Thứ Hai, 13 tháng 2, 2017

Some data logger plots from kC's '8' part 1

solo-x 11-15-2005 01:45 PM

Some data logger plots from kC's '8'
[IMG]http://www.we-todd-did-racing.com/wetoddimage.wtdr/wMTEyOTQzNzZzNDEzZGZkMzF5NTQx.jpg[/IMG]
[img]http://www.we-todd-did-racing.com/wetoddimage.wtdr/wMTEyOTQzMDZzNDEzZGZkMzF5NTQx.jpg[/img]
[img]http://www.we-todd-did-racing.com/wetoddimage.wtdr/wMTEyOTQyOTZzNDEzZGZkMzF5NTQx.jpg[/img]
[IMG]http://www.we-todd-did-racing.com/wetoddimage.wtdr/wMTEyOTQyNzZzNDEzZGZkMzF5NTQx.jpg[/IMG]
[IMG]http://www.we-todd-did-racing.com/wetoddimage.wtdr/wMTEyOTQyNjZzNDEzZGZkMzF5NTQx.jpg[/IMG]

these are the plots generated in keith's BS RX-8 at the Tri-State a few months ago. runs were done back to back and these were our 5th runs for the day.

the first image is the course map of 5th runs for both keith and i. keith is the red trace, i'm the black trace. notice the difference in lines.

the second track map is of the same runs but shaded with total g plots. red means higher g's, blue means lower g's.

the third image has three graphs in it. the first is GPS speed, again i'm the black trace, kC is the red. notice the missed shift by keith. :lol: the lower graphs are time slip and rate of time slip. on the bottom graph, keith is loosing time to me when the trace is below the x axis, and gaining time back when the trace is above. notice the finish corner (course was run cc) where keith made up a big chunk of time with an early apex line. my drive off the corner was better, but the straight was too short to capitalize on it.

the final two images are g circle plots. keith's is first, mine is last. notice that keith turns one way better then i do. when we looked closer at the data, the car accelerated better and turned right better with me driving then with keith. for him it turned left better. the resolution of this thing is so good you can see our weight difference. (me ~160lbs, keith ??)

ignore the peak g forces. we did not cancel out chassis roll. the car is still probably capable of 1.2g's steady state though. same with accel/decel. pitch and dive will artificially boost those numbers.

the data logger was a borrowed DL1 unit. i hope to have one in my possession next year. the data this thing can generate is insane. the guy that owned the unit we borrowed also measured TPS and steering angle as well as monitored the brake light switch. there are enough channels that you could also use damper pots to see what your suspension is doing.

nate
ratt_finkel 11-15-2005 01:49 PM

So the real question is, who was faster?
solo-x 11-15-2005 01:51 PM

i cannot reveal that. the graphs tell you all you need to know. ;)

trying to fix the images.....fixed
KC 11-15-2005 02:05 PM

*mumble mumble* missed shift *mumble mumble*

[QUOTE]the final two images are g circle plots. keith's is first, mine is last. notice that keith turns one way better then i do. when we looked closer at the data, the car accelerated better and turned right better with me driving then with keith. for him it turned left better. the resolution of this thing is so good you can see our weight difference. (me ~160lbs, keith ??)[/QUOTE] 245 back then.

Next year... 200ish. ;)
cfvwtuner 11-15-2005 02:50 PM

Wow, that's a cool piece of equipment. Tristates was a good day. I saw that first plotting and just knew it was a CART autocross.
Other than being really cool to look at afterward, how can this be used to make yourself quicker?
solo-x 11-15-2005 03:09 PM

by looking at the data i can reach a couple conclusions. 1) missing a shift is a very costly thing to do. 2) i brake too early, too much 3) i need an early apex on corners where the exit doesn't matter 4) i need a later apex on the big sweeping right hander in the middle of the course 5) any bit of oversteer that you have to counter steer to correct is time lost. 6) i KILLED keith in the offset/slalom on the back straight by giving up some early

this was the first time i had driven keith's car. i typically drive an ST honda. v710's, rwd, good chassis dynamics and brakes that don't quit needed some time to get used to. i thought i was leaving the majority of my time in the middle of the corner and just a little under braking. turns out, i was loosing 95% of my time under braking, and the other 5% in my line. keith is no slouch with the middle pedal. if i drove the car again i could take what i learned from this event and apply it to the next. i KNOW what to focus on and "where the time is at". it's not in the middle of the corner like i thought it was.

