C4 LS swap a different perspective
Burning Brakes
Joined: Sep 2016
Posts: 1,133
Likes: 319
From: Ohio
Cool. How do I, for pennies, feed the Gen III PCM OBD II engine data to my 8192 baud CCM so that my original gauges work? I don't want to toss the original gauges because a lot of vehicle diagnostic information is displayed there. And I do use that data. I recently diagnosed a no-crank condition using the CCM diagnostic mode.
You've already talked yourself out of the swap. Move on.
Instructor
Joined: Jun 2019
Posts: 105
Likes: 15
From: Portland, Oregon
I think the gauge cluster and A/C issues are just excuses for a lot of these guys because they hate the LS swap idea in general.
If you install an LS, the car becomes unoriginal so what difference does it really make if you install an aftermarket gauge cluster?
I can understand folks not wanting to hack the K-member for the C5 A/C compressor location as there really is no reversal of that, but not wanting to do a swap because you can't use 24-30 year old gauges seems like a weak argument to me.
If you install an LS, the car becomes unoriginal so what difference does it really make if you install an aftermarket gauge cluster?
I can understand folks not wanting to hack the K-member for the C5 A/C compressor location as there really is no reversal of that, but not wanting to do a swap because you can't use 24-30 year old gauges seems like a weak argument to me.
Instructor
Joined: Jun 2019
Posts: 105
Likes: 15
From: Portland, Oregon
Melting Slicks
Joined: Mar 2016
Posts: 2,778
Likes: 580
From: Langley BC
In my comment I was referring to the gauges in the Pre 1990 C4's. The later C4's are more complicated. However I'm quite sure it can be done. I've Done a fair bit of reading/ research in preparation to LS swap my 88' and I have some threads/articles bookmarked Where later C4's had LS swaps completed:
I think this one was a 1992...
https://ls1tech.com/forums/conversio...-t56-swap.html
I think this one is a 1991...
https://ls1tech.com/forums/conversio...my-swap-2.html
And another 1991 swap....
https://lsswap.parts/1991-corvette-c4-ls3-tr6060-swap/
You'll have to spend the time to read through these threads as I don't remember What page number talked about the dash etc....But if your considering an LS swap then it will be time Well spent.
2 of the threads linked above are by corvette forum members that still respond to PM's so any questions you have after reading the threads they can proabbly answer for you.
Best of Luck!
I think this one was a 1992...
https://ls1tech.com/forums/conversio...-t56-swap.html
I think this one is a 1991...
https://ls1tech.com/forums/conversio...my-swap-2.html
And another 1991 swap....
https://lsswap.parts/1991-corvette-c4-ls3-tr6060-swap/
You'll have to spend the time to read through these threads as I don't remember What page number talked about the dash etc....But if your considering an LS swap then it will be time Well spent.
2 of the threads linked above are by corvette forum members that still respond to PM's so any questions you have after reading the threads they can proabbly answer for you.
Best of Luck!
Last edited by DMITTZ; Dec 23, 2019 at 06:22 PM.
Le Mans Master
Joined: Aug 2017
Posts: 6,942
Likes: 1,490
From: New Jersey
Cool. How do I, for pennies, feed the Gen III PCM OBD II engine data to my 8192 baud CCM so that my original gauges work? I don't want to toss the original gauges because a lot of vehicle diagnostic information is displayed there. And I do use that data. I recently diagnosed a no-crank condition using the CCM diagnostic mode.
And I didn't say the factory gauges. They're ****. Ditch them. If you're hacking the thing up to get it in there originality is of least concern.
Burning Brakes
Joined: Sep 2016
Posts: 1,133
Likes: 319
From: Ohio
I use a tablet for my gauges.
I have FAR more gauge options than the factory cluster as well as being able to design my own layouts and view custom sensors, all of my music pre-loaded as well as satellite radio, GPS navigation, GPS datalogging, ECU datalogging, check-engine light diagnosis, heads-up display capability, touch-screen functionality, built in acceleromoter, cameras, GPS tracking if it gets stolen, I could go on and on.
Ditch the factory crap cluster, wire your interior to operate independently of the CCM. Stop letting the factory cluster keep your car from being a considerably more enjoyable experience. The End.
