Behind the scenes: SRT Viper GTS-R lead engineer Matt Bejnarowicz shares the latest leading into Road America.
Q: What hopes, expectations, or goals do you have going into Road America?
A: Our goal for Road America is much like Mid-Ohio. We want to finish the race with the cars intact, develop the race team, and learn as much as possible in the short time that we have in Wisconsin. The GTS-R is still a very new car and we learn more and more with every lap we turn. Everyone knows we aren't in a championship position this year, but this doesn't change our focus to win races and run in the front. This does however mean that the most important thing we can do this year is develop the GTS-R and the team into a position to run for the championship in 2013. That's why we must keep the pressure on and stay focused at all times.
Q: Were there any major changes for Road America?
A: No, not really. The team was only in the shop for 6 days after Mid-Ohio. The concentration was mainly on servicing the GTS-Rs, repairing crash damage, and addressing any problems we found at Mid-Ohio. For instance, the drivers were extremely hot in Ohio. This is a big deal for their safety as well as consistency through a race. Therefore, we prioritized making improvements to the air conditioning system on the car and made several design changes to improve their environment. During the Mid-Ohio race, we were also monitoring a fuel pump diagnostic that we couldn't explain. The engines were running fine, but something was developing. Back at the race shop, the team found debris in the fuel filters due to contamination in the fueling rigs in combination with the E85 that the Viper runs. This was a relatively simple problem that was easily fixed, but could have developed into a big problem during a 10-12 hour race. These are exactly the problems we need to find this year – the smallest and simplest ones are usually the ones that will hurt you the most.
Q: During the Mid-Ohio race, other teams and the announcers kept talking about something called "Balance of Performance." Can you explain this and how it applies to the Viper?
A: Balance of Performance refers to a process that the series uses to equalize the performance of all competitors to a level playing field. This is one of the reasons why the ALMS is so successful and also why it's possible for cars such as the BMW or Lotus to compete equally with supercars like the Viper. Currently, nearly all of our competitors have been given enhancements in restrictor size, weight, wing height, fueling restriction, or fuel capacity to improve their performance beyond where the standard rule book would allow. The Viper is not currently in a position to be balanced, simply because it is a new race car and the series must measure the performance at several venues to understand if the advantages given to others are also justified on the Viper. This is part of the normal process and just takes time.
Q: Interesting, are there any other adjustments to the rules for the GT field that would be different from car to car?
A: Yes, all of the GT competitors have certain rule book "waivers" which the series has granted. Manufacturers request these waivers before the race car is homologated, and they are only allowed if they fit within the spirit of the Le Mans regulations or are required to allow a car to compete effectively in the series. Waivers are mainly granted due to durability issues or in certain cases where a car needs to be modified to be at an equal level to competitors. Waivers may also be needed to allow aspects of the street car that are simply outside of the regulations by design. For instance, the Viper has been granted two important waivers. One allows the Viper to compete with a large displacement V10 engine (8.0L). Normally the rules do not allow a displacement higher than 5.5L. However, the rules also require that the production engine for the Viper be used and the street car block and heads be used without adding material to any of the castings. In the Viper's situation, it would be impossible to reduce the displacement to the level of a 5.5L, so the 8.0L was allowed. The other important waiver is to allow the Viper to install a transaxle in the rear of the car. All others in the GT field are either a mid-engine or front engine with a transaxle, so this modification was required to move the Viper's weight distribution to an equal level to the other competitors.
Q: Instead of asking to be allowed to run the 8.0L Viper engine, would you ever ask to run a lower displacement 5.5L engine (perhaps a V8)?
A: LOL! That would just be wrong. In fact, that question has fairly offended me and I will ask that you don't talk of it anymore.
Q: How much of an advantage is the big V10 engine?
A: Many people think that the large displacement is an unfair advantage, but under the current regulations, this really is not the situation. Due to balance of performance in the series, the Viper is given the smallest restrictor (a device that starves the engine of air, much like only allowing you to open the throttle by a small percentage). This is intended to remove any advantage gained by high displacement torque. However, the sonic restrictor sizes overall are much smaller than those used in the late 1990's by the original GTS-R. The result is much less horsepower, but a similar level of parasitic losses due to 10 cylinders of friction, pumping losses, and rotating inertia. The race engine as restricted makes nearly 200 hp less than the street car, peaks around 4200 rpm (when the sonic restrictor chokes) and shift points are typically at 5000 rpm or below.
Q: Since you are running a limited season, how do you decide whether to enter a race or skip one and go testing at a closed track instead.
A: There are many reasons to go racing. First, nothing accelerates your program like the pressure of racing. We need that on our race team right now. Remember, we are not only developing the GTS-R for performance, but we have a new team that requires similar development. You can't simulate the intensity of pit stops or repairs at a closed test or at the shop like you can at a race weekend. That's why we have to be racing now. But there's really a much larger reason to be and that's the Viper community and the fans. They have been asking us for the last 12 years, when will the Viper be back in GT racing, and they have waited too long already to wait any further. SRT is a bit unique in the automotive world. Our fans and the Viper community are part of our team. We want to bring them along on this trip with us from start to finish. We want to have them share in our successes and failures. We want them to be behind the scenes with us – this is the best part of racing and why it will be even sweeter as we aim to move forward in the field. We have a long way to go and are certain to have our fair share of good days and bad days (and honestly, I'm sure we will have more of the later before the first). But in return, we also have the best team I have ever had the privilege to work, the support required coming from all directions, and make no mistake, the drive to get to the front. Six months ago, these cars and this team didn't exist. I like to think about this and wonder where we could be in another six.