himself

One thing I found particularly helpful is a benchmark from someone else driving my car (I had data from a few pro drivers). This gave me a lot of insight into where I was losing tenths (or more). One thing that became clear pretty quickly is that I don't trail brake enough or get to throttle early enough.

-td

TeamDrugMoney

I have collected data from other drivers with a similar car to get most of the way there. I know that different cars might have different competitive advantages in certain areas, but since I have quite a bit of learning to do I find it useful in my quest to find seconds as opposed to tenths. I do find your idea interesting and might see if David Murry will take my car out at VIR this October at his VIR track day. That'll be pretty cool to then have some apples to apples comparison data.

TeamDrugMoney

LOL, leave it to you for something like this!

RickBetterley

This is why I haven't spent time with the data; I know my improvement opportunities are huge, and for quite a while will be More Gas/Less Brake.

Van

One big thing I've found is that lots of people are inconsistent with braking and leave a lot on the table in this regard.

Below are 2 examples of how to look at data to analyze your braking patterns. Both screen shots are the same, just the notes and comments are different...

The top graph is Acceleration/Braking force as measured in Gs vs. distance - i.e. what the G force value is for a given location on the track.

The middle graph is Velocity vs. distance - i.e. the MPH for a given location on the track.

The bottom graph is the Time Gap chart, it shows, for a given distance, the time differential (in seconds) between the red lap (graph line) and the blue lap (which is the reference lap and is "0" (zero)) which is the x-axis. For a given location on the track, we can see how far ahead the red lap has become.







Everyone should be looking at their braking data and asking the questions:
-When do I start braking?
-How do I transition off the gas and onto the brakes?
-How quickly do I achieve full brake pressure?
-What is my peak brake pressure?
-When do I release the brakes?
-How progressive is my brake release?

Rassel

Some general tips, you might now them all already.

Find someone better than you and get a logged lap. (Worth much)
Best compare is when laps are in the same stint or at least day.
Don't stare yourself blind at your race line - Brake and Throttle data is just as important.
Do your analysis ASAP. Don't wait for it when you get home.

I don't know how available track is for you however: If you do your own analysis, don't try to cure all problems at once. Every change you do changes the input and if you do too many at once, you will not know the outcome. So it's trial an error with steps.

Keep it simple!

TR6

Does anyone have problems with what appears to be GPS drift when comparing laps, especially from different days and recorded from different drivers? There are times when I'm trying to compare lines that someone else sent me using their Traqmate on a different day, and it appears that the GPS is not lining up. I know traqmate has a tool to move it around manually to correct it, but when you do that, you are making assumptions about how far off it is. Sometimes it is obvious (if your line shows you are inside the curbing on a turn) but sometimes it isn't obvious which lap needs to be corrected, or by how much (if any). In other words, I sometimes wonder how much of what I'm seeing is GPS drift and how much is really the two laps were physically taking different lines. Or a combination of both.

924RACR

Yes, GPS drift is a PITA; I've seen it both on Trackmate and DL1, both GPS systems I've used. Another great reason to work on speed vs. distance, and not get so wound out about plotted line.

One more basic rookie tip I have found to hit many people, and in fact was the first thing I noticed with my data, when I first installed the system, before I even got the speed sensor installed:

Check your max lateral acceleration for lefts vs. rights. It's a very common condition for less experienced drovers to pull more g's turning left than right - often 0.2g difference side-to-side, hitting, say, 1.2g peaks to the left, and only 1.0g to the right.

My theory is that it feels a lot more comfortable - less like the car's about to tip over on top of you. Never mind that the car isn't rolling at all. Obviously, I'd expect the opposite result in a RHD car, but haven't gotten any data to confirm this.

But that's usually a hard one to overcome without some faith in the car - supported by the data.

Of course, on our primarily LH-turn tracks - that's a lot of time!!

Just a quick sanity check I use when I get a new drover in the car...

Sean F

Van, what system are you using in your examples?

pmason

This the thread I really need, have the traqmate and chase cam, just need more time analyzing the data, my problem is just how to read the data. This great, thanks guys.

Van

Sean, that's the Traqmate system.

Vaughan, I've also seen people who have the accelerometer unit (frequently called the sensor unit) mounted where it's not perfectly flat. This will show and artificial G value in a certain direction. For example, a 944 track car that only pulls 0.6 Gs braking, but 0.7 Gs accelerating... instead of 1 G braking and 0.3 Gs accelerating.

Additionally, a 2-axis accelerometer will also show erroneous G force data on banked turns - higher end systems use a 3-axis accelerometer.

Gary R.

Van - throttle position would help you a lot as the differential of how fast you transition from gas->brake and how quickly you get to full throttle (and stay there) is important.

924RACR

LOL! Very good point - RTFM on the install!

Van

Yes, Gary, logging your throttle position is great - but you can also see a lot of this with just accelerometers.

This data is 2 different drivers, same car, same day. Comments should speak for themselves:

Circuit Motorsports

FWIW whenever people are planning on being at VIR I'm happy to give people the 30 minute what to look for on a data trace talk or setup a group class session where we can go much further into what you are and should be seeing. I have access to a great classroom where we have a serious technology setup designed for instructing people on data.