Possible to swap an 8.1L into a GMT900 truck?
11-07-2015, 08:53 AM
#11
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EFI connection makes an adapter kit:
EFI Connection, LLC - EFI Connection 58x BBC System
58x System for Gen VI BBC Engines
EFI Connection's 58x system for Gen VI BBC engines is a 58x crank and 4x cam signal solution that satisfies the crank/cam signal requirements of all GM Gen IV LS-Series ECMs and aftermarket ECUs compatible with Gen IV LS-Series engines. Our customers are using our 58x conversions with FAST and Holley EFI.
EFI Connection's 58x system for Gen VI BBC engines is a 58x crank and 4x cam signal solution that satisfies the crank/cam signal requirements of all GM Gen IV LS-Series ECMs and aftermarket ECUs compatible with Gen IV LS-Series engines. Our customers are using our 58x conversions with FAST and Holley EFI.
11-08-2015, 12:19 AM
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EFI connection makes an adapter kit:
EFI Connection, LLC - EFI Connection 58x BBC System
This is why I wonder about the 2007 and up ECM - and whether or not it would run the 8.1L , because all the other potential sticking points - appear to have solutions.
EFI Connection, LLC - EFI Connection 58x BBC System
This is why I wonder about the 2007 and up ECM - and whether or not it would run the 8.1L , because all the other potential sticking points - appear to have solutions.
11-08-2015, 12:58 PM
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If you pick up the kit above, everything should be simple for your tuner. You'll just need to dial the air/fuel in and away you go. Our shop suburban and shop corvette both run stock LS computers with modifications to the program for the added displacement without any issues.
I haven't done a ton of reading up on this yet, but my understanding is that the later year GMT900 (2007 and up) - use a different engine computer - the E38. There are other changes too - the transmission control module is now separate - and I believe it was the 2009 and up trucks came with VVT (variable valve timing).
What I would REALLY like to do - if this whole thing comes together and looks like a feasible project, is to put a 6spd behind the 8.1L. I'm reading up on this - and I'm not sure if the Allison or the 6L90 would be a better choice. Not sure if an Allison - even if it had a separate control module - could be made to work behind a gas engine running from an E30 ECM.
Lots of details to try and work out.
Just for the record my goal here is to have a truck that can be hooked up the OBDII during the inspection process - and have it pass. In this state up to 2007 or 2008 - there was no emissions test. After that - 8600 GVWR trucks started getting emissions inspected. But they just hook it up to OBDII and call it good if it passes that.
This is part of the reason why I'm avoiding diesel - you'd have to be half retarded to not notice a truck has a diesel engine under the hood - emission inspection or not. With a gas engine - they'd REALLY have to know what they were looking for to even notice. I know in CA they get really picky - out here not so much. They just hook up to OBDII and call it a day.
11-09-2015, 07:46 PM
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Thanks - but you're running the earlier gen electronics though aren't you (from the GMT800 series) ?
I haven't done a ton of reading up on this yet, but my understanding is that the later year GMT900 (2007 and up) - use a different engine computer - the E38. There are other changes too - the transmission control module is now separate - and I believe it was the 2009 and up trucks came with VVT (variable valve timing).
What I would REALLY like to do - if this whole thing comes together and looks like a feasible project, is to put a 6spd behind the 8.1L. I'm reading up on this - and I'm not sure if the Allison or the 6L90 would be a better choice. Not sure if an Allison - even if it had a separate control module - could be made to work behind a gas engine running from an E30 ECM.
Lots of details to try and work out.
Just for the record my goal here is to have a truck that can be hooked up the OBDII during the inspection process - and have it pass. In this state up to 2007 or 2008 - there was no emissions test. After that - 8600 GVWR trucks started getting emissions inspected. But they just hook it up to OBDII and call it good if it passes that.
This is part of the reason why I'm avoiding diesel - you'd have to be half retarded to not notice a truck has a diesel engine under the hood - emission inspection or not. With a gas engine - they'd REALLY have to know what they were looking for to even notice. I know in CA they get really picky - out here not so much. They just hook up to OBDII and call it a day.
I haven't done a ton of reading up on this yet, but my understanding is that the later year GMT900 (2007 and up) - use a different engine computer - the E38. There are other changes too - the transmission control module is now separate - and I believe it was the 2009 and up trucks came with VVT (variable valve timing).
What I would REALLY like to do - if this whole thing comes together and looks like a feasible project, is to put a 6spd behind the 8.1L. I'm reading up on this - and I'm not sure if the Allison or the 6L90 would be a better choice. Not sure if an Allison - even if it had a separate control module - could be made to work behind a gas engine running from an E30 ECM.
Lots of details to try and work out.
Just for the record my goal here is to have a truck that can be hooked up the OBDII during the inspection process - and have it pass. In this state up to 2007 or 2008 - there was no emissions test. After that - 8600 GVWR trucks started getting emissions inspected. But they just hook it up to OBDII and call it good if it passes that.
This is part of the reason why I'm avoiding diesel - you'd have to be half retarded to not notice a truck has a diesel engine under the hood - emission inspection or not. With a gas engine - they'd REALLY have to know what they were looking for to even notice. I know in CA they get really picky - out here not so much. They just hook up to OBDII and call it a day.
Yes we're running LS1/2 computers which the stock vehicles came with. The C5 came with an LS1 / 6 speed and is now running a stage 2 496cid kit on the stock computer. The Suburban was a 6.0 LQ4 / 4L80E and is running the stage 1 540cid kit on the stock computer.
