Tires
Hanhook Ventus R-S4
- Set of 4, we ordered from tire rack.
- Installed at the local garage.
- 1 week lead
Thunderhill Race
Tires heat up a lot. Get the PSI of the tires down to 32/33. Assume that the heat of the asphalt and running will bring the tire internal PSI up to 35 on track. Our car is FWD, so you if the fronts read lower before going out on track, that’s fine (don’t waste too much time pumping to target pressures).
If you’re paranoid, measure the PSI right as the car comes back from track, the temperatures should still be relatively accurate.
Sonoma Winter 2025 Race
Sage advice in this thread (lots of discussion about RS4, Sonoma, and wet conditions)
- https://forums.24hoursoflemons.com/viewtopic.php?id=41345 Discussion of RS-4 vs RE71RS
- https://rennlist.com/forums/racing-and-drivers-education-forum/842625-tire-advice-2.html
- Thread finds that RS-4 lasts longer, and still performs ok in the wet. More discussion:
- https://www.reddit.com/r/Autocross/comments/olttmh/which_is_better_in_the_rain_ventus_rs4_or_re71r/
- https://f80.bimmerpost.com/forums/showthread.php?t=2009112
Pressures?
- You may want higher pressures when there’s a lot of standing water on track. This may help evacuate water as it keeps the center of the tread elevated, and allows pushing from the center.
- You may want lower pressures when the track is moist/wet. Softer tires allow more tire deformation and will help keep the operating temperatures of the tires up.
Verdict:
- Most of the time, the track is just wet err on the side of pumping down.
Brakes
Lead Times
Porterfield R-4E
- 10 day lead
- We bought two sets of fronts and one set of rears