_The Cup series heads to Charlotte for the final night race of the season. Teams will be dealing with a more stable racing surface since the entire race will be run after the sun is below the horizon. The teams will also be sleeping in their own beds and racing in front of friends and family that don’t normally get to see them compete live. As the Chase reaches its halfway point, Tony Gibson shares his views on preparing for 500 miles at Charlotte Motor Speedway._
_Gibson touches base on how smart the EFI system is, squashing tires to calculate spring rates and how much better racing would be if the tires wore out more. Check out his opinions in this week’s edition of Tech Talk._
Mike Neff: *This is the only night race in the Chase, as they like to advertise it. It is different from the 600 in that the green flag waves when it is already basically dark outside. Does that change how you’re setting up the car for this race?*
Tony Gibson: Yes, it does there for sure. It is one of the tracks where the track is very sensitive to temperature changes. Five or ten degrees of track temperature is a lot of speed and grip. The practice time that we get that is close to the time we start the race is going to be crucial. Anything before that is really not going to make a crap. I would rather it start later like that because it makes your adjustments a little bit closer together. With the 600, it is such a huge swing that you have to account for. It is still tricky, but the night race is much easier than the 600.
Mike Neff: *It hasn’t been that long since they repaved Charlotte. You’re just now starting to get some bumps back in the track, but it is relatively smooth. Does the lack of bumps let you have a more aggressive, stiffer setup since you don’t have to account for a bumpy surface?*
Tony Gibson: Yes, but it is getting back to it. It is beginning to lose some grip and get some bumps in it, but for now we can be more aggressive with our bumpstops and packages than you can at tracks like Atlanta and Chicago and Kentucky. It is a little more user friendly for setup side of things, but it is still tricky because of the temperature sensitivity of the track. That is the tricky part of setting up for there.
Mike Neff: *With this race being the halfway point of the Chase, if you were in it would you be able to go into the race with a mindset of having to win or do you have to worry about your point situation and protect your spot considering it is a night race?*
Tony Gibson: A lot of the teams that make it into the championship deal, they are more about points racing and protecting what you have. You don’t have time to make up a huge deficit, so it is more about making sure you get a top 10 or a top 5. If you win that is awesome, but everyone can’t win it so you have to make sure you have a solid night.
You saw that last year with Tony and Carl. Carl didn’t win any races, but he was consistent which kept him right in the hunt until the very end. You want to win but you also have to focus on getting those top 5s.
Mike Neff: *At Charlotte there are guys who make time around the top and other guys who make it around the bottom. Sometimes it depends on what your car is doing, but can you go into a race, especially since the whole event is held at night, with a setup that is specifically geared to run the top or the bottom or do you have to adapt to what the car will give you?*
Tony Gibson: It changes throughout the night. By the end of the race it seems like you’re going to have to be on the bottom to win, but there are times during the race that you have to be able to go where the rest of the traffic isn’t. There’s a lot of speed up top, not like it used to be, but there is speed up there, but mostly it is just getting clean air on your nose. Getting into a different lane where the other drivers aren’t. You have to be good in all three grooves, similar to Atlanta. You have to be good on the bottom, in the middle and the top because at some point you’re going to be running in all three lanes.
At Charlotte you’re so fast there and the grip is so high that you’re just trying to find clean air to get away from everybody else but you’re going to win the race on the bottom.
Mike Neff: *Since they still bring rock hard tires to Charlotte, do they give you the spring rates of the sidewalls so that you can calculate the rebound rates of the tires?*
Tony Gibson: Goodyear gives you some information and the teams take it from there. They do their own data search on it and do their own analysis and figure out what the spring rate is and the compliance of the sidewall, the grip of the tire and each team has a different answer on what air pressure it wants. Goodyear gives you a baseline and each team takes it and makes their own assumptions on what it needs to be.
Mike Neff: *Is there a method of testing what the spring rate is on the sidewalls of the tire?*
Tony Gibson: There are several different methods. Back in the beginning of looking at this 15-20 years ago, when we were first looking at this stuff, we’d take a tire machine like they balance your car tires on and we’d put a load cell in the rollers in the bottom and, as the tire was spinning, we could crush the tire and take the tire deflection and measure the rate of the tire. We’d run each tire across that and, it was kind of a redneck way of doing it, but for what we had it worked. It is a similar process that they do now but I can guarantee you, if you go to each of these organizations they’ll all say something different about tire. You just have to pick one and believe in it.
Mike Neff: *They’ve taken an inch and a half off of the side skirts to where they won’t get down to the ground now so that you’re getting air under the car. Have you seen that that is making a difference in your setups?*
Tony Gibson: Oh yeah. It is a lot of downforce and sideforce that it took off of the car. The first cut was bigger than the second cut, but the second cut really was a huge underbody hit. When we went to Charlotte with the first one it was a good little bit, but you could manage it. Now what we’ve got you can’t get back to where we were. There is no way to get back there. You can get them as low as you want, but you won’t be able to get them all of the way down. The next step is taking them all of the way off, but I don’t think they have to do that because they accomplished what they wanted as far as taking grip away.
Mike Neff: *Running at night causes the engine to deal with a little more moisture in the air. Does that impact the way the engineers map out the engines for the fuel to air mixture?*
Tony Gibson: Not really. The EFI does a really good job of adjusting as long as you stay within their parameters. It can adjust for the engine getting richer, leaner, higher air density. It does a really good job of sorting all of that out so that we don’t have to worry about that. It is a pretty cool ass system that is far smarter than we are really.
Mike Neff: *A personal opinion question about the tires that they seem to be giving us these days. We mentioned earlier the rock hard tires they bring to Charlotte and we are seeing more and more of at other tracks. Do you like tires that you can run a long time on or would you rather have tires that give up so you have to change four every time you come in?*
Tony Gibson: I would rather do that. The hard tires, I hate ‘em. You’d be better off, with the downforce that we have on these cars now, you’d be better off to have a little bit grippier tire and let the driver manage it. When you put a hard tire that lasts forever on a car that doesn’t have a lot of downforce, then basically you’re going to stay out and gamble. You know the tire is going to last so you’re going to do whatever it takes to get out front and stay there because it is all about aero then, it isn’t about tire anymore.
When you put a grippy tire on there that is going to wear off, then guys are going to have to manage their tires and they’re going to have to make a pit stop and at least do two or four tires, which mixes up the field a little bit. When you get to where you don’t have to change tires because they’re so hard then hell, nobody is even stopping so it is all about who’s going to stay out and then it is fuel mileage and everything else. The racing would be better if they made you pit. If the tires dictated the pit stops rather than the fuel.
_Gibson and his No. 39 team did not make the Chase, so he’s going to be focused on the win rather than the points. It will be interesting to see on Saturday night, when the laps are winding down, just how many tires they put on the No. 39 for its run to the finish._