Hi guys,

As you all know (if you don't know you do now) the JDM Evo 8 does not come with a map sensor from factory. I got a manifold from Curt Brown ported so I bought an omni power 4 bar map sensor and installed it onto the manifold until I was able to get it wired into my ECU to be able to log boost via EvoScan, I did that today and it's reading etc but I notice at vacuum EvoScan reads from between -5.4608 to -6.8823 and on my AEM boost gauge it reads between -12 to -14 at idle.

I haven't been able to do any logs actually checking how much boost it reads compared to the gauge as I am currently waiting to be tuned but should EvoScan and my gauge be off that much at idle?

I used the formula 0.2369*x-14.7 under the JDM MAP option in EvoScan.

Let me know if I'm doing anything wrong please!

 

What ROM?

 

96530706. Does the ROM actually matter? Just for logging? I'm not doing ECU boost or anything.

 

Checked my OmniPower 4.0 bar setting in EvoScan and it's 0.2369*x-14.35 (which is compensated for my elevation of +700ft). Did you do the changes in ECUFlash as well? I don't know if it matters or not but there are changes that need to be made.

 

Yeh I'm on sea level that's why I used 14.7. I didn't do any changes in ECUFlash. What changes would I have to make?

 

Again, I don't know if this affects EvoScan or not, but here's what I had to do for my 94170008 ROM.

4 Bar OmniPower MAP

<table name="MAP Test 1: Mid VE Max Voltage" category="MAPSensor" address="2048" type="1D" level="1" scaling="Volts16"/>
<table name="MAP Test 1: Mid VE Min Voltage" category="MAPSensor" address="2046" type="1D" level="1" scaling="Volts16"/>
<table name="MAP Test 2: Low VE Max Voltage" category="MAPSensor" address="204C" type="1D" level="1" scaling="Volts16"/>
<table name="MAP Test 3: High VE Min Voltage" category="MAPSensor" address="2050" type="1D" level="1" scaling="Volts16"/>

Changed in ECUFlash

MAP Test 1: Mid VE High Voltage Test -- Change from 4.61 volts to 4.90 volts.
MAP Test 1: Mid VE Low Voltage Test -- Change from 0.10 volts to 0.06 volts.
MAP Test 3: High VE Voltage Test -- Change from 1.80 volts to 0.51 volts.

In ECUFlash, find the "Periphery2 (FCA) Bits" table. Change bit.9 from 1 to 0. Use the "minus" key on the keyboard. This disables the P0401 (EGR) test.

Changed in EvoScan
Boost(MAP) = 0.2369*x-14.3 (750 ft correction)

Granted, I'm not sure this applies as it's changing the values from my factory supplied MAP sensor to the necessary ones for my OmniPower 4.0 bar. I heavily suggest searching. Hopefully someone who knows more than I will chime in.

 

Damn that's way in over my head. I'll wait till Tom is ready and he can do that if he needs to lol

 

It appears as it's only not accurate at idle because under boost it's accurate.

 

Mines the same way. I left it alone. Reads fine when in boost.

 

The AEM is reading in inches of vacuum (when under vacuum) and psi gauge when at positive pressure while Evoscan is reading psi gauge pressure all the time.

 

What wreckleford said. As long as it reads 0 when logging with the ignition in the on position while the car is not running, you have it calibrated correctly.