Data-Logging

My missus hasn't got a clue what to buy me for Xmas so i was thinking along the lines of getting a data logger for the car. Do you think it is really worth it for club racing. Opinions please.

i dont do circuit racing, but hills/sprints, and am but a lowly clubman, but i find it useful. its usually more informative after the days runs to be honest, where you combine the data with photos and videos for the runs too, to understand why the car was faster or slower at certain points. can act like a 'spy in the cab' if you like. Not being of F1 standards, im often convinced that holding a gear over the line rather than shifting up, or taking a certain line into a corner is the best way, and have often found that the data shows im wrong. on the hills a few tenths is top to bottom in a class sometimes so certainly helped me.
bit of a ball ache to get your head around to start with, working out what information is relevent and whats not, but informative on the long evenings between meetings trying to work out a handling issue or where the drivers interference is causing trouble ;)

bit of a ball ache to get your head around to start with,

very true - but worth it. Id be interested in you system of choice and reasons for it

Having just started driving a formula ford, that has a logger fitted i'm amazed by how easy it is to spot errors in driving style. Little points like knowing that your lifting mid corner or not red lining it before changeing gear.

The best on the market for the Clubman is a SPA, model. Also on the dash display you can set it to show if your current lap is quicker or slower than your fastest. Particulary useful to know if you try a different line or braking point.

Richard

im using a Racetechnology DL90. its now a discontinued logger so bought it brand new cheap from racetech from ebay (less than half price). does for me. have wheels speed sensors fitted, rpm logged and will add steering angle before next season

im using a Racetechnology DL90. its now a discontinued logger so bought it brand new cheap from racetech from ebay (less than half price). does for me. have wheels speed sensors fitted, rpm logged and will add steering angle before next season

Thats the one i was looking at

does`it`show`angle`of`attack`from`mercs?

also got throttle position using ecu TPS sensor. i dont bother with a brake pressure sensor because you can use the inbuilt G sensor to see when you are on the brakes

If you really use the data logging (rather than just having it sit in a car) it can prove invaluable.

The most important things to decide are -

- Budget.
- Current requirements.
- Future requirements.

For most people just starting out, you only need RPM, wheel speed, oil temperature and pressure, water temperature and fuel pressure (if applicable). This gives you a hell of a lot of data to take in.

The temperatures and pressures are probably the most important to a clubman as they tell you a lot about the health of your engine, or otherwise! It is quite common to be able to spot a slowly worsening problem and rectify it BEFORE it suddenly becomes really expensive.

Let us know your budget and I am sure all will be happy to give their opinions on the best system.

What ever system you are thinking of getting, make sure you give the analysis software a good try out before hand. Not all are equal. As a minimum pretend you have just finished a session and see how "user-friendly" it is to get what you want out, including zooming, panning, different graphs, setting sectors, comparing runs etc etc.

Based on that and your budget make an informed choice.

Also its probably worth buying and reading http://www.amazon.co.uk/Competition-Car-Data-Logging-H653/dp/1859606539
Its a good introduction and takes you through choosing and buying and using.

Also its probably worth buying and reading http://www.amazon.co.uk/Competition-Car-Data-Logging-H653/dp/1859606539
Its a good introduction and takes you through choosing and buying and using.

I also recommend the above book. It is aimed at a non-computer proficient beginners level and is so easy to understand even my Dad has read it!

I also recommend the above book. It is aimed at a non-computer proficient beginners level and is so easy to understand even my Dad has read it!
yep i got it too :)

And there's a new one coming out in the summer of 2008
http://www.amazon.co.uk/Competition-Data-Logging-Manual-Speedpro/dp/184584162X

also got throttle position using ecu TPS sensor. i dont bother with a brake pressure sensor because you can use the inbuilt G sensor to see when you are on the brakes

The G sensor will show you when you're decelerating not if you're on the brakes or not.

As the Hamster was shown when he drove the Renault F1 car on Top Gear you need to get straight on the brakes as soon as you lift the throttle not half a second later.

If you're sure you're this quick on the brakes you don't need a pressure sensor.

Edit: even if you're that quick on the brakes you won't be able to analyse if you're braking against part throttle to alter the attitude of the car.

Ben

Theres some good stuff here : http://www.jameshakewill.com/tech.htm in respect to calculating a brake channel

We ran a system with a balance bar braking system using 2 brake pressure sensors , one for each brake circuit, and 4 wheel speed sensors , once you get a hang of it then you can set brake balance up very accurately and understand what is happening at what point .

The G sensor will show you when you're decelerating not if you're on the brakes or not.

As the Hamster was shown when he drove the Renault F1 car on Top Gear you need to get straight on the brakes as soon as you lift the throttle not half a second later.

If you're sure you're this quick on the brakes you don't need a pressure sensor.

Edit: even if you're that quick on the brakes you won't be able to analyse if you're braking against part throttle to alter the attitude of the car.

Ben
interesting. to be fair dont think im accurate enough in my driving and defo not good enough yet with the data to need to be that accurate. currently the TPS goes to idle and then the G sensor sees a big deceleration spike (braking). i will look at adding something over the winter to see if that clarifies things further. whats best, brake pressure sensor or brake pedal position sensor? i followed the advice of not bothering with a brake sensor from the McBeath book. to be honest, the data is interesting and helps make changes to the car (hillclimber), but i think certain people have more interest/aptitude for it than others. im more than welder, hammer and spanners type ;)
cheers for the help, Craig

I suspect http://www.jameshakewill.com/brake-trace.pdf is adequate for your needs, more importantly its free as long as your analysis software can do math channels and you have G sensors.

I used to log the 12v from the brake light switch but found it didn't really offer much, I suppose you could use it as a "gating" channel...

interesting. to be fair dont think im accurate enough in my driving and defo not good enough yet with the data to need to be that accurate. currently the TPS goes to idle and then the G sensor sees a big deceleration spike (braking). i will look at adding something over the winter to see if that clarifies things further. whats best, brake pressure sensor or brake pedal position sensor? i followed the advice of not bothering with a brake sensor from the McBeath book. to be honest, the data is interesting and helps make changes to the car (hillclimber), but i think certain people have more interest/aptitude for it than others. im more than welder, hammer and spanners type ;)
cheers for the help, Craig

Personally I would use two pressure sensors to get front and rear line pressure or a single sensor on the front circuit. A pedal position sensor won't tell you how hard you're pressing the pedal and it's the pressure acting on the caliper pistons that really determine your brake force. Plus the deflections should be minute if the system's properly bled. I suspect drivers modulate on the basis of force not displacement so pressure is a more meaningful measure.

Ben

Decided to go with the Race Technology DL90 as a start to see how i go. They are selling them on E-Bay for £230. It is GPS and has a digital input and 2 anologue. Will put a tps on carbs and try to adapt one for brake peddle as to monitor time on brakes ans how much i am pressing the peddle. That should be enough to tie me in knots for the moment. Then maybe go for the Dash 2 and DL1

Personally I would use two pressure sensors to get front and rear line pressure or a single sensor on the front circuit. A pedal position sensor won't tell you how hard you're pressing the pedal and it's the pressure acting on the caliper pistons that really determine your brake force. Plus the deflections should be minute if the system's properly bled. I suspect drivers modulate on the basis of force not displacement so pressure is a more meaningful measure.

Ben
thanks, that explains it well :)