ProCoach

Matt, the protocol AiM Tech cites is specifically for Porsche 996 GT3 Cup 2002-2005 and 997 GT3 Cup with the Bosch MS3 ECU. They have a great plug-and-play solution that uses a Deutsch Motorsport connector pigtailed off the factory harness. If you don't have that, I don't think that will work. Too old. Time for you to step up to an EVO 4! <grin>

The reason why it won't work is because the Solo DL is designed to accept a greater data rate in a different language than your car is sending. The EVO 3, EVO 4 and the MXL can get that RPM signal directly.

On SnB's issue, he's got an entirely different RPM interface issue (even though the symptoms are the same). He has a 997.2 Seimens street car that should be able to (and I have made work in the past) take advantage of AiM's newest protocol which allows many, MANY of the heretofore CAN-only channels (hard wired) to be pulled from the OBD-II diagnostic port. I know it works because I've done it on the past, but AiM is working on an answer to this because its one of their most recent (and valuable) releases! Stay tuned.

cchan

The stepped RPM data brought up earlier reminded me of a new question... does anyone know if there might be some sort of "bandwidth" limit when using the straight OBDII protocol? In my case it's on an '04 996 GT3 connected via the OBD port.

Basically I'm thinking should I reduce the sampling frequency of items that don't change often (like temperatures) to 1Hz, does that open up bandwidth to increase the sample rate for fast changing items (like RPM) to higher than 10Hz? Is there a potential "upper bound" in terms of sampling frequency (in aggregate or for individual items), perhaps due to the speed of OBDII communications? Or does ODBII have enough bandwidth that I can just up the high frequency data samples without any problems?

I can obviously do a bunch of trial and error and see what works, but thought I'd ask in case someone already has a more educated/knowledgable answer. Thx.

HiWind

I think that makes sense as it keeps the file size down too - I set everything not driving related to 1 and those that are to 10 or 100 if can be - but Sadly that alone doesn't make you faster

ProCoach

No, there's no "bandwidth limit" on the communications protocol on the logger's end. There is a limit to the speed the information is supplied on the vehicle side, which is why on the pre-2008 cars, the OBD-II connection IS "measure and sampling speed limited."

Where the sampling rate changes things is that it materially affects the amount of TIME and SPACE the logger has available for incoming information. You can see that on the upper portion of the screen in RS 2 when on the configuration screen.

Really recommend a minimum of 20 Hz on g-loadings, speed sensors (including GPS) and sensors like brake pressure and PPS (throttle pedal position). Oil temp, pressure, water temp can all be at 1 or 5 Hz.

cchan

Thanks! OK, so it's not an OBD-II limit, it's basically the car's communications/processing speed - and I'd assume older cars generally mean older/slower electronics. Is there a downside from setting the sample rate too high, in that it might overload the car with too many data requests? And if so, is there a good way to tell/figure out when that happens and the sample rate should be dialed back?

ProCoach

No, no downside to upping the rate.

cchan

Thanks!

amso3

Hi Peter, good info. I wonder if GPS data needs to be sampled more than 10 Hz. isn't that the speed that GPS refreshes in the system? I have been curious about this when I've set up sampling in the past.

Thanks

ProCoach

Jerry, while the 10Hz acquisition rate of the GPS is fixed, a higher (20Hz) sampling rate on GPS speed is a good idea. That way, if the GPS refresh and sampling "clocks" are slightly off, the refresh is less likely to "drop" the position change, especially at speed. Plus, all the mapping algorithm's "double up" at the higher rate and do a better job of plotting the right (and actual) course position of the car, real-time, IIRC.

HiWind

Hey Jerry/Peter?electro-gurus - can you help with this question?



I want to extend the ODBII cable I have. I thought I might be able to use the can cable that came with the SOLO DL? Question is which cable to join to which?

I assume red to red?
and maybe orange to black?
the can has 2 white/blue, which do I use to match up with the white/blue on the OBDII?

thanks!
Matt

amso3

This should help. The CAN harness has a blue and white for CAN and a blue and white for RS 232. Black is gnd and red is Vbatt. The OBD connector has blue (Can +) and white (CAN -) and Orange is for K line (diagnostics I think).

HiWind

Super! Thanks Jerry - I figure it's simplest just to splice in a piece in the middle so effectively ...
1. black to orange
2. ignore the can cables
....and then I can leave the end solders/boards alone.

ShakeNBake

Peter, on my configuration, with this ECU setup, the max seems to be 10Hz.

ShakeNBake

Does anyone know what solo dl firmware and protocol setting are verified to work on a '10 GT3RS? Many Thanks.

amso3

I tried all different protocols with the OBD II connector on a 2010 GT 3 RS and did not get it to work. I found this strange as I was successful with the 2011 RS. Hope someone has figured it out.

If you are connecting to the CAN wires, it does work.