Thunderhill really is one of America’s best club racing tracks. It offers good flow that allows most drivers to get up to speed quickly, yet the track is quite difficult to master. If you’re going to the Western States Championships you will need to know how to get around this track quickly.
What follows is a turn-by-turn instruction that will show you the nuances and finer points of what it takes to go fast here. Hopefully this will help all competitors at the 2017 NASA Western States Championships, and make for better racing in their quest to rise to the top of the podium.
Turn 1
At the end of Thunderhill main straight is a quick left hander, fourth or fifth gear in most cars. As you enter the brake zone, you will want to position your car to the right side of the track, crossing the pit out blend line. You want to get your braking done early so that as you turn in, you are on throttle to help set the weight balance to the rear. Aim for the midpoint on the apex curbing because you will slide past this point and end up with a slightly late apex.
With most cars you will be at or near full throttle by this apex clipping point. Once you pass the apex, the track flattens out as you track out. Unwind the steering wheel and look down the track toward Turn 2.
Turn 2
One of Thunderhill’s signature corners is Turn 2, and you are in it a long time. I like to start my brake zone left of midtrack and try and get most of my braking done in a relatively straight line. Most cars will go down one gear from Turn 1.
The transition from braking to off brakes is critical here. You want to be as smooth as possible in this transition to not move the weight balance around too much or too fast. In the first third of the corner, I like to position my car about one to one-and-a-half car widths from the inside of the corner and slowly tighten down to clip an apex around the two-thirds point in the corner. You can roll onto the throttle and keep the car at its max grip level by slightly playing with the throttle. The really important thing in Turn 2 is to not get into terminal understeer the last half of the corner. You can really destroy your right front tire pretty quickly by doing so. Find a small amount of slip angle and keep it there. You should be at full throttle around the apex as you track out. Make sure to open up the corner and track all the way out, even in high-horsepower cars. You will have plenty of time to set up for Turn 3.
Turn 3
Position your car midtrack, to left of midtrack in the brake zone at a slight angle into the corner. The entry to Turn 3 is downhill and off camber, not much grip here. Use third gear in most cars. Don’t over-cook the center of the corner. You want to be about one car width off the inside of the corner and make sure to get the car lined up to the right side of the track and parallel to the track at the exit to maximize your entry into Turn 4.
Turn 4
For most cars, slowing for the entry to Turn 4 is just a slight lift, maybe not even a full lift into this corner, third or fourth gear in most cars. If you are fighting the entry of Turn 4, make sure you are exiting Turn 3 all the way to the right side of the track. Get your eyes to look up toward the bypass, full throttle at or near apex, track out and start moving the car toward the left side of the track as you set up for the bypass.
Bypass/Turn 5
Just like Turn 4, in most cars the bypass is just a lift or partial lift to make your speed correction. Position the car to the left side of the track as you start up the face of the bypass. As you near the top you want to turn the car so it has a 15- to 20-degree angle to the right from the track edge. As you crest the top, this should put you about midtrack to slightly right of mid track as you blend back into Turn 5. A few things to watch for in the bypass: First you want to go over the bypass with a maintenance throttle to balance the car. On the backside of the bypass if you find yourself pushing out too wide you either did not preposition the car enough on the face of the hill, or you got a little too greedy with the throttle.
If you find yourself hitting the large bump in the transition to the old track, you are a little too far to the right on the backside of the bypass, try prepositioning the car slightly less on the face. Once you are in Turn 5, you want to be slightly off the right side of the track and late apex so that as you approach the Turn 6 braking zone you are parallel and at the right side of the track.
Turn 6
In most cars, Turn 6 is a light brake to set the car up for turn-in. In most cars, you’ll be third or fourth gear. Apex is slightly late, and you should be at or near full throttle just after the apex. Open up your hands and unwind the steering wheel and track all the way out. Turn 6 is all about rolling speed through the corner and getting on the throttle, you have a long “straight” section up next. Turn 7 is part of that straight.
