Brad Kettler Interview
At The Le Mans Test Day 2005
© Alan Lis

Champion Team Director Brad Kettler doesn't need introducing on these pages. Alan Lis caught up with him at the 2005 Test Weekend at Le Mans.

dailysportscar.comHow much experience did you have of running the R8 in Le Mans 2005 spec. before the test day?
The only time we ran the car in that configuration was during January tests at Sebring, which is hardly a fit comparison for Le Mans. We ran the car in narrow track Le Mans configuration, with the additional 50 kilograms of ballast in it to get at least a basic idea of what it was going to do. It really upsets the balance quite a bit because it is a lot of weight that the car was never intended to have.

How is the balance affected?
It puts the car in a position where it is crossing over its roll centres a lot. Although we got some data from the Sebring test, the first meaningful runs were on the test day itself. At Sebring, with the added weight and the smaller air restrictor, the car was about 2.5 to 2.6 seconds a lap slower - even with Tom K pedalling it as hard as he could. The worst effect seemed to be on braking, because there is a lot of pitch and heave motion associated with that extra 50 kilograms. That is a significant amount of weight for one of these cars.

Where is the ballast located?
It’s right alongside the cockpit, as close to the centre as we can get it, and at the floor level, as low as we could get it. It’s basically adjacent to the driver’s thigh. We found that if we put it any further forward it really, really changed the pitch motion on the car a lot.

What is the material?
It’s called Trimet, which is a very, very dense tungsten based ballast material that’s used in F1 a lot, and it allowed us to make the plate very slender, to get it as low as possible in the car.

What do you anticipate as the penalties in performance?
The smaller restrictor has just absolutely strangled the engine – we might as well be pulling a trailer behind the car. We are expecting to see top speed in about the 310 – 312 km/h category with the low downforce. That’s a good 12-16km/h down from last year, so the only place the guys are going to be able to pull out and get around a GT1 car is going to be under braking. That was an area we were working on at the test day because it’s one of the only things we have where we might be able to pick up an advantage.

We also did some shock work and tried a couple of different configurations purely based on our best guesses of what we were going to find. But I was most concerned about the braking motion, because it is one of the only places where these cars maintain any advantage.

How has the engine performance been affected?
Power down is not an issue now with the 30 horsepower we’ve lost, because of the smaller restrictor. The R8 is now quite gutless coming off corners: traction is not really an issue so we are going to try to control the geometry in the rear axle to keep it from heaving up too much.

Is the rear wing the same width as last year or even smaller?
It’s the same as last year. In the ALMS (above) it’s two metres wide, the way the car was designed. For Le Mans it’s 1.8 metres, but that is manageable and you can actually get a pretty good balance in the car. Audi Sport did a really good job aerodynamically, because the 1.8 metre wing is run in conjunction with a different side pod, that shifts the centre of pressure a little bit more to the centre of the car and allows the car to really have a pretty decent aerodynamic balance. We are quite happy with that part, but the deal with this weight, I mean, just to put the all that weight in the car, it really makes you feel bad…..

dailysportscar.comHas the 2005 spec. affected range with the 80-litre fuel tank?
We’ve had the smaller tank for a couple of years. Before the test day we didn’t know how the additional 5% cut in the restrictor diameter was going to affect the fuel economy. Added to that there was the penalty with the weight, so even though we were running 5% less air through the engine, it has to work a lot harder.

So the 13 lap runs we saw in 2004 are not for certain?
One way or another I am going to find a way to do it, I hope, because I see it as a critical point that we have to do that, because it is one of the few places that we still have something to offer the race.

I think the Pescarolos are just going to disappear from us and we are just going to be trudging along back here running our own race - that’s about the best that we can do. We have to run a tactically perfect race - where the drivers can’t make any mistakes and there can’t be any technical errors - and then I think it will come in our direction, but I am not predicting anything. I had to coach the team a bit for the test day because I knew that by the end it was going to look fairly grim. They are used to being near the front and I felt it was really going to take them by surprise. The ORECA guys have obviously got a little bit of experience running this configuration so they have got a little bit more experience, and they could have actually an advantage on us.

Is 2005 the last year we will see these cars at Le Mans?
I am pretty sure it is really and for me personally, I think it should be. The Audi R8 is such an incredible piece of equipment that it needs to be retired with its reputation intact. It’s such a damn good car, that even with all these handicaps it has been handed, it is still at the end of the day a player, it continues to surprise people. Of course what we saw in Mid-Ohio recently was a display of what the modern stuff can do. The Zytek was incredibly fast, but even then the R8 was a player in the race.

Are you looking down the road beyond the R8?
Of course I have got one of the best prototype racing teams in the world assembled at the moment, and it is my intention to keep them going. There are a lot of things going on right now, but there is nothing that I can comment on because that would be sheer speculation. I certainly would love to continue with a car of this calibre and I know that Audi can build one. It’s just a matter of where and when.


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