[Type123]

Hello everyone,

I've done searching around for a very basic and cheap race car data logger and I've bumped into a couple of Arduino based loggers. Does anyone have any experience with these? Is there one You would recommend and / or have used also?

Also as my car is from the '50s there's no OBD port to tap in

I'm not trying to have a tens of inputs, just pretty basic stuff like:

*Rear end squat at launch (for both sides)

*Front end height at launch / end

(both of the above with ultrasonic distance sensors?)

*Wheel spin

*RPM

*Speed

It would be beneficial if data points can be compared to real time i.e. when I push a button to start data logging time starts to run and above inputs can be plotted against time. Data should be stored into an SD card in *.csv format so that could be manipulated with Excel / LibreCalc.

I think I don't need gear as it would be 1/4 mile and I can figure out the shifting points from RPM change.

Any hints, tips, recommendations etc. more than warmly welcome. I'm not planning to tackle this *now* as I have other things to worry with my car at this point and it's more a "nice-to-have" than "must" as it's a street car 99.99% of the time - however this would be a nice little project for the winter. Perhaps

[cx500tc]

Getting suspension heights will be fun.

I don't have a solution, so to speak, but were I to take a go at this, I'd choose a suitable MCU first. Then, wouldn't worry so much about when to start and end logging- I'd have an "arming" switch to get things ready, then accelerometer that would trigger actual logging.

Suspension.
You mention ultrasonic... so maybe transducers in the fenders pointing at the tires or ground?
Might be able to link the trailing arms' ends to rods to potentiometers.

Wheel spin will be fun as you would need speed sensors at all 4 corners. If you don't expect to lift the fronts off the ground, those could serve as a reference for the rears, and after compensating for tire size difference, it wouldn't be too hard to detect a rear tire out accelerating the fronts, or the other rear tire. Such sensors could be something as simple as a VR sensing the flutes on the brake drums... if yours has them.

[zomesi]

Getting suspension heights will be fun.

I don't have a solution, so to speak, but were I to take a go at this, I'd choose a suitable MCU first. Then, wouldn't worry so much about when to start and end logging- I'd have an "arming" switch to get things ready, then accelerometer that would trigger actual logging.

Suspension.
You mention ultrasonic... so maybe transducers in the fenders pointing at the tires or ground?
Might be able to link the trailing arms' ends to rods to potentiometers.

Wheel spin will be fun as you would need speed sensors at all 4 corners. If you don't expect to lift the fronts off the ground, those could serve as a reference for the rears, and after compensating for tire size difference, it wouldn't be too hard to detect a rear tire out accelerating the fronts, or the other rear tire. Such sensors could be something as simple as a VR sensing the flutes on the brake drums... if yours has them.

by the way do you have any thought about something that in drifting can analyze drifting angle?any idea?

[androidcho]

One front and one rear accelerometers will do the job..

[cx500tc]

Getting suspension heights will be fun.

I don't have a solution, so to speak, but were I to take a go at this, I'd choose a suitable MCU first. Then, wouldn't worry so much about when to start and end logging- I'd have an "arming" switch to get things ready, then accelerometer that would trigger actual logging.

Suspension.
You mention ultrasonic... so maybe transducers in the fenders pointing at the tires or ground?
Might be able to link the trailing arms' ends to rods to potentiometers.

Wheel spin will be fun as you would need speed sensors at all 4 corners. If you don't expect to lift the fronts off the ground, those could serve as a reference for the rears, and after compensating for tire size difference, it wouldn't be too hard to detect a rear tire out accelerating the fronts, or the other rear tire. Such sensors could be something as simple as a VR sensing the flutes on the brake drums... if yours has them.

by the way do you have any thought about something that in drifting can analyze drifting angle?any idea?

Drifting angle? I assume you mean how far the rear hangs out from the front wheel steering angle?

That sounds a little difficult to figure since the drift is related to spinning tires, engine output and steering angle. One could theoretically go full lock on the steering and still have control based on how much power is applied to the rear. But I suppose, considering front and rear wheels' rotational speed, and steering angle may ... hmm....

An accelerometer at the front and rear may give you some sense of orientation, to the sides and fore/aft. Steering wheel angle could get you how far the wheels are turned. Relative wheel rotational velocity- front/left, front/right, rear/left and rear/right, combined with the steering angle and accelerometer may give some ideas... to get really accurate you would need some inertial position sensing so you could actually determine how much you have rotated in relation to ....

[androidcho]

Yeah, alot of math will go into this. Another idea is to use the ABS wheel sensors as long as some other sensors to determine if any of the wheels is slipping.

[cx500tc]

I suppose laser ranging could be used to place the vehicle within reference to the course, too.
But that assumes having hard, physical barricades around the arena.

[PSIG]

@Type123 - we already have RPMdot in Speeduino (which can give indicators by itself), so combined with a rear-wheel sensors would provide clutch slippage and amount of tire traction loss, even if front wheels are off the ground. The other suggestions for triggering and such are good ones. A piezo load sensor at each corner can give weight transfer readings. Potentiometers and encoders can provide swing-arm angles. The cheap accelerometer/gyro chips have a 'compass' in them for directional info. GPS for location on the track, speed, and so on. The more info you have, the easier it is to see what's going on. I would just search for Arduino projects that have used these previously for starting points.

David

Nine axis module (three-axis gyroscope + triaxial acceleration + triaxial magnetic field) online about $8US:

[jsantoro]

Possibly get some ride height sensors off an old Lincoln. They used these to adjust the air in the bags. Should have plenty of travel for what you want to do. Just plain old linear pots I think.

[PSIG]

Possibly get some ride height sensors off an old Lincoln. They used these to adjust the air in the bags. Should have plenty of travel for what you want to do. Just plain old linear pots I think.

+1, and many other 'luxury' car brands and models. Yet another great source idea Jim!

David