Map sensor 2bar - 3 bar resolution values. over boost question.

  • 300zxtravis
    300zxtravis
    Member
    • 98
    #1

    Map sensor 2bar - 3 bar resolution values. over boost question.

    So previously i ran a GM 2 bar map sensor on the Z as i was running under 10 psi of boost. Well its time to reinstall the system, and my map sensor is missing. so time to buy a new one, this time i am planning to run right a 15-18 psi boost. 2 Bar map sensors are designed up to 15 psi but many have been pressure tested to exceed 50psi according to specs. Has anyone here ran boost a few psi over "said" limits for map sensors? I am thinking the voltage will peak at ~15 psi and anything over wont be read. have any recommendations on a brand? just used generic cheapo last time.

    The reasoning. Price wise they cost is within $20 for a decent map sensor but the significant difference is in the resolution values the 2 bar general values about .9375 in. hg/location with a slightly faster response time, and the 3 bar 1.406 in. hg/location with a slightly slower response time. Though not a huge difference, according to my book i can have an additional 4-6 load points for tuning by staying with 2 bar.

    Any hands on experience here?
  • BLOZ UP
    BLOZ UP
    Senior Member
    • 2971
    #2
    I use the "3" bar one with Megasquirt, which is really a 2.5 bar one, the MPX4250. It's not a big deal, the reduced resolution. At least not for the VG30E. If you look a the spec sheets, it will list the voltages it outputs (http://www.freescale.com/files/senso…et/MPX4250.pdf). It looks like it works to about 260-270 kPa. After that you hit the 5v ceiling, which is bad. Perhaps the sensor reads past that but I know Megasquirt limits it, so either way you'd be screwed.
    BLOZ UP.com
    It is not recommended to confirm proper installation by driving into walls or other barriers as this could cause personal injury or damage to the vehicle.
  • 300zxtravis
    300zxtravis
    Member
    • 98
    #3
    That's exactly what i was afraid of. I wasn't so concerned with the resolution/response time, just thought it would be nice to have the points on the system to tune. The Manual shows it accepts up to 7 volts but likely that is just over voltage protection, was hoping that this might be utilized for slightly running over the 14.5-15psi rating I've been finding.