Data Logging in a 996.1 - How To
Discussion
If like me you track your car quite often then it's nice to have some data 
So here's a quick how to using an AIM Evo4 logger.
The Evo4 can be setup to take engine data from the K-Line on the OBD2 connector by configuring it for OBD2>ISO9141_2 which will give you:
- RPM
- Coolant Temperature
- Inlet Air Temperature
- Vehicle Speed
- MAF Sensor Output i.e. inducted air mass
- Throttle Position (DBW Body reported position)
On top of that from the Evo4 you'll also get:
- Battery Voltage
- Lateral G
- Longitudinal G
- Verticle G
- GPS Speed
- GPS Heading
- GPS Altitude
- GPS Gyro
Which gives you a basic but usable data set which is just about sufficent to do some useful stuff with for a club level driver.
You'll need to make three connections to the car wiring loom. Comms and Power. Comms is easy, the 996 OBD2 connector conforms to the standard OBD2 spec so K-Line is on pin 7:
The OBD2 connector also provides power and ground so if you don't want the logger permanently in the car then it's very easy to buy one of these:
And make yourself a cable up that will power up the logger and provide comms when you connect it to the OBD2 port. To do this you'd tie the EVO4 RPM Cable K-Line wire into Pin 7, the red wire from the Evo4 power spur into Pin 16 and the black wire into Pin 4.
Alternatively you can hard wire it, which I have done. For this you'll want an ignition switched power supply which you can pinch from the back of the cigarette lighter socket and comms from Pin 7 of the OBD2 connector, or rather the wire which feeds pin 7 on the rear of the connector. The OBD2 connector is in the PAS footwell on a RHD 996 and can be removed easily by dropping the flexible underdash cover by removing two plastic screw lock fasteners and then the three torx headed fasteners around the OBD2 connector, one on the right and two on the left. It can then be dropped down and the wiring loom to the connector accesed. The terminal numbers are marked on the back of the connector so it's easy to identify Pin 7. To splice the wire you can use whatever you are most comfortable with but please no scotchlocks! If needs be you can Posi-Tap it which does the same as a Scotchlock without the associated damage. Failing that cut, crimp and seal with adhesive heat shrink. Same for taking power from the back of the cigarette lighter.
The power and comms wires can then be run up the centre of the car (mind the hand brake assembly) and the logger mounted in the flip top storage bin:
To run the power and comms looms I removed the coin holder and drilled a 10mm hole through the curved section on the corner, this way if the logger is removed the coin holder can be refitted and hide the hole.
GPS reciever runs out the back under the hinge and under the removable cover at the rear of the centre console. It then runs under the carpet to the rear of the car and is velcro'd to the carpet under the rear screen so the GPS reciever gets a decent view of the sky.
The logger is then dual-locked to the side of the storage bin. USB offload cable can either be fitted as required or left wrapped up in the bin with the logger.
If you want oil pressure as well then you can either tap the standard oil pressure sensor or use a T-Piece under the standard sensor to allow fitment of a suitable "proper" 0-10bar pressue sensor like this:
And stick it into a spare analogue channel on the Evo4.
Easy as! Decent data on your 996 or 987 for under a grand.
So here's a quick how to using an AIM Evo4 logger.
The Evo4 can be setup to take engine data from the K-Line on the OBD2 connector by configuring it for OBD2>ISO9141_2 which will give you:
- RPM
- Coolant Temperature
- Inlet Air Temperature
- Vehicle Speed
- MAF Sensor Output i.e. inducted air mass
- Throttle Position (DBW Body reported position)
On top of that from the Evo4 you'll also get:
- Battery Voltage
- Lateral G
- Longitudinal G
- Verticle G
- GPS Speed
- GPS Heading
- GPS Altitude
- GPS Gyro
Which gives you a basic but usable data set which is just about sufficent to do some useful stuff with for a club level driver.
You'll need to make three connections to the car wiring loom. Comms and Power. Comms is easy, the 996 OBD2 connector conforms to the standard OBD2 spec so K-Line is on pin 7:
The OBD2 connector also provides power and ground so if you don't want the logger permanently in the car then it's very easy to buy one of these:
And make yourself a cable up that will power up the logger and provide comms when you connect it to the OBD2 port. To do this you'd tie the EVO4 RPM Cable K-Line wire into Pin 7, the red wire from the Evo4 power spur into Pin 16 and the black wire into Pin 4.
