Mike,
The limited research I have done says that the signal to the solenoid is a
digital one. To change the PWM (pulse width modulation) at the governor
solenoid the frequency and dwell must be modified. These are done via
tables (I think) in the memory of the JET chip. Some (most new) GM
transmissions have an electronically controlled regulator in the
tranasmission that can be modified via analog moethods. This is not the
case for the Mopar trans (from discussions with B&M and etc.)
I hope Im not too garbled..
bruce k bridges
At 01:45 PM 8/3/98 -0400, you wrote:
>Bruce/All
>
>>you are right. The Jet chip must change the pulse width modulation of the
>>governer solenoid. This essentially applies the regulated pressure to the
>>delivery port for "distribution" to the rest of the transmission. Its like
>>a chopper regulator in an electronic circuit. it can either be W/O and
>>deliver full pressure, or modulate the pressure by rapidly opening and
>>closing, say 0-100% duty cycle.
>
>OK, so if JET does modify the shift firmness then they have to
>be doing this via resistors or some other electronic means since
>the "chip" is actually an external module.
>If this is indeed the case, then, as Gene mentioned in earlier post,
>the shift firmness *might* be able to be change like we have done
>on our Impala's. I used a 20 ohm/10 watt resistor on my Impala
>and my part throttle shifts are firm and crisp. The WOT shift
>firmness is unaffected because the PCM uses full line pressure
>anyways. This is where the shift kit(s) really help.
>
>If someone can determine how the line pressure is controlled,
>current/voltage, values associated with this and what terminals are used
>we may be able to do an inexpensive partial shift kit.
>Unfortunately, I haven't sprung for the FSM yet, so until I can get
>some #'s from the FSM I can't confirm whether this can be done or not.
>Obviously, this is only true for the electronically controlled
>transmissions.
>
>Mike Marx
>'98 Durango (ducking;-))
>'95 Impala SS
>
>
>
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