Running a 6.0 LQ4 on an 8.1 ECM/cal

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March 3rd, 2015
DURAtotheMAX

Running a 6.0 LQ4 on an 8.1 ECM/cal

Quick question for the LSx tuning guru's...

I have a customer who wants to put an Allison behind an LQ4. What im planning on doing is one of two things:

1) Modify a factory 8.1/Allison harness to work with the LQ4 engine.
2) Modify a factory 6.0 harness to integrate the Allison wiring into it. <--- most likely option

Since an Allison/8.1 was a factory option, it will obviously all "work". I just have to re-tune the 8.1 calibration/ECM to be happy running an LQ4. Its just going to be stock, no crazy performance mods, etc. Am I stupid for thinking that I can just copy-pasta 6.0 LQ4 tables into an 8.1 tune and be good to go?

Does anyone know what the differences are (if any) with an LQ4 throttle body/TAC module and an 8.1 throttle body/TAC module?? I know the 01-02 stuff is different than 03-05 stuff, and then in 06-07 I think the TAC module and pedal changed. So Ill probably just use 03-05 stuff...

Thoughts/ideas?

Thanks
Ben
March 6th, 2015
Brads_rs

I think the TB in 2002 are the same between the 6.0 and 8.1 only difference is the one has coolant run through it and one doesn't. The tac and pedal are the same. Maybe someone can confirm or dismiss this. Im about 80% sure on this. If i get time ill try and run the part numbers.

As for tuning i haven't done this transplant but i have had lots of luck swapping transmission segments in pcms with no problems, (less work than copy and past all the values). Problem is finding two tunes with the same os to copy from.
March 8th, 2015
RADustin

did an 8.1 come with a 4L80? I think so..

If so just make a script between a 8.1/4L80 and 8.1/ally-> then apply to the 6.0 cal. that is how you can beat the OS having to match.
May 4th, 2015
LS-SWAPPER

Quote:

Originally Posted by Brads_rs

I think the TB in 2002 are the same between the 6.0 and 8.1 only difference is the one has coolant run through it and one doesn't. The tac and pedal are the same. Maybe someone can confirm or dismiss this. Im about 80% sure on this. If i get time ill try and run the part numbers.

This is few months old, but I'll throw in my $0.02 in case someone else is reading. The 8.1's that I have seen from the 2001-2002 range have a unique DBW TB, it is wide with the motor sticking to one side. Similar to an LS1 dbw vette, but the motor is on the opposite side iirc. Later on 2003 or 2004 it seems the 8.1s got the more squared off DBW TB like we see on all the 2003-2006 4.8/5.3/6.0s.

Quote:

Originally Posted by RADustin

did an 8.1 come with a 4L80? I think so..

If so just make a script between a 8.1/4L80 and 8.1/ally-> then apply to the 6.0 cal. that is how you can beat the OS having to match.

The 8.1s would have had a 4L80e behind them in the right application. Models that I am aware of are a 2500 Suburban, Avalanche, or Van. As far as I know none of the actual Silverado trucks with the 8.1 had anything other than an Allison.
October 29th, 2022
Anthony1991

Still no answer

Quote:

Originally Posted by LS-SWAPPER

This is few months old, but I'll throw in my $0.02 in case someone else is reading. The 8.1's that I have seen from the 2001-2002 range have a unique DBW TB, it is wide with the motor sticking to one side. Similar to an LS1 dbw vette, but the motor is on the opposite side iirc. Later on 2003 or 2004 it seems the 8.1s got the more squared off DBW TB like we see on all the 2003-2006 4.8/5.3/6.0s.

The 8.1s would have had a 4L80e behind them in the right application. Models that I am aware of are a 2500 Suburban, Avalanche, or Van. As far as I know none of the actual Silverado trucks with the 8.1 had anything other than an Allison.

I am trying to do the same thing but with no luck because I can't find anyone who has successfully done it so the question is can I just put the 6.0 parameters in the 8.1 ECU
October 29th, 2022
Anthony1991

Quote:

Originally Posted by LS-SWAPPER

This is few months old, but I'll throw in my $0.02 in case someone else is reading. The 8.1's that I have seen from the 2001-2002 range have a unique DBW TB, it is wide with the motor sticking to one side. Similar to an LS1 dbw vette, but the motor is on the opposite side iirc. Later on 2003 or 2004 it seems the 8.1s got the more squared off DBW TB like we see on all the 2003-2006 4.8/5.3/6.0s.

The 8.1s would have had a 4L80e behind them in the right application. Models that I am aware of are a 2500 Suburban, Avalanche, or Van. As far as I know none of the actual Silverado trucks with the 8.1 had anything other than an Allison.

Quote:

Originally Posted by DURAtotheMAX

Quick question for the LSx tuning guru's...

I have a customer who wants to put an Allison behind an LQ4. What im planning on doing is one of two things:

1) Modify a factory 8.1/Allison harness to work with the LQ4 engine.
2) Modify a factory 6.0 harness to integrate the Allison wiring into it. <--- most likely option

Since an Allison/8.1 was a factory option, it will obviously all "work". I just have to re-tune the 8.1 calibration/ECM to be happy running an LQ4. Its just going to be stock, no crazy performance mods, etc. Am I stupid for thinking that I can just copy-pasta 6.0 LQ4 tables into an 8.1 tune and be good to go?

Does anyone know what the differences are (if any) with an LQ4 throttle body/TAC module and an 8.1 throttle body/TAC module?? I know the 01-02 stuff is different than 03-05 stuff, and then in 06-07 I think the TAC module and pedal changed. So Ill probably just use 03-05 stuff...

Thoughts/ideas?

Thanks
Ben

I'm trying to do the same thing but I haven't been able to find any one that has successfully done it so the question is can you just put the 6.0 parameters into the 8.1 ECU