August 19th, 2014 by JaimeB
Twin Ring Motegi’s Oval course is one of the trickiest on iRacing. At first glance one would think that it is a very easy course. The racing surface is very wide and the pavement very smooth; however there is something about the Japanese asphalt that makes this track very difficult and lacking a lot of grip. With the superspeedway aero package being on the Dallara DW12 for Motegi, most drivers are having to lift on the fixed set through Turn One and Two and brake into Three and Four. There are some things that a driver can do to his or her car to significantly improve the handling here and find some time. For one, you are going to want a lot of downforce to help you carry speed and also get the power down. A lot of what I did to the setup to get it to handle well in Turns Three and Four had to be thrown-out to get the car to actually make it through One and Two, but in the end some overall pace was found.
Aerodynamically I positioned the rear wing as high as it would go and found an amount of rear wicker that would keep me from losing the rear through the corners at speed. On the front I put as much downforce as I could without having the same problem. I’m finding that in the rear the full wicker works the best and then if you want to trim out some aero use the beam wicker to do so in more fine adjustments. Meanwhile, upfront I seem to be stuck with the ½ x 5 ½ inch wicker. force as I could without having the same problem. I’m finding that in the rear the full wicker works the best and then if you want to trim out some aero use the beam wicker to do so in more fine adjustments.
In terms of the suspension I didn’t start with the fixed set, but rather something from before the season started that I had raced at Pocono. I softened the front ARB a bit and added some to the rear primarily. Then I shifted the balance a click forward. The next thing I did was soften my left rear spring rate and raise the left rear ride height which helped me with stability off of Turn Four. From there on out it was a few clicks here and a few there on the suspension. The main change after that was a radical change to the caster. I found that raising the right front cast to 9.08 degrees allowed for me to flat foot all the way around One and Two. However, it did hurt my entry into Three and made my exit out of Four really unstable. I fixed the exit of Four by adding more low speed rebound damping to the right rear tire and fixed the entry to Three by adding more low speed compression damping to the right front. This wasn’t enough to completely fix either problem, so I settled by putting the front toe to +2/-2 which significantly helped the car on the exit of the corner.
Normally I am not one to give handouts, but I have decided that I will provide you all with my (Q) setup for this week in hopes that someone may be able to improve it – if you do so please share it in the forum for everyone to use. It may not get you in the low 27s like the top guys, but it should find you a solid 2-3 tenths from the fixed setup. For converting this set to a race set I would focus on finding front end grip, maximizing down force and also keeping the right rear from overheating.