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Automatic TransmissionHigh Impact 518/618 “Bad Boy” [47RH 47RE 48RE] |
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BAD BOY Transmission:
There a number
of standard upgrades used in Bad boy units, such as an upgraded HD
torque converter with furnace brazed turbine elements and HD lock up
clutches, oversize sprags, upgraded pressure regulator and reverse boost
valve, and internal modifications for improved oiling and shifting. This transmission requires a computer for shift control. (Early 518 [47RH] units only controlled overdrive (and torque converter lockup when present) with the computer, however due to the nature of this trans it does not lend itself to simple non-computer control). The Factory Dodge computer used in vehicles with a 518 or 618 trans 1994 and up will work. Other systems will require the use of an aftermarket programmable Control Module. Power Capacity: 800 ft-lbs of torque, 800 HP. Controlling Dodge 47rh / 47re / 48re without the stock ECM: 95 and earlier trannies (designated –rh) The earliest version of the RH trans did not have a lockup converter. In 94 a lockup converter was introduced to the RH. Even though the RH is designated H, overdrive (and when present TC lockup) use solenoid(s) to turn on and off hydraulic fluid pressure to actuate these functions. These functions are controlled in an on-off electrical manner in a RH tranny. The 94 up trans with lock-up has a place in the trans for the lockup solenoid and has fluid passages that do not exist in the earlier non-locking 74RH On these transmissions it is possible to use a pressure switch on the governor pressure rail. Since governor pressure is directly proportional to vehicle speed, you can then set a speed for control. Once the trans is locked into OD, it will not downshift even at full throttle until the lock is shut off. Thus a throttle position detent sw must be installed to open the circuit under full throttle so it will downshift. Another problem is the converter clutches in the 47RH will not handle high throttle or engine braking. So the above w would not be full throttle, it would need to be set at maybe 2/3 or 3/4 throttle to prevent clutch damage. And clutch engagement must be disallowed for engine braking so a zero throttle release sw must be put in. You will need to get all this working and tweaked out so it works and the trans is reliable. It can be done. It is not something I can provide turnkey, and as it is fraught with many possible trans failure possibilities, I cannot guarantee it. 96-up trannies (designated –re) Were also not
true electronic trannies, in that 1-2-3- shifts are still hydraulic
controlled. They DID however - rather than use a cable to set throttle
position control like they did in the –rh trannies – decide to use a
PWM (pulse width modulated – a sort of digital control signal) to
operate a pressure control solenoid in the valve body. This is not simply
an on-off solenoid, it controls a variable pressure and REQUIRES a PWM
driver to control it. So the above “analog system will not work. It IS possible to control this function with the Powertrain Control Solutions Transmission Control Module. There are two ways:
Full data on the controller we use: Powertrain Control Solutions TCM Toll Free 888-316-2940 |
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