The Kitchen Sink: Homestead – Not a Typical 1.5 Miler
September 4th, 2014 by JaimeB
Homestead is one of those tracks that is so similar to yet so different from other tracks on the schedule. At 1.5 miles, Homestead is the same length as far too many high banked speedways; however, the differences between Homestead and other 1.5 mile circuits are easily seen as a driver. A typical 1.5 mile setup for the Dallara DW12 IndyCar will not work here: You will find a lack of rear grip and, at the same time, a lack of front end grip.
It may be a good idea to load-up a base 1.5 mile set for starters; the chassis, gear ratios, and dampers should be a good starting point. The biggest thing you are going to want to change is the aerodynamics, as well as a few minor suspension settings. The front wing is standard operating procedure; you’re going to keep adding wing until you get enough grip that you can flat-foot the bottom of the track in qualifying trim and without scrubbing speed.
The rear end of the car is where the aero settings are tricky. Even if you bring the rear to the maximum wing angle, if you do not play with the wickers you will not have enough downforce. However, if you run maximum wing angle and wickers you will have far too much downforce. So, some of you may be wondering what you should do then. The answer to this is try adding just a little bit of the rear wickers. Then, go out on the track with the zero degrees wing angle. If the car is still too loose, then you need more rear wing winger; try another click up on each of them. You should find the car much more drivable with these wickers. If this is giving you a satisfactory amount of rear wing stability, I would then recommend lowering the rear wing angle in 3-4 click increments until you start to lose the back end again; then add the rear wing back into it in small increments until you find enough grip again. Remember to keep balancing the front wing too. You are going to have to change them both together to get a comfortable balance, even after you establish where your comfort zone for the rear wing position.
“Homestead is so similar to yet so different from other tracks on the schedule.”
When it comes to the car’s suspension settings, there are a few things I would recommend changing. For qualifying trim, I’ve found putting the right rear camber as close to -0.50 as possible seems to be the fastest; however, in race trim you are going to want somewhere close to -2.00 so as to not overheat the rear tire. I also found quite a bit of benefit in adjusting the front anti-roll bar. For qualifying at least I found that making the bar stiffer generated a greater amount of exit speed. Intuitively a stiffer front bar would induce understeer, and at Homestead with proper aero settings you are generally a bit tight. However, the job of the antiroll bar is to prevent the chassis from rolling too far. Often times with a roll bar that is too soft the chassis rolls, and the car feels as if it binds up, especially in the mid-corner to exit area. So, going a bit stiffer on the front bar may prevent this.
For spring rates, anything around and above 2000 lbs. seems to be the norm, with ride heights peaking just over 1 inch in the front and between 1.3 and 1.5 in the rear. For gearing, look for something at 230 mph and maybe add one more gear just a click higher than that for race trim.
You will find in racetrim that in the slipstream of another car there is virtually no grip. So, in race trim you will often find that all cars are separated by almost a second so to conserve the tires and not overheat them. Some drivers will venture up to a half a second away from the car in front and wait for them to make a mistake – which seems to be the only avenue for overtaking. Adding downforce is always a good method to find grip, but – surprise, surprise — it slows the car down so much in the straight here that it makes anyone carrying a lot of downforce a sitting duck. For race trim, focus on something that is comfortable to drive over the long run and will not wear out the rear tires in a 50 lap stint.
Remember to check-out the Dallara DW12 forums in the Road Racing section of the iRacing forum to find more information and I hope you will join us for some more open series sim racing action!