Nashou66

I was wondering also about the scaling/conversion of those table numbers.

The second column are numbers the ECu uses instead of voltage values from 0-5
so 0=0 and 5=255. In the AEM 5 bar map sensor thread forum member roadspike
made a excel spread sheet for the 5 bar map https://www.evolutionm.net/forums/at...5bar-chart.zip . I was using the sheet for my 3.5 bar map by just changing the sensor range from 5 to 3.5. Now, in the upper corner he has a conversion for the voltage to "ECU voltage" values where he has the
ECU voltage of 1 = .019608 vdc . and 127 ECU voltage = 2.490196.

So with simple algebra we can find the correct voltage by using those "ECU Voltage" values I'll call the "ECU Voltage" ev so to find V you would just use this formula:

V=ev* .019608

so that table is off I think, here it is again(2005 USDM Evo 8 ROM 96940011)

Original changed values:

V ev
----- ------
0.51 32
0.90 62
1.29 88
1.68 122
2.07 153
2.46 183
2.85 216
3.24 245
3.63 255

For an example lets look at ev=183

with his algebra :

V= 183* .019608
V= 3.59

That is more than 1 volt difference.

Am I wrong ? Unless RoadSpikes spread sheet is wrong but it makes sense to me.


Athanasios

kpr

iTrader: (6)

There is a big difference in what my autometer boost gauge reads and my datalogs. Ive double check my local atmospheric pressure to make sure that is correct . At idle map logs about -8 to -10, gauge is at 15. Under boost ( just wastegate, no controller) gauge reads 16 increasing to 21 by 7500rpm, Datalog is 16 to max 18. Any ideas, something I may have missed.

rayman0690

iTrader: (15)

Yeah I have something similar after I installed my 4 bar MAP. I followed all the evoscan formulas and adjusted for my altitude and I changed the voltage readings for my ROM. Car runs fine but my boost gauge reading is dramatically different than my MAP reading.

At idle my gauge reads about 15 to 20 vacuum and the MAP is logging around 8 to 10 vacuum.

l2r99gst

iTrader: (2)

Your map sensor and boost gauge are using different unit for vacuum. Nothing is wrong.

kpr

iTrader: (6)

Yeah , figured that out after I posted that, was hoping no one saw it before I edited it lol. what about the boost being off?
With the controller connected, Gauge is 25 throughout, but map logs 26 dropping to 21 by redline.

gunhaha

iTrader: (5)

Can anyone show me exactly where to find this file Data.xml in Evoscan to make the necessary changes to be able to log boost?
I'm using V2.7 and I could not find this Data.xml file in the Evoscan 2.7 file folder.
Thanks.

And

what OS do you have if its win 7 or vista it'll be in your home directory in c:/users/YOURNAME/Evoscan/data

06RedRalli

iTrader: (49)

You can change it with evoscan open...

right click JDM MAP.
edit data
change eval to: 0.2369*x-b

b=your local atmospheric pressure...so change it to the necessary number.

altitude (ft) local atmospheric pressure (psi)
0 14.7
500 14.4
1000 14.2
1500 13.9
2000 13.7
2500 13.4
3000 13.2
3500 12.9
4000 12.7
4500 12.5
5000 12.2
6000 11.8
7000 11.3
8000 10.9

06RedRalli

iTrader: (49)

Boost gauges are quite known to be off by some degree...so I'd say go with what the MAP is telling you...because that is a def source of psi you're running.

gunhaha

iTrader: (5)

Fred's instruction says Ecuflash 1.4 or higher.
Can I do the changes in Ecuflash 1.42 but use Ecuflash 1.3 to flash to the car?
My cable works only on the older Ecuflash 1.3.

Thanks

gunhaha

iTrader: (5)

It worked
Thanks

Blitz

iTrader: (11)

Just wanted to say thank you for the awesome write-up. Did it today and this made it totally painless even for a complete n00b to the whole tuning thing. You're the man mrfred.

SunnyC

iTrader: (4)

I installed my 4 bar map today. Followed all the instructions for ECUFlash and EvoScan. When I take the car for a ride to log it. It bogs and kinda drop at 5000 or 5500 down and it goes back up. Didnt change anything besides adding the MAP to the xml and changing the values. Anybody have this sort of problem? ROM 96940011

Also after I took it for a ride and for some reason it feels like its slipping in 2nd and 3rd gear?? When I am about to floor in 2nd gear from 2500 it feels like it hesitates a bit. Don't know if my clutch is slipping or what. It only happened after I installed the 4 bar and flash the map scales and periphery settings.

Nashou66

I just got my 4 bar MAP and followed the instructions and all works well.

Your hesitation might just be bad plugs and or wires and coincidentally
began acting up after you made the change.I had the same issues and it was
both plugs and wires.

one thing I noticed with the new map sensor is when in vacuum/idle my AEM Digital Boost gauge with a 3.5 Bar sensor shows -18 and on evo scan from the OMNI MAP log it is showing -7.

But positive boost is fairly close.

Athanasios

HornstarBU

iTrader: (7)

I just installed mine this evening, it's pretty dead on.

At boost I show 6.5 psi, gauge shows 6 ish...not an accurate guage though
At idle, evoscan shows -11 psi (also known as 22 in /Hg) and my guage shows 22in/Hg

I noticed a lot of people say vacuum is wrong on theirs, it's just that the map sensor shows starting at absolute 0, and always in PSI, but most boost gauges show in/Hg and then switch to PSI at 0 atmospheric, or 14.7 absolute..

I think...whatever, -11 is the same as your boost gauge showing -22.