TGPR Part 1

Spent the day in Munford, Alabama at the Talladega Grand Prix Raceway. This is a little 1.4 mile technical track originally designed for motorcycles. It was the first track I ever drove back in 2006 with the Heart O’ Dixie PCA region and years before I ever autocrossed. I like it because it’s got some corners not easily deciphered and there’s very little to hit if you go off.

TGPR Early Morning

TGPR Early Morning

 

I will never forget Alan McCrispin spin-proofing me on the skid-pad that January day. After going around in circles forever, intentionally inducing spin after spin and learning to anticipate and stop them, Alan finally had me head to the pits. I thought we were done (everyone else was) but noooooo. Alan says, “Now we swap the tires.” So, we swapped all four of the wheels left to right and did the same exercise all over again while everyone else ate lunch. Thanks, Alan! It came in handy again today, though I was sorely pressed to avoid a wicked spin on one memorable occasion. At these speeds my normally pushy autocross car wants to oversteer just a bit at the limit.

This event was the Fall Time Trial put on jointly by the Tennessee Valley and Alabama Regions of the SCCA. They traditionally do two a year, Spring and Fall, and I’ve been to several. Not being a time-trialer, I was running my B-Street autocross Corvette on last-years’ Dunlop Star-Specs (which pulled a steady 1.2g’s lateral) in the PDX group (Performance Driving Experience) and I took data all day with the Vbox Sport, reviewing it between each session. The next post will probably be a data-rich analysis of what I learned, or at least confirmed or disconfirmed today, but for now I’ll just mention the best lap for each of the six sessions, starting in the cold morning: 109.9, 110.4, 109.4, 108.9, 108.7 and, um, well, there seems to be a problem with the data for the sixth session. Oh yes, now I remember: some sort of agricultural excursion occurred that will require in-depth explanation at another time!

I think that a certain amount of track-driving is necessary for the ambitious autocrosser. Unless your local site happens to be very big, there just isn’t any other way to get experience at higher speeds. We autocrossers get really good in the 35mph to 55mph speed range. In National competition we run into courses from time to time that are quite a bit faster than what most see regionally. While we may hit the same top speeds briefly locally, we rarely have to maneuver violently at 55mph+ at a regional competition.  Where else are we going to get the car-control skills we need at the higher velocities that will allow us to do well at Nationals? Most of us can’t follow the National Tour to every event around the country.

One of the nicest race-cars in attendance belonged to Bill Coffey Sr., up from Florida, who bought the car brand-new in 1971:

Bill Coffey's 240Z

Bill Coffey’s 240Z

This beauty puts down 315 hp, weighs 2200 lbs, (which is 300 lbs over the class limit) and sports 11″ wide wheels at the rear. (Not sure about the front, except they are not narrow!) Bill says he won’t take any more weight out of it… he doesn’t want to cut on it further. One of the best-looking Z’s I’ve ever seen.

By the way, in the background of that picture, left side, is a 1976 TVR 2500M. I know this only because I had to ask the owner what the heck it was. All I could tell was something British and that it’s a really well put-together machine.

We had a great group of PDXers today, some of them auto-crossers from the area that I’ve met before. Everyone was enthusiastic, safe and polite on-track, no doubt due to the instructor group led by Chief Instructor Brett Whisenant and the safety talks given by Safety Steward Andy Tow.

As usual at TGPR, my day gradually ground down and was finally finished due to severe front brake-pad tapering. This track can be tough on brakes (I hit 104 mph and brake below 50 mph three times each 70 seconds) and while I use good racing pads which do not overheat and good, fresh fluid which does not boil no pad can prevent the tapering that results from the stock Corvette calipers not being quite stiff enough, especially when they get really hot. The modulus (E) of aluminum drops with rising temperature, about 10% by 300F, and these calipers don’t seem particularly stiff to begin with.

Here’s the track map. The running direction is counter-clockwise.

TGPR Layout

TGPR Layout

2 thoughts on “TGPR Part 1

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