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Thread: 3 Port Boost Control Questions

  1. #1

    Default 3 Port Boost Control Questions

    I've been researching for days now, and can't find guidance, so figured I'd post my questions on here. I'm trying to setup a 3 port valve (557-200) by simply venting the wastegate (4.2 in the manual for 557-200). Controlled with MAP pressure. Using HP ECU. I'm currently running a 10 PSI spring on my wastegate, which nets me 6.5 PSI full boost. I want to have 10 PSI at all times (this is strictly a street car). So here are my questions:
    - As this will be a street car, would the best operation mode be Boost vs Time? (Will the last cell continue to be used even if the timer is done?)
    - Giving the fact that I don't have access to a dyno, should I let the PID control the duty cycle and then adjust the table after seeing where it likes to be?
    - Should I use the given table from Holley, or should I play with it before testing anything out?
    - When letting the Close Loop do its thing, is there a Learn Table afterwards that I can transfer the approximate duty cycle so that it works less hard to get there next time?
    - If I start adding boost slowly (8 PSI instead of 6.5 PSI) knowing that it might overshoot, do they usually stay withing 1-2 PSI or it can overshoot by +/-10 PSI?

    I see a lot of tutorials with dome pressure control, 4 ports, Open Loop, and 3 ports, and plumbed with the top of the wastegate also. I just can't seem to find much on just a 3 port vented from the bottom of the wastegate port. Sorry if some of these questions make no sense or seems stupid. Thank you!
    Last edited by YellowSVT; 05-16-2022 at 05:22 AM.

  2. #2
    Join Date
    Dec 2009


    If this isn't helpful, just ignore it:
    Originally Posted by Danny Cabral
    Holley EFI Boost Control Quick Start Guide: (A Step-By-Step Example)
    Holley EFI Boost Control Instruction Manual: (Full Fundamental Instructions)

    Holley EFI 557-200 Boost Control 3-Port Solenoid Valves, 1 "Fill" & 1 "Vent": (Tech Resources Supplement For Proper Wiring)
    Holley EFI 557-201 High Flow Dual Solenoid Boost Control Kit: (Tech Resources Supplement For Proper Wiring) (Shop Air Tuning PID Boost Control)
    Originally Posted by Danny Cabral
    The Holley EFI electronic boost controller uses one input & two outputs for the dual boost solenoid control type.
    The "Boost −" solenoid is the "Vent" solenoid, and the "Boost +" solenoid is the "Fill" solenoid. Both are Outputs.
    The solenoid +/− "Output Type" is selected in the Inputs/Outputs screen of the Boost ICF, then Pin-Mapped. (Boost Solenoid Wiring - Figure 21, Page 11)

    The HP ECU should use PWM− type of Output for the boost solenoids (LINK).
    The Dominator ECU can use either type of Output (PWM− or PWM+) for the boost solenoids.
    However, if using the PWM+ Outputs, they should be wired on the J2B connector. (Holley EFI Wiring Manual - Section 2.1 "Pin-Outs", Pages 6, 7 & 8)

    The dome pressure sensor should be a 554-102 pressure transducer, or a 554-108 5 bar MAP sensor (depending on your
    boost psi - LINK). (Dome Pressure Sensor Wiring)
    Originally Posted by Danny Cabral
    Boost ICF (Individual Configuration File):
    The Boost function is an "Individual Configuration" of the Holley EFI software.
    It's an electronic boost controller. If your forced induction is entirely mechanical, you don't need it.
    At top of screen, Click "Toolbox" and "Add Individual Config".
    At top of new window, select "Individual Configuration Library".
    At bottom of new window, select "Holley EFI Boost Config".
    Select "Boost" and open "Sample Config 1 Boost".
    The Boost icon will then be present at top of screen.
    Review Boost menu options to determine which apply to you.
    Ensure you initially set all seven of the Boost "Safety Setup" parameters to "Ignore".
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385"/6.3L SBF, Dart SHP 8.2 block, forged steel crank & rods, forged pistons, Trick Flow T/W 11R 205 CNC comp ported heads, 12:1 comp ratio, 232°-244° duration/.623" lift/114° LSA camshaft, TFS R-Series FTI comp ported intake, BBK 80mm T/B, Holley Dominator MPFI & DIS, Holley 36-1 crank trigger, MSD 1x cam sync, PA PMGR starter, PA 200A 3G alternator, Optima Red battery, 100HP progressive dry direct-port NOS, R134a A/C, Spal dual 12" fans, Frostbite 3-core aluminum radiator, Pypes dual 2.5" exhaust, off-road X-pipe, shorty headers, Earl's -6AN fuel system plumbing, Walbro 255 LPH in-tank pump & Pro-M -6AN hanger, S&W subframe connectors, BMR upper & lower torque box reinforcements, LenTech Strip Terminator wide-ratio AOD, 3000 RPM C6 converter, B&M Hammer shifter, Stifflers transmission crossmember & driveshaft safety loop, FPP aluminum driveshaft, FPP 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 M/T Street Comp tires.

  3. #3


    I would add a VSS and use Boost vs Speed. There are various ways to do this, depending on the transmission that you're using. Andrew

  4. #4


    I'm currently using the GPS Speed from a 6.86" Pro Dash. I do have a configured input coming from the dash to the ECU so that I can see my speed in my datalogs. I'd be afraid that the response time from the GPS would be too slow for Boost vs Speed. Like I said, I only want to be able to up my boost to 10 PSI (from 6.5) I did change the wastegate spring before to get 8.5 PSI, but I would rather just use a boost controller and be able to change it as needed. T56 transmission.

  5. #5


    The best solution for a T56 transmission is to use the Bowler all-in-one T56 box:
    It will handle the reverse lockout solenoid by itself, and also provides two user programmable Hall-Effect speed sensor outputs. One of which can be used as an input to the HP for VSS. Unfortunately, Bowler is currently out of stock. Andrew

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