Nerd Expo

Thunderhill Fast Lap Notes

Upgraded tires to 210 15" from 195 14" RT615s.
2:25.6 (previous best was 2:32)
Laps were really inconsistent. Still getting used to new tires.

Previous 14:
Actual: Slowed down to 50 before turn and drop to 45 going to 15
Note: Need to slow down more and stay on gas through 15

Previous 15:
Actual: Exit at 60.

Front Straight:
Actual: reach 95mph
53
Turn 1:
Actual: Enter 80mph and exit 76mph (Bad)
Note: Need to slow down more and get on full throttle before apex

Turn 2:
Wide: Enter 69; Slow to 44(come in) trying to come in; Exit 66; Time 5.3 seconds
Inside: Enter 70; Exit 53(slowest); Time 5.1 s
Normal:

Turn 3:
Actual: 1/3 from inside most of way (newer line)
Note: Try inside all the way again except entry (original line)

Turn 4:
Note: hit apex

Turn 5:
Actual: Slow to 34, turn and gas. Some oversteer due at crest to get car around.
Full throttle til 6
Note: Work on quick low speed turn without sliding back tire

Turn 6:
Note: Try to get on gas earlier

Turn 8:
Note: Need to tap, turn, go full throttle by apex and stay there until 9

Turn 9:
Note: Need to gas before apex. Hill will slow car down

Turn 10:
Note: Need to late apex more and get on gas sooner

Turn 11:
Note: Slow to about 30mhp(really slow), whip car around and gas

I got my Alignment done today after upgrading to 15" rims with 205 Falken RT615s.

Left Front
Camber: -1.1 (max)
Caster: 4.4
Toe: -0.03 (pointing out for better turn in and less stability)

Right Front
Camber: -1.2 (max)
Caster: 4.8
Toe: -0.05

Left Rear
Camber: -1.9
Toe: 0.10

Right Rear
Camber: -1.9
Toe: 0.12

Tire pressure was +4 in rear with 150lbs weight on driver's side with passenger seat installed.

For the next alignment, will try to get -2 to -3 camber in front with an aftermarket Camber Kit.

Front tie racks should be replaced.

Suspension: Upgrade to Coilovers and stiffer springs (Koni + GC 450/320)

Need to measure new ride height.

I finally got some time on the famous Laguna Seca and it did not disappointment. I ran this a few time on Forza a while back and it was quite similar minus the feel and fun.

Turn 1 as fast, downhill and blind. Never really noticed it on Forza, but quite dicey in real life. I don't think I got this one down as I was never position perfectly going into the braking zone.

Turn 2 is 2nd gear in a Miata, so it require 2 down shifts. Braking around marker 3 seems to be about right, but only after the brakes and tires warmed up. I enter the turn near the middle of the road or toward outside, look at the exit apex right away to gauge the line and speed.

Turn 3 is slow, but don't bother down shifting to 2nd.

Turn 4 looks like turn 3, but it's much faster. I tap the break just before turn in. The turn in point is between the 2 and 1 marker.

Turn 5 is uphill after the apex and all the high HP cars can pass easily here.

Turn 6 is also uphill and very fast. I tap the brakes before turn in and get back on the gas.

Turn 7 is preparation for the corkscrew. Start on the left and end on the right.

Turn 8 (cockscrew) is a slow double blind downhill turn. The braking area is blind and the turn in is blind. I found that there's a groove at the bottom where it's natural to turn into which helps to hold the car.

Turn 9 is the funnest turn on the course. After 8, get back on the far right. Look to the apex right away, aim your car, and gas it. Initially, I had a hard time hitting the apex because the traction decreases during the turn. When done properly, you drift out the outside edge. I see lots of cars early in the day(myself included), only using half the track on exit. It just takes a bit of time to get used to this section.

Turn 10 is nothing special.

Turn 11 is very slow sharp turn and the most important turn on the entire course. I'm going back to Forza and see what the recommended line is. I'm probably taking it too fast and not getting back on the gas early enough is all.