Turn 8
As you track out of the Turn 7 kink, you position your car to the far right side of the track to set up for Turn 8. If you need to brake or lift off throttle, do it early so that you can turn in under maintenance throttle. You should aim to be back to full throttle before the apex. You’ll be in four or fifth gear in most cars. The track-out runoff is wide, so use as much of it as you can. Most cars are full throttle or near full throttle in Turn 8.
One trick to build up to this is to do your speed correction early as you exit Turn 7 and then make sure you are at full throttle as you turn in for Turn 8. This allows the weight to be in a better balance, and the car will feel more stable and comfortable to the driver. Then just slowly start decreasing the size of the speed correction to maximize speed.
Turn 9
Enter the braking zone all the way right. The braking zone is straight and uphill, so you can get a lot done in a short amount of space. Use third or fourth gear in most cars. A smooth transition off the brake pedal will allow you to roll a good amount of speed into the corner. Aim for a mid apex on the first curbing, let the car track out all the way to the right side and roll over the hilltop with little steering input.
If you line this up correctly you will put your right side wheels on the right edge of the track at the top. This line is the most open and will allow you to carry more speed into the corner and get to full throttle sooner. You should be at or near full throttle on the face of the hill, not the back side of the hill. Once you have crested, let the car track out left about one car width from the left side of the track. Slowly begin moving the car back to the right side of the track to get the car set up for Turn 10.
Turn 10
The track slightly falls off right at the edge of the track. I aim to place my car 10 inches to 12 inches away from the right side of the track under braking. Braking is short and straight, in third or fourth gear in most cars. Turn 10 is a classic 90-degree corner. Smoothly transition off the brakes, roll speed through a slightly late apex, then start feeding in throttle and track all the way out. You can use this apex curbing to help rotate the car if needed.
Turn 11
The key to Turn 11 is don’t brake too late! Get the car slowed down early so that you can have the car balanced at the apex and get on the throttle early. You will carry full throttle from here all the way to Turn 14.
Turn 11 is taken in second or third gear in most cars. Use a mid- to late-apex, depending on where the Turn 12/13 barrels are positioned. The closer the barrels are to the racing surface, the later you need to make your turn-in.
Turn 12/13
Continuing the exit of 11, you will track out as far as the track allows that day/session/lap. There are typically barrels or cones that will dictate how far out you can track out. You want to maximize the amount of track they give you, so keep going wider if it is open.
Turn 14/15
Big brake zone! Position the car on the left side of the track, brake slightly earlier than you think since the braking zone is downhill. In most cars, you’ll use third or fourth gear. Smoothly transition off the brakes and start rolling to throttle as you hit the first apex slightly late. Aim to have your right side tires on the apex curbing. Pick up more throttle, unwind the steering wheel.
The runoff is quite wide here. I will go out all the way to the rumble section in the middle of 14/15, but not past it. Most cars will do a short shift in between 14/15 so they don’t run out of rpm too early on the exit of 15. Slightly late apex again for 15, track all the way out.
Turn 15
Two tips for 15: The apex curbing is quite high and abrupt, not one you want to hit. Second, if you find yourself in trouble exiting Turn 15, go wide to the outside of the track and drive in the grass, and slowly get back onto the track. Do not do a quick throttle lift and steering correction. If you do, the inside wall will appear quickly.
Front Straight
Why is he talking about the straight? Well the Thunderhill main straight has one trick to it. The finish line is not at the starter stand, it is slightly past the starter stand where there is a checkered line across the track. Make sure in timed sessions and races you don’t lift too early, and cross the line at full throttle!
Bio Info
Tony Colicchio is co-owner of TC Design Motorsport, a Campbell, Calif., company that specializes in custom roll-bar and roll-cage fabrication, seat mounting, harnesses and window nets and other racecar hardware, including a wide array of data acquisition systems. Colicchio has been a professional racing coach for 12 years and is the 2013 NASA GTS3 National Champion. He holds GTS3 track records at Mazda Raceway Laguna Seca, Sonoma Raceway, Thunderhill Raceway, Buttonwillow Raceway and Miller Motorsports Park.
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