oldtimer

Hi all , have just got a Race Technology DL1 data logger to use in my Porsche 964 trackcar. Have only use it once on circuit ( Castle Combe UK )

Obviously I am still learning how to use the analysis software , but I wanted some guide numbers to check against what system tells me.

The big surprise is that lateral acceleration ( measured as g ) in corners shows about 1g ie +1 to -1 depending on turn direction , which seems about right , and longitudinal acceleration shows approx -1g for braking , again seems credible...but only 0.25g for acceleration.

Not sure about the 0.25g figure as the 0-60 time of this model is about 6 secs ( bit less) which works out around 0.5g in acceleration terms according to my 67 year old's maths.....

If 0.25 is right - and its only half the 0.5g that should be available - then I obviously need a heavier right foot ??? Anyone got any comparable data ( car is 1200kg and 300 bhp)

ProCoach

Your conclusions are all correct!

(Race Technology DL1 user since 2002)

Matt Romanowski

But wouldn't you only see that .5G when you are going from a stop to 60 mph? As you go faster, the accelleration rate goes down, no?

ProCoach

^^This^^

0.2-0.3 is average range of "mid-speed" (100 km/h-185 km/h) and also, surprisingly, -0.2 is average for an upper RPM range (>4500-5000 rpm) "lift" off the throttle.

I've seen very few (and almost no Production) cars register more than a moment of 0.4+ positive long_G, and usually at speeds below 50 mph in a tall first or nominal 2nd gear.

Even the quickest cars tail off their acceleration rapidly as the speeds and cDrag increase. Something about hitting a "wall of air."

oldtimer

Thanks guys , that explains it. I am hitting 60 quite quick and then maxxing around 115 mph and slowing to around 50mph when pulling 1g lateral acceleration. So will be in the range 70-85mph most of the time with regards to a datum for acceleration.

I will however be pushing the loud pedal louder as DL1 gives you a simulated lap time that relates to the car parameters and I am a long way from that. My best lap around 1min 28 sec, a 964 cup car on slicks with a skilled driver same day was best 1 min 20 sec ....so sort of in same galaxy !!

alexjc4

A blast from the past I know but how are you getting on with the DL1 after a year?

I'm in the market for some electric trickery for the Skyline and the Race Technology DL1 VIDEO4 is on the radar.

oldtimer

Hi Alex, after a year I am still struggling to understand the user interface and the way the software creates all kinds of semi - processed data files and stores 'em in different places on your hard drive. You young uns have a better chance of getting to grips with it .
The system does not integrate with third party video very well . My original version wanted you to pay an extra £100 for a license to use video other than VIDEO4 . They have updated the s/w to take account of go - pro now but I have not tried it .
I did manage a manual synchronisation of a spycam video with the data analysis results after converting it from .avi to VIDEO4 format but it was pretty labour intensive......not something I would want to do as routine.

Anyway your question is timely as I am just getting the system lined up for Castle Combe on 24 May which will be the first real trackday for the orange 964 this year , not counting the disaster of subzero 'Spa-in-the-snow' that we both experienced back in March

alexjc4

Great info thanks

I few knowledgeable people have pointed me towards the Race Technology stuff. One of the selling points is the attentive UK support so you may be able to get some help. And there's a reasonable active forum too: http://www.race-technology.com/forum/index.php

The ability to quickly (and without frying my brain) combine the video and the overlay data feels like the key to me. Obviously it's possible to interpret the data without the video but would make it much more immediate and intuitive when they are combined. Ideally I want to just take the memory card out after a run and plug it into the laptop and watch it back without fussing in software and waiting for it to render.

I think Race Technology, AiM, Racelogic, Traqmate etc are all trying to make their products easy to use as they expand their market away from pure pro racer usage and are coming out with simpler combined solutions.

Racelogic VBOX Lite - one box, video and data overlay recorded at the same time.
http://www.racelogic.co.uk/Store/pro...AN-channels%29

Race Technology VIDEO4 - latest version does combined video and data (the early versions just did video and you needed to combine with the DL1). Not quite as powerful data logging as the DL1.
http://www.race-technology.com/video...s_2_31008.html

AiM Smartycam - very simple looking, but to go beyond GPS, G Sensor data you have to use CAN bus data - which we don't have, the two above have optional boxes for other inputs you can splice into the loom or wire up to additional sensors.
http://www.racedatasystems.com/aim-s...smartycam.html

Traqmate HD - looks like the video and data are setup to be easy to synch but are only actually combined on your PC after the fact.
http://store.traqmate.com/Traqmate-w...ideo-s/255.htm

I think there's no one yet offering a really slick solution with proper HD 1080p video, some offer a Go-Pro plugin but you end up combining the video and data by hand in some way. They are all basically "DVD" quality by which they mean PAL or NTSC. I think proper HD is in development but how long it will take I don't know and I'm not going to wait for it - though of course as soon as I fork out for a system someone will bring an HD system out.

ProCoach

Excellent post! Could have written it myself!

Again, for driver development, HD is overrated, in my opinion. But you are correct that several suppliers are working on this.

AiM SmartyCam HD is imminent. Video VBOX has announced availability of a single cam VVBL HD and like all things tech, the quality, power and ease of use will all get better with time. Also, at reduced cost.

Ease of use is the number one criteria my customers require. I sell all of these systems above in the US and see a marked rise in VVBL and SmartyCam sales for that reason.

Still, the ability to put together a GoPro HD (or even better, Replay XD 1080) theoretical best video composite lap is Traqmates best feature.

Powerful tools, all of these...

924RACR

Or take your data and video and merge them together after the fact, using RaceRender.

Works great, I love it, in fact I'll even use it for editing video without data. I have multiple racecars, data systems, and cameras, and it works for everything.

Done with a DL1 and video from a ContourHD:
https://vimeo.com/25741276

Matt Romanowski

I'm with Peter and Alex - it needs to be done realtime with maximum ease of use. Once you go to a system that automatically puts the data on the video, you'll never go back. For data to be a tool for the amatuer driver, it has to be easy and quick.

Also remember that for driver development, the SmartyCam or Video VBox Lite will give you everything you need. For the SmartyCam, add an RPM Bridge and you are set.

ProCoach

None of my customers want to do post processing. Very few people I've sold data systems to use RaceRender, TrackVision or Dashware to overlay exported .csv files to video, let alone PIP editing. Just my .02