I have FAR more gauge options than the factory cluster as well as being able to design my own layouts and view custom sensors, all of my music pre-loaded as well as satellite radio, GPS navigation, GPS datalogging, ECU datalogging, check-engine light diagnosis, heads-up display capability, touch-screen functionality, built in acceleromoter, cameras, GPS tracking if it gets stolen, I could go on and on.
Ditch the factory crap cluster, wire your interior to operate independently of the CCM. Stop letting the factory cluster keep your car from being a considerably more enjoyable experience. The End.
Last edited by JoeNova; Dec 24, 2019 at 10:20 AM.
Melting Slicks
Joined: Mar 2016
Posts: 2,778
Likes: 580
From: Langley BC
As I had referenced in my earlier comments I'm pretty sure you can make the stock gauges work on a late C4 with LS swap....
But here is another option that looks pretty sharp if you want to ditch the factory gauges...
http://vettaid.com/dash-kits-for-the...996-corvettes/
Hope that helps....
But here is another option that looks pretty sharp if you want to ditch the factory gauges...
http://vettaid.com/dash-kits-for-the...996-corvettes/
Hope that helps....
Last edited by DMITTZ; Dec 24, 2019 at 10:41 AM.
Instructor
Joined: Jun 2019
Posts: 105
Likes: 15
From: Portland, Oregon
I use a tablet for my gauges.
I have FAR more gauge options than the factory cluster as well as being able to design my own layouts and view custom sensors, all of my music pre-loaded as well as satellite radio, GPS navigation, GPS datalogging, ECU datalogging, check-engine light diagnosis, heads-up display capability, touch-screen functionality, built in acceleromoter, cameras, GPS tracking if it gets stolen, I could go on and on.
Ditch the factory crap cluster, wire your interior to operate independently of the CCM. Stop letting the factory cluster keep your car from being a considerably more enjoyable experience. The End.
I have FAR more gauge options than the factory cluster as well as being able to design my own layouts and view custom sensors, all of my music pre-loaded as well as satellite radio, GPS navigation, GPS datalogging, ECU datalogging, check-engine light diagnosis, heads-up display capability, touch-screen functionality, built in acceleromoter, cameras, GPS tracking if it gets stolen, I could go on and on.
Ditch the factory crap cluster, wire your interior to operate independently of the CCM. Stop letting the factory cluster keep your car from being a considerably more enjoyable experience. The End.
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Instructor
Joined: Jun 2019
Posts: 105
Likes: 15
From: Portland, Oregon
In my comment I was referring to the gauges in the Pre 1990 C4's. The later C4's are more complicated. However I'm quite sure it can be done. I've Done a fair bit of reading/ research in preparation to LS swap my 88' and I have some threads/articles bookmarked Where later C4's had LS swaps completed:
I think this one was a 1992...
https://ls1tech.com/forums/conversio...-t56-swap.html
I think this one is a 1991...
https://ls1tech.com/forums/conversio...my-swap-2.html
And another 1991 swap....
https://lsswap.parts/1991-corvette-c4-ls3-tr6060-swap/
You'll have to spend the time to read through these threads as I don't remember What page number talked about the dash etc....But if your considering an LS swap then it will be time Well spent.
2 of the threads linked above are by corvette forum members that still respond to PM's so any questions you have after reading the threads they can proabbly answer for you.
Best of Luck!
I think this one was a 1992...
https://ls1tech.com/forums/conversio...-t56-swap.html
I think this one is a 1991...
https://ls1tech.com/forums/conversio...my-swap-2.html
And another 1991 swap....
https://lsswap.parts/1991-corvette-c4-ls3-tr6060-swap/
You'll have to spend the time to read through these threads as I don't remember What page number talked about the dash etc....But if your considering an LS swap then it will be time Well spent.
2 of the threads linked above are by corvette forum members that still respond to PM's so any questions you have after reading the threads they can proabbly answer for you.
Best of Luck!
Edit: I read through the first thread. He's using a Gen 4 PCM and has had VSS problems that are not present with the Gen 3 PCM. He also spent a ton of money which is antithetical to the whole "Cheap LS Power" ethos. I have to go do a little work for my job today so the other threads will have to wait.
Last edited by Joshie225; Dec 24, 2019 at 01:01 PM.
