ECM Clarification
Thread Starter
Racer
Joined: Jan 2020
Posts: 470
Likes: 276
From: So. Maine
ECM Clarification
I have read the threads regarding the 84 ECM installation into an 82. However, I am slightly confused, maybe more than slightly. I understand that an 84 ECM for an automatic is compatible with an 82. My question is do I use an 82 PROM or an 84 Prom?
As always, clarification is greatly appreciated.
As always, clarification is greatly appreciated.
Thread Starter
Racer
Joined: Jan 2020
Posts: 470
Likes: 276
From: So. Maine
Fast81 - I may not be making myself clear.
It is my understanding from reading threads on this site that upgrading from an 82 ECM to an 84 ECM has inherit advantages, IE drivability improvements, throttle response time.
If I upgrade to an 84 ECM do I need the PROM for an 84 or 82?
Does upgrading to a Hypertec PROM for an 82 provide previously stated upgrade capabilities?
It is my understanding from reading threads on this site that upgrading from an 82 ECM to an 84 ECM has inherit advantages, IE drivability improvements, throttle response time.
If I upgrade to an 84 ECM do I need the PROM for an 84 or 82?
Does upgrading to a Hypertec PROM for an 82 provide previously stated upgrade capabilities?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
I don't know for sure, but I would think that an '84 ECM should get the "84 PROM. It is possible that an updated PROM might not be compatible with the '82 ECM.
The drive trains were essentially the same; but there were 'improvements' in 1984. And some of them might not be translatable.
The drive trains were essentially the same; but there were 'improvements' in 1984. And some of them might not be translatable.
Last edited by 7T1vette; Feb 14, 2020 at 05:17 PM.
Melting Slicks
Joined: Aug 2003
Posts: 3,415
Likes: 291
From: dayton oh
I'm not THE resident XFire expert (his name is Bucanner) but i dont think you'd know the difference between an 82 ECM with a hypertech chip and an 84 with its hypertech too.
The chip for either advances the timing a bit and delays the TC lockup to prevent the low RPM lugging GM created while chasing every % of MPG - thereby making the car feel more responsive and powerful.
Some swear BY them, some swear AT them
I have a stock 82 ECM with a hypertech "off road" version running a ZZ4 crate motor under a modified XFire top-end (renegade intake, 90lb injectors)
The chip for either advances the timing a bit and delays the TC lockup to prevent the low RPM lugging GM created while chasing every % of MPG - thereby making the car feel more responsive and powerful.
Some swear BY them, some swear AT them
I have a stock 82 ECM with a hypertech "off road" version running a ZZ4 crate motor under a modified XFire top-end (renegade intake, 90lb injectors)
Thread Starter
Racer
Joined: Jan 2020
Posts: 470
Likes: 276
From: So. Maine
7T1vette
I agree that it makes logical sense that an 82 prom would go into an 82 ECM and the same for an 84. I have read that the 84 ECM is compatible with an 82. What I am researching s if I purchase an 84 ECM could I use my current GM standard 82 PROM. The current ECM is fine it is just that I have read that the 84 offers improvements to the 82.
I agree that it makes logical sense that an 82 prom would go into an 82 ECM and the same for an 84. I have read that the 84 ECM is compatible with an 82. What I am researching s if I purchase an 84 ECM could I use my current GM standard 82 PROM. The current ECM is fine it is just that I have read that the 84 offers improvements to the 82.
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Melting Slicks
Joined: May 2015
Posts: 2,365
Likes: 428
From: Cape Girardeau Missouri
Did some searching and from everything I find you use the '84 EPROM with the '84 ECM. Note that the EPROM MUST be for an automatic!
I wouldn't expect mudh/any performance change. From what I find the main reason for the swap is that replacement ECMs for a '82 are far more expensive than for an '84. The '84 CPU does have a faster clock speed and [may] offer more diagnostic tools--I'm not sure.
I wouldn't expect mudh/any performance change. From what I find the main reason for the swap is that replacement ECMs for a '82 are far more expensive than for an '84. The '84 CPU does have a faster clock speed and [may] offer more diagnostic tools--I'm not sure.