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Thunderhill trackday; CFRA 10-17-2011

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I did the first trackday in my Boss this Monday - thought I'd post some of my thoughts.

First my background: I actually did trackdays and raced for a season and a half back in the early 90's. At the time I drove a race-prepared (SCCA ITA) Mazda RX2, followed by a first generation RX7 - think about 150 hp, 2200 or so lb cars.

After crashing both of the cars, I took a hiatus on track events until 2007, when I got into motorcycling. I did a number of trackdays on the motorcycle, including around a dozen days at Thunderhill. My last track event on the motorcycle was in 2008, when my work schedule got more hectic and I took another hiatus.

Fast forward to this year, when I bought my Boss 302 and decided I had to get out there again.

The president of a group called the Checkered Flag Racing Association (CFRA) posted on another Boss 302 that he would invite any Boss 302 drivers to his upcoming event at half price.

This seemed like to good an offer to turn down, so I signed up.

I was quite nervous about how I'd do, so I signed up for the "B" group - which includes everybody with less experience with this club.

In terms of car prep, I didn't have time to do much, so I did pretty much the minimum: I upgraded to DOT 4 brake fluid and swapped the pads - I chose Hawk HP+ pads all around.

My first session was pretty interesting; The car feels huge and heavy compared to the bike, and the track seems considerably narrower. Also, without the lean of the bike to change perceptions, the camber of the turns was much more evident.

Add to that the fact that I haven't heel-toed in many year, and the pads were still a little green and probably not the right ones for track use, and my braking zones were quite exciting.

The trackmap for Thunderhill can be found here: http://thunderhill.com/staticpages/index.php?page=TrackMap

Overall thoughts:
- I got progressively more comfortable throughout the day, but my laptimes weren't going down by much. CFRA doesn't allow laptimers in group "B", but it's not rigidly enforced. I kept myself within the spirit of the rule by running Harry's laptimer on my iPhone, but in a position I couldn't see it, purely for post-trackday analysis.
- My best lap was a high 2:16 - about four seconds slower than my bike (my bike is not that fast, but has a slightly better power to weight ratio than the BOSS - it's a 70hp Suzuki SV-650)
- Interestingly enough, the car's handling was characterized mostly by understeer, especially in off-camber sections. There was one on-camber stretch (turn 5a, after the Cyclone) where the understeer would switch to oversteer. I was dropping tire pressures throughout the day, which brought out a little more oversteer in sections (and presumably balanced the car a little better elsewhere).
- Many of the faster cars were running DOT-race tires (i.e., race compound) and I definitely noticed the difference in grip in the twistier sessions. In general, it felt like I wasn't sticking that well on the stock tires. I may have to play more with tire pressures if I do another trackday on the stock tires.
- I started with the shocks at full-stiff but ended up going down to 4 front and 3 back based on the recommendation of a pro driver (he was one of the drivers at Ford's Dearborn event last week) who was coaching the driver who parked next to me in the paddock. This helped me a little bit through turn 7 - which is a kink which should be flat out in the Boss. In the end I was able to go through flat out, though the rear did step out on me a little bit on the exit of the turn when I went over two undulations in the track - pretty scary when tracking out to the side of the track at around 100 mph. Changing the shock settings made the "step-out" a little more controlled - at the higher settings, it seemed a little more abrupt.
- The brakes were a huge limiting factor all day. I was braking significantly earlier than I would on the bike, and the bike was going a little faster before the braking zones. In the first sessions, I was getting fade in the deep braking zones (e.g., end of back straight before turn 14). The fade seemeed to diminish in later sessions, but it still seemed that braking was a little non-linear, and I could feel the ABS just trying to come in under hard braking. In general, I just didn't have confidence in the brakes, so I was braking quite early.
- The power of the car was great. The guy who parked next to me was running a BMW M3 with a supercharger - he estimated around 570 crank horsepower for his setup. In any case, we seemed very even on the straight. I think my gearing was a little better than his for this track, but I was still impressed.
- This club gives you five 30-minute sessions, and I was reminded just how intense track time can be. By the end of the day, I was wiped out.
- I ran out of gas during the last session (noticeable by a few misses in/after left turns), even though I was indicating over a quarter of a tank at the beginning of the session.
- I had a blast, and I can't wait to do it again.

I'm not a big video editor, so I'll leave you with a couple of unedited videos from a couple of the sessions. I'll try to post more of the sessions over the weekend (including a rather lurid slide I managed to recover from in the first session).

