Piggybacking two PCMs??
#1
Piggybacking two PCMs??
OK Short story, building a TPI 383 For LOW RPM torque to put into a 93 Chevy van.
The van has a 4L60E transmission, and I am hoping I can piggy back the PCM for the TPI on top of it so the original PCM can control the transmission and the TPI controls the fuel.
Can it be done??
IF yes any tips of information on how to do it?
Thanks in advance.
Rich
The van has a 4L60E transmission, and I am hoping I can piggy back the PCM for the TPI on top of it so the original PCM can control the transmission and the TPI controls the fuel.
Can it be done??
IF yes any tips of information on how to do it?
Thanks in advance.
Rich
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Car: check
Engine: check
Transmission: check
Re: Piggybacking two PCMs??
It is do-able. Need to share the common stuff such as battery feed, ignition switch feed and grounds.
Then for sensors need to share the distributor ref high and ref low, TPS and VSS.
Move from the stock PCM to the added ECM the engine control terminals/wires. IAC, injectors, MAP, EGR, CTS, O2 gnd and signal, 5V ref and so on.
RBob.
Then for sensors need to share the distributor ref high and ref low, TPS and VSS.
Move from the stock PCM to the added ECM the engine control terminals/wires. IAC, injectors, MAP, EGR, CTS, O2 gnd and signal, 5V ref and so on.
RBob.
#5
Re: Piggybacking two PCMs??
This is why I asked this question.
Rich
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Re: Piggybacking two PCMs??
RBob.
#7
Re: Piggybacking two PCMs??
Thanks, I need to figure out what sensors the transmission PCM will need.
VSS, throttle position, RPMs?? I believe the TBI Computer uses a MAP to adding one along with the fuel PCM’s MAF so each is all by themselves should be easy.
At this time I cannot think I need any more sensors…the Transmission PCM needs...at lease to control the shifting, it might freak out lacking the rest?
Rich
VSS, throttle position, RPMs?? I believe the TBI Computer uses a MAP to adding one along with the fuel PCM’s MAF so each is all by themselves should be easy.
At this time I cannot think I need any more sensors…the Transmission PCM needs...at lease to control the shifting, it might freak out lacking the rest?
Rich
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Car: '88 Formula, '94 Corvette, '95 Bird
Engine: LC9, 355" LT1, LT1
Transmission: T5, Zf6, 4L60E
Axle/Gears: 3.42, Dana44 3.45, 3.23
Re: Piggybacking two PCMs??
It's not a fantastic idea to piggy back ECU's in general unless they are communicating over CAN. My attitude is spend a few more bucks and buy a standalone that can do EVERYTHING you need done.
-- Joe
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Car: '88 Formula, '94 Corvette, '95 Bird
Engine: LC9, 355" LT1, LT1
Transmission: T5, Zf6, 4L60E
Axle/Gears: 3.42, Dana44 3.45, 3.23
Re: Piggybacking two PCMs??
Thanks, I need to figure out what sensors the transmission PCM will need.
VSS, throttle position, RPMs?? I believe the TBI Computer uses a MAP to adding one along with the fuel PCM’s MAF so each is all by themselves should be easy.
At this time I cannot think I need any more sensors…the Transmission PCM needs...at lease to control the shifting, it might freak out lacking the rest?
Rich
VSS, throttle position, RPMs?? I believe the TBI Computer uses a MAP to adding one along with the fuel PCM’s MAF so each is all by themselves should be easy.
At this time I cannot think I need any more sensors…the Transmission PCM needs...at lease to control the shifting, it might freak out lacking the rest?
Rich
-- Joe
#10
Re: Piggybacking two PCMs??
This should be cheaper than buying a eprom burner and a eprom eraser and a few eproms.
This card runs around $300.00 I do not think any good after market PCM will do cost that little.
And how about running both PCM's 5 volt supplies together, thus provide enough amps to carry the system??
Rich
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Car: '88 Formula, '94 Corvette, '95 Bird
Engine: LC9, 355" LT1, LT1
Transmission: T5, Zf6, 4L60E
Axle/Gears: 3.42, Dana44 3.45, 3.23
Re: Piggybacking two PCMs??
I am trying to use the original Camaro PCM both for it controlling the Fuel Injection but also for its hidden feature of High Way Mode to farther improve MPG, and later to buy a add on card to allow flashing the program chip and to allow full control of all settings including High Way Mode.
This should be cheaper than buying a eprom burner and a eprom eraser and a few eproms.
This card runs around $300.00 I do not think any good after market PCM will do cost that little.
And how about running both PCM's 5 volt supplies together, thus provide enough amps to carry the system??
Rich
This should be cheaper than buying a eprom burner and a eprom eraser and a few eproms.
This card runs around $300.00 I do not think any good after market PCM will do cost that little.
And how about running both PCM's 5 volt supplies together, thus provide enough amps to carry the system??
Rich
Don't tie the vrefs together.
-- Joe
#12
Re: Piggybacking two PCMs??
Or perhaps I need to add a stronger higher AMP 5 volt supply to run both??
As for the Van:
Well the van has plenty of power as she stood. Especially off the line where is counts. This new motor should be a little better at take off. But the darn thing seems to get 14 MPG no matter what. And sadly I lost a oil line to a cooler and then lost the motor, so want to try for a little better MPG.
Everything seems to point to what I plan, a low torque peek so I can gear for it as cruising speed and under 2000 RPMs at the same time.
I think my idea of adding a second old Borg Warner Over Drive will do the trick, I can drop 3rd gear+ OD and have a good gearing at lower speeds and then at higher switch to 4th (OD) + 5th (OD too) and drive at say 75/80MPG and be doing under 2000RPMs. AND by having my torque peek there as well I will not NOT be lugging the engine, rather be running it in its prime.
Then add in the climes of TPI Giving 30% more torque, HP and Mileage...
And then add in the High Way Mode that is on record here for getting 20/25 MPG Camaros to 30/35 MPG, well that should also help.
I have cars that will get 25/30 Highway MPG stock, it is a little hard to take out a Van that at best gets 14 MPG, but get IT to run in the 20s, well it is easier to use it.
Get it to say 25MPG on the highway, even better.
I believe I can reach 20MPG, any thing over that is gravy.
It is a great van, just needs to cure iits drinking problem.
Rich
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