The e38 works the same as the previous LSX computers, it just has more provisions in it for things like VVT (which your tuner will be turning off as the 8.1L doesn't support this feature). I would find a tuner who knows what hes doing with LS3 engines in Corvettes / Camaros and explain to him you're basically just building a great big version of a small block stroker (like the LSX454). If hes tuned a LS2 turned into a 408cid stroker, he'll be able to handle this.
Once tuned, the computer doesn't know the difference between the small or big block. It only knows how much fuel / air / timing to add based on what its seeing from your oxygen sensors and programming.
If it were us, we would build the 8.1L behind the 6 speed auto and forget about the Allison. The separate transmission control unit is similar to GMT800 trucks with the Allison - again, your tuner will be the one to setup all of the shift points and transmission related information.
12-25-2015, 08:19 PM
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Raylar, I am also in San Diego.
I am preparing to swap a 8.1 from a 2002 Suburban donor into a 2006 Express van 6.0. This should be a relatively simple swap but nobody has done it yet (except GM in 2001-02), and if all works out well, a few months from now I would want to put a built 8.1 behind a newer van or Class C RV with a 6-speed.
1) Will the L18 bolt to a 6L90E? It seems that it should with no issues, but EFI Connection website states "Bolting a 6L80E/6L90E transmission to a non-LS engine will require fabrication skills."
2) What tool will I need to use to install a 58x wheel on a 8.1 crank and line it correctly?
3) Will you be able to tune this project so it runs?
Artem.
I am preparing to swap a 8.1 from a 2002 Suburban donor into a 2006 Express van 6.0. This should be a relatively simple swap but nobody has done it yet (except GM in 2001-02), and if all works out well, a few months from now I would want to put a built 8.1 behind a newer van or Class C RV with a 6-speed.
1) Will the L18 bolt to a 6L90E? It seems that it should with no issues, but EFI Connection website states "Bolting a 6L80E/6L90E transmission to a non-LS engine will require fabrication skills."
2) What tool will I need to use to install a 58x wheel on a 8.1 crank and line it correctly?
3) Will you be able to tune this project so it runs?
Artem.
12-30-2015, 01:07 PM
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Raylar, I am also in San Diego.
I am preparing to swap a 8.1 from a 2002 Suburban donor into a 2006 Express van 6.0. This should be a relatively simple swap but nobody has done it yet (except GM in 2001-02), and if all works out well, a few months from now I would want to put a built 8.1 behind a newer van or Class C RV with a 6-speed.
1) Will the L18 bolt to a 6L90E? It seems that it should with no issues, but EFI Connection website states "Bolting a 6L80E/6L90E transmission to a non-LS engine will require fabrication skills."
2) What tool will I need to use to install a 58x wheel on a 8.1 crank and line it correctly?
3) Will you be able to tune this project so it runs?
Artem.
I am preparing to swap a 8.1 from a 2002 Suburban donor into a 2006 Express van 6.0. This should be a relatively simple swap but nobody has done it yet (except GM in 2001-02), and if all works out well, a few months from now I would want to put a built 8.1 behind a newer van or Class C RV with a 6-speed.
1) Will the L18 bolt to a 6L90E? It seems that it should with no issues, but EFI Connection website states "Bolting a 6L80E/6L90E transmission to a non-LS engine will require fabrication skills."
2) What tool will I need to use to install a 58x wheel on a 8.1 crank and line it correctly?
3) Will you be able to tune this project so it runs?
Artem.
Don't know that you'll need any special tools for the job, though this link may be interesting to you.https://www.lingenfelter.com/sites/l....6%20small.pdf
We don't do tuning, but we know lots of people who do. In San Diego, your best bet for a dyno tune is Excelsior Motorsports or for a mail order tune Black Bear Performance. Take a look at our tuning page for more information on either of these companies.
If you have any more questions, feel free to call the shop and / or drop by. Larry should be able to answer just about anything you throw at him.
01-05-2016, 05:48 PM
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Don't know that you'll need any special tools for the job, though this link may be interesting to you.https://www.lingenfelter.com/sites/l....6%20small.pdf
We don't do tuning, but we know lots of people who do. In San Diego, your best bet for a dyno tune is Excelsior Motorsports or for a mail order tune Black Bear Performance. Take a look at our tuning page for more information on either of these companies.
If you have any more questions, feel free to call the shop and / or drop by. Larry should be able to answer just about anything you throw at him.
We don't do tuning, but we know lots of people who do. In San Diego, your best bet for a dyno tune is Excelsior Motorsports or for a mail order tune Black Bear Performance. Take a look at our tuning page for more information on either of these companies.
If you have any more questions, feel free to call the shop and / or drop by. Larry should be able to answer just about anything you throw at him.
For tuning, seems to me I'm better off buying my own EFI Live. Do you know how you went about different firing order on the 8.1 vs LQ4? Do you know if your tuner has locked the tune?
02-03-2016, 08:23 PM
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Figure it out?
OP, did you ever get the details figured out? It sounds like you have a good set up, the real issue is when you try to run the gen IV ECM in the Gen III trucks, ending up having weird set ups. I was under the impression you could almost use a tune off an LQ4 for an L18. I have an 01 RCSB Sierra and find used 8.1L's all the time for 4-500 and always wonder how much fun it'd be to build it, stuff it under the hood mated to a 4l80e and call it a day(or year). Looks like Ray Eng has done it a couple times before...