Gary Z

I would like to start a discussion of track data recording and analysis. I am somewhat surprised that this isn’t a routine topic here. I record almost every run using HPTuners Scanner software on my laptop. I typically record engine speed, vehicle speed, throttle position, ignition timing, and air/fuel via my Innovate LM-1 wideband. I keep the number of parameters low in order to maximize the sample rate. I use Microsoft Excel for data display and analysis. Within Excel, I always create an xy scatter chart with elapsed time as the x-axis and engine speed as the y-axis. Other parameters are displayed on the secondary y-axis. I am not an Excel expert and I create my charts manually. This is fairly time-consuming but it is also very flexible and I have not attempted to automate chart-creation via templates. I have found this data to be very helpful, especially for evolving my launch technique. I know my launch rpm exactly and am able to create very good estimates of wheelspin. My charts have exposed an exhaust leak and a slipping clutch. I know when high IAT pulls timing. I have attached a typical worksheet. I chose this particular run, not just because it was my quickest so far, but more because my granny-shifting was less embarrassing than usual.

Wnts2Go10O

iTrader: (12)

hmm, what about somehow going a step further and doing it by gear? maybe thats wht the scatter chart is for. i would think you would base it more off of vehicle speed vs et

mrdragster1970

Wait until you have a car with a computech or racepak, I still have a headache from reading all the info. I think you're being smart, I'm a big big fan of data recorders. I also caught a few things, a hole real lean and a valve spring going. Good luck.

Gary Z

Mrdragster mentions a significant problem – too much data. I have a good example of data reduction. When trying to discover effective launch conditions, you obviously need to know your engine speed. It is difficult to accurately control launch rpm but it will be precisely recorded. Taking just this one number (launch rpm), from each of a group of runs and plotting it against its resultant sixty time, can sometimes be interesting, as in the accompanying chart. This chart clearly shows that I need to launch near 6000 rpm if I want to consistently cut 1.6x sixtys. Since I don't have a scattershield, I've decided to be satisfied with 1.7s for now.

Magnus

iTrader: (4)

Gary, well done on recording your run's.. I do the same..

Just a tip, I save my logs as yy-mm-dd ## description.hpl, that way i can have all my logs for a particular vehicle in one folder and they are automatically all in order.

Gary Z

Thanks, I couldn't ask for a better endorsement.

z-ya

iTrader: (1)

Isn't it illeagal to have a computer hooked up to the car in nhra?

Magnus

iTrader: (4)

With HP Tuners, and our MPVI Pro interface, in many cases you can log over an hour of data by just having the interface and OBD cable in the car, no need for a laptop.

z-ya

iTrader: (1)

I guess that solves the problem

mrdragster1970

Data recorders are not computers, they do not control any function, and they are legal in all the fast cars, not sure if there is a et rule, class rule or no rule. Obviously check your car against the rule book before wasting a ton of money.

RedHardSupra

iTrader: (1)

how about then you make it automatic in HPT to used the date, and some unique identifier, it's a PITA to do it every time yourself?

Ben R

www.racepak.com

Far superior to anything else available for serious data recording.

Gary Z

Racepak is intended for professional racers. I’m trying to encourage more novices like myself to take advantage of systems they probably already own. Even if you don’t have tuning software, simple OBD scanning software, like Autotap, is very cheap. I just remembered another benefit of analyzing recorded runs – the data helps you improve your driving. Maybe it’s not so important for those with automatic transmissions.

kp

iTrader: (34)

1.5 years of 'black box' logs here, mostly every pass except I dont log when I'm 'really' racing. Dont really need to put it in spreadsheets since I can glance at the graph and see whats going on in a few seconds. I'm using the internal logger in the BS3 now but its pretty much the same except it can only log one run at a time and you have to download it right away where the EFIlive logger could do like 50 and store all of them.

Either way its the only way to see whats going on and why, cant see racing one of these without logging it since the hardware is already there and great software is so readily available plus you dont even need a laptop in the car.