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Stock converter stall and general converter discussion

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    Stock converter stall and general converter discussion

    Can someone help a tachometerless brotha out and give me an idea what the stock stall is behind a mildly modified engine? Just the speed the engine gets up to in drive when you press both the gas and the brake to the floor before tire slippage/car movement.


    Also, I'd love to hear any real-world experience from people who have put mild performance converters on their panthers in the under 2600 range. Mileage, driveability, ET changes, etc.

    85 4 door 351 Civi Crown Victoria - Summer daily driver, sleeper in the making, and wildly inappropriate autocross machine
    160KMs 600cfm holley, shorty headers, 2.5" catted exhaust, 255/295 tires, cop shocks, cop swaybars, underdrive pulley, 2.73L gears.
    waiting for install: 3.27's, Poly bushings, boxed rear arms, 2500 stall converter, ported e7's, etc

    06 Mazda 3 hatch 2.3L 5AT (winter beater that cost more than my summer car)

    #2
    Depends on how well your brakes hold. Stall speed of the converter is negated by brake stalling. Stall speed of the converter comes into play from idle to wot from a standing position . Letting off the brake and stabbing the throttle is when converter stall comes into play (called flashing the converter). Stock AOD torque converter shouldnt stall more than 1500 rpm. I foot brake all the time to help reduce will spin on my launch. When i was all stock I could brake stall over 2000rpm but it would spin as soon as i got off the brake.

    2011 Grand Marquis LS Ultimate Edition
    Dual Exhaust w/ AP XLerator mufflers and 3 1/2" tips, Eibach 1" rear sway bar, Pioneer Head unit and speakers, 17X8 Drag DR-72 wheels

    RIP 1984 2Dr Crown Vic "The Millennium Falcon"
    Carbed 5.0 HO w/nitrous , Performer RPM intake, GT40P heads, E303 cam, FRP Shorties, FRP 9mm plug wires, Off-Road H-pipe, Magnaflow round mufflers, 2000 rpm stall
    NA-15.78@91.21, 80hp shot-14.48@96.21

    Comment


      #3
      Originally posted by Smokestacklightnin View Post
      Depends on how well your brakes hold. Stall speed of the converter is negated by brake stalling. Stall speed of the converter comes into play from idle to wot from a standing position . Letting off the brake and stabbing the throttle is when converter stall comes into play (called flashing the converter). Stock AOD torque converter shouldnt stall more than 1500 rpm. I foot brake all the time to help reduce will spin on my launch. When i was all stock I could brake stall over 2000rpm but it would spin as soon as i got off the brake.
      It is actually the opposite. In order to reach the peak converter stall, the car must be stationary. In practical applications, it takes a trans-brake to reach peak stall rpm. The reason many people flash the converter is that the suspension is not "loaded" until right as you are leaving the line. You get the benefits of weight transfer. If you preload the suspension by foot braking, you often times get a worse 60' time and less traction due to less weight transfer.
      Last edited by Mercracer; 01-28-2011, 09:22 PM.

      Comment


        #4
        Originally posted by Mercracer View Post
        It is actually the opposite. In order to reach the peak converter stall, the car must be stationary. In practical applications, it takes a trans-brake to reach peak stall rpm. The reason many people flash the converter is that the suspension is not "loaded" until right as you are leaving the line. You get the benefits of weight transfer. If you preload the suspension by foot braking, you often times get a worse 60' time and less traction due to less weight transfer.

        Are trans brakes as self destructive as they seem? As I understand it, they just lock 1st and reverse together and when you hit it, reverse lets go and power goes to the wheels. Seems like a big shock to everything from the transmission to the tires
        sigpic


        - 1990 Ford LTD Crown Victoria P72 - the street boat - 5.0 liter EFI - Ported HO intake/TB, 90 TC shroud/overflow, Aero airbox/zip tube, Cobra camshaft, 19lb injectors, dual exhaust w/ Magnaflows, Cat/Smog & AC delete, 3G alternator, MOOG chassis parts & KYB cop shocks, 215/70r/15s on 95-97 Merc rims

