Located about an hour north of Sacramento, one of Thunderhill Raceway Park’s claims to fame is that Ford shot their famous GT-40 Super bowl commercial there. It really is a track that has a bit of everything about it. Single apex fast swooping corners, off camber high slip angle back ‘n forth’s, long straights and short esses, blind turns, elevation changes, bumps and smooth surfaces and a really nifty double apex at the end of the long second (or third depending on how you count) back straight, that you need to get right for the even longer and faster front straight. It’s a bit like Sears Point but longer, faster and with more far more run-off and far less history to it. Technical is word some people use to describe tracks like Thunderhill or Sears, but I would prefer a word like ‘nuanced’ or at least ‘challenging’ since technical always seems to me to mean specialized or scientific rather than the way it’s meant in racing, which would be “exhibiting or deriving from the technique or use of technique.” Thunderhill is a challenging track with many nuances that requires a driver to exhibit a high level of technique. That’s a longer and clumsier way of saying it, but one I like a lot better than just saying “technical.”
One item of particular nuance is on the front straight. The starters stand and start line are not in the same place as the finish line. This is one of those little things that, perhaps deliberately, the local track elves put in place and can use to steal a position at the last second. It’s all too common for a driver to hit the start line, lift and start celebrating, while a crafty local driver on his tail stays on the throttle for another two hundred yards and beats him to the finish line. Well after you pass the start line, if you look to your left right around the end of the pit wall, you’ll see this little sign that says, “Finish.” It’s easy to miss.
One reason it’s easy to miss is that drivers are looking for their marks for turn one, on the right hand side of the track. Turn one is a fast wide uphill less than ninety degree left hander that gains increasing amounts of grip from track-in, thru the apex and all the way to a blind track-out. There are brake markers, on the right side of the track, just past pit out, and a nice bit of curbing on the inside that makes a good reference for your apex point. At the right entry speed, which is hard to judge, if you hit the apex you’ll wind up just shy of, or just onto, the curb at track-out. Miss the apex and at least there is a lot of run-off. Be warned though, after turn-in is a very bad place to lift completely, at speed, since it will give you some throttle lift over-steer. Don’t be afraid to go fast, however, since even if you mess up by lifting from fear and getting some over-steer, putting any throttle back on at all will plant the rear end and pop you right out of the corner like a cork from a Champagne bottle. You’re gaining grip the whole way around, so while in other cars over cooking turn one probably means it’s too late to check your life insurance policy, in a Mazda GT just give it a whisper of throttle to avoid a spin and remember, if it makes the highlight reel on movie night, you planned on doing that.
In qualifying trim it’s useful to actually use the pit out on the way into turn one, by moving over after the end of the pit wall, to get a bigger arc. The problem with doing so in the race itself is that it is a high speed passing corner, and if someone gets inside of you and brakes just a smidgen later than you, at that speed, they’ll have your lunch, breakfast and dinner served up to them by their favorite swimsuit model. You’re at the end of the front straight at this point and are just flying…
The exit of turn one leads to a short straight that runs over a modest rise just before you need to brake for turn two. You don’t need a whole lot of braking here, since if need be you can scrub speed on entry, but if you “have one on your tail” you need to get all the way down to the inside since it’s a good passing move to slip inside the car ahead and try for an earlier throttle. Turn two is a long constant radius sweeper, again to the left, that starts to gain grip on track out and which leads to a very short sucker straight.
Now most everybody is familiar with a sucker turn, a corner that seems to require more entry speed than it really does and either suckers you off the track or keeps you off the throttle; that is, in fact, an excellent description of turn three. However it tends to start suckering you in during the short straight between two and three since the entry for three is very deceptive as well as nearly blind and the temptation is to get some speed on the straight on the way to it. The way the track is configured, from the exit of turn two all the way around turn three you are driving around the side of a hill. Turn three actually goes around the hill, but they didn’t actually cut into the side of it much, so it is, if you can imagine it, a right hand turn glued to the side of a hill leaning to the left. What is worse is that you can’t really tell from the driver’s seat that the camber gets worse, far worse the farther away you are from the inside. Imagine standing on the side of a hill, with your right shoulder pointing to the top. Now pave it without digging. That’s turn three. Just to add a bit of spice, since a lot of drivers stay up against the inside of the turn, where the camber falls off is also where their klag winds up. Joy.
