Time to get into some more Assetto Corsa simulator time. This time we’re heading up to Michigan (or actually down to my basement) to Grattan Raceway. Not only do I have zero experience at this track, I actually didn’t even know it existed until it was listed on the One Lap of America route. Fun fact… this race track is for sale, so if you are in the market for a track to call your own you should check them out.
Being a regional track without a historical significance means it was actually pretty hard to find a sim representation for Grattan. Thankfully, EKO Sim-Racing came to the rescue. He does high quality tracks based on LIDAR data and at the prompting of several One Lappers put together a version of Grattan Raceway for us. Initial practice is on his version 0.01 (very early beta), and as I talked with him last night he mention that he is already working on some enhancements and will continue to work on it.
Grattan Raceway is just over 2 miles in length with 10 turns and a jump. The learning process is the same here: study the track map to get a mental model for the flow, find a good instructional video and then go to the sim and test your assumptions.
Between 4 and 5 is the jump. 5-6-7 is an awkward series of corners that requires patience to get a good time. 8 has an off camber bump before the apex. And 9 is a blind apex that determines your maximum velocity down the main straight.
You’ll always be faster in a sim than in real life (unless it is a bad sim) because you are not bound by any consequences. Off track? No big deal. Slam into a barrier at 150mph, flip and burst into flames? Reset and try again. I’ve found that I’m roughly 5-15% faster in a sim than in real life. The more time and experience I have on a track the lower that number gets, but for the most part I think 10% is a good number. Most of the laps are in the low to mid 1:30s. The faster of the laps are 1:31.8 and 1:31.9. If we add the 10% to that, then I think real life pace would be in the low 1:40s.
Drivers notes:
- Braking point for T1 is tricky, roughly at the end of the guardrail on the inside
- Wide track out, carry 3rd gear
- Brake for T2 when road flattens, stay left on exit
- Hug the inside of T3, setup for fast T4
- T4 apex later than it looks, full throttle towards “jump”
- Lift off throttle just before the jump to help settle the car and setup for entry to T5
- Slowing as you go through T5 into T5a
- Stay right into right hand turn coming out of T5a, setup for T6
- T7 should be accelerating / flat
- Straighten brake zone into T8, brake early to not upset car for bump/camber change at apex
- Setup left side for T9
- T9 apex blind at top of hill, lined up with big tree
- Flat from T9 apex to finish / front straight