I got the SuperMID yesterday and did the install last night.

http://babelfish.altavista.com/babelfish/trurl_pagecontent?lp=ja_en&url=http%3A%2F%2Fpriusd iy.fc2web.com%2FNENPIKEI.html

I had a few problems getting power to the unit, but it works fine now. The
only problem is that the Tach signal is intermittent. I will check the connection to IGF tonight. As far as calibration, the distance is dead on and the FE meter registers 1.5 to 2 MPG low compared to my MFD. But since my MFD tends to be 1.5 to 2 MPG high, I guess it is dead on.

Some data from today's drive to work....

Multifunctional Display
- 25.4 Miles, 83.0 MPG

SuperMID
- 41.03 km (25.49 Miles), 34.65 km/L (81.6 MPG)
- 1.184 Liters used
- ICE ran 39% of the time
- While ICE was running, the average FE was 13.42km/L (31.6 MPG)
- Starting Water Temp 34C
- Max Water Temp 90C

Very Cool!
Dan

 

How is it hooked into the car? Does it hook into the computer or do you have to run wires to the cars sensors?

 

In addition to the 12V and ground wires (I use the cigarette lighter) there are 5 additional signals needed. you pick up the Tach signal, the injector signal, air intake temp and water temp at the Engine Control Module behind the glove box. The speed signal comes from the Hybrid Control unit, (right next to the EV Button wire) also behind the glove box. I used the connectors that dig into the wire insulation and snap in place. Not for a novice, but not overly complicated either.

 

That sounds like a pretty cool setup, but how does it know what the fuel pressure is? As everyone knows, fuel injected is a function of the injector size, pulse width, and fuel pressure. It sounds like you probably program in the injector size, the box measures the pulse width, but it would need a way to know what the fuel pressure is, which of course changes based on manifold pressure when you have a 1:1 rising rate FPR.

 

My guess is it assumes a constant pressure. I spent a lot of time with the schematics identifying all of the signals going to and from the ECM. Nowhere did I see fuel pressure. That is not to say that there isn't a fuel pressure sensor, just that the info doesnt seem to make it to the MFD, the combination meter, the ECM or the Hybrid ECU.

This instrument measures the duration and ignition signal. There is a parameter that you can change for calibration. Also there is a parameter for distance calibration. The way it is calibrated now, it is more accurate than my MFD.

 

Hello all,

This is my first post, I believe, to this greenhybrid site.
I designed and built the SuperMID. :-)

Dan is right. We now know the fuel pressure is constant, and the fuel usage is proportional to the injector ON duration.

More preciously, the fuel usage is proportional to "injector ON duration" minus "injector operating delay(mechanical delay)" .

Ken@Japan

 

Welcome to GH Ken.

We look forward to hearing from you on what is going on in Japan. Also, please correct me if I have said anything wrong about the SuperMID. I am still not sure what all of the menu's do. I will have time to play around with it after the marathon.

 

ken1784,
Welcome to GreenHybrid. I've seen your posts on other forums and hope to hear more from you here. The SuperMID is a great tool. Thanks for sharing it with the world!

 

I'm just curious, but what did you use to measure this? I've never seen a fuel injected car that did not have a rising rate fuel pressure regulator.

 

Toyota Technical Manual says the specification of the fuel pump is more than 50 liter/hour at 284 kPa and the specification of the fuel injector is about 160cc/min.
The fuel pump supplies fuel with fix pressure.

I did experiment of measure/calibrate/try type, and the result is very consistent.
The overall error is now less than 1% which is very good, I think.

Ken@Japan