next time down. If it was off by more than that then you’d get another violation. Is that a plausible explanation, and what do you utilize to calculate your maximum pit road speed?

Owens – NASCAR has gotten good at giving us a speed during at least one of the practice sessions of our pit road speed. We can run pit road and get a speed reading. I think what has led to some of the penalties is a team sees they are doing 4 mph over the speed limit, as opposed to the 5 that they are allowed based on the tolerances provided by NASCAR. They are then pushing their tolerance closer to the maximum just because they are able to get a speed reading before the race. In the past we didn’t get that; all of our initial settings are based on a simple calculation based on gear ratio, tire circumference and RPM. It is simple math that will calculate the speed. We then go out and run and get the number that NASCAR sees and we’ll tune on it accordingly.

Back to my earlier statement, if they give us 5 mph before we are over, we’re going to try our best to run 4.9 over. That is how it is with every rule. The thing about Bristol is you have that radius in turns 3 and 4. You can actually run faster if you take the outside of the radius and not exceed the pit road speed. You stand a chance of getting busted if you are running the outside radius and turn it down to quickly to get on the front straight pit. We do about a .5 mph cushion. The engine doesn’t run smooth at all RPMs so that can cause people to have errors as well, just because it is hard to hold it steady. In the end, what it mostly comes down to is guys just getting greedy and going over the tolerance.

Neff – Is it possible to have your speed fluctuate by 100 RPM or so just because of the circumference of a given set of tires?

Owens – When you compare the radial to a bias ply, if we see a 1/16th of an inch of variance in the radius, that is substantial in our world. The Goodyear tires are pretty consistent on the size. When we measure our tires and we see a 1/16th of an inch off, that is huge in our world, and in reality, it is nothing compared to bias ply stuff. In reality, that variance might translate to 50 RPMs. It is really minor.

Neff – Do you have the group who packs the hauler load on extra snacks and munchies in anticipation of the extra down time this weekend, especially if it rains?

Owens – (laughs) It is funny you say that; it has been a trend there and at Pocono Raceway as well. We buy a little extra groceries because the kitchen cabinet definitely takes a hit when it rains. Hopefully it won’t happen this time and we can get it in so everyone can have their Sunday off.

Neff – Tires have been somewhat of a factor at Bristol of late but not what they were years ago. Do you think there will be significant falloff this trip that will have an impact on the race and late strategy decisions?

Owens – We will have to get up there and run some practice sessions and see what happens. Last year, between the two races, we had a little bit different tire wear in one race vs. the other. I don’t know exactly what we can attribute that to. We had extreme left-side wear when practice first started, but it evolved over the weekend, and by the end of the race, it didn’t seem like it was a factor at all. It is a tough call today to talk about it and think I know exactly what to talk about. We need to run practice, get a wear reading and then we’ll have an idea of what is going on. We’ll see at that time how much the speeds are going to fall off. Track position is so important at Bristol. If new tires give you an advantage for 10 laps, you may be able to pass three or four cars, but it is going to be hard to say if it will take you all of the way to the front.