Data Acquisition

[fvkartguy]

What kind of data logger would you recommend? Is there a good one that doesn't cost thousands?

[brian]

Racepak makes one called the G2X which is great. Racepak is a prat of MSD ignitions so it's not a small company. The system is a GPS based system, meaning no receivers or beacons needed, comes with a really neat dash and the software is easy to use. It has to be easy for me since I'm a klutz with software. The kit sells for just over $900 and comes with everything except for a rpm sensor that is needed for our old ignitions. If you want to add oil pressure and temp to the dash, it's about $300. I chose to retain the VDO analog gauges but really like the tach and shift lights on the dash. Go to the MSD web site and check it out.

[SR Racing]

What kind of data logger would you recommend? Is there a good one that doesn't cost thousands?

We carry the AIM systems. You can get a fully configured system with track mapping and sensors for well under $1000.

See them here: http://sracing.com/Store/DataAquisition ... sition.htm

Jim

[kevin willmorth]

What kind of data logger would you recommend? Is there a good one that doesn't cost thousands?

How far do you want to go?

You can get good information from an Aim system, including some inputs for engine tuning, etc., for around $1,000 +/-, which is good enough for many to gain better timing and active performance data, but not a However to get USB connection, and other features to make the package a true analysis/data acquisition system starts at $2,000, plus analog inputs. http://www.aimsports.com/products/mxl-chooser.html

A basic race pack system will run you about the same as a Mychron XL... but is more scalable over time to include greater functionality. http://www.racepak.com/PriceList.html The cost of a full blown system can add up to much more.

If you want the full monty with integrated steering input and throttle position sensors in the package, and software that is designed to provide analysis of performance in ways that will reveal driving issues with more clarity, one of the most popular systems is CDS (Competition Data Systems). The cost will land you in the $3,500 neighborhood with GPS (the only way to go). http://www.competitiondata.com/packages ... drange.htm

Then you can go nuts and get the same stuff they use in pro cars, like the Stack systems, which start in the $5,000 range and shoot up from there. http://www.stackltd.com/engineering.html These things can be set up to indicate you heart rate, blood sugar, and opinion on politics, while recording the effect of the car behind you on your exhaust gas temperature (okay, I;m exagerating for effect... they can't calcualte political views accurately.)

One issue with any system being considered is how they function on the track, and provide analysis in the pits. For sportsman, I personally fee the features that are part of the CDS system nail the most important stuff. The display can show incremental times live, which allows you to see continuously where you are in that segment, compared to your best in that segment, while showing overall performance. The system also has excellent analysis software, showing lateral and longitudinal G's with throttle and steering position, and coparitive analysis that is useful for figuring out where you need to fix driving issues. This sophistication is on par with the Stack mega-bucks systems, at a fraction of the cost, and superior to the Aim product. I reviewed many data analysis software packages associated with each of the systems shown above, and was most impressed with the CDS analysis program. It displays track mapping with data overlays, so you can visually see on the track map where what is going on. I have experience with the Aim software on many levels, and find it adequate, but not as revealing as the CDS. Stack software is complex and demands some serious investment to configure properly, not to mention some serious reading to get a handle on what its telling you. Looks like space shuttle data to me... The Racepack and Aim analysis programs are very similar in function and appearance.

If you want nothing more than a really good timing system, its hard to beat the Aim products for simplicity and durability. If the budget can stretch to the $2,000 range, the Mycron XL with track mapping is good stuff, and the USB download excellent.

If you want to step up and get serious analysis, in a package solution with all the parts you need integrated, and software to back it up, Competition Data Systems is the way to go. It's highly functional, has GPS track mapping/timing, includes throttle/steering position, and can be augmented over time, as well as integrated with video capture. The company is also small enough to work with you on customization, working through details, and fixing special problems.

If you have aspirations to go race with the IRL boys one day, or have money flowing out an orifice, and need a place to throw it before it stacks up and creates a fall, either by the CDS, and send me what's left (I'll make good use of it, I promise), or go for the Stack system, which has more than anyone needs to know about what they are doing, which is perfect for information addicts who think knowledge is power - literally.

