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Thread: MSD 8762 Boost Timing Master

  1. #1

    Default MSD 8762 Boost Timing Master

    Does anyone know the part number or type of MAP sensor the MSD BTM uses? Is it a 2 bar manifold absolute pressure sensor? (0 bar atmosphere to 15 psi). Or a 1 bar gauge pressure sensor? (0 psi to 15 psi). Is it a regular 0-5V signal sensor? (Voltage increases with pressure). Also, is the controller (0 to 3° knob) a potentiometer or a 4 position click knob, can you set timing per psi anywhere on the dial at say 0.5° or 1.25°?

    I'm asking because I'll buy one if it runs a 2 bar MAP sensor. This would mean its start set point (0-5 psi) would be from 2.5 volts to about 3.4 volts. This would be perfect for my application if I use a 0-5V 2.5 bar gauge pressure sensor (0-36 psi) in the BTM. This would give it a start setpoint of 18.4 psi to 24 psi and pull the dial set timing (from 0-3°) every 1.225 psi up to 36 psi or 15° maximum timing retard.

    The cars factory timing is fine up to 22 psi on 94 octane gas and with 400cc of 49% methyl hydrate/51% distilled water injection is fine to 30 psi. Above 15 psi fuel is controlled by an extra injector controller and two 650 cc injectors, the controller used to run a 2.5 bar MAP sensor limiting control to 22 psi and full injector duty cycle above 22 psi. I replaced it with a 2.5 bar gauge pressure sensor giving it fuel control up to 36 psi. The controller has a start point knob (0-36 psi) and a gain knob (1-4). It's always set to start at 15 psi, so only the gain knob is used to tune fuel.
    Now that the fuel can be controlled above 22 psi, I really want to pull some timing in higher boost. My plan is to run 200cc more water/meth, have it come on at lower boost, run less fuel and pull timing accordingly.

    This is why the MSD 8762 BTM would be perfect timing control to go with my low tech piggy back fuel control if it runs a 2 bar MAP sensor & operates withing a voltage signal range that works with other pressure sensors (2.5V-5V = 0-15 psi).

  2. #2
    Join Date
    Jan 2010
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    Default

    The MAP sensor is a built-in on-board 2 bar absolute pressure sensor to allow 15 psi of boost retard. The control knob is a potentiometer. Gary
    Regards, Gary

  3. #3

    Default

    Gary, thank you for the answers to both my questions.

  4. #4
    Join Date
    Dec 2009
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    Connecticut
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    Default

    Yeah, Gary's post was clear, concise and to the point.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

  5. #5
    Join Date
    Jan 2010
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    Default

    Thank you boys for your kind words. Gary
    Regards, Gary

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