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View Full Version : Concerns for E78 standalone use?



LS-SWAPPER
July 4th, 2018, 03:48 PM
I have a guy wanting to use his original e78 from his 2011 L96 6.0 engine in a swap project. I have some concerns but I know so little about the e78 I wanted to verify that my concerns are legit and that I am not making more out of it.

First off I see evidence that the E78 cannot control discrete fans in any way

2nd I read that it cannot produce any sort of tach output signal outside of the can-bus info..

He wants to run a 4L60e trans behind it because that's what is currently in the vehicle (1997 truck), I have a feeling that isn't even possible.

I would prefer to just set him up with an e38 ecm, t42 tcm, and a harness to match and be done with it.

I would love some input on these ecms, or maybe even a point in the right direction to some other threads. I have searched around some, but I don't feel like I am getting the complete story. Any info is very much appreciated. THANKS!

ScarabEpic22
July 5th, 2018, 06:44 AM
I'll admit, I've only tuned the E78 in my Sonic (factory ECM) so I cant help with the swap part. I will say, compared to an E38 or E67, it will be a bit more difficult for swapping. You'll need to use a T42 regardless to control the 4L60E, but thinking about it, did any E78 ever pair with them or just T43s in V8s and T76 for I4s?

LS-SWAPPER
July 5th, 2018, 06:58 AM
That's what I'm concerned with. As far as I know there was never a t42 with the e78. Not even in the L96 vans. I'm pretty sure they were all 6L90es.

ProperTuningOG
July 5th, 2018, 08:29 AM
Usually if we run into a E78, it gets swapped for an E38 or E67. Definition on them is not that great.

LS-SWAPPER
July 6th, 2018, 04:01 AM
Ok, thanks for the input guys. I see that people rarely use them for a swap. For whatever reason I like to torture myself and try things just to see if I can do them, but in this case it seems like it isn't worth the effort.

Just for my knowledge, am I right about the lack of traditional tach output signal and lack of discreet fan option? What other holdbacks are there? Like I said, I just like to know so I know what I'm dealing with. The next person might want to use a mechanical fan and Dakota digital gauges that get info off the obd2 port, sounds like that would be ok to use the e78...other than the "weird" approach to tuning them.

ScarabEpic22
July 6th, 2018, 05:44 AM
That's what I'm concerned with. As far as I know there was never a t42 with the e78. Not even in the L96 vans. I'm pretty sure they were all 6L90es.

That was my thought as well, I know the HD trucks had E78+T43s too. You could maybe run a swap harness for the T43, but I've only heard of the T42 wiring -> T43 TCM for people wanting to swap 6spds into 4spd vehicles. We're also getting super solution-ny vs just going the easier route of E38+T42 (Express Van would be super easy combo, segment swap the Express 4L80E T42 with a TBSS 4L70E segment).


Ok, thanks for the input guys. I see that people rarely use them for a swap. For whatever reason I like to torture myself and try things just to see if I can do them, but in this case it seems like it isn't worth the effort.

Just for my knowledge, am I right about the lack of traditional tach output signal and lack of discreet fan option? What other holdbacks are there? Like I said, I just like to know so I know what I'm dealing with. The next person might want to use a mechanical fan and Dakota digital gauges that get info off the obd2 port, sounds like that would be ok to use the e78...other than the "weird" approach to tuning them.

I understand the torture bit, I'm always dreaming up crazy swap ideas but then come back to earth when looking at feasibility :)

Have you looked at a Sonic E78 tune file? Im seeing Discrete fans as the factory settings in my file, and the vehicle has efans from the factory. The E78 doesnt have all of the options available that E38/E67s do and you may need to use another software to adjust the efan parameters like E38/E67s or get cax-ing.

For speedo, not sure unfortunately.

ProperTuningOG
July 6th, 2018, 07:04 AM
Even with other software, a truck base and discrete fan has never worked. Tried it with more than one other option......

With the VSS over can. If you can log it in the scanner, odds are you can use the OBD2 to get it to the gauges.

minytrker
July 9th, 2018, 06:28 AM
We just swap them them to E38, to many issues with E78 in swaps and lack of options on trans combinations.

LS-SWAPPER
July 11th, 2018, 05:06 AM
I agree, and that's what I'm doing. My deal is I want to know what those "too many issues" are. I just like to have a full understanding of what's what. Thanks for the input everyone.