Session 2: http://www.youtube.com/watch?v=xP_yYsMT6Kw
Session 4: http://www.youtube.com/watch?v=xY6xDeHxTk0
 
Welcome to BMO. Where do you live? I was at TH the day before you and have similar impressions of the car but I'm not running as fast as you and didn't have any brake fade using the HP+ pads. I'm also using DOT 4, brake cooling ducts, and the tranny cooling scoop on the stock Pirelli's. My fastest lap on Harry's was a 2:19. I'll compare notes with you later this evening.
 
Hey - I live in Redwood City. Definitely interested in hearing your experiences. Brake cooling ducts are high on my list.
 
Sunday was my second track day plus I had one day in a Boss at Track Attack for three days total in a full sized car on a track. I raced karts, KT100, back in the mid 90's and also raced dirt bikes for many years.

Anyway I'm not going real deep into the corners but I'm starting to push it harder than I was. The only difference with my setup between the two days was adding the HP+ pads on the front only for last Sunday. I had a touch of brake fade with the stock pads my first time out and none last Sunday. I had the brake cooling kit installed for both days. I ran my shocks at 5 front and rear both days mostly going off what other members are doing with the stock staggered tire setup. I ran full TC my first day and used Sport Mode my second day. Next time out I'll try a later session with TC off to try some Vaughn Gitten Jr. moves. 8) The last two sessions I had the temp gauge move to 3/4 and it was about 80 degrees outside.

Going into turn 1 deep takes more nerve than I have so far. I bounce off the rev limiter in fourth and don't shift to fifth. Maybe next time I will. Turns 1, 2 and 3 are the corners where I lose the most time. I seem to be able to drive the line in 2 but get some understeer if I try pushing it. I exit under hard acceleration and then brake hard for 3 but if I'm late braking the car gets light over the hump and I pucker up. I'm careful not to get off the track there as that seems to be a favorite spot for off-roading. ;) I seem to do fine in the cyclone and 5a although I do get some oversteer there if I'm too aggressive with the throttle. I was told to take a late turn in at 6 and hit the apex a touch late and that seems to work well for a nice run down the back stretch. The kink at 7 is a white knuckler for me. I can almost go WOT there but I'm still getting out of the gas for a second or two. Getting sideways at almost 100 is not something I'm used to. ;D I can make up a lot of time through the rest of the course and really like 8,9, and 10. Anyway I have a lot to learn and really like that track a lot. There's lots of run off for beginners like me.

Photos and a one lap video.

https://trackmustangsonline.com/boss-302-racing/track-day-at-thunderhill-9-25-11/new/#new
 
Yeah, Thunderhill's a great track as far as safety is concerned.

You look like you're doing great out there! Nice driving for only three days of experience in the big cars.

Watching your video, I had a few thoughts:
- You could definitely gain time by not lifting for 7 - it took me until the last session of the day to get to that point. (see 6:30 in this video for a flat out run through 7 - you can see the car wobble twice on the exit, pretty exciting: http://www.youtube.com/watch?v=uYkk4eb4J5c) Sticky tires would probably make this a no-brainer.
- In general, you're doing much better braking than I am.
- The other place I think I heard a lift was coming out of 11 as you transitioned into 12. That's another place to keep the pedal to the metal - especially since it precedes a straight. I'm shifting to fourth between 12 and 13
- I think we could both use more of the track on the exit to 9 - it's hard to judge because it's so blind. My mentor gave me a good hint - he said to line up with the water tower on the exit
- There were several other turns where you could use more of the track on the exit - your entries look good to me, but you don't quite track out all the way to the outside
- In this theme, you could go wider out of 14, which would set up a better run through 15 onto the straight
 
Your comments are similar to the instructor I had at my previous track event there. That video is from my fourth session and my fifth session, which I don't have any times or video, I was going a bit faster and was lifting less in 7. I tend to lift coming out of 11 because the rear wheels break loose there for me but I understand what you are talking about carrying more speed onto the long straight.

Are you shifting into 5th on the front straight and are you still in 4th through 1 and into two?
 
Yep, I'm hitting 5th on the front straight and doing one downshift going into 1.

I'm actually carrying 4th all the way to 5, and doing the downshift on the uphill just before 5. There isn't that much opportunity for hard acceleration in this segment, so I don't think I'm losing much time here (with stickier tires it might make more of a difference).

It's interesting that you're getting loose coming out of 11, because my car feels very planted through this section - I'm using a lot of the painted "curb" on the right hand side, so maybe I'm taking a straighter line than you are. I think I'm also over-slowing for 11 a little, so I may just not be going quite as fast when I hit that section.
 

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