Scanners/gauge monitors for 2012 tdi?

[shwagon]

Im currently playing around with Engine Link on iphone. Im looking to add boost to the custom display. Going off of what bassman said, Im guessing it will go something like this.

ECU address or Header: 0
ModeandPID: 0170
Formula: ((D*256)+E)*32
Min Value: -.5
Max Value: 3
Description: MAP
Unit: B

If anyone has input on this whether they think this will work, please let me know.

Thanks

 

[Diesl]

Shwagon, a little bit earlier I replied to bassman that you have to divide by 32, not multiply.

 

[shwagon]

Shwagon, a little bit earlier I replied to bassman that you have to divide by 32, not multiply.

Ok thanks, I saw your original post but nothing further on it. Thanks for the help.

I have attached a screen shot of how it is reading at idle, something seems off about the formula. Any suggestions? How should I write it to show up as psi?

Thanks again!

 

[Diesl]

Ok thanks, I saw your original post but nothing further on it. Thanks for the help.

I have attached a screen shot of how it is reading at idle, something seems off about the formula. Any suggestions? How should I write it to show up as psi?

1 bar = 14.5 psi. It's odd that it shows 12.55 bar at idle; it should show 1.04 bar or something similar. My ScanGauge formula tells it to display hundredth of a bar.
If you look at post #33, you see that for actual boost in PSI, I multiply the reading by 91hex=145decimal, then divide by C80hex=3200dec, and subtract 147 (add FF6Dhex):

 BP2 70 05418670 4810 00910C80FF6D psi     actual boost

The '147' depends on your altitude and standard pressure; you want to adjust it so you read just above zero boost at idle.
So your formula should be (D*256+E)*145/3200-14.5 .

But by converting from absolute manifold pressure in bar to boost in psi, you lose the easy interpretation as 'power multiplication factor' due to boost. The absolute manifold pressure in bar tells you in one number how much more air your car is shoving into the cylinders compared to no turbo.
1 bar a.m.p. = no help from turbo, 2.5 bar = 2.5 times as much air (and potentially power) as unaspirated.

 

[Diesl]

I finally started to look into into PID 71,
'variable geometry turbo control', according to Wikipedia.
71 has two bytes.
The screen shot shows the bytes of PID 70 and 71 plotted in Torque.

Top row: 71 B (turbo1b) and C (turbo1c) seem to be normally in the 240s, and decrease a bit when the exhaust flow (due to opened throttle and higher revs) goes up; so that would agree with the vane opening throttling a bit back as flow increases. But it could also be turbo RPM going down with increasing load/manifold pressure.

The 2nd row shows that adding the lower 8 bits (shown in the third row) to manifold pressure values seems to slow down the torque update rate (rightmost 16 bit MAP graph is more ragged than the two 8 bit curves). Are we actually sure that 70 C and E are the lower 8 bits of manifold pressure, or could they be something else?

 

[1854sailor]

Pricey, but I know several folks who have this: http://www.p3cars.com