I personally chose the CDS system after putting all of these against one another in a comparison. If you want to talk with someone who knows them in the FV application, call them directly, or better yet, call:

Steve Dreizler
Phone:
417-858-3794
Email:
sdd04@centurytel.net

Steve is a CDS rep, and has so much of the stuff on his car it looks like a coma patient.

[jpetillo]

It's interesting that the web sites suggest that GPS can provide a more accurate track mapping and track timing than the accelerometers. I guess that it all depends on the quality of the components that racers can afford to buy for accelerometers (or lack of quality). Without gyros, you can't easily tell about rotation, and that eats into the usability of the accelerometer data as the vehicle tilts front to back and side to side, and dealing with uphills and banked corners. For GPS, they can have good speed accuracy, but relatively poor location accuracy. I don't know about the direction accuracy.

Anyway, I can understand why Steve Dreizler's car would look like a coma patient. It takes a lot of sensors to really understand what a car is doing in detail. It sounds like fun to have all the data. I'm just thinking out loud.

[SR Racing]

To each their own and other opinions will vary, but..... I can 't imagine investing more than $1000 into DA on a Vee. SPS (Steering position sensors) TPS (Throttle Position) and linear shock pots, etc. seem like a bit of overkill when there is so much slop in steering gear boxes, front beams, swing axles, etc. etc. These things (Vees) are great fun, but when you measure with an micrometer and cut with an axe, I am not sure of what value the additional stuff is. Tach, Wheel Speed, Track Map, Oil Press, Oil Temp, EGT or O2 (and maybe TPS) is great and useful and can all be had for $1000. (Those alone will help to protect your engine, determine your rear wheel HP, give you some driver feedback and hours of fun playing with the data.) More than that, and I think you would be much better off using the extra for a set of tires or track session.. I will be more than happy to sell it to you, but will advise against it, UNLESS you are just wanting to play with the data. (And that in itself can be interesting, but probably not of much value.) If you want to collect $5000 worth of data, do it on a car that can be adjusted to the data.

Jim

[hardingfv32-1]

Are FV's sleek dune buggies or road racers? Just because the parts are crude does not mean we have to treat our Vees with any less attention to detail than any other SCCA race car.

Data Acquisition: Get a book on the subject and do your homework. Figure out what you want to do with a DA system, then call Jim and allow him to match your requirements with a AIM system.

Brian

[SR Racing]

BTW, Regarding the beacon requirement with the AIM system.. I have never removed one of our beacons from the box.. In over 15 weekends of using the AIM, there has always been several beacons already set up on the track by someone else. So let the FC/FA guys set them up for us. BTW, multiple beacons don't bother you since the AIM (like many others) has a "blanking range" that is programmed into them. So once it sees a beacon it trips, and ignores all other beacons for the next 30, 40, etc seconds. In regards to lap time accuracy, it compares to within .01 seconds or better of the SCCA and AMB transponders in every case. Once in a while in a session a spurious trip takes place. but this can be fixed later in the raw data on the PC, if you REALLY need to.

Track mapping takes place using input from the wheel speed sensor, G-sensor(s), and Beacon. This is all the metrics that are needed to draw a decent track map and show your position on the track at any point in time. The maps it draws are quite good, but can be manipulated if the map is off slightly. I have seen the units that draw maps apparently using GPS data also. They are about the same.. In any case, I wouldn't plan on using the track maps for seeing where you are on the track in regards to the apex. Two feet off the apex is bad and neither system (GPS or non) will get you that close. The map is most useful for analysis of your time on segments, breaking points, speed into and out of corners, etc. Either type of system will do this quite well. If you want your apex position, use video.

Brian, I don't mean to insult the Vee. As I said, it's a fun car. But we are certainly closer to a dune buggy than F1 car. Throwing $5k at a $10K car to collect questionable data for a trophy is probably not a good idea. Even if it does attract lots of women. I agree with your statement about getting a book re: DA. Even if it isn't all applicable to a Vee, it certainly is a good learning experience.

