[ja1217]

Originally Posted by dradernh

My take is that the other car has a somewhat better power-to-weight ratio than yours does. I think that partly from looking at the data, and partly because I don't think you're leaving 1.56 sec. on the table - more like .5 to .8 would be my guess. You'll find that time by being more consistent.

Some thoughts:

0) Your line is very good; I only saw a couple of places where I'd make or consider making a change (see below).

1) Because he's braking earlier, he likely has his car more settled at turn-in. You're frequently a bit abrupt at turn-in. I'd leave the late-braking to others, and concentrate on being as smooth as possible all the way through the corner with the goal being to go flat at the apex and stay flat after it (in the corners where that's possible). You can then play with adding entry speed, which is easier when you've got your major braking out of the way and the car is settled.

2) As was mentioned, he's got way more torque than you do (~200, I would guess), and because his HP is greater than his torque, he's not having to pay a price for that advantage. If you solve that, I suspect you'll no longer be in TTD.

3) You're aggressive, and that's good - for example, I really like the way you use all of the track coming out of T10. I would focus now on being as consistent as you can be. You might have to reduce the aggressiveness to nail that, and then add the aggressiveness back in as you take it back up to 9-10/10ths.

4) Except for the exits of T3, T9 & T10, on that track I can't think of a curb that it helps to be up on. Of course, YMMV. As part of increasing consistency, I think you'll want to ensure that you've got the car exactly where you want it to be in every part of every corner on every lap. Absent that, you're shortchanging yourself.

Another way to help achieve that consistency is to install a race chair and a harness, assuming that's an option. That would make the car much easier to drive at those corner speeds.

5) Your line through T5 looked good on L8 - I wonder if that isn't the line you should be aiming for on every lap. (You'll have a much better idea of this that I do.) If you try it, you might have to move a bit further to the right before turn-in to make that line consistently.

6) You're turning in early at the end of the main straight. Fast drivers do a sort of mini-Scandinavian flick at the end of the straight to widen the arc of the turn. I'm guessing that you're a full three to four feet right of that line (ex.: ~6:31 in the video). In the screen shot below, you would turn left such that your left front tire travels in the dark asphalt on the left side of the white line (see red arrow). It's all over with in a hurry, and then you're headed to the apex on a much better line due to the wider arc.

7) I'm wondering if you can't get more from T4 turn-in to T5 turn-in. T4 has more camber than is generally realized, and when I walked it last year it also had a really grippy surface from the repave. There have been some bad accidents in T4, so make sure you stay off the inside curbing.

8) You ran faster on every lap - good job!

Some questions:

1) Can you post a graph of both of your laps (like the one below) showing speed, throttle, and brake with the x-axis showing distance as it is now?

2) Do you have the adjusted weight-to-power for both of the cars?

3) Did you ask the TT Director to see Marc's classification sheet - unless you already know what's on it. It's always interesting to see what others are turning in.

4) How many heat cycles were on your tires? Do you know how many heat cycles before they go off? (They didn't appear to be off, and if so they certainly didn't go off during the session.) Any idea how many cycles were on Marc's tires?

1) Here's speed/throttle/brake for my car. Marc's doesn't have that data:


2) My adjusted weight to power can be up to 13.8 I believe (TTD is 14.25, -0.8 for tires < 245, and +.35 for weight under 2900), so at a minimum weight of 2885, I can make up to 209 whp. I might consider seeing what I can do about this for next year. Currently I have 3 points left. Right now I'm considering going down to 215 Hoosiers, doing full exhaust, and maybe spending my last point on a clutch type LSD.

3) I have not seen his classification sheet, but I believe its +3 suspension, +2 springs, +3 chassis reinforcement, +6 tires, +4 wing, +1 hood vent. As for his power, I would not be surprised if he just has a much larger area under the curve, as others have speculated.

4) This last session was the 20th heat cycle on the tires. I have also worn off one of the grooves on all but one of the tires, so while they still feel relatively grippy they are probably on their way out. That said, this was my first set of Hoosiers ever, so I'm just comparing them to my Z2's, which I was a little more than a second faster on the hoosiers compared to the Z2s this weekend. I have a sticker set that I won earlier this year and I'm torn on either using them for my next event or just running my current set to the cords.

As for a race chair/harness, its something I'd like to do. My legs are always sore from bracing my self against the door and transmission tunnel. I hit a peak of 1.78g's in one of my sessions and ended up cracking my windshield at this event. I think a rock chipped it and then it cracked under the g force later in turn 1. See:

The crack isn't there at the start of the session, but it shows up either after turn 10 or turn 1.

That said, if I did get a seat and harness, I would want to do it properly and probably put in a 1/2 cage in the back, which probably means I wouldn't be able to fit 4 hoosiers, tools, jack, jack stands, camping equipment, and girlfriend in the car