Alternatively you can hard wire it, which I have done. For this you'll want an ignition switched power supply which you can pinch from the back of the cigarette lighter socket and comms from Pin 7 of the OBD2 connector, or rather the wire which feeds pin 7 on the rear of the connector. The OBD2 connector is in the PAS footwell on a RHD 996 and can be removed easily by dropping the flexible underdash cover by removing two plastic screw lock fasteners and then the three torx headed fasteners around the OBD2 connector, one on the right and two on the left. It can then be dropped down and the wiring loom to the connector accesed. The terminal numbers are marked on the back of the connector so it's easy to identify Pin 7. To splice the wire you can use whatever you are most comfortable with but please no scotchlocks! If needs be you can Posi-Tap it which does the same as a Scotchlock without the associated damage. Failing that cut, crimp and seal with adhesive heat shrink. Same for taking power from the back of the cigarette lighter.
The power and comms wires can then be run up the centre of the car (mind the hand brake assembly) and the logger mounted in the flip top storage bin:
To run the power and comms looms I removed the coin holder and drilled a 10mm hole through the curved section on the corner, this way if the logger is removed the coin holder can be refitted and hide the hole.
GPS reciever runs out the back under the hinge and under the removable cover at the rear of the centre console. It then runs under the carpet to the rear of the car and is velcro'd to the carpet under the rear screen so the GPS reciever gets a decent view of the sky.
The logger is then dual-locked to the side of the storage bin. USB offload cable can either be fitted as required or left wrapped up in the bin with the logger.
If you want oil pressure as well then you can either tap the standard oil pressure sensor or use a T-Piece under the standard sensor to allow fitment of a suitable "proper" 0-10bar pressue sensor like this:
And stick it into a spare analogue channel on the Evo4.
Easy as! Decent data on your 996 or 987 for under a grand.
P.S. This will also work for a 997 with the same channels available. However on 997 there is much more data on the ECU CANBus available such as oil temp/pressure and seperate wheel speeds so it's much better to use that.
Connection for 997 can be made by splicing the CAN+ and CAN- wires at the ECU, they're on the 40way amp connector. Pins 36 and 37 are CAN+ and CAN- respectively - yellow/white and black/white twisted pair. Splice these to the CAN cable that came with the EVO 4 and configure the logger with Bosch>997GT3.
Doesn't matter if it's not a GT3 you'll still get Data on this profile.
Connection for 997 can be made by splicing the CAN+ and CAN- wires at the ECU, they're on the 40way amp connector. Pins 36 and 37 are CAN+ and CAN- respectively - yellow/white and black/white twisted pair. Splice these to the CAN cable that came with the EVO 4 and configure the logger with Bosch>997GT3.
Doesn't matter if it's not a GT3 you'll still get Data on this profile.
Thanks - that's interesting and comprehensive. I assume well suited for the more committed/club driver.
From an amateur track day user, I currently use a racelogic video vbox in my 996 GT3. In a way it's fairly simple. Fully integrated data and video.
I also use their CAN bus (induction?) clip on cable. This wraps around the CAN bus pair at the ECU without needing to splice any cables (and can be easily removed if moving cars, etc)
The data fields I get are:
Full GPS data : speed, gps map data
Timing : lap times, splits, fastest lap, etc (of course not interrogated during the day on a track day)
CAN bus data : engine revs, throttle position, apparently you can also get wheel speeds but I have not bothered so far
Video : integrated dual camera
I also use additional GoPros for improved image quality. The vbox unit simplifies the subsequent synching of an interesting lap.
I don't think the vbox unit has a G sensor...
The real limitation as you highlight is the limited data on the 996 CAN bus. I would have loved to have brake position data to see how hard the pedal is being pressed. I believe can be done as a bespoke exercise but then that is going away from amateur interest!
From an amateur track day user, I currently use a racelogic video vbox in my 996 GT3. In a way it's fairly simple. Fully integrated data and video.
I also use their CAN bus (induction?) clip on cable. This wraps around the CAN bus pair at the ECU without needing to splice any cables (and can be easily removed if moving cars, etc)
The data fields I get are:
Full GPS data : speed, gps map data
Timing : lap times, splits, fastest lap, etc (of course not interrogated during the day on a track day)
CAN bus data : engine revs, throttle position, apparently you can also get wheel speeds but I have not bothered so far
Video : integrated dual camera
I also use additional GoPros for improved image quality. The vbox unit simplifies the subsequent synching of an interesting lap.
