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OK! I give up. I have been searching this site, the DSR forum, and Amazon... to no avail. I even tried calling Ellen (I hope Ellen isn't shoveling out of a mudslide, all I get is her machine.)
Somewhere, I think recently, somebody posted what they thought was the best beginners data acquisition book to purchase. Hum... maybe I read it in Grassroots... Damn, the memory is the first to go.
Please post it again... here. So I can buy it.
Data Power by Buddy Fey?
Hey Frog. Ellen just called to tell me they finished hooking up my AIM system to my Zetec so she must be home [1:30pm Pacific] ! She lives in the flats so no mud slide,just soggy lawns. ;)
I remember the same thread. I believe it was in the FF section. Data Power is out of print but I found some used ones on Amazon in the $150 range. Ouch!
Amazon has Frey's book for $2,473.74! A bit rich for my taste.
I have found that the relatively new "Competition Car Data Logging" book by Simon McBeath is quite good. Though the more I learn, the less useful the book is. Find THE forum, and read through the archives. Check the forum daily, to catch the once-a-week post.
http://pub6.ezboard.com/fs2racingfrm4
Mostly populated by dumb schmucks like me scratching our heads and guessing, but a dozen folks who work for race car teams doing it full time. . . Few posts there, but some answered by pages of detailed tech and physics.
And experience. Expect 6 months or more before you discover anything useful. . . ("Oh, I'm just looking at 0 to 60 and g's." Hah!) Though the light bulbs will start flashing immediately.
But the real solution is an expert. There are several top guns for hire. Most are hard to find. . . Mine (don't ask! mine! mine!) has taught me more than the book, the installer, the seller, the installer's expert, and 6 months experience. And in one or two conversations. . .
Lots of sensors and channels, I hope? You will become quite greedy quite quickly, and learn that there are some weird things that are very important.
I have "Data Power" by Buddy Fey. It's a very good introductory book, but DA has come a long way since it was published. If I were just starting with DA now, I'd take one of the many seminars being given now and have them point me in the direction of literature.
Hey! I've got a copy that I'd gladly sell ya for half that!:DQuote:
Originally Posted by Purple Frog
Hey guys,
It was funny to be reading along and discover that the wherabouts of my bride were in question. She was out shopping for her new 340 HP hotrod (Audi S4 Avant).
Anyhow, Data Power is now long out of print. The rights have reverted back to the author, Buddy Fey, and he was busy with his own race engineering projects, but he has said he's going to update the book. The Simon McBeath book is good if you aren't quite sure how you would learn anything from a data system. He demonstrates analyzing just the RPM trace to help figure out what was happening on a hillclimp course.
I agree that there has been a lot of good discussion on our Data Acquisition forum,
http://p081.ezboard.com/fs2racingfrm4 To see more discussion all you have to do is participate and ask questions. I would love to see people making screen shots of their data (or posting links to data files that can be downloaded), and having others take a look at analyzing it.
I am very surprised how little discussion there is about data acquisition. Maybe it is because no one wants to publicly show how ignorant or stupid they might be. At least that’s my excuse. I find it the most fascinating part of our car. I believe we have shaved seconds off our times last year by using it. Having someone who knows what he's looking at is extremely helpful. We had Rob from Liberty Engineering helping us out and he was invaluable. Thanks again Rob. I have read the Simon McBeath book and didn't find it too helpful. Maybe it is over my head. We find that when we make changes in the setup or driving style it shows up in the form of data. Pretty cool. Keith is also getting better at looking at the data and figuring out how to us it. We are just scratching the surface. Can't wait for this year. Current systems now cost less than a couple sets of tires. I would recommend them to everyone. Isn't that right Dave?
Dale,
Maybe you answered you own question. If you truly shave seconds off (and I believe you) by have data aquisition, then no one wants to share their competitive advantage with us by sharing data aquisition secrets.
Between shocks and data, no driver should ever get bored with this sport!
