Lt1 To Lt4 Computer Swap
Thread Starter
Intermediate
Joined: Jun 2008
Posts: 42
Likes: 0
From: Grand Terrace California
Lt1 To Lt4 Computer Swap
Want To Change 1992 Lt1 Computer To 1996 Lt4 Because Am Doing Engine Change...do I Have To Change Harness If So How Much Of Harness...is This Going To Be Real Difficult And Is It Worth It.
Melting Slicks
Joined: Oct 2006
Posts: 2,238
Likes: 10
From: College Station TX
I think you're going about this swap all wrong. You can run an LT4 using your 92 LT1 computer, and this will be way easier than swapping to OBDII. If anything, you want to swap to a 94-95 OBDI setup because it's much easier to tune.
You'll need to swap knock sensors from the LT1 to the LT4. You'll also need to use the LT4 opti harnesss, but it *should* plug into your harness. You'll need to use your 92 ignition parts (ignition control module and coil), but they should bolt right on.
No, it is NOT worth it to swap harnesses. Before you swap harnesses, I'd just swap the heads, cam (or maybe even a bigger cam) and intake onto your LT1 short block. The OBDII stuff is no better, and your early computer will run it just fine with a custom chip, a la PCMForLess.
Not to be a dick, but based on your questions and responses, I doubt your ability to tackle this swap yourself.
You'll need to swap knock sensors from the LT1 to the LT4. You'll also need to use the LT4 opti harnesss, but it *should* plug into your harness. You'll need to use your 92 ignition parts (ignition control module and coil), but they should bolt right on.
No, it is NOT worth it to swap harnesses. Before you swap harnesses, I'd just swap the heads, cam (or maybe even a bigger cam) and intake onto your LT1 short block. The OBDII stuff is no better, and your early computer will run it just fine with a custom chip, a la PCMForLess.
Not to be a dick, but based on your questions and responses, I doubt your ability to tackle this swap yourself.
Thread Starter
Intermediate
Joined: Jun 2008
Posts: 42
Likes: 0
From: Grand Terrace California
Thread Starter
Intermediate
Joined: Jun 2008
Posts: 42
Likes: 0
From: Grand Terrace California
I think you're going about this swap all wrong. You can run an LT4 using your 92 LT1 computer, and this will be way easier than swapping to OBDII. If anything, you want to swap to a 94-95 OBDI setup because it's much easier to tune.
You'll need to swap knock sensors from the LT1 to the LT4. You'll also need to use the LT4 opti harnesss, but it *should* plug into your harness. You'll need to use your 92 ignition parts (ignition control module and coil), but they should bolt right on.
No, it is NOT worth it to swap harnesses. Before you swap harnesses, I'd just swap the heads, cam (or maybe even a bigger cam) and intake onto your LT1 short block. The OBDII stuff is no better, and your early computer will run it just fine with a custom chip, a la PCMForLess.
Not to be a dick, but based on your questions and responses, I doubt your ability to tackle this swap yourself.
You'll need to swap knock sensors from the LT1 to the LT4. You'll also need to use the LT4 opti harnesss, but it *should* plug into your harness. You'll need to use your 92 ignition parts (ignition control module and coil), but they should bolt right on.
No, it is NOT worth it to swap harnesses. Before you swap harnesses, I'd just swap the heads, cam (or maybe even a bigger cam) and intake onto your LT1 short block. The OBDII stuff is no better, and your early computer will run it just fine with a custom chip, a la PCMForLess.
Not to be a dick, but based on your questions and responses, I doubt your ability to tackle this swap yourself.
I have had the 1992 for 15 yrs but always had work done. Am ok
mechanic dont think will have problems except with electronics. The
responses I get from this fourm is extremely helpful...thank you
Melting Slicks
Joined: Oct 2006
Posts: 2,238
Likes: 10
From: College Station TX
92 and 95 are NOT the same.
92-93 are the same, and not interchangeable with anything else. These require you burn a chip to change the tune.
94-95 are OBDI and are the most desirable. These are flashable through the diagnostic port and easy to tune yourself.
96-97 are OBDII. They are physically the same as OBDI and share the same connector, so you can switch between them somewhat easily. Also flashable through the diagnostic port, but you have you buy more expensive software than OBDI ($450).
You're stuck with your 92 computer with that setup.
92-93 are the same, and not interchangeable with anything else. These require you burn a chip to change the tune.
94-95 are OBDI and are the most desirable. These are flashable through the diagnostic port and easy to tune yourself.
96-97 are OBDII. They are physically the same as OBDI and share the same connector, so you can switch between them somewhat easily. Also flashable through the diagnostic port, but you have you buy more expensive software than OBDI ($450).
You're stuck with your 92 computer with that setup.
Le Mans Master
Joined: Apr 2000
Posts: 5,713
Likes: 105
From: Manassas VA
If you are putting a 96 motor in the 92 it will be much easier to move the sensors and harness over from the 92 car to the 96 motor.
Two other issues to deal with, with the computer swap are. 1. how will your new engine computer (pcm) communicate with the cars computer (ccm) It is designed to work with your existing engine computer (ecm) 2. If it is an automatic, the 94 and up are controlled by the computer. 92-93 are not, other then TC lockup.
If you do a search, there was a thread concerning this a few years back. Not sure if you will be able to locate it or not though.....
Two other issues to deal with, with the computer swap are. 1. how will your new engine computer (pcm) communicate with the cars computer (ccm) It is designed to work with your existing engine computer (ecm) 2. If it is an automatic, the 94 and up are controlled by the computer. 92-93 are not, other then TC lockup.
If you do a search, there was a thread concerning this a few years back. Not sure if you will be able to locate it or not though.....
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Le Mans Master
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From: South-central Missouri
MAP vs. MAF vs. OBD-II
Changing to an LT4 is going to introduce a lot of obstacles: OBD-I vs. OBD-II and their attentive sensors and CCM interface differences. And, the fuel management systems are different.
MAP vs. MAF:
82-84 L83 = MAP sensors
85-89 L98 = MAF
90-91 L98 = MAP
92-93 LT1 = MAP
94-96 LT1/LT4 = MAF w/ MAP backup*
I'm not claiming expertise here, but I think I would rebuild/mod the 92 LT1 before I went with the LT4 swap. In the end you can make close to 400 hp with a Hot Cam (or similar) and some head and plenum porting work at the hands of Lloyd Elliott and some LT headers, for example..And, avoid all the ECM headaches, except for a chip, perhaps.
One of the best reads I've come across for our C4s is Charles Probst's book. It soooo clears up so many questions about what makes our cars tick and what to do if they don't!
P.
*"Corvette 1982-2001 Fuel Injection & Electronic Engine Management" by Charles O. Probst, pp. 70-72; Bentley Pub, ISBN 0-8376-0861-9
MAP vs. MAF:
82-84 L83 = MAP sensors
85-89 L98 = MAF
90-91 L98 = MAP
92-93 LT1 = MAP
94-96 LT1/LT4 = MAF w/ MAP backup*
I'm not claiming expertise here, but I think I would rebuild/mod the 92 LT1 before I went with the LT4 swap. In the end you can make close to 400 hp with a Hot Cam (or similar) and some head and plenum porting work at the hands of Lloyd Elliott and some LT headers, for example..And, avoid all the ECM headaches, except for a chip, perhaps.
One of the best reads I've come across for our C4s is Charles Probst's book. It soooo clears up so many questions about what makes our cars tick and what to do if they don't!
P.
*"Corvette 1982-2001 Fuel Injection & Electronic Engine Management" by Charles O. Probst, pp. 70-72; Bentley Pub, ISBN 0-8376-0861-9