I was out there on 11 Nov 2007 with NASA. It was the Indy configuration with turn 9 and NASCAR 7. This was about as close to a high speed autocross as I've seen, but still with plenty of time to think about your grocery list. I was running HPDE 3 which starts with HPDE 2 passing rules on the 1st sessions and progresses to open track by the last session barring too many instances.

The cars are generally more powerful and more heavily modified in this group than HPDE 1 and 2. I would venture to say 30%+ of the cars run racing tires, and everyone else had high performance street tires. I've replaced my 195 R14 Hankook RS2 with a 195 R14 Falken Azenis. They seem to stick a bit better but wear quicker. It's possible that I need an alignment again, but I want to wait until I get a new suspension setup.

Infineon being so close to the Bay Area had a much larger attendance than Thunderhill. I guess we had about 50 people in HPDE 3 all running at the same time. About half the group just moved up from HPDE 2 and a good portion of the participants had not been on Infineon before, me included. I ran into someone I meet on my 1st track day who drives a white BMW. I’ll be sending him updates of my future track days and hopefully meet up again.

The track conditions were very good that day. It rain the day before, but what little water was on the track dried out by the 2nd session. There was also a 2 hour of racing before HPDE groups hit the track, so the track did have some fresh rubber laid out for us.

This was the 1st time I did not touch dirty all day. I felt much more controlled and was able to put the car pretty much where I wanted. I was pretty smooth all. With stiffer springs, I should be able to push a bit hard on the turns and still be in the sweet suspension travel range.

Driving the Track:

http://www.youtube.com/watch?v=anzucv0N-IM

Here's my video which is exactly the line I'm going to describe.

http://www.youtube.com/watch?v=pDd08rv25Wk

The turn numbers will be the same as counter-clockwise, but I'll be starting on 15.

15. Downshift to 3 and run over the inside berm. This is a no no going clockwise. Get a couple of wheels on the run off, but not all 4. You may get black flagged if you use too much run off.

14. It's still a blind turn where both the apex and exit points are not visible at turn in. I put the Miata's inside wheels into the ditch at apex and it did not disturb the car much. An instructor in a Super 7 tried it and did not like the feel of dropping the inside wheels into the ditch.

13. Tap the brakes and apex early for 13. Do the hard braking between 13 and 12.

12. This is a throw away turn. Do the entire turn on the inside and stay left. 11 will come up so fast, there's no time to position the car after the turn. Downshift to 2nd in the small straight after 12.

11. Put 2 wheels in the run off area, but like 15, putting 4 wheels on it may get you black flagged.

10. I upshift to 3rd before the turn. A small tap or lift is all that's needed in the Miata.

9. At the bottom of the hill, you should be on the right side. Move toward the left such that you'll be parallel with the berm coming over the top. The only way to learn this is to start very slow and find the proper line. You can get in trouble here if you come in full speed to the top of the hill and find the car pointed in the wrong direction. You'll need all your traction for braking at the top.

8. If it's not wet, get 2 wheels on the outside berm before the turn in. You'll be carrying a lot of speed coming downhill from 9 and will need to get on the brakes at bit. It's questionable when it's the best time to shift to 4th. I do it before the turn in because I don't want the risk of hitting the rev limiter when I'm going full throttle around the turn. It'll be a spin out if the gas cuts off for a bit.

7. Wow, this is actually a turn now. Your best bet is to spot the braking zone for 6 ASAP. Go slow and find some type of landmark if possible. It's pretty hard to do out here.

6. I downshift to 3 and hit the apex. However, I let the car drift out to the outside instead of staying inside. The turn in for 5a(passthrough) will be sharper, but manageable. Many people will stay tight to the right side here and my line provides me with a passing opportunity.

5a(Passthrough). You can get air on the left side. Stay around the middle to avoid this. Getting air is fun, but time in the air is time you can't accelerate.

4. Nothing special

3. You can start inside or near the middle. I think starting in the middle and slowly coming back inside is a better line. The car seems to settle better. But if someone is on your tail, then stay inside. Otherwise, they'll sneak inside and you'll get stuck in the negative camber part of the track all the way around the turn. Alternate between looking in front and at the side of the hill. The latter helps somehow, but I'm not sure why. Have patience and don't drift out until you near the crest. Learn where to drift out bit by bit, else you'll find that the road can run out quickly.