        - 2007 Ford Escape XLT - soccer mom lifted station wagon - 3.0 Duratec, auto, rear converter delete w/ Magnaflow dual exhaust

        - 2008 Mercury Grand Marquis Ultimate Edition - Daily driver - 4.6 2 valve Mod motor, 4R75E, 2.73s. Bone stock

        Comment


          #5
          Originally posted by 1990LTD View Post
          Are trans brakes as self destructive as they seem? As I understand it, they just lock 1st and reverse together and when you hit it, reverse lets go and power goes to the wheels. Seems like a big shock to everything from the transmission to the tires

          A trans brake is much less severe a shock than what a standard transmission and a clutch are. The converter still acts as a shock absorber although less so when you are at the "stall" RPM.
          Your understanding of the inner workings of an automatic transmission are not quite correct. Gear reduction or overdrive and forward or reverse are a function of different parts of a planetary gear set being held in place. If there is no path for the torque to travel, there is no movement. There are several videos on the web graphically showing how a planetary gear set functions.

          Comment


            #6
            my bad
            sigpic


            - 1990 Ford LTD Crown Victoria P72 - the street boat - 5.0 liter EFI - Ported HO intake/TB, 90 TC shroud/overflow, Aero airbox/zip tube, Cobra camshaft, 19lb injectors, dual exhaust w/ Magnaflows, Cat/Smog & AC delete, 3G alternator, MOOG chassis parts & KYB cop shocks, 215/70r/15s on 95-97 Merc rims

            - 2007 Ford Escape XLT - soccer mom lifted station wagon - 3.0 Duratec, auto, rear converter delete w/ Magnaflow dual exhaust

            - 2008 Mercury Grand Marquis Ultimate Edition - Daily driver - 4.6 2 valve Mod motor, 4R75E, 2.73s. Bone stock

            Comment


              #7
              so I never got a clear answer here, though it led to some interesting points.

              If you have one foot on the brake, one foot on the gas, in a stockish (under 250hp) box panther with a stock converter, what RPM do you hit? Smokestack was the 2000RPM figure holding it with foot brake and with the original trans?

              85 4 door 351 Civi Crown Victoria - Summer daily driver, sleeper in the making, and wildly inappropriate autocross machine
              160KMs 600cfm holley, shorty headers, 2.5" catted exhaust, 255/295 tires, cop shocks, cop swaybars, underdrive pulley, 2.73L gears.
              waiting for install: 3.27's, Poly bushings, boxed rear arms, 2500 stall converter, ported e7's, etc

              06 Mazda 3 hatch 2.3L 5AT (winter beater that cost more than my summer car)

              Comment


                #8
                I haven't driven my car that much, but I did blast it around in the parking lot before storing it. Even with the carb stumble, I could footbrake it up over 2000 rpm. I think my car has a supercoupe converter, though.

                I'm planning a 2800-3000 stall unit, though.
                **2012 Ford Mustang Boss 302: 5.0/ 6 spd/ 3.73s, 20K Cruiser
                **2006 MGM,"Ultimate": 4.6/ 2.73/ Dark Tint, Magnaflows, 19s, 115K Daily Driver
                **2012 Harley Davidson Wide Glide (FXDWG):103/ Cobra Speedsters/ Cosmetics, 9K Poseur HD Rider
                **1976 Ford F-150 4WD: 360, 4 spd, 3.50s, factory A/C, 4" lift, Bilsteins, US Indy Mags, 35s Truck Duties

                Comment


                  #9
                  I will be able to give you info on stock stall vs a 3000rpm stall as soon as I stop buying other stuff lol.


                  '90 LX 5.0 mustang
                  Big plans

                  Comment


                    #10
                    thank the lord my DMM has a TACH function
                    1985 Mercury Grand Marquis ls-302 CFI
                    Carb swap planned .
                    c90 heads
                    475 lift cam
                    Weind stealth intake(looking for reasonable air gap or manifold for 2bblsidedraft)
                    Built aod(want c6 tryin to fin vac mod model)
                    331 stroker kit
                    Work in progress

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