Racelogger - Lakeside Data

[MountainRunner]

Hi Guys,

We were testing my new RaceLogger project at Lakeside in the white Subaru Liberty. It was the first track test of the unit which was very exciting. We had the 5Hz GPS connected, lateral G / longitudinal G sensors, RPM, Throttle, Boost, Battery Volts and Water Temp connected.

The unit has the capability to take 10 analog channels, 2 rate channels, 2 digital channels, GPS and expansion to the Engine Monitor. We only connected a few of the channels for the first test. We also did only a rough calibration of the sensors for proof of concept. The logger records the data straight onto a USB Key so you can have as much memory as you want. You can log at rates upto 25Hz. It will also have a USB connection to a laptop. I will put up the full specs of the unit in another thread soon.

Here is Lap 3 of Pierce's session at Lakeside. The data has been graphed in EXCEL as I have not finished the data analysis software yet

Also some quick words about each trace. Once the data analysis software is ready a lot more info will be quickly available from the data including lap / lap comparisions, split times etc.

Plot of the Course. Not totally proportionally correct as trace is drawn in EXCEL. With a track map the lines taken by the driver would also be shown. This will be available shorlty.

Speed trace from the GPS. The absolute speed of the vehicle. Another speed trace connected to the drive train will also be setup, this will make wheel spin also obvious.

Engine RPM taken from Tacho output of ECU. The trace shows slight over-revs on gearchanges.

Lateral G Sensor. This trace is showing the cornering forces. When viewed with the throttle position traction loss can be easily seen. The peak cornering forces through sections can also be seen.

Longitudinal G Sensor. The accelerating and braking force of the car. YOu can see how the acceleration is upset by wheel spin as the driver lifts and re-applies the accelerator pedal.

Throttle Position. Taken from the ECU input. The throttle shows the driver battling with wheel spin / traction loss.

Gear Selection. Maths channel. RPM divided by Speed. Obvious wheel spin in 3rd gear (lowest on graph) with some still in 4th and non in 5th. The track was wet and the car has 200+rwkw. Most interesting is the build up of wheel spin between 40sec to 60sec. If you also look at the throttle trace you can see the driver lift to recover traction. you can also see a dip in the lateral G trace where the car stepped out.

Boost Pressure. Taken from ECU. The car is holding steady boost with no spikes etc.

Battery Volts. The voltage is dropping as RPM and Boost is increasing. The driver reports an occasional engine miss under power. The electrical load of the car was greatly increased with the upgrades but the alternator / battery left standard.

Water Temperature taken from ECU. You can see the coolant temperature rapidly rising under power. The temp at the end of the lap is much higher than at the end. The car is definately under-cooled for the track.

[GeeTR]

10 inputs, nice.

How are you guys positioning yourselves alongside racelogic?

What are the "rate" channels thankx

[MountainRunner]

10 x analog channel inputs are for sensors such as throttle position, G forces, temperatures, pressures etc.

2 x rate channel inputs are for pulsed channels such as RPM from the tacho and vehicle speed from the gearbox.

2 x Digital inputs can be used for any on / off signal. We put it on the clutch and brake pedals for a test.

1 x acknowledge button input for any alarms set. These can be viewed on EM Pro II if connected.

The 5Hz GPS gives track map, lap times, sector times, race lines etc.

The DataLink to my EM Pro II project (see other thread) expands the unit to log the additional 6 channels from that project and gives the display.

I will get the full specs posted up shortly.

With just a quick look at the Racelogic link you put up it appears to be a GPS logger. Split times, lap times etc. Nice package / screen and easy to use.

I've built my unit from the angle of doing race logging with the addition of all the GPS stuff. With the additional inputs required to do driver analysis, chassis and engine work. Thats the dream anyway

The sorts of inputs I see being added to the unit are:

Water Temp, Fuel Pressure, Rear Diff Temp, Brake Pedal, Oil Temp, Steering Angle, Front Diff Temp, Brake Pressure, Oil Pressure, Ambient Temp, Intake Temp, Longitudinal G, Wheel Speed, R.P.M., Throttle Pos, Boost, Gearbox Temp, Battery Volts, 4WD Torque Split, yaw rate, suspension channels etc etc. Each driver will have a different set of inputs that are important to them.

There will be data analysis software coming as well. I want to develop this system with the guys who are using it. All feedback from the user group will be taken on board. The data analysis software will be free and I would like to think it just keeps evolving with the feedback I get.

My position is I want to build the best logger I can for the best price I can.

All feedback is welcome.

[Duncan]

sure...my feedback is "Add Bluetooth"

Looking forward to getting this my car as soon as it is available

[MountainRunner]

Duncan, emailed you last night about an option for trialing Bluetooth on beta test logger. Let me know what you think.

We performed the final test I wanted to do on the prototype last night. Piggybacked the logger on a HALTECH and ensured there was no signal interference. All worked fine. So next step is the beta test units.

[Duncan]

Thanks mate, looking forward to getting it sorted