Toby Pennycuff

Quick question for those of you better schooled in automotive electronics than I......

My 2001 GT3 Cup has a factory-installed throttle position sensor on the intake throttle body and it is wired on the standard factory harness. The TPS is Porsche part number 996-606-116-00, which is also Bosch part number 0 280 122 016 (Bosch calls this a Rotary Position Sensor RP 86). Bosch offers a useful site that will cross-reference several manufacturer's part numbers to a Bosch part number, including Porsche - Bosch Automotive Aftermarket site. I found some details about the switch on the Bosch Motorsport site - Bosch Motorsport site.

Specifically, it indicates that the TPS is a 5V unit that should work with AiM loggers and dashes. My question is whether anyone has obtained the Bosch .SDF files that provide sensor configuration data? If so, would you be willing to share? I think this info would be necessary for building the proper sensor definition file for use by AiM dashes.

I'm also going to try and find sensor data and Ohm plot characteristics for the factory water temp sensor (996-606-405-01), the oil temperature sensor (996-606-150-90) and the oil pressure sensor (996-606-203-00). If I can find them, I will publish the data I can find.

As ViperBob1 pointed out in another thread, it would be nice to capture sensor type and plot data and share them among the AiM users on the board.

One other question...... If I tap into the signal wire for these sensors, do I run the risk of degrading or impeding the signal values? Alternately, can I simply add a second lead to facilitate connection of the factory gauge AND the AiM custom sensor? Would appreciate any suggestions or input anyone can offer.

Toby

amso3

Here is a document I wrote about creating custom sensors. If the sensor provides variable resistance or variable voltage 0-5 volts, it can be calibrated to work with AIM dashes. You can download a copy with this link:

http://media.virbcdn.com/files/2b/19...stomsensor.doc

Viperbob1

I know Toby you cant use the Cupcar bridge (which is WONDERFUL) due to the year. Not sure but cant the older Cups still use a standard AIM Bridge to access this info instead of going after individual data? Jerry?

amso3

Bob

This car is that same as you are going thru with the Targa. No CAN info

Viperbob1

Oh that is a drag... Note to self, only 02 and later cups...

Toby Pennycuff

Jerry is right. 2002 was the first year for the Bosch MS3.1 ECU where tons of information was available. And upgrading the ECU from the stock Motronic 5.2.2 unit to the Bosch unit is unbelievably expensive! So I get to learn how to program sensors in AiM! The "journey" is made all the more interesting because many of the resistance values for the sensors found on the car are either not published or found in the most obscure, unexpected places in the factory documentation. Was pretty cool to find the Bosch Motorsports catalog and see a LOT of detail about a ton of sensors.

924RACR

WTF is an SDF file?

Toby Pennycuff

Apparently, Bosch maintains a database of sensor information. I thought these might be either a CAD format or a PDF-like format. No joy though. I'm still digging trying to figure it out. Windows wants to resolve an SDF file as a SQL Server file. I'm pretty sure that is not what Bosch is offering up.

kgorman

Fwiw.

Of course AiM can be calibrated for any 0-5v signal.

There is danger that you alter the circuit by taping it. That said, if it's a 0-5v signal, and depending on the harness design you tap with you only May alter it slightly (per ohms law). That said, I have no idea what signal the ECU expects.

My advice would be to engineer an out of band TPS sensor directly to AIM. The pedals in the 996 cars are cheap, and not conducive to adding sensors in any reasonable way, but aftermarket pedals like rennline could be easier. Adding on on the cable/throttle body itself may be easier, I have used string pots for this in the past with mixed results. Lots of custom bracketry involved. Maybe someone here has a clever design?

Toby Pennycuff

This is exactly what I worry about. If it were an instrument like one of the dash gauges, I'm not so worried about signal degradation. However, a feed to the ECU is a different matter entirely.

You may very well be correct that some sort of string potentiometer may be the only viable option in my case! Thanks for the comments!

Toby

Krokodil

If you decide to go this way, I have a couple of used AiM throttle potentiometers that I will sell.





Cheers,

amso3

Toby

I'm pretty sure my friend made the throttle position switch work as "throttle" on his Boxster with no ill effects, I'll check with him. I was able to tap into the temp sensor on an early Boxster and get data to the Pista.

Toby Pennycuff

Jerry, which temp sensor were you able to tap into? There are two on the 996 Cup motor - one for water temp (996-606-405-01) and one for oil temp (996-606-150-90 in the early cars and 996-606-224-9A in the '02-05 Cups, max 150 degrees C).

I'd like to take the dash instrument feed for water temp and feed that into my MXL2. If I can get Ohm ranges that would be awesome!

There are three wire connectors on the back of the instrument cluster, and the White connector appears to house the wires for the various instrument feeds. I'd like to tap into the GREEN/RED wire for Oil Pressure feed, and the BLUE/RED wire for Coolant Temp. If Ohm values are available, or someone knows these Ohm ranges and will share, that would be extraordinarily helpful.

According to the factory wiring diagram, the oil temperature sensor ONLY feeds the DME. The connection is directly from the oil temperature sensor located on the oil/water heat exchanger console to Pin 73 on the DME. It's a GREEN/RED 0.5 wire.

So, I am presented with the same dilemma as the throttle position switch. I don't thinking "tapping" the existing wire would make sense and likely cause issues with the DME. However, can I wire in a separate lead at the sensor connector to supply both a TPS and oil temperature feed for the MXL2 without creating resistance issues?

Sure would appreciate inputs from the collective wisdom of the sensor gurus on this board. I have a reference from another thread here in the Racing forum on the TPS connection, and that thread suggests it is possible to do what I described above. I need to call to confirm HOW the feed was created (i.e. - where the new lead was created), so perhaps I can do the same thing with oil temperature.

Thanks in advance for any help available from other Rennlisters, and Merry Christmas to all of you!

Toby

Toby Pennycuff

Trying to add to the body of sensor information for AiM data acquisition systems...... This one is about Coolant Levels.

In the expansion tank for the 996 Cup, there is a coolant level sender that will alert the driver if coolant levels are low. This sender seems to be more of an "idiot light" sender (either on or off) than a resistance sender (measuring a range of temperature or pressure). So, the question revolves around how to build a sensor in RS3 for an on/off type sensor.

A little background on why this would be important - especially in a water cooled race car. Steve Weiner reminded me that if one's coolant level goes low and ultimately exposes the water temperature sender to "air" instead of being immersed, the sender will begin measuring AMBIENT temps in the system instead of what will likely be MUCH HIGHER water temps - right before the engine mimics the Chernobyl or Fukushima or Three Mile Island power plants! So, there is real value (it seems to me) in having an alert light on the MXL2 for low coolant. Luckily, there is a sensor in place already!

So again, how would one program this kind of sensor in RS3? Thanks in advance once again for any contributions. Just trying to add to the body of knowledge here on Rennlist.

Toby

amso3

Toby I tapped into the water temp on the Boxster. Don't remember any colors.