So if you take a classic entry line, too fast, into turn three you’ll have no help recovering. You could have Batman’s suction cup tires on your car, but you’re still going to lose the tail end. And since it’s mostly on the other side of the hill, you have to remember, rather than see, that it leads to a slow series of tight, high slip angle bends whose camber and elevation both change pretty radically. In short, you can afford to throw away the entry to turn three, along with some of the speed on the very short straight, without losing all that much on a race lap. I tend to stay inside all the way around the corner, especially since it helps get back onto a bit of throttle at the exit of turn three, which is a back ‘n forth section leading into turns four and five. An alternative, good for qualifying, is to start outside, but with the right entry speed and angle to get and hold the inside of the turn from the apex on. Either way you want to be on or near the inside curb at turn three’s track-out.
As soon as you get around the side of the hill in turn three, you’ll be in turn four. A flat left hander whose main purpose in life is to set up turn five. Turn four is sort of like the third Manning brother. It exists, but only because they wanted something between Payton and Eli.
If you are all the way to the right hand curb at the exit of turn three you’ll be perfectly set up to get on the throttle, apex turn four, and use all the track out before five. And here is the one variable in track configuration. Turn five can either be turn five, an enormous elevation change to a very sharp, blind left hander whose apex is at the top of a very steep hill. Or it can be ‘the bypass’ which peaks to the left of turn five, needs far less braking, but will try it’s best to pitch you sideways while you are off balance going over a very nasty bump while the car is light.
Turn five is easier. You get huge braking with it going uphill in a straight line, get the right turn in speed for the apex at the top of the hill and just try to carry what speed you can on the other side. The other side of the hill is, again, off balance and way off camber since, like turn three it’s going around the side of the hill, but this time downhill as well, without them having dug into the side, so again, farther out means less grip (although this time only at the beginning). Downhill and off-camber, you still need to, once you are going down the other side of the hill fight your way back to the right to get set up for turn six.
If you are using the bypass, like we were in the ‘Best of Thunderhill’ video, then your biggest goal is to get over the crest of the hill without the car getting pitched completely sideways, and throwing you off the side of the track, while carrying as much speed as you can, but without messing up turn six. To start, after the exit of four instead of drifting right and staying right, which would send you to the brake zone for five, you need to continue the arc and pull back over to the left. When you are going over the crest of the hill on the bypass, you need to start far enough left to get an angle even with the bump that is just past the crest of the bypass. If the car is turning at, or just past the crest, it’s going to hit that big bump at an angle while light. This is a bad thing.
The end of either turn five, or the bypass, still involves going around the backside of the hill, which is still sharply downhill and off camber. To carry the best speed you need to use track out, but not so much track out that you blow the entrance to one of the most important corners, turn six.
Now I am a devotee of the type I, II, & III corner schema. Where a type I is a corner leading onto a straight and is the most important, a type II is a corner leading off of a straight and less important, and a type III is a corner leading to another corner and so is the least important of all. The whole complex of back ‘n forth from turn three to turn six is pretty much all type III’s, while turn six is not only a type I, but the third or fourth most important type I on the track. A speed advantage carried out of six can be held up to and almost through turn eight in theory. In practice I’ve found that a better exit holds an advantage all the way to the brake zone of turn nine.
Turn six itself is a basic, flat, ninety degree left, with good curbing on the outside if you need to use it, but don’t over use it or you’ll drop a tire. A classic apex, it leads to turn seven which is just a kink, with no lift unless traffic forces it, and into turn eight. Turn eight is an uphill left that again gains grip on the track out while going sharply uphill. Eight is less than ninety degrees and doesn’t usually require much, if any, braking. Instead consider a nice throttle lift before turning in, get the car turning a little earlier than you might think, and go through it full tilt boogey. Just don’t miss the apex. The one thing to try to avoid, if you can, is going side by side through eight. I tried that with Dave exactly once when he got a run on me off six, had the inside to eight but wasn’t ahead. Turned out there was only enough room for one car at a time, and it wasn’t mine, although on a positive note the run off there is terrific, just make sure you’ve taken your hay fever med’s.
Which brings us to nine. Nine is a high speed blind staggered S, left then right, at the crest of the hill you just started going up with the right hand part being on the blind, back side of the hill. A decent passing zone if you can get inside while braking to the crest, one thing to watch out for is the angle at which you’ll be leaving the corner relative to the curb at the top right hand side of the hill. The corner starts left, goes right, but you need to continue drifting left since if you hit the top of the hill in a straight line you’ll be rather startled when the track suddenly moves out from under you at a high rate of speed.
