A lap of Thunderhill in a 1969 MGBGT

WARNING: These are my personal notes about my driving Thunderhill in my car, a nearly stock 1969 MGBGT with very little power (75hp to the ground). The reference marks I mention work for me, in a slow car. Just because I conjecture that I should be able to take a turn without braking, or even lifting, don't assume that you can in your car. My MG barely breaks 80 mph at the end of the main straight. A stock first generation Rx7 will hit over 100 down that straight.

For contrast, look at my more recent notes at Thunderhill

Turn 1:
I've been braking for turn 1, but I think that I remember being able to take it with just a lift, if not flat, in the MG. I'm definitely not using all of the track at the exit. The MG does not feel quite solid going through turn 1. I suspect that stiffening up the shocks will help. I also think that the track entrance from the pits is slightly off camber, so going all of the way to the outside entering the turn may not be a win.
(3 July 01) Last weekend I was doing turn 1 with just a lift and not even running out of track at the exit. It's taking a lot of strength to get the MG in to the apex, plus occasionally a few cuss words and other shouted encouragement to the car. I seem to be turning down a bit early (fear) causing me to apex a bit early (bad). Note that the MG is only carrying 80-85MPH at the end of the straight.

Turn 2:
I'm going in very deep and just lightly stroking my brakes. I wonder if I could do this with just a lift. Before I try this, I should get turn one wired first. I slowly work my way to an apex about two thirds of the way around the turn. I'm usually flat out long before the apex. When done right, my speed would carry me all of the way to the berm on the right side of the track at exit.

Turn 3:
I work my way about two thirds of the way back across the track to enter three. I aim at the dark conical mountain in the background. It used to also line up on a flag pole and possibly the lunch trailer. I've been giving it a light stroke of the brakes going in. The outside edge of the track is way off camber. The inside line is a good opportunity for passing. Through turn three, I work my way over to the right so that I exit the turn on the right edge of the track entering four. I'm also flat out on the gas fairly early into the turn.
(3 July 01) Ralph Alexander reccomends taking the inside line through 3. There's a big hump at the exit that seems to unsettle the car. Ralph says that he trailbrakes into it, and this brings the tail end around but with the front wheel on the inside edge of the track that it hooks in. I haven't been able to get this to work comfortably yet.

Turn 4:
Enter turn four all of the way on the right side of the track. Make a good sharp turndown and there is no need to lift.
(3 July 01) If running with the bypass, let your speed carry you out on the exit after the lefthander.

Turn 5:
(cyclone) Enter turn 5 on the right. Brake about two carlengths before turndown, on the way up the hill. Make a quick turndown, get the car turned and get back on the gas before apexing at the top of the hill. Take a straight line across the top of the hill. This lines you up on the right hand side, going straight down the hill. Even though this puts you on the inside going into 5a (the right hander) this is not a problem because the track flattening out at the bottom of the hill, gives more traction to keep the car on the pavement.

(bypass) The top of the hill at the bypass is at an angle. If you go straight over the top based on the path of the pavement you come over the top with the left rear wheel in the air. When the left rear wheel lands it makes the car want to spin. The trick is to take the top of the hill angled slightly to the right so that both rear wheels land at the same time.

Turn 6:
I'm still lifting for 6. The MG should be able to take it flat. Looking at the inside berm as you come up to it, there is a distinct "point" where you should exit.

Turn 7:
Apex seven to keep from scrubbing speed.

Turn 8:
Turn eight looks scary but with the hill right afterwards, can be taken flat.

Turn 9:
I've been braking for turn 9, the left hander at the top of the hill. I'm sure that it can be taken with a lift, possibly flat. Cross the top of the hill with the right tires at the center of the track, that lines you up with the right side of the car at the edge of the track heading straight down the hill.
(3 july 01) I've done 9 with just a lift. Again, my natural tendancy is to turn in too early. When I get 9 "right", rather than crossing the top of the hill with my left tires in the middle of the track, my speed carries me all the way over to the right side of the track at the top, but since I don't run out of pavement, it's just fine. This line is definitely scarier, and I don't reccomend it for students, but I suspect that it is good for a second or two.

Turn 10:
I'm doing a lousy job of turn 10. I thought that there was a plastic reflector at the turndown point, but I didn't see it on my last visit. Maybe it was under the cone? I'm definitely not getting good exit speed out of ten. Making sure that I look at the exit of 10 rather than the entrance helps a lot.
(3 July 01) I'm getting turn 10 better. Coming down the hill, I brake at the 2 (pavement changes color) and turn at the 1. When I do it right, I'm looking through the apex to the exit and my speed will carry me all of the way out to the edge of the pavement.

Turn 11:
I'm also blowing turn 11. I just can't seem to get a good exit off of it.
(3 july 01) I've been braking perhaps between the 2 and the 1, there is a pavement color change (light stripe across the track) that I use for my braking marker. When I do it right, I can feel that I'm carrying more speed. I suspect that this is a turn like 11 at Laguna Seca where if you don't feel that you could ahve done it faster, you went in too fast.

Turns 12 and 13:
With my slow exits off of 11, 12 and 13 are no problem.

Turn 14:
Turn 14 takes a late apex. Don't target fixate at the entrance and look around the turn. An early apex can cause you to go off track between 14 and 15 and get passed by a Frogeye sprite down the straight.
(3 july 01) There is a cement anti-berm (gutter) on the inside, hook the right front wheel in here.

Turn 15:
A good line out of 14 will set you up for a good line through 15. In the MG this is taken flat out, using all of the track exiting onto the main straight.

Last modified 07/03/01

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