Secrets! Someone has secrets? I'm crushed. :(
I shaved seconds off by following Treat after he got his DA setup, and it didn't cost me a cent. :~)
(Thanks Nancy!!!)
This is not a criticism of my all time favorite site, but I did like it better when we had a separate section for electronics. ;) For years I didn't have to read anything posted in that section, now I would probably read everything.
I can admit complete stupidity in the area, so the next few month will be a case-in-study of a rapid learning curve. Fortunately Ellen has been a great help so far.
I worked for a few years besides Duane from CDS, so I do know it can be a powerful tool. I also know it can be a powerful distraction. To keep it from distracting me, I assigned the whole deal to my brother-in-law. If only I had the massive computer of a brain that DaveW has and the millions of racing miles, I wouldn't need DA.
So maybe I'll keep notes over the next few months of learning and write "Data Acquisition for Dummies" :)
Just a test to see if I can post a data sheet. This could be fun Froggie.
I don't know if 600 x 400 is going to be readable. I'll try something else later. Need to consult with my guru sons. I could be dangerous.
Looks like my EKG...
Dale,
Now that you proved to everybody that we can do what Ferguson wants, how are the rest of us going to learn how to post them? I'm so low-tech I'd have to print them and FAX them to you. ;)
Ferguson is probably going to wish we would post them on only one site. Every night after work he is going to have to cruise through 8 different sites looking to see how bad we've screwed up our systems. :)
Wasn't that the week I ran the race stuck in 3rd gear ? :o
I do know one thing, DA does not lie! At first I showed it proudly to my wife but the POS system started showing all my mistakes. Just like my in car video last year showed me missing all the apexes... DOH!
Greg has one of the best pieces of advice just before we go out to do batlle: "Just drive!"
I would be interested in a new topic area on DA. Until then, here;s my first real question to you guys that don't keep secrets:
When looking at the lateral G chart, if all of the G peaks are the same, say 1.6G's, are you driving the car to it's limit? To ask it another way, should the goal be to get the maximum g reading in every corner to be close to the same or are higher g's achievable in some corners?
I am able to see Dale's trace. It would be better if saved at the native resolution of the screen, and with no jpeg compression applied. From looking at just that trace which has only RPM & Speed, I would have a few questions, and would want to move the cursor in the data to get the answer.
- It looks like the top gear might be too tall. What is the maximum RPM pulled on the straight?
- The shape of the speed trace in the turns looks pretty good. For most slower/tighter corners, you like to see a very short time at minimum speed, then full acceleration from that point. The signs of trail braking (or tire scrupping) are the reduced slope of the speed trace approaching the minium speed.
- I'm guessing the wheel speed sensor is on a rear wheel. I think I noticed slight signs of wheel spin following the minium speed in some corners (wheelspin looks like a slightly higher slope to the speed trace, that will be followed by a drop back shortly after the corner exit. I would move the cursor over this area looking for a sudden 2+ mph change.
Data systems answer questions -- were they any questions from that session? Temps, Gears, TopSpeed/power are common ones. Was there any particular section of the track that was presenting difficulties?
Similar corners should have similar G peaks. Of course it's possible to be far from the limit (but consistent!), however it's likely that you will be better in one corner than the others unless you really are at the limit. Eventually you bulid up knowledge about what maximum G is expected for your car in a specific type of corner, so it's easier to identify places where either the driver, equipment or setup don't allow you to reach the same limit.Quote:
Originally Posted by T.A. Treat
When looking at the peaks of the G-trace, you first want to compare corners in the same speed range. For cars with downforce (like FC, FS), you would expect to see higher G forces in faster corners. If you have two 95-100 MPH corners (like T1 and T13 at Mid-Ohio), you should be able to see the same peak G's.
Remember, banking and hills may positively or negatively affect the expected G's, so make sure that your corners are really similar. Now, if the G's aren't the same between similar speed corners, you've discovered an opportunity to improve -- the questions becomes -- what needs adjusting - driver or setup? (we presume the equipment was the same the whole lap!).
