924RACR

The steering input is IMO the single most valuable data source for rating the driver, as it's the primary way the driver interacts with the car (especially true for less experienced drivers). I'd say it's the #1 item on the list for tuning the driver, not the car. Unfortunately it's also much more difficult and expensive to set up that instrumentation than other inputs, so naturally it's much less common.

fatbillybob

924racr wrote"The steering input is IMO the single most valuable data source for rating the driver, as it's the primary way the driver interacts with the car (especially true for less experienced drivers). I'd say it's the #1 item on the list for tuning the driver, not the car."

Vaughan,

I'm really new to DAS just starting to read about it. O.K. lets assume that is true. How can anyone with a brand new AIM ever hope to use this new data? If I go out to a track and find my steering input angle to be "x" in turn 5 what does that mean? I would think you need to have data from a pro to also compare what you do. You could use GPS to fix your turn-in to the pro's turn in etc but don't GPS unit still have an error of 3 or 30meters? Is the GPS in the AIM type units have enough resolution?

FixedWing

I agree with Billybob. How can you make use of the steering data? What exactly does it tell you?

I can see the possible use in comparing the car under one set-up to the same car with the same driver under another set-up -- i.e. for diagnosing the car -- but how can you use this to examine the driver (other than basic stuff like he isn't being smooth -- the sort of thing that is obvious to just about anyone watching from the passenger seat).

In playing with the DL1 I do find that the GPS is very accurate. I have some doubts about how they combine the GPS and accelerometer data though. I get the feeling that if they were doing a better job of using all of this data then it could become highly accurate (inches).

Stephen

RJay

If we factor out traffic issues, the car setup is largely invariant through the course of a session. I don't even have brake bias. let alone cokpit adjustable sway bars or any F1 style stuff. Beyond tires going away, inconsistencies in segment times can be correlated to brake, throttle and steering inputs. Sprinkle in video so you can see what you were doing and what worked and what didn't and I think I'll learn more quickly. If I look at my lat-g and its .7 in a corner where my butt thinks its flying, I can at least know that heres a spot that I might try to push a little harder. If I'm wiggling the wheel too much, while thats happening, I know I was too agressive, over driving, dial it back and be smoother.

fatbillybob

Is there a website that is kinda like a DAS primer? I have one book on the subject on order and the only one I could find.

fatbillybob

What Rjay said made sence. Is there a DAS that shows Lat G's on a screen you can see while driving like a tachometer? It seems to me all the systems log and then you analyze post race.

RJay

Both Aim and Race Technology wil let you download their software for free. With the software they include some test data so you run the programs with some laps they recorded. Initially I was interested in the DL-1 but after playing with the software, decided that the AIM was a bit more sophisticated from a software POV so I went with them. Its a little daunting at first, you'll have to screw around for a while to figure out how to run these things, but if your interested in this stuff, playing with these programs is a great primer for what they can do.

The Aim stuff (Race Studio) can be downloaded from http://www.aim-sportline.com

924RACR

RJay's pretty much covered it. Yes, you can get the same info from a video, but DAS allows much more detailed and precise evaluation of steering input. Furthermore, when you feed steering angle into some of the higher-order calculations (think Ackerman steering bicycle model of yaw rate - may want to consult Gillespie's vehicle dynamics book on this, I don't have my copy handy) you can get an even more detailed analysis.

Most simply put, you can generate a driver's request yaw rate based on the Ackerman model for steering (steering and vehicle speed as inputs) and compare this with recorded yaw rate (from the sensor). If these are smooth and close, you're probably doing a good job of driving the car at the limit. If you're not consistently holding the car there, due to lack of smoothness or over/undershoot, you'll be able to draw some conclusions about your driving technique.

Sorry if this sounds a little vague, but I don't have any data I can post to discuss this with - as mentioned, I still don't have a steering angle sensor on my car either.

95m3racer

If anyone would like detailed info or would like to purchase a system, please contact me and i can hook you up not only with a good price from a very reputable distributor (aimsports recomended) but also a year of support for free! As well as other things that most other companies don't do,like test all the sensors/systems before they ship out, custom make harness's, offer Sensor data anlysis if you feel something is wrong, etc etc etc.



For $2500 you can get a fully loaded top of the line Aimsports MXL Pro system with some sensors!

Shpeyeda

For all the other DA novices like me, let me add my $0.02.