I don't think the vbox unit has a G sensor...
The real limitation as you highlight is the limited data on the 996 CAN bus. I would have loved to have brake position data to see how hard the pedal is being pressed. I believe can be done as a bespoke exercise but then that is going away from amateur interest!
The Racelogic CAN patch lead is produced by a company called CANGO, specifically it's a CANGO-Click and will work with anything not just Racelogic stuff, it can be used with the above EVO4 logger for example to take the engine ECU CAN into the logger. You will need to provide power to it, either 5V or 12V depending on which version you plump for, 5V is useful because it can be powered from the 5V sensor rail on most loggers.
The GPS on the AIM unit above is very quick compared to something which is spec'd for timing and map so allows GPS Gyro etc. to be used to look at estimation of yaw rate etc. You can do video sync too if required.
The Racelogic stuff is great for a quick video and timing solution though and it's enough to look at lines etc. which is always, always useful!
If you want brake then there are two ways you can do it, either with a 0-160bar pressure sensor tee'd into the brake master cylinder or a linear pot on the pedal. The latter won't give you pressure but will show you pedal travel which if you scale as a 0-100% between off and maximum pedal compression will give you a decent idea of how much brake you are using without having to break into the brake hydraulics.
The GPS on the AIM unit above is very quick compared to something which is spec'd for timing and map so allows GPS Gyro etc. to be used to look at estimation of yaw rate etc. You can do video sync too if required.
The Racelogic stuff is great for a quick video and timing solution though and it's enough to look at lines etc. which is always, always useful!
If you want brake then there are two ways you can do it, either with a 0-160bar pressure sensor tee'd into the brake master cylinder or a linear pot on the pedal. The latter won't give you pressure but will show you pedal travel which if you scale as a 0-100% between off and maximum pedal compression will give you a decent idea of how much brake you are using without having to break into the brake hydraulics.
poppopbangbang said:
The Racelogic CAN patch lead is produced by a company called CANGO, specifically it's a CANGO-Click and will work with anything not just Racelogic stuff, it can be used with the above EVO4 logger for example to take the engine ECU CAN into the logger. You will need to provide power to it, either 5V or 12V depending on which version you plump for, 5V is useful because it can be powered from the 5V sensor rail on most loggers.
The GPS on the AIM unit above is very quick compared to something which is spec'd for timing and map so allows GPS Gyro etc. to be used to look at estimation of yaw rate etc. You can do video sync too if required.
The Racelogic stuff is great for a quick video and timing solution though and it's enough to look at lines etc. which is always, always useful!
If you want brake then there are two ways you can do it, either with a 0-160bar pressure sensor tee'd into the brake master cylinder or a linear pot on the pedal. The latter won't give you pressure but will show you pedal travel which if you scale as a 0-100% between off and maximum pedal compression will give you a decent idea of how much brake you are using without having to break into the brake hydraulics.
I agree, I do find the integrated solution easy - normally on a track day you tend to really be interested in the clearest/smoothest laps and therefore the vbox can zero in on that very quickly. Plus useful to compare lines/performance with a pal if both are using vbox units (I have a friend who does also in a 996 GT3).The GPS on the AIM unit above is very quick compared to something which is spec'd for timing and map so allows GPS Gyro etc. to be used to look at estimation of yaw rate etc. You can do video sync too if required.
The Racelogic stuff is great for a quick video and timing solution though and it's enough to look at lines etc. which is always, always useful!
If you want brake then there are two ways you can do it, either with a 0-160bar pressure sensor tee'd into the brake master cylinder or a linear pot on the pedal. The latter won't give you pressure but will show you pedal travel which if you scale as a 0-100% between off and maximum pedal compression will give you a decent idea of how much brake you are using without having to break into the brake hydraulics.
I also have a previous racelogic performance box mainly for 'back up' now. Normally this would require too much faffing around to sync and overlay with video.
Interesting solution with the brake pedal...thanks for that. Think i prefer the simple pedal travel solution instead of interfering with the hydraulics. May be a project I try over the winter for next year.
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