this is also a great tool to use when you feel like you're stuck in a rut. find a good driver that can beat you in your car, then log some runs back to back. the littlest things add up to some crazy amounts of time.

and finally, a t&t day now becomes useful. did that change actually make your times improve, or did you just drive better? without it, say you disconnect your front bar and run a faster time. did the car get better or you? with a data logger, if you see that peak g's and steady g's both declined without the front bar you KNOW that the bar change hurt the car. you just drove it better.

nate
KC 11-15-2005 03:10 PM

[QUOTE=cfvwtuner]Wow, that's a cool piece of equipment. Tristates was a good day. I saw that first plotting and just knew it was a CART autocross.
Other than being really cool to look at afterward, how can this be used to make yourself quicker?[/QUOTE]
If I was a sole driver in the car, I'd be able to compare "I did this" in run one "I did that" in run two... and say "X was faster because..." and actually see it...

Better line through the turn, got on the gas sooner, braked too late, went wide through a section, aimed at a cone instead of late apexing it.... etc. There's actually a wealth of info you can get from it and look at it between runs if you're quick (like Cart offers the time to analyze between runs).

In this case, I saw some things I did that day that are what I call errors. Being too wide on most turns, missing a shift, etc...

Looking at that last turn before the finish goes against what most of us have learned about auto-x being mostly late apexing a turn... by me diving at the turn with greater speed, I actually gained time through the corner and beat Nates run to the finish by fractions of a second through that one corner. If the finish wasn't right after that turn, Nate may have carried more speed out of the turn to the next element.

This software also allows you to place the runs at the same point in time and play real time playback... you can physically see the differences between the runs. When the win or loss comes down to 10ths/100ths of a second... every little bit can help you become a better driver.
ratt_finkel 11-15-2005 03:50 PM

[QUOTE=solo-x]i cannot reveal that. the graphs tell you all you need to know. ;)

[/QUOTE]
Except times :lol:
solo-x 11-15-2005 04:44 PM

[QUOTE=ratt_finkel]Except times :lol:[/QUOTE]

the time slip graph does better then just times. it shows you when and how much time you gained or lost. it's cumulative, so as that line moves away from the zero axis the lead car is gaining time, as it moves closer to zero the slower car is gaining time back. (i didn't really explain that part well). the end result was that i beat keith. he had a faster scratch run that was not logged. his final run (the one in the logs) had a missed shift that cost him .4xx seconds or so. i don't remember exact times but i'm pretty sure i only beat him by .38x or so. see what i mean about those missed shifts? theoretical best is pretty close to the time keith ran with the cone.

nate
vintagemilano 11-15-2005 06:32 PM

Ok, that's cool.
Imprezivblue 11-15-2005 07:10 PM

:eek: :huh: That's freak'n awesome!!!!
Tirewarmer 11-15-2005 07:51 PM

Nate, if you crunch data between runs when are you going to have time to adjust your rear toe out? :p

Those plots are awesome. I'd love to have one to compare my runs to each other. Nate, what do you find more beneficial, the datalogger or the video from the Chase cam? I am pretty much set on buying a Chase cam for next year as a learning tool.

Joe
KC 11-15-2005 08:11 PM

Joe,

This can show you the details. Using this in combination with the chase cam would be nuts and really show you what's going on.... but between the two, I'd take the DL1.

--kC
solo-x 11-16-2005 08:03 AM

DL1 shows you about ten times more data. for one, it wouldn't take us 17 veiws of the same section of the north course with a stop watch to determine which was quicker. ;) me personally, i'm going DL1 as soon as i can afford it.

nate
ratt_finkel 11-16-2005 09:10 AM

How much does that setup run? Nice job by the way Mr. Whipple.