2. I have a hard time around this one regardless of which direction I go. I alternate between looking in front and at the exit. If someone is not to my inside, I use throttle steer to get the front pointed in so I can hit the apex. You got time, so look in your mirrors to see who's catching up and may attempt a pass at turn 1.

The Legend cars I watched exit turn 3 and pushing all the way to the outside (this is hard to do and I spun once trying this when I misjudge the exit as it's hard to see until you get over the crest). The the Legends move all the way to the left side before entering turn 2. I guess they're taking the largest geometric arch around the turn.

1. You can get a bit of a drift around this corner, but don't spin out. The pit wall is painful. There's probably a blend line that's consider out of bounds for safety. Do be aware of other cars before the turn because this is a popular passing corner for cars that catch up in turn 2.

Buttonwillow Raceway

I just ran there yesterday for the 1st time and that track is great. It's got lots of turns and configurations. I ran Race Configuration 1 clockwise with the Golden Gate Lotus Club. These guys put on a great bare bones event. There were about 60 of us divided into 2 groups. There are 3 20 minute sessions every hour from 10 to 12 and 1 to 5. The 1st group can run the beginner or intermediate sessions. The 2nd group can run intermediate or advance sessions. That comes out to 40 minutes of run time per hour for 6 hours. That's 12 20 minute sessions. NASA gives you 4 20 minute sessions. SCCA and most other vendors gave you 5 25/20 minute sessions. This is basically 3 track days in one and most guys don't run all the sessions they're entitled to, including myself.
I ran off track twice, but that's only 0.66 run off average per normal track event. considering how many sessions I got. This track have lots of run off space, but it's full of soft dirt that'll shoot up in the air and hang for minutes. Your car, inside and out will be completely covered. Even my center console compartment got dirty that time I spun out in the dirt. I checked all my wheels and had to gouge out small pebbles lodged between the wheels and tires. Running clockwise on Race Configuration 1, there wasn't really any chance to hit solid objects, but if this same configuration was ran counter clockwise, Sunrise will be quit dangerous.

Here's my strategy for Race Configuration 1 running clockwise. All the turns there have names instead of numbers because of the ability to configure the track in so many different ways.

Sunrise:
Standard 90 degree turn. Becareful not to get you wheel on the outside berm when braking. Hit the inside berm.

Offramp
Late apex on the left before the tight loop. Brake hard and down shift to 2nd. Turn hard toward the the apex and add gas. The inside of the track is banked before the apex. The car should be straight enough to shift to 3nd near the exit.
Another line is to early apex the left before the tight loop. You would be coming down the middle of the track approaching the tight loop have have a better braking area. Do a double apex here.

Cotton Corners (CC)
Slow down a lot, and turn at the end of the left berm. Run over the inside berm and stay inside. Tap you brakes and late apex the left turn and run over the berm. Stay inside. Slightly late apex the right turn out of CC and get on the gas ASAP. Upon exit, get to the outside to prepare of Grapevine.

Grapevine
If you exit CC right, you're car will push all the way to the outside. As soon you get to the outside, you'll probably start your right turn for Grapevine. Make sure to run over the inside berm to maximize you exit speed.

Club Corner
The funnest series of turns. This turn is much faster than it seems and the Miata is full throttle here. I had to lift slight before or after the turn to get back on the right side for the next turn. It may be possible to take the next turn at full throttle w/o moving all the way to the right side. Something to try next time.

Bus Stop
Be careful not to touch the outside berm when braking. It's easy to do and will seriously unsettle your car. Look at the exit point and run over the inside berm completely. This turn is pretty fast. Immediately move to the left side to prepare for the next turn, however, you probably won't be able to get all the way to the left before starting the next turn. This is full throttle for the Miata until Riverside.

