Performance benchmarking, balancing on tap for TUSCC tests

Performance benchmarking, balancing on tap for TUSCC tests


Performance benchmarking, balancing on tap for TUSCC tests


The sports car future gets a little closer, and clearer, next week in Florida. (LAT photo)

Next week’s test at Sebring will mark the first official outing for the TUDOR United SportsCar Championship. The series, through IMSA, its sanctioning body, will begin the laborious process of benchmarking and performance balancing the cars in its four classes on Nov. 16-17, and then move the test north to Daytona for two additional days of testing on Nov. 19-20. Scot Elkins, IMSA’s VP of competition and technical regulations, will oversee both tests, with special attention being placed on the increased speed of the Daytona Prototypes with their new high-downforce bodywork, and the gap between the DPs and GT Le Mans cars.

Balancing the speed between DPs and their P2 counterparts in the Prototype class, along with setting the relative lap time splits between Prototype, PC, GT Le Mans and GT Daytona will also be on the docket.

Speaking with RACER in advance of the tests, Elkins listed some of the goals for those who attend and the processes that will be employed by IMSA to gather the necessary data to tune and tweak the TUDOR Championship cars.

?There’s a couple of different targets: the first one is we want to give everybody the opportunity to go and run at Sebring because a lot of folks haven’t been there before,? he said. ?We also wanted to give the opportunity for the teams to try drivers out and give them an opportunity to put deals together. Typically, this type of test in the Grand-Am world has kind of been what that’s for, to help everybody get their packages together and get some drivers signed and try some drivers out and evaluated.

?The second element is obviously with the changes we’re making to the class structure and the changes we’re having in GTD and the changes we’re having in the prototype class, we’re going to use it as a chance to try to gather some data and get some reasonable ideas on what the performance levels of the cars are to set us up to where we can write Balance of Performance (BoP) regulations and define some things a little further before we get to the ROAR Before the 24 test in early January.?

Entry lists have grown significantly for both tests, giving Elkins and IMSA a lot of options to pull on-board data and quantify the various lap speeds and how each car/class makes its speed. Beyond simply balancing cars within a class to hit an identical lap time, Elkins is looking to take DPs and P2s, for example, and balance their performance on the straights, in the corners and under braking.

The original plan for the November tests included real-world evaluations of the new high-downforce DP bodywork ” one that would compare the controlled data generated in the wind tunnel to what was seen around the 3.7-mile Sebring circuit ” but that will likely have to wait until the “Roar” test in January.

?We have the ability, especially with DP cars that are running now due to everybody having the same ECUs, to pull data from the cars to look at the parameters we need,? Elkins explained. ?We’re going to set up the circuits the same way we would on a race weekend with all the multi-loop timing systems to where we can go through and gather information the same way we would and the same way we do from the calculations during the race season. So getting that information won’t be that difficult.

?The part that does make it difficult is that we’re not in the position we wanted to be going into this test. What we wanted was to basically do a BoP test in the wind tunnel prior to this test and we had that scheduled and then unfortunate circumstances came about where the tunnel that we used had some maintenance issues and so they’ve been down for repairs for a while. So we’ve had to reschedule that wind tunnel test until after this track test. We’re not on the schedule that we wanted to be, in terms of being able to come to this test with adequate adjustments to the cars for downforce.?

Elkins had hoped to run through a range of downforce settings in the wind tunnel and then reproduce the same settings at Sebring and Daytona to capture like-for-like data. Although he won’t be able to apply a correction factor to the wind tunnel figures at the November tests, previous wind tunnel data should provide a decent idea of what to expect next weekend.

Photo courtesy of IMSA

One item that has already emerged from the updated DP aerodynamics, which includes a significant downforce increase at the rear through a tunnel and multi-strake diffuser package and dual element rear wing, is the need for more front downforce to balance the cars.

?We did the scale model test you and I talked about before, and we’ve got some ideas on what should be done there because we’re seeing that we need to add some downforce to the front to balance out the DP to get it kind of back to where it was, with the changes we’ve done to the rear,? he continued.

?We didn’t get a chance to effectively define that prior to this track test, which is what we wanted. So that’s why we need to rely on the teams and the constructors to work through what they can to set some things up going into the track test. So it’s not the ideal situation, but it’s what we have and it’s what we’re going to have to work with.?

In a perfect world, IMSA would have numerous cars at its disposal and specific run plans for each team to execute on their behalf. But with the teams needing to gather their own data, to sample different drivers and accomplish other tasks ahead of the season opener, Elkins says his team will gather what they need in a less formal manner.

?The two circuits that we’re going to, obviously, are very different in terms of the layout and architecture, and will give us different looks at things,? he noted. ?We’re not going to do technical inspections of the cars because everything’s not defined yet, and frankly what we’re trying to do is we’re trying to work with a new aero package in a way that we help define some things. So right now it’ll be, the teams that are coming to the test, I’ve had conversations with them and said, ‘Hey, look, the ride height rule that we had last year with the DPs, kind of ignore that and don’t worry about that. Let’s work on different items to try to get, to see what performance levels are with the different type of testing matrix.’

?And nobody’s better at doing that than the race teams themselves. When you tell them to go faster, they’re going to figure out a way to go faster. So instead of us trying to dictate it, I think it’s better that we just let the teams show up and do their job. We’ll monitor what’s going on; we’ll work with them hand-in-hand and go from there.

Once the test moves to Daytona, IMSA will have a different agenda to carry out.

?At Daytona, it’s a little different animal,? said Elkins. ?We’re adding a ton of downforce on the DP cars and it will be interesting to see where those end up and we’ll have some work to do after that test, for sure, in terms of what we need to do with the aero kit. We still have some top speed targets that we need to look at. Especially, when we try to balance the different classes with each other.

?We don’t want a GTD car being faster on the banking than the DP car. So we’ll have to do some work with that afterward, analyzing that data. Most of that we can do with the timing loops that we have in terms of speed traps and other things that kind of give us an idea of where we need to go with that. It’ll just help us set up for when we come back to Daytona for the Roar test.?

Once the Sebring-to-Daytona testing swing has been completed, Elkins will take the data and the different 2014-spec DP cars to conduct the aforementioned full-scale wind tunnel test.

?We’re still going to do the test after this track test, and what that will entail is taking a body and a chassis from each car and putting it in the tunnel and then going through a balancing process,? he said, referring to the different shapes worn by chassis makers Coyote, Dallara and Riley.

?We really want to try to get total downforce to match but that’s not always possible because of the different bodies on the cars, so we want to try to work on that. And by doing that, and then tweaking on the aero to create a high-downforce kit that we pull some drag out of it just for Daytona, and then maybe an Indianapolis kit, we should be in a pretty good place with the wind tunnel work that we have.

?Because then we could take the aero from the tunnel, go back and see it in some simulations and give ourselves an idea where the top speeds are. We should be in a really, really good place to have things locked down by the time we get back to the Roar by using the resources that we have.?

It’s unclear exactly how many DP cars will attend the November tests, but Elkins did confirm some teams have started to receive their high-downforce kits.

?We set it up to where we’ll have eight diffusers and wing packages delivered this week, and the first three went to the chassis constructors so that they could go through and do fitment because obviously the chassis are slightly different in the way they’re built,? he said. ?And then we started delivering to teams. So the idea was that we try and get a kit out, one per team.

?So, if you’re a two-car team you’ll only get one kit, but you’ll be in a position to have the car in the correct specifications, at least as far as the parts go, going into the test. Diffuser and wing eight is scheduled for delivery Friday this week. And our target was to get parts in everybody’s hands by the eighth, so we’re on schedule there.?