I recieved some hardware I ordered from the US to help me in one of my projects. It allows me to connect a computer (such as a PC/Laptop or PDA) into the RX-8 and comunicate with the vehicles On Board Diagnostics (OBDII to be precise) interface.

I have to write all my own software, partially because the RX-8 uses a very new CAN protocol, and partially because I didn't want to spend 5 times as much just to get started.

As this project develops it will be an invaluable tuning tool, as we will be able to monitor critical aspects of the engines operation - all without having to cut/splice into a single wire in the wiring loom, or unplug/bypass any connector!

Since I am writing my own serial comms layer, it has been a little slow getting started, but I have had some very simple comms happening already. My goal for tonight will be to read the VIN number from the PCM/BCM. Once I have that sorted I can go up to the next level and start monitoring RPM, then all the other lovely juicy pieces of information in there.

I'll keep you all up to date.

My other present from Santa is an acellerometer to allow real on-road performace to be accuratley measured. Have a look at www.mrdyno.com . I had to order this via a US forum friend, and get him to on-ship it to me. MR Dyno would not ship to AU, not take payment from a non-US credit card. Wierd, but I guess they have their own valid reasons. It left the US Monday PM, so I hope I have it within a week.

Cheers,
Hymee.

PS - Today I saw the first "Offically Dealer Fitted" Hymee Grill Kit! The boys in the Grand Prix workshop where pretty impressed. After all - they were the ones who found the stone damage to my A/C condensor, and had to replace it. Now they probably can make more money for less effort by fitting some protection!

I guess that makes those 2 grills a pair of Hymee's DAACs! (Dealer Approved ACcessory) :p Sorry - bad humour this time of night. Can't wait to see some of my comments in my code in a few minutes time...

 

Hymee

Congratulations with your new hardware computer equipment and plug ins , i am sure you will master its systems and put it to good use .

May the RX8 force and your knowledge be with you.

I think that you are extremely fortunate to have such skills .and the forum members are fortunate that you are prepared to share .

Maybe u would like to share some time with ...... in springbrook with me .ha ha ha.
michael

 

Nice work Hymee, I'll be following your progress with interest as well. Where is the on board Diagnostics plug just out of interest?

 

Under the steeing wheel. The SAE J1962 standard mandates it's postion to a certain degree. (All 1996 cars onwards have one) There is only one physical plug type, but there are a number of electrical protocols to contend with over the years.

I will only being working with RX-8 compatibility, which is a "CAN" bus.

Cheers,
Hymee.

 

I have got some basic logging done for my proof-of concept.

I'll post some screen shots when I make a slightly better looking UI. But I went for a drive, and I had digital readouts on my laptop of RPM, vehicle speed and TPS (Throttle Position Sensor) :D

Cheers,
Hymee.

 

I did some more over the weekend, and logged / displayed real time parameters such as:

RPM, MAF (g/s), wideband o2 (lambda & AFR), cat temp, baro, fuel level, speed, commanded AFR, IAT etc.

Nothing pretty enough to show off though

Was shocked to find the Knock Retard is not a standard OBDII/J1979 PID. I'll have to dig lots deeper for that one. Also of interest, the RX-8 doesn't support/report MAP - so maybe it doesn't have a MAP sensor.

I check on the Mazda 6, and it does report MAP, but it doesn't have Baro. They are related to a certain extent.

Cheers,
Hymee.

 

Hymee, pardon my ignorance, what is the adv/disav of having a MAP sensor

 

The only reason I thought it was going to be good was it might help to determine if there was any intake restrictions, i.e. at WOT/High RPM the MAP should be pretty close to the ATMO.

But maybe all this helmholtz resonance stuff makes this moot.

Cheers,
Hymee.