Riverside
Stay around the middle of the track and look for the exit apex. The outside of the track may have debris. I have to lift slightly to get the front pointed to the apex, but don't do this abruptly. This is like Thunderhill turn 2 running backwards. At the exit of this turn, get back to the right side before Lost Hills.

Lost Hills entry turn
Full throttle, throw the car at the apex, and run over the inside berm. You got lots of space on the right side, but don't use it all because you want to be on the left for the next turn.

Lost Hills exit turn over blind hill
Slow down a lot and use a really late apex. I turn at the very end of the berm on the left and run over the inside berm. You should be able to go full throttle as soon as you get the car pointed at the apex. There's some broken pavement on the blind side of the inside berm. Don't worry about it and it's OK to hit a bit of dirt here. coming over the hill, your car should be pointed toward the apex of the next turn already. Just stay on the gas and run over the inside berm for the next turn too.
If you take this car too early, and find that you are still turning after the apex, you'll probably have to lift off the throttle to avoid running off. This is due to the traction lost while going downhill plus there's a small dip.

Mazda Star
I got a few different suggestions for this turn from fast drivers. I believe the line for this one depends solely on the type of car. If done right, both turns can be turned into a single big turn. I was able to do this a couple of times, but I also ran off here and got my car covered in dirt. This is almost like Thunderhill 14/15. I late apex the 1st turn by waiting until I'm past the left berm before my turn in. I see another Miata with 15" R compounds turn in early and faster, so it depends on the car and setup. Once I get the car turned, I start to get on the gas and aim for the exit point. The exit is about 3/4 of the way on the exit berm. For the exit turn, I suggest you maintain full throttle and aim the car the best you can toward the entry for Esses.

Esses
Run over the 1st berm complete and then just touch all the other berms. My Miata is running ~6000 RPM in 3rd here, so I shift before I hit the berm. You should be able to accelerate all the way though here including the last left. I did run over the last left's inside berm once and it wasn't too unsettling. But a car with stiffer suspension or higher speed may want to just touch that last berm.

Sunset
This turn is much slower than it appears and you'll be carrying lots of speed into it. I slow downed to about 4000 RPM in 4th before DS to 3 while still braking. I start my turn in near the end of the berm and can gas it pretty hard through the turn. I was pretty careful with this turn because I ran off the track here in the morning.

Here are a bunch of stuff I got from different instructors.

1. Slow in and fast out
Contrarian View: Keiichi Tsuchiya says drifting may not be the fastest way around a turn, but it's the most fun.

2. Use the entire width of the track. Every inch counts, especially getting close to the apex. Read "Techniques of Motor Racing" by Piero Taruffi to see how much difference this makes.

3. Hands follow the eyes. Obvious, but when the shit hits the fan, instinct takes over and people stare at what they want to avoid.

4. THROW car at apex and add throttle to plant the rear. This translates to turning the steering wheel much faster and harder than normal driving. Despite performing this abrupt control movement, the car transition should be smooth. The car should be settled when initialing the turn.

5. In a slalom, thinking about planting the rear on the cone.

6. When 2 tires are in the dirt, ease off the throttle and ease the car back in, or steer the car to the dirt. If you turn too sharply toward the road, then when all 4 tires are back on the pavement, the car will shoot toward where the wheels are pointed quickly. Possible hitting another car or a wall.

7.Allow 1 second to go from no braking to full braking. This allows time for the front to settle(more weight to transfer to the front). More weight means more traction. The actual time it takes for the car to settle depends on the anti-squat geometry of the car and stiffness of the shocks.

8. Despite what your instructor says, roads will be slightly more slippery in a misty morning.

9. When you brake so hard that the tires spin, ease off the brake until they roll again.

10. For sever under-steer, ease off throttle and unwind steering. The latter sounds logical, but is anti intuitive when you're actually driving. Normally, when you point the wheels at something but the car isn't turning enough, you turn the wheel more, not less.

11. On street tires, it's faster to slip a bit, as long as there's no corrective steering needed. The suggestion came from a kart racer and seems to help my autocross time. Different tires have different sounds when it's near the edge of traction, but you'll learn what your tires sound like after a few spin outs.