I don't consider AIM to be a low-cost solution for a novice/intermediate. Something like $1500 - $2000 for the system plus $500 - $1000 for installation depending where you go. Compare this to the Race Technology DL-1, which sells for $900 with no installation costs. Now THIS is a low-cost solution, but it does have its limitations. First, you don't have any/many sensors with the basic install, but heck you're a novice/intermediate and you'll already be overwhelmed with the basic info that GPS/accels give you. Second, you don't have cockpit display with real-time info, but heck you're not trying to win an endurance race. As far as the GPS accuracy, I've found it to be accurate enough to differentiate different lines I've taken. It's gotta be at least as accurate as using accelerometers and wheel speed sensors to draw the track map (i.e. AIM), or so I'd think.

I've also found the DL1 software a bit difficult to learn, although they released a new version a few months ago that is much improved. I've been simply walking through the help file to learn how to use it, and this seems to suffice. I've checked out the book "Competition car data logging" by McBeath but I've found it useless. Total waste of money. Even if you don't want to buy a DL1 you can download their software and work thru the help file with sample data to learn the basics. One thing I just learned is how to look at the spped traces of a few laps along with the "time slip" curves, which tell me exactly where I'm losing time (compared to the theoretical best lap) or where I'm consistent from 1st to last lap, etc.


Anyway, I'm not affiliated yada yada yada just a satisfied customer.

ColorChange

Shp:

I agree, the DL1 looks pretty nice but the software issue is critical. If you can't get at the data and perform the analysis, collecting the data is worthless. I don't know if the software is good or bad, just that it better be pretty good (the aim is) if you want to use the system. I think the DL1 GPS is likely much more accurate than the Aim accel (now - aim is coming out with GPS also). The data logging book is terrible. The Dash Display is nice because you can look at and alarm different parameters.

Finally though, and my biggest problem with the DL1 is if you want all the data, like you should get with the Aim and CAN link, You would need a new system of would need to get your own drivers written.

Shpeyeda

The previous versions of RT's software were pretty weak, but the current is good. I'm only vaguely familiar with AIM's software (a buddy has it) but I'd have to think that AIM's is better. But for my basic stuff, RT's seems fine.

I totally understand how this would be useful, but that display obviously costs a lot of money, and so does getting all the sensors hooked up. While I'd love to have it, it's just not worth it for my level of skills and my goals.

Allow me to demonstrate my ignorance: that statement went right over my head. I'm nowhere near the point where I'd find it appropriate to manually process raw data! That said, I do have an engineering degree, but I lack the time or inclination to get very deep into data analysis.

Our exchange sounds a lot like the discussion between my buddy and I last winter when we were trying to decide which system to buy. He said "AIM because it's technically better and has a helpful display" and I said "DL1 because it's a great value and gives us novices sufficient information." We were both right, I suppose, but in the end, it totally depends on what you want to get out of the system.

FixedWing

I am using the DL1 and I really couldn't call the software "good". It still needs a lot of work. Even basic usability things like remembering file locations needs work.

In my opinion, Race-Tech would do well to concentrate on getting this most important part of their product into better shape rather than working on trying to expand it.

Stephen

RJay

The Aim Mychron 3 Log XG is roughly the equivalent of the DL-1. The Aim has a dash, the DL-1 has GPS. But the M3 Log has a can bus interface and will accept the video option which, to my mind is probably the most important option I can buy. M3 is available over the web for ~$900. Installation cost is pretty trivial for a simple AIM installation, the only big skill part of the install is the speed sensor, but if you want a tach, throttle, steering input etc, the install cost is the same. If I recall correctly, the DL-1 has 4 or 5 analog channels as does the M3. Don't know the cost, quality, availability of the DL-1 sensors. BTW, if you had jumped on the band wagon as late as last december, you won big time. I bought my Pista for $1185, which was a no brainer.
The reason I suggested downloading the software in a previous post is because it was the software that convinced me to go with Aim. Its not perfect, but personally, I felt it was superior. My general impression, opinion, feeling, what have you, is that the DL-1 as a system is more or less a high end G-tech, while the Aim is a low end Motec. I.e one more a consumer level device, while the other is a professional tool. I also suspect that there a lot more data sharing, track map sharing with Aim units that there will be with the DL-1. I think there are some real nice features with the DL-1 and I certainly would never criticize anyones decision to go with it, but I feel strongly the extra cost of the Aim system is justified. And I too have no associations either of these companies.

924RACR

Hell, AIM MyChron3's start at closer to $500! You also get the same pro-quality analysis software as for the $2000 unit, if I'm not mistaken. My AIM MyChron3 Gold XG was around $500 IIRC. I'd love to be able to use one of those AIM systems with CAN capability - but the poor thing would have no other computers to talk to in my racecar! It's the only bit of silicon in my racecar outside of the electronic ignition!!! CC et al are talking about a much higher level of DAS than what is needed for starters.