It’s a reasonably fast corner that allows you to gain more speed quickly since it’s sharply downhill, in a straight line to turn ten. The braking zone for ten is a bit deceptive. You exit nine going sharply downhill, bottom out, and then start a gentle climb just before ten. Of course the track design elves decided that an uphill braking zone off the second (or third depending on how you count) longest back straight would be too simple, so ten, from turn in to track out, is flat. That means the car gets just a bit light in deepest part of the braking zone. This is a trick the track design elves will repeat, only much more so, in turn fourteen. They put more brake markers here, at ten, but to avoid getting them run over every weekend they are on the left hand side and hard to reference.
Between ten and the eleven to thirteen esses is a very short straight, where you can gain some speed, but give it up in time for the turn in for eleven because that complex is another type I, probably the second most important on the track since it leads to the 2nd (or third depending on how you count) long back straight. Turn in to eleven is classic, fairly tight and a bit downhill. They replaced the gravel traps, between the apex’s, with a better run off back in 2006 to stop people from kicking gravel all over the track each weekend. Because of that you can, not that you should of course, cheat by cutting the apex of the esses by nearly a car width. Not that I would do such a dastardly thing.
Eleven to thirteen rewards an nice exit, and you should be able to carry full throttle from the apex of eleven all the way down the second (or perhaps third depending on how you count) back straight; which brings us to the braking zone of turn fourteen.
Fourteen and fifteen should really be seen as the same corner, in terms of the arc of your line, but are distinct since the entry of fourteen is the second most important type II (end of a long straight) while the exit of fifteen is the most important type I (beginning of the longest straight). If you were going make a corner into a VIP at the Oscars, everybody in the know would be waiting on the red carpet to see who fourteen and fifteen were wearing. For myself, I’m always rooting for as skanky as possible…
The brake zone for fourteen has some markers, just past the bridge on your left hand side. Problem is the design elves really went to town here. The straight starts with a bit of downhill out of eleven thru thirteen, flattens, then has a nice sharp rise with a lovely amount of grip just before you could actually use it. Of course the rise, and the grip, ends right where you normally reach threshold braking. I can hear the elves giggling from here.
Just to make it more interesting fourteen is an excellent passing zone under braking with just one exception. The exit of fifteen is the one corner you most need to nail to get speed down the longest straight. And if you don’t complete the pass in time to use the single car line into and out of fifteen, then you and the driver you are trying to pass will lose many…many places before you reach turn one. You’ll be a Dead Duck if you don’t play nice and get single file before the track-out of fourteen. Trust me I’ve been there.
On a qualifying line you hit the hill, brake a smidgen early knowing you’ll have to back off at the crest and from a left side track-in position hit the apex of fourteen at the curb with enough speed to carry you back out to a fourteen track-out position on the far left side, which is also the track-in for fifthteen. Balance the car by getting off the brake (if you trailed) and on the throttle before fifteen, while the line is continuing the turn through a double apex, hit the inside right side and drift all the way out onto the curbing at the left, outside, track-out, of fifteen and find yourself on the main straight with a hint of a wiggle over the outside curb. In 2006 they put more of that run off between fourteen and fifteen, along with some padded barrel like doohickey’s to discourage using all the run off to widen the arc. Not that yours truly would ever go wider there and just miss the barrel in order to get a huge run on somebody all the way down the front straight. Nope, that would be cheating… and great shame comes to those who get caught cheating…
Pit in is at the apex of fifteen, so sometimes you may come up on pitting traffic that forces you off the second apex by a car width, but it is extremely important to get a good launch here, so don’t give up more than you have to. Need be, better to give it up early, and get on the throttle early, than to catch a pitting car in the wrong spot.
Like I said at the beginning, Thunderhill has a lot of every kind of thing going for it, which makes it really fun track that can also keep the racing close. High speed, slow speed, with just plain wicked elevation changes, it’s a bit difficult to get fully up to speed on, but once you do it’ll probably be your favorite track. You can also, sometimes, bide your time a bit, put on some pressure, and wait for your opponent drop a few wheels off the track somewhere. It’s worked for me.
I can’t wait to get back and do it again…
Update: I corrected a numbering mistake, I had labeled the last two corners 13 & 14, when they are actually 14 & 15. Also turn one is less than ninety degrees.
No comments:
Post a Comment