NASCAR Race Weekend Central

Tech Talk: Trent Owens On Martinsville Handling, Truck Arms & Tire Wear

The No. 43 and Martinsville Speedway are synonymous with each other. Richard Petty took the car to victory lane 15 times in his career. North Wilkesboro was the only other track where The King took as many checkered flags first. Prior to Aric Almirola’s win at Daytona in 2014 the last win by the legendary number was at Martinsville in 1999 with John Andretti behind the wheel. As the series heads back to southern Virginia this weekend it is Trent Owens chance to try and score another grandfather clock for the Petty clan.

The paper clip shaped track outside of Martinsville is extremely challenging for crew chiefs due to the difficulty in getting the cars to slow down, turn and accelerate in the opposite direction. In this week’s Tech Talk, Owens talks about the new aero package to date and how it will impact Martinsville. He also discusses tire wear, drive off of the corner, travels and fuel mileage. He also touches base on what happened during his off week.

Mike Neff – We’re coming off of the first off week of the season. Did you actually get to have some downtime or did you work the entire time?

Trent Owens – We had some downtime on Thursday and Friday last week. Early in the week we had to get organized, somewhat, for Martinsville. Everything was on the West Coast for so long that we spent a couple of days restocking the trucks and stuff like that. We got that knocked out and then took off Thursday and Friday. I took off Thursday and Friday, a lot of the guys took off Wednesday, Thursday and Friday. Tried to get a little reset before we hit this next stretch of races.

Neff – We are five races into the new season, four of which utilized the new downforce package. How do you feel like it is working for you so far?

Owens – I like the new package. We’ve struggled a little bit to put a complete race together. We’re lucky we are still 13th in points. It is really tight through there. Performancewise I feel like we have had some competitive race cars, we just haven’t been able to throw a solid race together and get the finish we need to compete. I’m excited about the low downforce package. I think that was a good call and is a good direction. I think, in the future, we’re probably going to see NASCAR take a stab at knocking even more downforce off of the car. I feel like the cars are more raceable in race conditions, around traffic, and I feel like that was the ultimate goal.

Neff – Tires are also changing with the new race package. Do you feel like the tire package is heading in the right direction just like the aero package?

Owens – As you take downforce off of the car it allows the tire manufacturer, which in our case is Goodyear, to make some softer tires and have a little more freedom when you’re talking about safety factors and stuff like that. We’re seeing more speed fall off from start to finish of a tire run. That is great for racing and great for the crew chiefs. It allows them to tune the race car and spend a little more time on the mechanical side of the car to try and save the tires to be better late in the run rather than early. Some of that had been set aside with the harder tires. There is still some room for improvement but Goodyear has done a good job so far, with the tires we’ve raced, and the speed fall off has been there. All of that equates to good racing and I think, as we continue down the road, you’re going to see more downforce come off of the car and even softer tires yet.

Neff – So now we are headed off to Martinsville. It is a different aero package but the track is only half of a mile around. Some people think aero doesn’t come into play there but you are still doing 100 MPH before you lift to turn into the corner. Is the new package going to change how you attack Martinsville?

Owens – I don’t think the new package is going to really affect what we do at Martinsville. Although, when you talk aerodynamics at any time, you have to have it period. Just working through stuff in simulation, when we go from our race trim package to our qualifying package, we put more downforce on the car by taping the front grill area off. It affects our travels a little bit, in a positive way. It is still something you have to have. With the shorter splitter we have now the cars may be a little easier on the curbs and running around the curbs. In the past you’ve seen some cars get the front end knocked off, come out of the garage and be really fast on the race track. While people are quick to judge and say that aero doesn’t matter, in most cases it is the fact that their front tires are running cooler (laughs) thanks to not having a nose on the car. That is what is giving them more front grip and allowing them to turn. We still have to have aero. We do our best to keep the fenders on it. It isn’t as important at Martinsville, but everywhere we go it is important. I think the low downforce package for short track racing will be fine. In the past, the higher downforce package showed up more negatively at the faster race tracks. In the past we didn’t see the racing change much at Martinsville. The biggest thing now is that we have a shorter splitter and that will probably help the cars at Martinsville.

