Andretti Autosports Race Setups

[JagtechOhio]

Tommy Kendall was a race car driver, not sure if he is directly involved in any capacity with the IndyCar Series, and maybe he's just a reporter now. If you guys know, clue me in.

The other day, he tweets that four cars failed post-race tech inspection at Chicago. Nobody else seemed to know about it, although there is a guy who posts on another board who sounds like an insider who was aware.

Tonight I see this article, and it sure could explain why the AA cars have qualified so lousy for most of the season, and often been able to charge through the pack during the race.

http://www.autoweek.com/article/20100904/IRL/100909937

[NaBUru38]

ESPN Latin America broadcasters mentioned this yesterday. It would be seriously bad news.

[PabloTeK]

Baring in mind you can make a raft of changes to a car that can make it much better in the race than qually, look at McLaren and how they've won 5 times this year, only once from pole! Their cars can be seriously quick in the race but usually struggle slightly with one lap wonders...

And what on earth is an underwing, is it the undertray, the diffuser?

[JagtechOhio]

Yes Pablo, the "underwing" is the undertray, which on IndyCars has two venturies (tunnels) that run the length of the tub. If you want to get a good look, search for pictures or video from Mike Conway's wreck at Indy this year. Sad to say, you can see the tunnels very prominently.

At Indy, the cars run with very little downforce from the wings...often they are set neutral, or even produce a slight amount of lift.

That means the approximate total downforce of 1,000 lbs is generated from the tunnels on the undertray, which is a spec component.

The outlet angle of the tunnels...this is what you would also call a single diffuser on each side...is shallow. You can increase the amount of downforce by increasing the diffuser angle, up to a limit of maybe 14 degrees. But you're not allowed to.

So I'm only guessing, but that could be the way to play a game like this. The car goes through pre-race tech, then you remove a few shims and raise the back of the entire undertray 1/2", for example.

Now you can run a 1.5 mile oval with some of the downforce trimmed off the wings. And the decrease in drag gets you up to 217, when you could only make 215 before.

Then it just becomes a question of whether the undertray height gets checked after the race. And what the officials are going to do about it when they catch you.

Supposedly there will be more public information to come about this, but it seems like there is a problem. How it was done and what the consequences are hasn't been discussed publicly.

[bjohnsonsmith]

How sneaky. Reminds me of F1 during the ground effect era in 1981/82, when the cars were banned from using sliding skirts and the rules dictated a higher ride height.

Fixed skirts and hydraulic suspension were used, in order to get the full ground effect. The hydraulic suspension could change the ride height of the car, so that the fixed skirts had contact with the track.

As the cars came back to the pits the hydraulics raised the car, so the ride height would comply with the new regulations. It was impossible to police and ground effect was banned but it is making a return in 2012.

[JagtechOhio]

There has been a lot of rumor about this little story, but nothing official from IRL. What and who were actually caught is still unclear.

Very interesting to read that gound effects are to re-emerge in F1, and will be enhanced in IndyCar. Must be I read some history that was incorrect, or didn't read it correctly.

[bjohnsonsmith]

There's some good stuff on the F1 part of 10-10ths about the reintroduction of ground effect and the adoption of the GRE; just right up your street Jag.