And despite this being a very spec series, you can speed up or slow down the steering according to taste, and add or reduce castor?
BG: Yeah, you can adjust both. But on an oval, especially one where you're light on downforce, you put castor in to bring some steering feel back, otherwise some drivers start doing this [he moves an imaginary steering wheel in an agitated manner] because they don't really know where the car is. And all that does, obviously, is make the back end really nervous.
But at the same time, when you put castor in, you get a lot of kickback through the wheel, so although there are fewer unnecessary movements, the movements the driver does now make are more deliberate and the steering is heavier, and so that's more physical effort. So it's a very fine line between putting enough feel into the steering so the driver knows what the car's doing but not giving him so much physical effort that he starts getting tired – especially when, just because of the nature of the track, he's being pulled 5G one way and 2G vertically.
The other two issues to bear in mind with regards to the steering: 1) Although Iowa is wide enough to go two-wide, the high line really starts to tighten up and get squeezed on the exit of Turn 2. And 2) On the exit of Turn 3, the banking starts to unwind itself, it warps. So you hit a compression, the bottom falls out from underneath you and that's why people crash on the exit of Turn 4.
So it's safe to say that Iowa is a physical challenge as well as a mental one.
BG: It's probably the most physical track we go to in terms of lateral G, and so on a 17-18sec lap, after 250 laps, the driver gets out of the car and wants to keep walking to the left!
You're also changing gears four times a lap – upchanges on the exit of Turn 4 and exit of 2 and downchange for entry to 1 and 3.
What is the speed difference between Turns 1-2 and Turns 3-4?
BG: Very similar: in qualifying, they're doing about 190mph down each straight and around 175mph through each turn. But Turns 3-4 are probably a little easier because 4 opens up, whereas, like we said, Turn 2, you've just gotten over the bump and then the wall starts coming in on you on the exit…
Yeah so I found it odd the line that Graham Rahal ran in the Ganassi car last year really odd. It was right up by the wall.
BG: Right, and Graham does typically drive the high line around here. Is it the best? Hmm… I don't know. The really fast guys around here, like Marco Andretti and Tony Kanaan, turn in late, taking a really wide entry into Turn 1, and then turn down the banking and get most of their turning done before the high-G point so they then have a really shallow exit from Turn 2, which also gives themselves a safety margin if the car steps out.
Graham's line was about taking a shallow entry into Turn 1 but it means he's still got a lot of turning to do as he goes over the compression, and then he's up by the wall on the exit, so there's no room to catch the car.
If you turn in late like Tony, like Marco, you're also having to turn in more sharply. Doesn't that take the edge off the tires quicker, especially the right front?
BG: Yes, and that will be something to watch for here. The tire is the Iowa 2012 left, but the Texas 2013 right… and we all saw the tire degradation in Texas. OK, so here we have a different setup, more downforce here, but you are also working the tires harder. The drivers just gently floating the cars through that kink in the Texas straightaway, whereas here, the front “straight” truly arcs, so the right-side tires aren't really getting a rest.
So I think you'll see everyone hold onto their tires and hold position for the first 15 laps after a pit stop, but after that, you're going to get some cars dropping off the pace, others staying up front, and some kinda dropping back but not falling off the cliff-edge.
As an engineer, I like the challenge of trying to be the guy who has his tires fall off less. There's not much room for development on these spec cars, so you grab every chance you can to find the thing that will make the difference.
Well, talking of tire degradation, everyone but Helio [Castroneves] had major fall-off in pace at Texas this year, like last year – some 15-17mph from the start of a stint to the end. That being the case, had there been a late yellow, do you think everyone would have dashed to the pits for fresh tires?
BG: Yes. We actually discussed that in the pre-race meeting because we felt that even if the yellow came out with 10 laps to go, and the green period at the end was going to be five laps, and there were only about 10 cars on the lead lap then it would be worth pitting. That's how much of an advantage new tires were. If we'd been eighth and pitted, and Helio had stayed out on old tires, I think we could have been past him within three or four laps.
And then everyone would have said it was a great race, too.
BG: Right. The problem was that these cars do push such a big hole in the air that the following cars can't use the downforce they have. And in that way, this car is almost self-policing in that with such low downforce levels, you cannot get the pack racing of old. But I was discussing this with Tom Wurtz [team manager], places like Iowa and Milwaukee, they should give us push-to-pass again. On these short straights, you can get a third of the way alongside the guy in front, maybe halfway, but if the guy ahead then dive-bombs into the apex then you have to back off and he takes the air away and you push up the track and lose your momentum.
As happened to Scott Dixon a couple of times.
BG: Exactly. So if you have a push-to-pass facility, then the car trying to make the pass is right alongside at turn-in, so then the cars are going in side by side and properly fighting. So Tom mentioned reintroducing the 20-30hp push-to-pass to Derrick Walker.
But I thought the Milwaukee race was good, anyway, and going back to your point about what fans say is a good race is very much down to the TV direction and commentating. The director needs to know what to look for, the commentators need to explain what the viewers are watching. Why does a following driver run staggered behind the car he's chasing instead of directly behind him going into the turns? You or I know it's to get clean air on his wings, but will all the people watching at home know that it's not just to get air on the nose of the car but also to get air on the underwing?
And to go full circle – what we were talking about at the start – do the fans know how much punishment the driver's being put through physically? That a 1,500lb car with 5,000lbs of downforce is going around here pulling 5G? It's that stuff that makes IndyCar what it is. And in this particular case, it's what makes Iowa Speedway what it is.