Also, I noticed that you took a much tighter line that Keith. Is that your preferance, or just because of the car you normally pilot?
solo-x 11-16-2005 09:19 AM

the DL1 goes for ~$965.

thanks! i took a tighter line in a couple places, but not in the place i should have. a lot of that tighter line is probably due in part to my excessively early and aggressive braking. i'd overslow the car and then try to minimize the damage by keeping it nice and tight. keith is typically an early apex/tight line driver as well. his wider line might be some of the "mistakes" he's talking about.

nate
KC 11-16-2005 09:53 AM

[QUOTE=solo-x]the DL1 goes for ~$965.

thanks! i took a tighter line in a couple places, but not in the place i should have. a lot of that tighter line is probably due in part to my excessively early and aggressive braking. i'd overslow the car and then try to minimize the damage by keeping it nice and tight. keith is typically an early apex/tight line driver as well. his wider line might be some of the "mistakes" he's talking about.

nate[/QUOTE]
Mistakes? I was just 'tryin' somethin. ;) Oh hell yeah. Duh! Going wide will 95% of the time be slower than running over the bases of the cones. I still carried more speed through the turns... I was slaughtered in the slalom because of my overaggressiveness and charging the slalom instead of braking earler and powering/maintaing through it (it wasn't an exaclt slalom, more like a series of offsets over moguls)... that and the missed shift cost almost a 1/2 second.

KC looks up bank account... damn... Decals for sale!!! :lol:
WRX_Mundi 11-16-2005 01:01 PM

That's cool. I've been thinking about a DL1 for a while -- haven't been able to bring myself to spend the money yet. I didn't have such a good experience with my Geez unit (mostly issues with the Palm Pilot interface meaning I'd lose all the data -- not an issue with the DL1).

There seems to be a group buy going on on s2ki, for 20% off or about $772 for the DL1. See this link:

[url]http://www.s2ki.com/forums/index.php?showtopic=334558&st=0[/url]

Or we could plan on setting up a group buy here next year. 12+ units needed for the 20% discount.

Now I just need to be convinced to buy one myself. One nice thing about the DL1 is the availability of the very inexpensive [url=http://www.trackvision.net/]TrackVision[/url] video overlay system, as well as some other options. Video overlay for some of the big-name logger systems (MoTec, Stack) are very expensive.
KC 11-16-2005 01:14 PM

Thanks for the link. :)
ratt_finkel 11-16-2005 02:59 PM

[QUOTE=KC]

KC looks up bank account... damn... Decals for sale!!! :lol:[/QUOTE]
I hear ya on that note :(
solo-x 11-16-2005 06:46 PM

looks at cc balance.... smiles.... gets smacked by SO....

nate
zoomfactor 11-17-2005 01:53 PM

KC & Nate - What additional sensors/doodads were on the unit that you used? The DL1 link is very generic in nature, but I'd be interested in something that generates data like you have presented.
solo-x 11-17-2005 02:06 PM

no additional sensors. all the data you see was generated with the onboard accelerometers and a gps antennae.
bouchon 11-17-2005 02:50 PM

solo-x:
Was it easy to switch the devise from one car to another?
We are planning to buy one and share with a friend of mine but we don't know if it will be practical to change it back and forth from one car to the other. I am thinking especially for the power supply. Let me know because it is the only worry we have about it.
It looks really net otherwise.
Thanks.
KC 11-17-2005 03:32 PM

It was easy. Power from cigarette lighter into the GL1 'box' that contains the guts of the system. One connection out to the GPS receiver.

The trick is securing the GL1 as to not to move.

Both the unit and the GPS receiver were held down by some removable adhesive putty.

--kC
bouchon 11-17-2005 03:36 PM

Ok. So you can plug a cigarette lighter. They didn't advertise that, that's why I was wondering how you did it. They do advertise it with the AX22 but not with the DL1.
So where did you put the unit and GPD receiver? Under passenger seat?
Thanks for the info.
angryfist 11-30-2005 11:45 AM

anyone know the difference between race technology's DL1 and AX22??
zoomfactor 11-30-2005 01:16 PM

[QUOTE]anyone know the difference between race technology's DL1 and AX22??[/QUOTE]
Interested also...the Group Buy on the S200 forums is getting near the end...I think this might be a nice toy. I was considering the GEEZ/G-Cube but for double, you get something that has incredible potential.
zoomfactor 12-01-2005 02:47 PM

This link seems to have a product comparison...
[URL=http://www.balancemotorsport.co.uk/images/Race%20technology%20product%20comparison.pdf]http://www.balancemotorsport.co.uk/images/Race%20technology%20product%20comparison.pdf[/URL]

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