There is much discussion about the bigger teams custom manufacturing parts for their cars. Does anyone have an idea what some of these parts are and how they affect the performance of the cars.

I know that the teams can make their own mirrors and wings, not too sure past that...

Penske manufactures their own suspension/A-arms.

Suspension parts, wing end-plates, mirrors (although it seems I read or heard on the broadcast that they were going to make a certain mirror mandatory?), Larry Curry got fired for making reverse wing wickers that were illegal so you might be able to at least make your own (as long as there legal), rear wheel aero "kick-ups". probably more stuff that I can't think of off the top of my head.

There are still plenty of "gray" areas for teams to exploit as well as areas where teams do some minor cheating.

Indycar interview - 12 June 2008 08:11 PM

Q. June is the month of short‑track racing for the Indy Car Series, first Milwaukee and then Iowa and Richmond. You've had a strong qualifying run at Milwaukee, so what do you feel about the short ovals suits your driving style best?

WILL POWER: Well, it's not only the driving style it's also the fact that you're running maximum downforce. I think where these other guys have got us is all of the work they've done on wind tunnel and wheel bearings, coatings for the gear box and all of those little things that add up to the mile‑and‑a‑half or two‑mile‑an‑hour they have over us on the faster ovals.

I get the feeling that trying to get lowest friction bearings is almost as important as wind tunnel time. I've noticed differences in rear wing endplates as well as front wings as somebody mentioned. Helmet designs differ also, another poster has said that could mean up to 2-3 HP or about .1-.16 MPH difference.
There's also an interview somewhere that Dale Coyne mentions things like lightweight wheels and the adjustable wheelbase of the dallara. Can't find it right now.

Places where you see failures have generally been areas where the teams have some freedom. Justin Wilson's A-arm failure at Texas, Penske rear wing mounts at Milwaukee, the AGR wheel bearing failures of a few years back, Dale Coyne's and AGR's mirror mounts.

Hmmm...I think what you're looking at here is a spec that is not frozen but is VERY tight. The pre DP01 CART/CHAMP regulations laid down certain parameters but anything within those limits was permissable. An N/H mech told me for instance that you could use any kind of wing you wanted as long as it fit inside an imaginary box of certain dimensions. The IRL regs are a lot tighter than that, and all parts probably have to be approved. Unlike Champ Car's DP01 spec, however, changes can be made. Pretty minor and subtle ones, they don't make much difference in performance. On a high banked oval however, those slight differences can make big differences in finishing position. On road courses, the small advantages are swallowed up by bigger differences of setup and driver skill.
That's just off the top of my head of course

TURN8 - 14 June 2008 06:19 PM

Hmmm...I think what you're looking at here is a spec that is not frozen but is VERY tight. The pre DP01 CART/CHAMP regulations laid down certain parameters but anything within those limits was permissable. An N/H mech told me for instance that you could use any kind of wing you wanted as long as it fit inside an imaginary box of certain dimensions. The IRL regs are a lot tighter than that, and all parts probably have to be approved. Unlike Champ Car's DP01 spec, however, changes can be made. Pretty minor and subtle ones, they don't make much difference in performance. On a high banked oval however, those slight differences can make big differences in finishing position. On road courses, the small advantages are swallowed up by bigger differences of setup and driver skill.
That's just off the top of my head of course

I thought the DP01 couldn't be played with. What you got from Panoz was what you had to run and it all came down to driver and setup.

indydude - 14 June 2008 08:40 PM

TURN8 - 14 June 2008 06:19 PM

Hmmm...I think what you're looking at here is a spec that is not frozen but is VERY tight. The pre DP01 CART/CHAMP regulations laid down certain parameters but anything within those limits was permissable. An N/H mech told me for instance that you could use any kind of wing you wanted as long as it fit inside an imaginary box of certain dimensions. The IRL regs are a lot tighter than that, and all parts probably have to be approved. Unlike Champ Car's DP01 spec, however, changes can be made. Pretty minor and subtle ones, they don't make much difference in performance. On a high banked oval however, those slight differences can make big differences in finishing position. On road courses, the small advantages are swallowed up by bigger differences of setup and driver skill.
That's just off the top of my head of course

I thought the DP01 couldn't be played with. What you got from Panoz was what you had to run and it all came down to driver and setup.

I think that's what I said.

I don't believe parts HAVE to be approved. For instance I do not think that Penske got approval for the rear wing mounts and if you bring a new wing endplate it doesn't have to be approved.