Burning Brakes
Joined: Sep 2016
Posts: 1,133
Likes: 319
From: Ohio
Do you have a list of inputs that the CCM needs from the ECU? That would be a start. Everything I see on every page is something that the Gen 3 PCMs all have outputs for.
Instructor
Joined: Jun 2019
Posts: 105
Likes: 15
From: Portland, Oregon
The '94 PCM passes data over the ALDL serial bus to the CCM. That's E13/F12 Serial Data on page 6. That's where this whole mess breaks down. Torqhead have a solution for this, but I haven't gotten a response from them. I will try again in the new year.
Le Mans Master
Joined: Aug 2017
Posts: 6,942
Likes: 1,490
From: New Jersey
The other alternative is hacking the LT1 ecm to work with the LS but I'd feel that would be next to impossible to have working correctly. The reluctor wheel for the ls crank being the biggest issue I see. You can get around drive by wire and the rest of the sensors however. The later LT1s ran sequential injection so that isn't an issue... this is actually really interesting. Since people do 411 swaps into C/K trucks it may be able to be done...
Instructor
Joined: Jun 2019
Posts: 105
Likes: 15
From: Portland, Oregon
you may, note may, be able to hack the gen 3 serial output and modify the coding to interface with the CCM data stream. However you would need someone who is exceptionally better at coding than I am. But I have seen instances where people go that far into the ecm.
The other alternative is hacking the LT1 ecm to work with the LS but I'd feel that would be next to impossible to have working correctly. The reluctor wheel for the ls crank being the biggest issue I see. You can get around drive by wire and the rest of the sensors however. The later LT1s ran sequential injection so that isn't an issue... this is actually really interesting. Since people do 411 swaps into C/K trucks it may be able to be done...
The other alternative is hacking the LT1 ecm to work with the LS but I'd feel that would be next to impossible to have working correctly. The reluctor wheel for the ls crank being the biggest issue I see. You can get around drive by wire and the rest of the sensors however. The later LT1s ran sequential injection so that isn't an issue... this is actually really interesting. Since people do 411 swaps into C/K trucks it may be able to be done...
I had considered running an LS engine with the LT1 PCM, but the LT1 OptiSpark position information wouldn't be there so there would need to be a box to synthesize that from the 24/58x signals. On the surface this seems far easier that translating Gen 3 PCM data to satisfy the CCM and all the interconnected systems. Of course this gives up having a modern PCM, but the rest of the car stays working. If Torqhead will support C4 LSx swaps then we get better engine hardware, a better PCM and a fully functional late C4 Corvette.
Last edited by Joshie225; Dec 24, 2019 at 01:23 PM.
Melting Slicks
Joined: Mar 2016
Posts: 2,778
Likes: 580
From: Langley BC
Thank you, I am now digging into the first thread. Also, since my post on 12/15 regarding working with the LT1 in my '94 to meet my modest power goals I have bought a '93 with a built engine so the '94 is likely to stay stock. If I want to pursue LS power I'll use the '93 as it's a base car while my '94 is a well optioned Z07 package car.
Edit: I read through the first thread. He's using a Gen 4 PCM and has had VSS problems that are not present with the Gen 3 PCM. He also spent a ton of money which is antithetical to the whole "Cheap LS Power" ethos. I have to go do a little work for my job today so the other threads will have to wait.
Edit: I read through the first thread. He's using a Gen 4 PCM and has had VSS problems that are not present with the Gen 3 PCM. He also spent a ton of money which is antithetical to the whole "Cheap LS Power" ethos. I have to go do a little work for my job today so the other threads will have to wait.
Ya I know you can do a 'Cheap' LS swap and some have accomolished it (at least on early cars)... But ya to do it right gets expensive, at least my swap is getting pretty expensive, but then again a lot of stuff I just choose to do for fun vs need to spend money to make it work. Mine will be similar in cost and scope to the first thread when its all said and done.
For sure if your happy with the output and manners of a modified LTX engine then leave it be. I've had my C4 for 16 years, its had a stock engine, cammed engine, built SR engine etc... so I just want to take it in a new direction doing the LS swap, cause I get bored... and building something is more fun to me than just buying a C6 or C6Z06. But that's just me.
