Built from a riveted aluminum skin over steel, the McLaren M6B was as modern as sportscars could be. Forty years ago. (Photo: Marshall Pruett) » More Photos

The next session out, Tony suggested I try clutchless upshifting. Well, I've got lots of experience with that from the formula cars I'd driven. I rolled out with a tiny bit of confidence that quickly grew once I started the clutchless upshifts. Now I could accelerate through the gears with very little effort and really feel how the car pulled. MAN! What a feeling! The McLaren just pulled and pulled. Through this next session I was still having trouble downshifting until I just gave up on rowing down through the gears and went right for the gear I wanted. So for turns 7 and 11, this meant downshifting from 5th right to 2nd. It got so that by the time I came in from my second stint I was pretty comfortable with the gearbox and just starting to get some feedback on the balance.

I was able to tell Tony that I was starting to detect mid-corner understeer. Not enough to anger me, as I still wasn't really pushing the car yet, but it was definitely there. I also noticed a huge amount of inside wheelspin over turn 2 and 3b, despite the limited-slip differential. I had to be so delicate with the throttle over these crests and just wait, wait, wait until I started to unwind the wheel before giving it any throttle. Tony looked around the rear of the car and noticed there was way too much rebound damping in the car, so he softened the rear dampers. He also removed the stiffer rear sway bar and put the softer bar on in an effort to get the inside tire down to get more traction. It helped--I dropped my lap times to the high 1:39's and the guys from the shop seemed pleased with that.

I went out for my third session with a lot more confidence in my ability to shift the car and was ready to start exploring the limits of the car. I started pushing the car through 3a and 3b and it didn't really do anything scary. I started picking up understeer through 5, 6, 8a and 8b and turn 10. One thing that was really noticeable is that the wheelspin over the crests of 2 and 3b were much reduced. It was still there a little but, but mostly gone. Finally, I started to feel some type of rhythm with this car and I felt like I could drive it the way I wanted to.

(Note: the video footage shown is from Sheehan's last session when he was most comfortable with the car and able to drive it at its limits. ~Ed.)

As this picture tells us, the extreme power, narrow chassis, and short wheelbase make the M6B a perfect candidate for instant oversteer. » More Photos

It's probably worth saying that this is a rare, historic and very expensive race car. One that's probably not very suitable for crashing (financially or physically.) Considering that Bob was going to be racing it at the Wine Country Historic races over the weekend, I tried to take good care of her. I took it relatively easy in the high risk corners, like turns 1, 9 and 10. Still, the car loaded up the right side tires pretty hard through turn 1 and man, did the steering get heavy! It took great effort to get the car to the left to set up for turn 2. Coming through Turn 5 was a real workout as well and there was more than one time I came out of 5 breathing hard and trying to catch my breath. It was the same thing through turns 8, 8a, 9, and 10.

I was definitely feeling lots of understeer by this time and I felt it was slowing me down. Now that I had some confidence in myself and the car I felt I could quickly get a sense of what it was doing and give some feedback. I came in and explained what I was feeling. Tony suggested some additional rear ride height increase, and three turns of the shock collars later, I was back out. It felt a little better over the next couple of laps, so I came in and we tried a little more rear ride height.

CLICK HERE to watch Sheehan wring the life out of the ex-Bonnier McLaren M6B Can-Am car.