Jim

[jpetillo]

Jim & Brian, very good points - I agree with both of you. I agree that you can do a lot for $1000 (more than I'm willing to spend at this point), but also whether the cars are sloppy or not, data is data and can help tell you what's going on - like that something is improving as you make modifications. To those of you who have not done so, as Brian suggested, get a book on data acquisition. I was surprised at the different ways the data can be used - you find yourself saying "yes, of course!" As is often the case, everything is obvious once it's brought to your attention.

Jim I agree with you about there always being a beacon at the track. My thoughts before on GPS came from many people jumping at the word GPS, but it adds cost, has some benefits, but also has its own performance limitations that we hope the suppliers have mitigated against.

[smsazzy]

I purchased an AIM MyChron XG LOG from SR Racing about a year and a half ago. I really like the system for the price. I am logging Oil Temp, Oil Pressure, Cylinder Head Temp (CHT), Steering Position Sensor (SPS), Throttle Position Sensor (TPS). Wheel Speed, Lat G's and Long G's.

I too, have never unpacked my AIM Beacon, as there are always an over abundance of them set up.

I have also combined this with a camera system from ChaseCam. You can also overlay the two. I have a sample on my website (http://www.tcrmotorsports.com - click on Multimedia) I have not figured out exactly how to feed all the data into the video yet, but have only tried once.

The biggest help from the data for me, with the sensors I use, has come from learning what I am really doing. TPS has shown me when there are corners that I thought I was flat through, and I wasn't. Or has caught me lifting early before a braking zone and seeing a "coast" before applying the brakes. Being able to recognize these has helped me as a driver.

SPS has allowed me to see where I may not be unwinding the wheel after an apex, possibly indicating an early apex, etc. Combining that with video has really allowed me to focus in on that.

I am just now learning how to use the DA to make setup decisions. Shock Setting, etc.

Also, the engine diagnostics have helped with a few things as well. For example, I took a fresh SR motor up to about 7800 RPM during a spin when I went to lock up the brakes and also hit the gas at the same time with the clutch in. By reviewing the oil pressure throughout the incident, I was able to see that there was never a drop in oil pressure - which put my mind at ease that the engine was probably alright. (It was - 8 more races on it that season)

Here are a couple pointers though. Increase the logging frequency on things like SPS, TPS, Oil Pressure, etc. Things that change rapidly and need to be monitored. SPS at 10 or 20 Hz Logging is just about useless. That needs to be bumped up to about 50+Hz. However, decrease CHT, Ambient Temp, etc to 1 Hz.

In regards to the CDS stuff. If I had the money, I would get that system over the AIM system. The user interface and expandability far exceeds the AIM system, and I like some of the reports that system has over mine. But....for the price, the AIM system is hard to beat. I do recommend the XG Log system over the standard AIM system though. You get Long G's and an extra sensor input. You can also mount the display on the steering wheel as I have and it makes it very easy to see.

For what it is worth though, if you don't have video, get that first. You will learn way more about what you are doing (and the competitor in front of you for that matter) with video than you will with DA.

[SR Racing]

All good points... Stephen. I think I would go video before DA also if the main issue was driver input.

One nice thing about the AIM (and some others). A full good gauge set will cost up to $500, not to mention the time to wire them. An AIM IS a gauge set + and it includes data that you can't get with gauges.. all for under $850 for the standard Vee system. It is also easier to wire than a set of gauges. So if you are building a car from scratch or refreshing one, it's a good investment.

Jim

[sabre1]

I have a Pi system but I would recommend an AIM system mostly because most of the Vee drivers I know have AIM systems; this makes it a lot easier to compare data. Also, since the AIM analysis package has been free in the past (and hopefully still is), you can send your data to anyone, and they can download the analysis package and review it - you can't do that with the Pi software. Also, you have to pay extra to get the bells and whistles from Pi, but all the extra capability is included with the free AIM software. Another point already touched on in other posts is don't go overboard with your first system. Data analysis can be an amazing time sink, and a lot of drivers seem to be excited at first then lose interest because of the time it takes to download then analyze the data. This subject has been covered previously in this forum and it would be worth looking at those posts as well if you can get to them.

