If their actually useful and functional, I want to get a bunch of them to put up for sale on my site.. I'm also putting together plug and play boost control solenoid kits for the stock ECU once I get my connector kits in stock to figure out which is the right ones..

 

Well cant wait til that comes.

 

^^ Me either.... maybe i'll hold off playing around with the Perrin solenoid.

MJ, are you trying to get a connector so your kit will simply plug into the stock solenoid's harness? I've no problem messing with the stock wiring.... but something that easy would be nice.

 

Yeah I've made several "hand made" plug and play harnesses for plugging stuff into the stock harness connectors, but I ordered an entire stock of Japanese/Euro/American car interlock connectors to be able to figure out what connectors need what.. But the plug for the stock harness is what I'm trying to match (and a few other connectors on our car)

 

Sweet. MJ you cease to amaze me and probably the rest of us

 

MAP sensor left Japan yesterday. Took a little longer than I thought, but its on its way now. Should have it by middle of next week.

 

1.334x is the calibration for bar absolute that I worked out for my JDM MAP sensor on my UK car from the service manual. Doesn't quite match atmospheric pressure from the Baro sensor, but pretty close, and close to AVC-R for boost logging.

It would be nice to know what inputs and outputs are available, I guess someone clever could log all the ADC channels and connect things to what appear to be unused inputs. Most microcontrollers wouldn't mind an input or output being connected to the wiper of a 5K potentiometer for example, although might be best not to take it to 0 or 5V directly by having the wiper at either extreme end.

 

I received the JDM Evo IX sensor a few days ago. Its physically identical in appearance to the USDM sensor. Just had my first chance this morning to take it into the lab and compare it with the USDM Evo IX sensor. Output voltage vs pressure for the JDM and USDM sensors are in the attached plot below. As I expected, the output from the JDM sensor is much different than the USDM sensor. I would have also liked to have measured output when pulling a vacuum, but my equipment doesn't have the capability. The good news is that both sensors appear to have a linear output vs pressure, and the output range appears to be 0-5 V for both sensors. Also note that the USDM sensor saturates at about 3 psi which is where the output from the ECU saturates at 255. This means that 255 from the ECU correlates to 4.82 V from the sensor. So, this means that the JDM sensor can easily be used for logging boost on a USDM car.

To log boost with the JDM sensor, it a simple matter of making sure that the correct formula is used in the data.xml file for EvoScan or Mitsulogger. The formulas are:

For boost in psi, use: 0.185x - 14.5

For boost in bar, use: 0.0127x - 1

I derived the formulas using a linear correlation with two pairs of points: (0 [ECU], -14.5 [psi]), and (255 [ECU], 32.7 [psi]). 32.7 psi is what it takes to push the JDM sensor output to 4.82 V (saturation).

That's all the good news. What's still unknown is whether the ECU is going to throw a code or whether the emissions equipment may not work properly. I need to look at the emissions equipment logic in the FSM to see what I can find out. If anyone has any info on this, let us know.

 

mrfred

where did you get the JDM sensor and how much did it cost?

Edit: Just saw the post above. Are those figures accurate? Still curious where you purchased it.

thanks

 

Wow mrfred great work. Just out of curiousity what do you do for a living? You seem to know quite a bit about the technical aspects of the sensor.

Now only to make it so electrical idiots like myself can plug it in and log!!

 

For all the others wanting a more simple way to log wideband, AFR, Lambda, RPM, TPS, AUX 0-5v input and 3.5bar map BOOST, look into the zeitronix which can be logged simultaneously with Evoscan and Mitsulogger via usb or serial cable.

 

Nice data mrfred. Now just to plug it in and try?

 

Nice work. Now, one of the EcuFlash experts needs to figure out where the cal table is located in ECU to remap it.

 

Subscribed.

 

At worst, one of the people working on the Evo rom disassembly will have to make some minor mods to the rom to get the sensor to work with the emissions or whatever subsystem it may be affecting. At best, it will be plug-n-play. :-) As jcsbanks suggested, I'm tempted to just install the thing and see what happens. The car is on jackstands for some maintenance though, so I won't be able to do that until Saturday or Sunday.

If people are interested in getting the sensor, probably the easiest thing to do is to start a group buy. I can order up a big batch of these things.