LFX engine conversion into LLT
 

Anyone ever taken a LFX engine and installed it into a LLT? My understanding is that it can be done by installing the wiring harness from the LLT In place of the LFX, changing the Throttle body to LLT, adapting the exhaust. I understand everything else should work. Only issue is the high pressure fuel pump in the LFX will throw a code at idle and goes into limp mode unless the idle is raised to 1000 RPM.

Does anyone have any additional knowledge on a conversion such as this and how to overcome the issue discussed other than raising the RPM?

Don't wanna be that guy but out of curiosity why do you want to swap to the LFX? I get it's a more updated/ powerful engine. It would probably be cheaper to just modify the existing LLT

With full bolt ons and tune I easily would take my friend in his lightly modded LFX with no back seats, now with e85 it wouldn't be very close

from a tuning perspective wouldn't it be ideal to have an LFX (E93 ECU)? if the engine needs replacing and it's relatively straightforward - why not i say.

I think he is looking at getting rid of the Bosch ECU and going to the much easier to tune Delphi....but I may be mistaken. Not much different in the lower end, but pistons and heads are.

Well that's true, tuning would be much easier. As long as cost wouldn't be too bad I say why not. If it get too expensive I'd say your probably better off at getting a stands alone engine management system installed.

I don't know anyone who makes a stand alone management system for doing something like this. Can anyone direct me?

As LLT's get older, my thinking is that it would be advantageous to install the LFX engine rather than the weaker LLT. There are many upgrades in the LFX. Only issue is that you cannot plug the Delphi system into the LLT body harness due to differences in the plugs. Of course, the LFX harness and ECU work together OK but it's the body harness that is the problem. If anyone can shed any light on this, chime in please!

So, you would use the Bosche harness and ECU in the LLT, as is, and simply plug it into the LFX engine. Only issue is the HPFP in the LFX will throw an overpressure code at idle and go into limp mode. Only way to overcome this is to raise the idle to 1000 RPM. Don't know if it can be tuned out. The exhaust adaption is easy. I have a twin turbo LLT and acquired a 2014 LFX complete engine and would love to do this but I need to understand a bit more about the feasibility of this conversion. Would love to use the Delphi ECU but the body plugs are the issue.

If anyone has any solutions and knowledge about this, please let me know. Lot's of LLT owners, sooner or later, will want to do this conversion, if for no other reasons than LFX engine availability and improvements in the engine itself.

Haltech build stand alone systems; however, they are very expensive.

I've been told the same, the body harness is the problem.

Stand alone systems are very expensive but honestly probably about the same price or less than switching to a lfx engine. Probably just easier to trade to an LFX

There are a lot of LLTs out there. Since I have invested a ton of $ in my twin turbo LLT and I will be keeping it, I still want to pursue the conversion. Yes, a stand alone is expensive but if I transfer the LLT wiring harness to the LFX engine, the only remaining stumbling block is the idle issue with the LFX HPFP. If anyone has a suggestion on how to address this issue, please let me know. If this can be worked out, many more LLT owners who will eventually change engines, can upgrade to the LFX. Low mileage LFX engines are plentiful and very inexpensive and have all the upgraded goodies from the factory. A much better engine than the LLT. More power potential, as well. Chime in on this if someone can shed some additional light on the subject.

LFX into LLT
 

This is the latest on installing a LFX engine into a LLT after months of research. We are 98% sure that this can be done. So sure, that I am in the process of preparing a new 2014 LFX engine with auto transmission for a transplant sometime early 2016. Lots of work still to be done but making progress. Attached are pics of the twin turbo Camaro LLT, along with the new LFX engine, still in preparation. Note that we took the oil filter casting and threw it and machined an adapter plate for a remote, chassis mounted oil filter. Also, added is the fuel filter GM forgot. A "must have" item for clean fuel for DI. We also have added many other features in preparation for the transplant. Once we have everything in place, we will schedule the swap and try it to see if it will work. Nervous, to say the least. The worst thing that can happen is that we will have to reinstall the LLT engine but all indications are it should and the only way we will ever know is to try it.
Pictures of the car in this post. Pictures of the new LFX engine in the next post.

Pictures of the new 2014 LFX engine.

Good Luck with the swap!