AaronGTR
07-04-2006, 04:54 PM
I'm in the process of switching to a 2bar MAP sensor. Has anyone done this yet and got the car running? I know a few grand prix gt guys that are now boosted have done it but haven't seen anything for GA's yet. I figured I'd start this thread to get some info out there.
Here's what I have so far. The stock 1bar MAP from my '00 gagt is part #16254719. I got a 2bar MAP for a '00 grand prix gtp from GMpartsdirect part# 12569241 for $40.90 +S/H. They are almost a direct swap. Same size, bolt holes, plug and vacuum port locations, etc. The only thing different is there are some little plastic tabs inside the plug holes on the MAP that slide into channels on the harness plug and they are in a different place on the 2bar. You can either get a GTP plug, or just cut some new slots with a dremel tool and you're set.
I'm using the powrtuner beta v1.2.0 which now has the ability to change the MAP scale in the pcm. Inside the fuel folder there is a MAP folder now that contains MAP_Scaling_Factor, MAP_Sensor_Offset, and Default_Max_MAP. My stock values for those are 94.39, 10.33, 98.01.
The problem is figuring out how to change those values to get the proper scale. I don't know what those numbers correlate too in order to re-calculate them. I'm trying to see if I can just get the GTP values and plug them in since thats what the GPGT guys have done.
Only problem I've heard of so far is the GPGT NA program measures the maximum barometric pressure at startup and while driving (WOT would =no vacuum and be max baro pressure). It uses this to determine air density for fueling purposes of course. I guess this part of the program hasn't been modified yet to work like the GTP program when it sees boost, so it resets the max baro pressure to over 104kpa (the normal maximum) and when you go from boost back to idle your idle gets all screwed up until you turn of the car and re-start it to reset the max baro. I don't know if the grand am bin will do the same thing or not, but as soon as I get this MAP in and test it you can bet I'll let everyone know. :thumbs: Keep in mind this is still in beta testing so I'm sure a fix will be devised soon enough.
Here's what I have so far. The stock 1bar MAP from my '00 gagt is part #16254719. I got a 2bar MAP for a '00 grand prix gtp from GMpartsdirect part# 12569241 for $40.90 +S/H. They are almost a direct swap. Same size, bolt holes, plug and vacuum port locations, etc. The only thing different is there are some little plastic tabs inside the plug holes on the MAP that slide into channels on the harness plug and they are in a different place on the 2bar. You can either get a GTP plug, or just cut some new slots with a dremel tool and you're set.
I'm using the powrtuner beta v1.2.0 which now has the ability to change the MAP scale in the pcm. Inside the fuel folder there is a MAP folder now that contains MAP_Scaling_Factor, MAP_Sensor_Offset, and Default_Max_MAP. My stock values for those are 94.39, 10.33, 98.01.
The problem is figuring out how to change those values to get the proper scale. I don't know what those numbers correlate too in order to re-calculate them. I'm trying to see if I can just get the GTP values and plug them in since thats what the GPGT guys have done.
Only problem I've heard of so far is the GPGT NA program measures the maximum barometric pressure at startup and while driving (WOT would =no vacuum and be max baro pressure). It uses this to determine air density for fueling purposes of course. I guess this part of the program hasn't been modified yet to work like the GTP program when it sees boost, so it resets the max baro pressure to over 104kpa (the normal maximum) and when you go from boost back to idle your idle gets all screwed up until you turn of the car and re-start it to reset the max baro. I don't know if the grand am bin will do the same thing or not, but as soon as I get this MAP in and test it you can bet I'll let everyone know. :thumbs: Keep in mind this is still in beta testing so I'm sure a fix will be devised soon enough.