-Jim

[kevin willmorth]

To each their own and other opinions will vary, but..... I can 't imagine investing more than $1000 into DA on a Vee. SPS (Steering position sensors) TPS (Throttle Position) and linear shock pots, etc. seem like a bit of overkill when there is so much slop in steering gear boxes, front beams, swing axles, etc. etc. These things (Vees) are great fun, but when you measure with an micrometer and cut with an axe, I am not sure of what value the additional stuff is. Tach, Wheel Speed, Track Map, Oil Press, Oil Temp, EGT or O2 (and maybe TPS) is great and useful and can all be had for $1000. (Those alone will help to protect your engine, determine your rear wheel HP, give you some driver feedback and hours of fun playing with the data.) More than that, and I think you would be much better off using the extra for a set of tires or track session.. I will be more than happy to sell it to you, but will advise against it, UNLESS you are just wanting to play with the data. (And that in itself can be interesting, but probably not of much value.) If you want to collect $5000 worth of data, do it on a car that can be adjusted to the data.

Jim

Actually, I am less interested in wheel speed, oil temp, oil pressure, and engine speed - those things can be done with $50 worth of cheap gages. Tracking that information is also pretty useless for anything but a log book, another $3 on paper at best.

Actually, my biggest interest is in Throttle position, lateral and longitudinal Gs, track map, and steering position. I don't want really care what the car is doing, I need to find out what I am doing - so am looking for data that tells me that. This is like having coach telling me when I am lifting too early, braking into the turn, too late on the throttle, turning in too late, and making the car do stupid things that slow me down. Some will say they know all this stuff - I don't buy it. Without qualified help to watch every corner, and as little experience I have in the seat of the car, all the information I can get about what I am doing at the wheel is very valuable, and to be used to keep the learning curve vertical.

I've had simpler data recording hardware on a kart, which track mapped and recorded all the vitals. Good for a start, and for those who are not looking to amp up their performance through serious driver evaluation and sole searching (where is god anyway - braking marker 2 or is that 1, or???) then all the extra stuff is not going to do anything. However, I believe those experts who offered me the advice that the additional information is well worth the investment.

But what the heck... I spend more than the cost of the system on driver schools every couple of years. I'm at a point where I need to learn much more, in as short a period as possible. Seat time is the secret to success - but a lot of seat time at sub-par levels is worthless. Hopefully being able to evaluate driver behavior will give me what I need to amp up the quality of those precious minutes in the seat.

FWIW: I placed the steering sensor on the steering arm itself, not at the wheel, to elliminate the slop from the steering box showing up as actual steering movement...

So, that's the counter point... just to contrast as it were.

[smsazzy]

Actually, you do want wheel speed too. It is needed to assess what you are looking for as well. Plus, it shows you just what you gain in the draft (in front and behind) and it helps you know if you exited a turn before a straight better (speed at end of straight)

Pulling higher G's through a corner will not tell you if you went through a turn optimally or not, only speed at the end of the straight tells you that.

Also, if you do race on any NASCAR tracks (where you use part of the oval) it will tell you where on the oval you are scrubbing speed.

[kevin willmorth]

Actually, you do want wheel speed too. It is needed to assess what you are looking for as well. Plus, it shows you just what you gain in the draft (in front and behind) and it helps you know if you exited a turn before a straight better (speed at end of straight)

Pulling higher G's through a corner will not tell you if you went through a turn optimally or not, only speed at the end of the straight tells you that.

Also, if you do race on any NASCAR tracks (where you use part of the oval) it will tell you where on the oval you are scrubbing speed.

I get car speed from GPS data. We tested this in our street car against a rally computer I've had for years. I was dubious about GPS, but have since been amazed at how accurate the thing is - so my concerns over using it as the data point went away. I do agree with your points, just not necessarily where the data comes from I guess - so mispoke about my data priorities... Vehicle speed is definitely a key factor in performance assessment and driver performance.