I've recently installed a JDM map sensor on my 05 and everything seems to be working well. For the most part my boost gauge matches what I'm getting on my logs VIA EvoScan (20.3 initially, then tapers down to 18 psi).

Today, I decided to adjust the boost by turning my Hallman up a 1/4 of a turn. My boost gauge showed something along the lines of 23 psi initially and tapers to 21 psi. Now my JDM Map sensor showed a log of 22.0 initially, tapering off to about 18 psi.


Could my Mechanical boost gauge be that off? I know it's not exact but wow, 21 psi vs 18 psi.

Another thing I find strange, the first pull that was done, there was no knock at 18psi (via JDM MAP) but the second pull, there was plenty of knock (7 counts) at 18psi (via JDM MAP). Keep in mind that my manual boost guage showed and increase in 3 psi from one pull to another which would makes sense with the knock.

 

temps matter as far as knock.... thats my thought on that...

the other, yes mechanical can start to lose accuracy

 

right I understand that, but conditions were similar. I did notice and increase in load 2byte between the two pulls so I'm guessing that there was an increase in load. So why is it that both my Mechanical gauge and ECU noticed this increase but my JDM Map didn't?

 

it is an MBC, it isnt exactly the most accurate thing in the world... maybe your gauge is off a bit... or a setting is off in evoscan. Did you turn up the boost between pulls or before the first

 

Between pulls. I guess what I'm getting at is, kind the JDM Map scaling be off in the JDM MAP sensor setup?

Note: I've adjusted the altitude setting in the data.xml file (in evoscan), so that when the car's ignition is on (but the car is off), it reads 0.001 psi.

 

log with the car off and see what the pressure reading is... should be close to 0

 

if you have done the checking and its reading .001 psi with the car off then its your gauge then.

 

It did. You said it was first 20.3, the 22. THE MAP saw the increase in boost, the gauge just saw more.