ProCoach

The publicly available information for many tracks is not correct.

That's why the IMSA event track walks are populated with engineers, including Porsche AG engineers taking actual measurements. Some of the raw laser-scanned data is useful, but I like OptimumLap, myself.

Also, there exists a portable "learning"'device that will deliver that information real-time, that is likely to be available soon...

sbelles

I see just under 1.3 Gs (1.26) max in my SPB across several fairly flat tracks. It's a little less at Sebring though and I'm not sure if that is because of slight camber at other tracks or less grip at Sebring. I'm looking for the Vmax for corners in isolation for that LatGmax and a given R. I know published radii would only be valid for a corner if it's taken square but it's a good starting point. I could extrapolate a bit from there.

My problem; and it's one that most driver have, is that while my conscious brain has no idea how fast I can enter a given corner, my subconscious has a very strict idea. Whenever I KNOW, from comparing data that I can carry more speed, I'm able to convince my subconscious and it lets it happen. I'm just trying to find other ways to do that.

Matt Romanowski

It's available now and has been for a bit. They exhibited at PRI too. https://apextrackcoach.com/

It's a great device. I've been evaluating one for a couple of weeks. I was playing with it in the Yukon XL today!

Use your data and then you will have the correct radius that you actually drive.

Assuming you have an AiM device, the math channel for corner radius is band_pass((Speed*MPH2FTS)^2/(LatAcc*32.2),-2000,2000)

You have to make sure the "Speed" and "latacc" match what your logger channel name is.

I posted up a thread on how to create math channels and gave Roger Caddell's math channel info at https://rennlist.com/forums/data-acq...nel-video.html

ProCoach

Well, they showed proof of concept at PRI and have a few demos out, including yours and mine.

It's a really cool piece, but the first production batch has yet to be made.

ProCoach

I prefer to have concrete circuit info. This is a good way to do it: https://racelogic.support/02VBOX_Mot...n_Google_Earth

sbelles

Well, yes and no. I have an AIM MyCron and it has a lot of inputs but it doesn't have GPS so I use my Traqmate which has almost none most of the time. I guess it's time I upgraded.

Matt Romanowski

The proof of concept was about 16 weeks ago. I've been following them about that long. I actually have 2 units here. They have had them in use about that long and did the prototypes and other work before that. Smart guys and a neat device.

That just gives you the track outline. I'm not sure if Google Earth would could/would give you the radius based on that. Isn't that just the Circuit Tools required workflow to add a track map to the video?

Plus, why would you not use the driven line? It will always be different than the actual inside/outside/mid track radius, usually by a good amount. For instance, the published radius for turn 13 at Sebring is 130', while the data shows the driven radius is about 190' feet.

Matt Romanowski

An original Mychron I? That would be an oldie! I'll offer you a good upgrade if that is what you have. Heck, I'll offer a deal either way!

sbelles

I think it's a 3 XG but it's still an oldie. Came with the car. When my door fell off at the glen a couple of years ago it took the cord with it so now I can't even get the data off of it. I just use it for shift lights.

ProCoach

Yes, the way the device learns, and the fact that it does it off MEASURED info is really cool. Will save a lot of time. Lots of potential for improvement in the GUI, though.

Hah! I wouldn't EVER want to calculate the theoretical and desirable velocity or loading through THAT corner, based on a number like that! Too many variables with surface height and tire loading. Besides, the hard part is before the steady radius...

ProCoach

Yep, a Solo would give you the information you need more than the Mychron3 Gold or XG. No way to add GPS to the MC3...

Matt Romanowski

It does work around the measured metrics, but it really comes down to what you do with the info. I think it is already pretty good and has a ton of potential.

So do you get radii from Google Earth? I know you can draw a radius circle, but that would take a long time to do for each corner, let along track. What you posted before is for a track map in a video, not corner radius measurement (which was asked).

Manifold

Keep in mind that driven radius generally varies through a corner. Typically, you're spiraling in to the apex (decreasing radius), then holding a constant or gradually increasing radius for most of the corner exit past apex until opening the wheel near the exit.

And of course the average radius driven is bigger than the radius through the centerline of the track (which isn't always constant either). If you want to factor in camber, the camber will transition into and out of corners, which further complicates things.

zzyzx

I started reading this wonderful thread months ago, and Wow, now I'm finally at the end.


I have a question on line theory.


Let's say Driver A begins his line into a corner staying, say, 3 feet away from the outside of the track on turn in. He hits the apex and uses all the road on the exit.
Driver B turns into the corner using all the entry, and he also uses all the road on the exit, but he misses the apex by 3 feet.
Now, my understanding is that both drivers have reduced the radius of the corner an equal amount, and that therefore both of these compromised line would result in an equal maximum speed through the corner. Is this really correct? Is the effect on the radius the same?


If it is, then what I don't understand is why is just doesn't feel like it when you're driving. Not being exactly at the outside edge of the road on the entry just doesn't feel like it has as much of an affect on your speed through the corner. On the other hand, being able to cut the apex, such as by using all of the apex-marker curb or even hanging a wheel over the grass, really does feel like it allows you to carry more speed through the corner.

ProCoach

FIFY.