Detroit Grand Prix 2007 Wrap: IRL Behind the scenes

Marco Andretti's crew swapping gears, click for more

During the Detroit Grand Prix weekend, we got a backstage tour of the IRL paddock area and learned about some of what goes on. The tour kicked off in the tech inspection area, where every car has to go before and after each on-track session. As the cars are rolled up the ramps to the inspection platform an inspector actually lies on the floor under the ramps to check out the bottom of the car. They look for anything that should be there that isn't, things that are there that shouldn't and signs of damage.

Once the car is on the platform, it sits on four scales that check to see whether the car meets the minimum weight. At this point, ground clearances and wing heights and positions can be checked. Once that's done, the scales are actually lowered and inspectors verify that the car's floor is flat where it should be. Only after a car has passed the tech inspection is it allowed on track.

Continue the backstage tour after the jump.

The next stop was the Firestone tire truck and service area. Firestone has been the exclusive tire supplier to the Indy Racing League since it launched and it handles all the servicing of tires at the races. Firestone has a standard tire leasing deal that it gives to all the IRL teams for $200,000 per car per year. Firestone selects the tire compounds that will be brought to each track and everyone gets the same tires. For the set price, teams get a fixed number of tires per car per race and unlimited wet tires.

The teams supply their own wheels at about $2,000 per set including tire pressure sensors. The team crews are responsible for bringing wheels and used tires over to the Firestone truck at the start of the race weekend and between track sessions and picking them up when they're ready. The Firestone crew mounts and balances the tires. At the end of a race weekend all the used tires are loaded up on a truck to be returned to a Firestone facility in Ohio where they are shredded and recycled. Even for overseas races in Japan, Firestone packs up the used tires and returns them to Ohio so that they don't have to deal with customs and disposal regulations.

Another major exclusive supplier to the Indy Racing League is Honda. Ever since and Chevrolet and Toyota pulled out at the end of 2005, all IRL cars have used a Honda V-8 which this year is running on 98-percent ethanol. You may wonder why you would bother to mix in two percent gasoline with the ethanol? Apparently it has to do with liquor taxes. If you buy pure ethanol it's counted as liquor regardless of what the end use actually is. Adding a bit of gasoline gets around that.

As the sole supplier, Honda is currently charging a lease rate of $900,000 per car per year for IRL engines. That rate is based on the current 17-race schedule plus whatever open test sessions the IRL conducts. The engine management systems include full data logging capability that includes tracking over-revs and total run time. The engines are designed to run 1,400 miles between rebuilds and have a rev limit of 10,300 rpm. Over-revs are counted if the engine exceeds 12,500 rpm. If a driver misses a shift and over-revs, that gets logged and the rebuild interval is reduced. A certain number of over-revs is factored in, but if a team does extra testing or the driver over-revs too much the team will get charged extra for additional rebuilds.

The 3.5L normally aspirated V-8s are assembled at both Honda Performance Development and at Illmor engineering. The engines are assigned to teams randomly by serial number and they don't know which facility they come from. Honda guarantees the performance of all engines to be within three percent.

Cars in the IRL run other standardized components such as wings and gearboxes. One of the things that gets tested in tech inspection is wing flex. Weights are hung off the wing and deflection is measured. If a team modifies the components it gets penalized. There are, of course, production tolerances on all parts, and teams regularly buy multiple wings and measure them to find the ones that will give the best performance.

Inspectors also wander the pits checking the placement of stickers from certain sponsors who pay out contingency awards for carrying their signage. If a team has the stickers in the correct locations they make some extra cash. The more serious teams actually go the extreme of painting on the logos instead of using the stickers to avoid that tiny extra bit of drag that a sticker would cause.

In the individual team work areas, crews can be found swapping out gearsets between sessions in order to get the optimum combination of performance on any given track. After the cars come in from a track session the bodywork is often removed and put on a special rack where wet rags are placed over the back of the side-pods to cool them down. That helps reduce blistering of the paint in those areas.

In the pits and paddock areas, the wings can usually be found with covers draped over them to prevent other teams from seeing what settings are being used. Owners like Penske and Ganassi, drivers and other team members are regularly spotted running around the pits on scooters usually painted in the same livery as the cars. Apparently it's important to watch out for any scooter-riding Andrettis in the paddock area, because they consider themselves to have right of way everywhere. Then of course, there's IRL owner Tony George on his Segway. The teams' transporters have storage for all the tools and parts in addition to the race cars.

One other truck that can be seen in the paddock at all IRL races is the safety team's. It has a fleet of Honda Ridgelines equipped with all the lifesaving equipment needed to assist divers in case of an emergency. During every track session the safety team is placed at strategic locations around the track so that it can respond quickly in the event of an emergency.