I was just wondering; has anyone tried to tune the OEM ECU now that sr5guy "unlocked" the code? I am curious to see what can be achieved.
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OEM ECU Tune
- Thread starter Blackhorse06
- Start date
I just had a chip tuned for my NSX using SR5guy's "definition" yesterday. My tuner said the definition worked great and it was obvious how much time Matt put into it. There were only two things that my tuner kind of missed in the definition: 1) access to the rpm at which the VVIS changes the volume of the intake manifold, 2) access to the rev limiter. Since I don't want to raise my rev limit above stock, point number two doesn't bother me.
Additionally, my tuner said it would have been nice if data logging had been possible in order to see exactly what cells in which map the PGM-FI is currently accessing, what signals the knock sensors are sending, etc. That doesn't have anything to do with the definition, I gather. To do that in an OBD-1 car, it seems you have to solder a new port into the PGM-FI and program something. With more modern cars, you just plug your computer into the OBD-2 port.
As it stands, using SR5guy's definition my tuner could program a chip and do dyno runs with a wideband oxygen sensor in the tailpipe. He also said that no tuner can duplicate the months of work Honda put into programming the original maps in specialized load cells, using additional sensors to collect data, etc. If you change something in the car that goes beyond the ability of the PGM-FI to compensate (like injectors with a higher flow rate), you have to tune a new chip. If you want to change the ignition timing to optimize it for a higher octane fuel, you can now do that by loading the JDM NSX ignition maps into your chip, which "SweetChuck" uploaded here on NSX Prime somewhere. Those 1994 JDM ignition maps are optimized for Japanese super premium gasoline which, from what I have heard, legally had to have an octane rating of at least 96 RON but usually had closer to 100 RON.
Additionally, my tuner said it would have been nice if data logging had been possible in order to see exactly what cells in which map the PGM-FI is currently accessing, what signals the knock sensors are sending, etc. That doesn't have anything to do with the definition, I gather. To do that in an OBD-1 car, it seems you have to solder a new port into the PGM-FI and program something. With more modern cars, you just plug your computer into the OBD-2 port.
As it stands, using SR5guy's definition my tuner could program a chip and do dyno runs with a wideband oxygen sensor in the tailpipe. He also said that no tuner can duplicate the months of work Honda put into programming the original maps in specialized load cells, using additional sensors to collect data, etc. If you change something in the car that goes beyond the ability of the PGM-FI to compensate (like injectors with a higher flow rate), you have to tune a new chip. If you want to change the ignition timing to optimize it for a higher octane fuel, you can now do that by loading the JDM NSX ignition maps into your chip, which "SweetChuck" uploaded here on NSX Prime somewhere. Those 1994 JDM ignition maps are optimized for Japanese super premium gasoline which, from what I have heard, legally had to have an octane rating of at least 96 RON but usually had closer to 100 RON.
Hey Andreas, I received your email. I must have missed adding in the VIS settings for the NSX as I have them defined in the hack. I will make it a point to add them in at the next update, as well as the VTEC specific rev limters.
This project has taken a bit of a hiatus since I moved to Chicago and started working at HPTuners back in December. I do have my lab set up here and I'm ready to get back to work on it soon. All of the issues and limitations we discussed in the past with datalogging have been resolved with some custom code. The issue now is putting the finishing touches on it. I am not the best with documentation so I probably will end up having to hack some of my own code to figure out what I did
-Matt
This project has taken a bit of a hiatus since I moved to Chicago and started working at HPTuners back in December. I do have my lab set up here and I'm ready to get back to work on it soon. All of the issues and limitations we discussed in the past with datalogging have been resolved with some custom code. The issue now is putting the finishing touches on it. I am not the best with documentation so I probably will end up having to hack some of my own code to figure out what I did
-Matt
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What kind of power/tq gains did you see? I have the prospeed mod which I am not happy with (no customer service!) and I would like to see what can be done with the OEM ECU.
Matt, it would be absolutely great to be able to do datalogging in an OBD1 NSX. Not only would it be helpful on a dyno, I'd love to be able to monitor my car's short and long term fuel trims, the signals from the knock and oxygen sensors, etc. on the road to see if the tune can be further improved. If there's anything I can do to help move things along, I'd be glad to. Just let me know.
Blackhorse06, after removing my stock NSX injectors, installing turbo RDX injectors (part number 16450-RWC-A01), and tuning the PGM-FI, my torque curve basically shifted upwards by about 11 Nm across the board, which increased peak horsepower by 14 PS.
Blackhorse06, after removing my stock NSX injectors, installing turbo RDX injectors (part number 16450-RWC-A01), and tuning the PGM-FI, my torque curve basically shifted upwards by about 11 Nm across the board, which increased peak horsepower by 14 PS.
