Need help with DL-90 analysis

[cstreit]

Okay guys, I have my entire group of Sunday sessions recorded from my DL-90 but I'm struggling with how actually improve my driving with it. So far I have some up with:

1. HP and TOrque (nice, but doesn't make me faster)
2. Identifying the car's maximum G's in a corner, then making sure I am pulling close to that in similar corners
3. Identifying that I am shifting at the right RPM.

But that's it...

In general my laps are within .3-.4 seconds of each other, so there's no easy area to see what I did differently...

Any ideas?

[gchappel]

Just a couple of quick ideas- I have used the DL90 for a little more than a year. Here are the things that come to mind that helped me-ymmv.
Look at a G circle of the session- are you turning right and left with the same force? Are you turning while braking, and while acclerating?

Break the lap up into segments- and concentrate on a different segment each run. Try some different lines, etc- see what works for you and your car.

Try some minor suspension adjustments- sway bars, tire pressures, etc. Go drive. Check the above segments- what helped, what didn't.

Biggest help by far. Get a better driver to take your car out, record his data and overlay it with your own. Or, put your datalogger in his car- it helps if it is a similar car. Compare data. You will probably be amazed at how late they are braking and how early they are acclerating out of each corner. Compare their segment times with your own- you will see where you can make the most improvement.

I found the DL90 to be very helpful. I did not find that one days data really did me any good. Just because you can pull 1.3G's on one corner, doesn't mean you can do that anywhere else- surfaces vary, etc. It was the comparison of data that did me the most good. Keep good records, and watch as you improve. Heck, I look back at last years data and wonder who the slacker was that was driving my car back then

[jluetjen]

Chris;
Break the lap into sections which are conceptually related, such as:

Last corner and longest straight
"High speed sweeper section"
"tight technical section"

Find your fastest time through each section, total them together for your ideal "fastest lap". Compare that to your actual fastest lap. What's different? Look at breaking and turn-in points. Identify specific things that contributed to your "ideal lap" and work on incorporating them into your normal lap.

There are other things that you can do depending on what variables you kept track of.
* Percentage of lap at full-throttle (are you lifting?)
* Smoothness of throttle application (are you upsetting the car with the throttle?)
* Steering ange (understeer and oversteer, steering technique - are you upsetting the car?)
* Exhaust temperature or O2 sensor (engine tune throughout the rev range)
* Wheel speed (is the car hooked up or not? How is the LSD working?)
* Suspension travel (This can enlighten you on a world of things regarding the success of your springing and shock settings)

[TimT]

I agree use the friction circle, it tells you if you favor turning left or right. If you have the track map playing, you can watch the cursor on the friction circle and track your progress.

I am going to hook up the brakes to one of the spare inputs so I can compare braking points, entry speeds etc.

Im just playing with the logger driving around large parking lots though.

my first event is next weekend Im jonesing big time

[cstreit]

What are you guys using for the Aerodynamic drag setting? I tried to calculate mine, but it came out so low that I'm sure that it's wrong...

[cstreit]

John,

I tried doing the split sections, but the problem is my sections don't vary more than a few 10ths lap to lap... Maybe I just didn't run enough laps...

THe G-circle is good!

[TimT]

Chris do you have the brake pedal wired to one of the inputs? I think that and RPM will tell you alot..

I know one some tracks I need a bigger set of B#lls maybe the braking and entry speed map combined with the friction circle can give some good insight.

[cstreit]

Thanks TIm, any thoughts on the Aero drag calculation?

[TimT]

Chris the factory data gives aero drag as 0.397 (front spoiler and ducktail) for the carrera RS

I havent played with the corrections you can use to apply to the DL90's calculations.

Ive only played with it in my SUV....... if I tried the coast down and aero correction inputs it would say BRICK.

8 more days till I'm on the track. Im sure Ill have some more Ideas about the DL90...let me know if you have any tips as well

[cstreit]

I'll have to figure it out. I'm coming up with .637 and I wonder why the software default is so much higher? They do it in a panel van maybe?

[TimT]

Chris I wouldnt worry so much about the HP numbers you are seeing.

Is your car faster than before you rebuilt it? What are your lap time now compared to before the rebuild..? you need a reference point...before you make suppositions on the data you are interpreting..

If you turned a 1:30 last year, and now post rebuild you turn a 1:25, you have more power...or you became a better driver during the off season.

from what I can see you can get tons of info from ther DL90

lots of data takes lots of time to interpret and digest..

One of the first things I would do is throw out the first few samples you have... Use the data you have from the afternoon runs

cant wait to get on the banking at Pocono

[cstreit]

Tim,

I'm trying to keep that in mind. On my first run after the off season, 30 degrees outside, year old tires, I bumped off 2 seconds, so I must have done something right...

Just dampened my enthusiasm a bit...