Video Guide
Who am I, and why should you trust this guide?
I've been to East 12 times over the last few years, I've gotten podiums and won here in 86 Challenge, and my personal best at East Bypass is "only" 1 second off the all-time record. I'm not saying this guide will help you shave the last tenth, but folks who are chasing the last tenth typically aren't looking up guides.
I already watched the video, why should I read this?
Honestly, fair. I'll try to minimize the overlap between this article and video. I'll add more technical details, because you must clearly be a nerd if a 37 minute video wasn't enough for you.
Pre-repave vs post-repave
Here are the main differences I noticed:
- Pavement is coarser but less bumpy. Means less sliding, but more predictable.
- Apex curbs are way easier to attack. Flatter, grippier. T1, T6, T9, T11, T14 especially.
- Some entry curbs have been added, which lets you open up the entries a bit. T6, T8, T11.
- T12 rally line is gone, and in its place is an annoyingly serrated curb that you still have to cut.
- T8 runoff is gone. Can't send it willy-nilly.
- T14 runoff is gone. Doesn't feel slower because there is so much more traction and you can cut the apex curb more.
How does coarse pavement affect handling?
After a fresh repave, the pavement is rough, like sandpaper. The thunderhill folks did a good job of making sure it behaves like fine grit sandpaper, but it still bites really hard into the tire. You might think this just purely adds grip, but tires can also grip when the surface is smooth if the surface has been rubbered in - rubber on rubber is pretty grippy. So a repave doesn't simply add grip, it changes how the tire works.
Pre-repave, we had to micromanage the car to stay at the limit. The car behaved more like a curling stone, where you'd set its trajectory on entry and pray it held through the turn. Post-repave, the tires dissipate energy a lot more quickly. You can rotate the car a lot harder on entry (almost like a flick) and not worry about spinning. Places where we were previously using maintenance throttle and praying the car would stick, we now have to carry heavy trail braking to get the nose to point.
Coarser pavement also means much more on-throttle understeer. The increased dynamic coeffient of friction means your inside rear doesn't spin up as much, which reduces the torque split between the inside and outside tires. Instead of getting a tank-turn effect on the gas, your rear axle just pushes the car forward. That's a good thing - ideally the gas should make the car go forward. But if you're used to being able to rely on the gas to turn the car, that's not going to work as well anymore.
For most normal cars, the net effect is that the track feels more understeery. You can't get away with light trail braking, early throttle and turning using the steering wheel mid-corner. You need to carry a lot of brake pressure on entry, hold the brakes almost all the way to the apex, pivot as much as you can before getting on the gas, then get on the gas with authority when you do. You can mitigate this by tuning your steady-state balance a bit (softer front ARB or stiffer rear). Even then, you will probably need to adjust your driving style drastically.
Beginner Guide
Car prep
East isn't too hard on brakes compared to some other tracks but we do have some long, high-speed braking zones. I recommend upgrading pads and fluid before coming.
If you have an 86/brz, I recommend running thicker oil and a ~0.8qt overfill. There are a couple spots (T3, T5, T15) where you lose oil pressure if you're driving very fast.
Lead-follow
This is not the time to try to go fast. Focus on your leader, replicate their line as precisely as you can. Use serrated exit curbs to feel out how wide your car is. T1, T2, T6, T10, T12, T14 are all good places to focus on track usage.
Going fast
Lucky for you, East is very safe. There is only one wall at T15. If you have the car control to go wide into the dirt instead of oversteering into the pit wall, you will most likely have no issues besides maybe some dirt on your car. Take it easy in high-consequence turns like T1 and T8, but send it everywhere else. Just remember that your ability to get yourself out of trouble should always exceed your ability to get into trouble.
Intermediate Guide
Trail braking
As I said above, you can't rely on drifting or just turning the steering wheel to turn the car anymore. Don't try to immediately get to the limit. Try to see how much you can turn the car on the brakes without really sliding it - that's where the speed is.
Track usage
Please please don't drag gravel and dirt onto the track if you can avoid it. Get your car placement and control nailed down first, then focus on using the last few inches of track.
Downshifting
T1, T2, T3, T9 and T11 are marginal downshifts. If your heel-toe technique sucks, maybe just skip the downshifts in these spots. If your car is really traction-limited or oversteery, that is also a good reason to skip these downshifts until you're actually chasing those last tenths.
Advanced Guide
Rotation
The repave dissipates yaw more quickly and throttle induces more understeer. This means braking later, squaring off corners a bit more, and focusing your rotation. If you aren't getting close to spinning, you're going slow.
Throttle ramp
You need to minimize the time to 100% throttle. You'll initially be nervous to smash the gas, and sometimes, if you don't get your entry right, even a steep throttle ramp will cause understeer. But start with the assumption that the optimal way out is a steep ramp to 100% and work backwards. How can you set up the exit so you're doing less turning after the apex?
Bypass
You should be very comfortable carrying speed over bypass. The limiting factor for you should be the grip of the car going down the hill. In a stock-ish GR86, you should not be using brakes over the crest (no brakes!), but instead carry light throttle until the car starts to land, at which point you should trail brake until you clip the curb at the bottom. It sounds absurd but that's the game, at least with an understeery car.
Downloads
AIM XRK Data - Session 5Download
AIM CSV Data - Session 5Download