Hondata and GM 3Bar

TorinF · Post by **TorinF** » Fri May 16, 2003 9:19 am

exactly....

the conversion within the hondata software is off (reads too low!!)
that is what everyone seems to be getting. anywhere from 3-4 psi too low.

I hope that Derek is seeing this.

QUICKSILVER RACING · Post by **QUICKSILVER RACING** » Fri May 16, 2003 6:12 pm

Is there a data sheet somewhere for the GM 3 bar map?

Torin,

Dariuz might have a point and the conversion may be correct. The hondalogger will read a low value if it is given a low voltage for a certain value.

Isn't the 2.47V a standard output for 10 psi?

If all GM 3 Bar Maps are like this then we can adjust as necessary.

TorinF · Post by **TorinF** » Sat May 17, 2003 7:08 am

i understand that, but why every car I've tuned now has this issue? obviously something is dropping the voltage, assuming the logging software is using the standard conversion. i am not the only one reporting this.

Dariusz · Post by **Dariusz** » Mon May 19, 2003 5:33 am

TorinF and QUICKSILVER RACING:

I can obtain in the web a excel file that have all the conversions from 0v to 5v of the GM 3bar (I you like I can send it you to a e-mail). The voltage drop that say TorinF is a interesant point... but I make the measures in 2 points: one in the ECU imput (using the hondalogger) and the other using a voltmeter in the connector of the 3bar and the 2 voltage are the same.

TorinF · Post by **TorinF** » Mon May 19, 2003 5:44 am

then hondata needs to redo their calibration settings in the software, right?

Dariusz · Post by **Dariusz** » Mon May 19, 2003 5:55 am

I think that your comment is correct... I think that hondata can make a conversion table to solve this problem.

A very interesant point is that the reading form 0bar to 1bar (aspitrated) is very accurated.

TorinF · Post by **TorinF** » Tue May 20, 2003 7:28 pm

ok, now that the software has a place to adjust the calibration, has anyone worked out one that works?

torin

Post by **Hondata** » Wed May 21, 2003 7:10 am

As you have found, I have added a place for 3 bar MAP calibration in HondaLogger and RomEditor. The four calibration settings are a voltage and pressure point at each end of the MAP sensor range, and the MAP sensor output is assumed to be linear between these values. The default calibration setting in HondaLogger/RomEditor was generated from information given by the manufacturer of the MAP sensors we supply, and is different from the old calibration by approximately 1 psi @ 30 psi pressure. You are free to change to calibration settings to suit your own MAP sensor.

Since most people seem to use the GM 3 bar MAP sensor, I'll buy a few of those and see if they measure differently from the sensors we sell. If anyone can provide me with more calibration information (apart from 'it is incorrect') then that would help.

Dariusz · Post by **Dariusz** » Wed May 21, 2003 8:02 am

This is the reason I deside (1 year ago) to buy honbdata and not the AEM... the service and the interest in solve the problems.

Thanks a lot.

TorinF · Post by **TorinF** » Wed May 21, 2003 9:39 am

if i can get a chance to set up a test on a car, i will do it. with my schedule, someone will hopefully beat me to it.

thanks derek.

hows the work on fixing the ignition advance logging?

silverl2000 · Post by **silverl2000** » Tue Jun 03, 2003 5:15 pm

so this is all worked out now? GM map sensors are fine?

tonyn · Post by **tonyn** » Wed Jun 18, 2003 1:52 am

i noticed this as well on an older 2b system using rom editor 2.5 where in rom editor shows lower value rather then what the mechanical boost guage shows.

does this mean i would need to update to the latest rom editor ver in order to have gm 3bar map conversion capability?

Jeff_Atwood · Post by **Jeff_Atwood** » Sat Jun 28, 2003 8:04 pm

This 'error' isn't really a big deal... so what if your gauge
says 15 psi and the sensor reports ~12psi.

Why, you ask...

the ecu does not care about 'pressure' it wants voltage.
meaning, example: the 2.52 volts signal that used to
'report' only 12 psi and now 'correctly' reports 15 psi
DOES NOT MATTER because the ecu is still using the same
column in the fuel table as before.....

call them widgets....it doesn't matter as long as the labels are
consistent from the logger to the editor.

Just some thoughts....

Jeffrey Atwood

hack · Post by **hack** » Fri Aug 01, 2003 8:26 am

i'm not sure yet but this sounds consistant with my problem.....the car goes lean at 3-5 psi of boost and feels like someone turned off the ignition key.... i'm headed for 11 + lbs of boost as before ( before hondata and 3 bar ) but have not reached that because of this problem. i'm currently trying richer fuel maps which seem a bit out there , but if it works...the o2 gauge doesnt lie.