Neff – You talk about cooling the tires. That makes a big difference in getting the car to turn and rotate in the center of the corner. Similar to New Hampshire, getting the car to turn at Martinsville is one of the biggest challenges of the whole season. Is the package going to be a little different due to the tire combination that we have for Martinsville to get the cars to turn and point in the opposite direction?

Owens – The tires we have for Martinsville are the same as we ran last season. The construction of the tire is the same but when we start talking about the speed and package at Martinsville, the change probably doesn’t affect the tires as much. I think they had success with the tire there last time so they decided to bring it back. The challenge we are faced with this year, and we saw it at Phoenix too, without having the drag and downforce on the car, we do seem to be using more brakes to slow the cars down. Brake temperature and bead temperature seems to be more of an issue than what we experienced last year. We saw some cars have problems out in Phoenix and we’re going to do our best to have some cooling, not only on the brakes, but on the tire bead as well.

Neff – In recent years we’ve had some issues with the left side tires giving people some grief. How do you go about balancing the load on the car to keep from abusing the left side tires?

Owens – In the last couple years the left rear tire has worn the quickest and the car has gone away thanks to that. One of the toughest challenges we have at Martinsville is getting the drive off of the corner and getting the car to use both of the rear tires equally. We are so quick to wear out that left rear trying to search for a lot of rear grip. It is hard to take a reading in practice. You just have to really study your post practice tire wears, tire temps and all of the basics of racing. You have to pay attention to all of that to make sure you don’t wear that left rear out. We’ll play with spring rubbers and the spring rates up and down. We have the ability to change our frame heights up and down now and all of that stuff is going to be critical when it comes to race trim and trying to save those rear tires.

Neff – You just mentioned changing frame heights. Is that something you’re doing with the suspension parts that are bolted to the frame or are you changing the way the frame is constructed?

Owens – The frame construction is still specified by NASCAR. A few years ago NASCAR changed the rules to where we had a tech heighth of six inches in the front and eight inches in the rear. We only do that for inspection now. Once we clear inspection we are free to do what we want with frame heights when the car hits the race track. Let’s say we have a 300 pound right rear spring in the car and we may be using a six inch frame height in the rear. If we decide to go to a 600 pound spring, but we’re happy with our travel, we will have to lower the frame height down to five and a half inches to get the same travel on the race track, with the stiffer spring. It is a balance of how far you want the car to come up on the straight and how low you want it to squat as you exit the corner. That all has a large effect on the tire wear.

Neff – Truck arms and pinion angles can have a great impact on your drive off of the corner and how you apply the horsepower to the ground. How much time and effort do you spend on the truck arms to get the tires to hook up coming off of the corners?

Owens – We pretty much have adjustability in truck arm heights on the front side of the trailing arms. We can have the left side higher than the right, we can have the right side higher than the left. We can also have both of them high or both of them low. That is probably one of the biggest adjustments for short track racing. You talk about the pinion angle, where the driver shaft hooks into the rear gear. You change that angle in travel based on where you have the truck arms located. We’ll definitely qualify at a different setting than we’ll race. When it comes to race trim we’ll definitely try some different settings of lower versus split and some things like that. I’ve seen that area work in different ways. It is not always a given that low is always better grip or high is always better grip. The car will definitely turn better with the truck arms higher. Sometimes that relates to a little better exit just because it turned better through the center. Just pure throttle we seem to get a better drive with the truck arms lower.

Neff – It is hard to believe that a half mile track can turn into a fuel mileage race. With the tires wearing out the way they are now it is probably not a possibility at this point. Is EFI and fuel mileage something that you worry about when you head off to Martinsville?

Owens – No, the fuel part of it is kind of what it is. If it is a caution toward the end of the race where it is a possibility to make it to the end of the race then we’ll make sure it is packed full. Every other pit stop during the race we will never wait on fuel. We want the engine company to get us the maximum power that we can get. We don’t focus on fuel mileage at all. We’ll tell the engine guys to do what they need to do for performance and not worry about the fuel mileage. More times and not we won’t even leave our pit stops with a full tank.

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