We may be able to determine something about the line from the shape of the G-graph (and speed trace) in those corners, or maybe we'll just head back to the track to test some changes (driver technique, line, or perhaps car setup: shocks, alignment or wing settings) -- we know how to measure the results we're looking for.
Guys,
Please, pleae keep this going!
I got a data system early in my driving, .. and still can't use the thing.
I know some basic stuff, .. but am really at a loss at how to benifit from it.
While sitting in the Formula Car party bus at Sebring, .. I showed Marc Miller some data, ..
he started going, "oh, you did this here, .. oh, under steer, . yep look at that"
and Im like, .. "look at what", .. "where do you see that, .. Rob , . gimmie another beer"
I too would LOVE to have a data coach to at least get me the basics, ..
Curtis
I'm considering a data system like one of the AIM units. I'm afraid that I too, like Curtis, will only be scratching the surface. Maybe there is an opportunity here for someone with experience to offer a class/seminar. Possibly a manufacturer or a vendor could step up. It would go a long way towards promoting their brand to our community. Class can be in person, or maybe on video/dvd, to make it accessible to all.
Just a suggestion...
Dale, Although I've never raced there, is that from Mid-Ohio? From looking at the data there is one long straight and a bunch of technical stuff. And turn 1 comes quickly after the pit straight which would explain the speed getting scrubbed off right after passing the beacon. Just curious.
Yes, that's definitely Mid-Ohio club-course.
You can tell that Dave has looked at these before.
David,
I'm guessing the reason you questioned 4th gear as being too high (the graph section after 4) was that the slope sort of flattened out and he didn't hit redline by the braking zone?
I'm thinking that some of those things I've learned to sense over time just through the seat of my pants. I looked back at my track notes and see where I've noted wheelspin and trail braking, etc.
But the g thing is interesting. As an old guy I'm thinking I'm giving up the time either by over braking, and sometimes turning in too early. Will analyzing that require a steering trace, and a graph of somebody doing it correctly to overlay?
I can see a lot of questions coming. :)
With the way we currently have upload attachements set up, you should be able to send fairly large file sizes to the post. If the files seems to be too big without editing, let me know, ad we'll up the size allowed in the posts.
d
Doug increased the attachment file size so the data will be easier to read.
What I saw was that the peak in 4th gear was significantly below the peak in the other gears. With the larger (thanks Dale!) graph, you can see that 6700 RPM or so was the 4th gear peak, while shifting in other gears was done at 6900+. That's enough difference that you could put a shorter gear in -- or you could trim out the car allowing the car to go faster and thus need the RPMs. Judging from the 100mph minimum speed in T1 - reducing downforce is not going to help driver confidence.Quote:
Originally Posted by Purple Frog
Now that we know this is Mid Ohio, we know from experience that the best drivers are carrying a minimum speed of 105ish in T1 (our no-wing S2's do 103ish for guys 1 second off the pace). So finding a way to carry more speed there will probably be the single largest time saver on the lap. We might want to look at a G-trace to see what we can figure out from the line taken. (See more questions...)
Over braking shows up as a minimum speed that is too low -- often you will be on the throttle right at the peak G's -- if the car is at the limit cornering (i.e. you slowed the minimum amount necessary to make the corner), you will not be able to apply power until the G's have reduced slightly from their peaks. If you have full-throttle and peak-G's at the same time you are below the potential limit of the car.Quote:
Originally Posted by Purple Frog
Your seat of the pants (biometric data acquisition system) told you were going to slow - so you went to the throttle to correct the situation.
That is one reason I love the corner minimum speed feature found in Pi (and possible in Motec) system. This feature remembers the minimum speed through a corner, and displays it until the next corner. You can get to the exit of a corner and glance down to see how close to your "target" you were. That helps you decide how big a change to make the next lap. For me, this is really helpful for the high-speed corners, like T1 at Mid Ohio, or T10 at Sears Point.
As for turning in early -- this usually means that you will early apex the corner. This can be seen on a G-Trace as a rising G's (early turn in means a larger radius and lower Gs-- that's why it's more comfortable) through the corner. But I bet you've driven behind plenty of fast guys, and you are pretty close to running the ideal line -- the difference is probably the speed they are carrying from the moment they start to brake, until the corner exit -- just 1 or 2 mph will make quite a difference, and the funny thing is it doesn't seem like you are losing in the corner -- it's always the following straight :)
This reminds me -- a great section on comparing two data traces looking for performance gains is in the Carl Lopez book "Going Faster! ..."
Was out of town for a few days and not able to respond till now. Rick Hiland of RIC RACING and I are holding a basic DATA ACQUISITION seminar on Sunday Feb. 6th. at his shop in Bow, NH. (just outside of Concord, NH). It will be full day of reviewing the various systems, helping you to determine the system for you, and how to interpret the basic data. This is a hands on seminar where we review installation, set-up, etc.
You notice I say BASIC seminar. Asking questions in this forum on data acquisition are somewhat like asking what computer I should buy, what software I should have and how do I use it once I have it. Like so many other areas of our lives, we tend to look for more and more data, as though volumes of data were an end unto themselves. Not true. Knowing what data is the most useful for solving your particular issues is the critical question.
Also, realizing that you should have a dedicated lap top at the track (not trying to use the one from the office), having the time to analyze the data, etc., etc., is something new drivers often don't take into account.
Email me if you would like further details on this seminar.
Don Denomme
catdon2@worldnet.att.net
If your max rpm in 4th was 6700 rpm and the shift point of the other gears was 6900 rpm, that would be about right in accordance with QuickSilver. In the how to treat an engine data sheet they gave us after a rebuild, they recommended, as a general rule, a max rpm in 4th gear of 6700 without drafting and using 6800 rpm as a shift point for the other three gears. Note that the 4th gear rpm is with no draft, as drafting will help you to go faster and hence achieve a higher rpm. They also stated that this can vary at certain circuits. Using their advice has worked well for us and we set our shift lights accordingly.
OK - I have a more basic DA question - here's the background:
I am running an EVO3 system on a F500. Currently, I have the following sensors in use:
RPM
Wheelspeed (rear)
Water Temp
EGT(2)
Long & lateral Gs
Ambient temp (logger temp)
I have (2) available channels; one is speed-only (pulse input), the other is analog. If I assume that I can tune my engine with a single EGT (should be OK once I get it properly baselined), that leaves (2) analog available. With the RPM and rear speed, I have my transmission ratio; since F500 runs a solid rear axle, that's everything needed for the drivetrain (could do tranny temp for efficiency, but I'm more worried about driver tuning for 2005).
Now here's the question: What additional sensors would be most useful for driver training? Given that I could add steering, brake, throttle, front wheelspeed(s), etc., where is the most relevant information to be found? I'm pretty good with the electronics and software side of this stuff (my day gig is industrial metering & data acquisition), but I'm just getting my hands around how to use it in this application.
Thanks in advance,
Marshall Mauney
Steel Cities Region
F500 #64
I'm not at all fmailiar with the EVO3, but if it were me I'd add steering and throttle. If the software lets you do it, you can do some clever x-y plots with steering and lat G's (thanks Satchell!) to give you some indication of understeer and oversteer. I also like to create a speed sensitive steering channel (per the Fey book) and overlay that with the lat G graph to pick apart US and OS issues. Also, per Fey's book, (not sure how this applies to an F500) it IS helpful to see how much the lat g's have fallen before you get to full throttle. Like Fey says, in general, if you can get back to full throttle before lat g's fall to 90% of that corner's peak g's, the car's hooked up.
Not sure if anyone saw this:
http://www.race-cars.com/partbd/messages/11414.htm