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!

Can not wait to see it all done

I love seeing "outside the box" thinking being done. Good Luck.

Looks good!

good-luck!!

Do you need the LFX computer? Can you use the electronics from the LLT?

Yeah any updates on this?

I would think you'd need a LFX ecru to run it since the two engines have different ecu's ones bosch (llt) and the other is delphi (LFX ) if I'm not mistaken


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Yes, you must use the LFX computer. LLT will not work with LFX engine/transmission. Still prepping engine and car so minimal time will be required for transplant. Taking my time. February is target. Dotting the I's and crossing the T's. Takes more time for details than installing the engine.

Update! FINALLY, I am at the point of engine completion and ready for the first initial test. Tracy has agreed that before going to all of the effort of installing the engine/transmission assembly in the vehicle and finding out that problem/problems exist, it would be wise to pull the new LFX engine along side the car, unplug the LLT computer and the (2) body plugs that connect the LLT engine to the body harnesses and body control modules, match the VIN numbers to the LFX computer, then load the stock GM programs for the LFX engine and transmission from the ODB2 port in the car. Then, we can note can buss communications and body control modules compatibility. This should give us a very clear indication if we have a potential winner or not.

Being this vehicle is my daily driver, I can't afford to have the car down for extended periods, so we have decided to perform this very important, interim step. One of the LFX engine harnesses had to be extended 10" in order to do this but it was only 18 wires and only took several hours. The other engine wiring harness was long enough, as is. GM doesn't give you any excess wiring, so this was necessary. That operation is completed and my GM programmer is scheduled to come to my shop next week to program the LFX computer and transmission module with a stock 2014 program. Today, I even decided to make a temporary fuel line extension so I can hook the fuel system to the LFX engine at the same time we do programming. Of course we can't start the engine at this point. This is as far as we can go on this critical test with the engine sitting beside the car but should reveal a significant amount of information and data.

If, and that's a big if, all goes well on this test, we will fabricate the new exhaust and schedule an install into the vehicle and see what happens. Vince at Trifecta has also been helping out with the can buss compatibility and electrical & component modifications to the LFX engine, so if and when it comes time to bring him in for programming, he can give me one of his superior tunes. Stay tuned and a BIG thanks to Vince and Tracy for all the collaboration on this "first time" conversion.

I'm exited to see how this turns out. I've got my fingers crossed for you.

Today, we rolled the new engine beside the LLT and plugged in the harnesses and LFX computer. Although we ran into an issue with the programming of the engine side, we were able to do a VIN match and program the automatic transmission successfully! A great first step. So indications are, that this might just work. Thank goodness we didn't install the engine in the car because the car would be down until we worked this all out. Ran out of time, so unplugged everything and got the car back on the road so I could drive home. Next week, we will spend more time to see if we can figure out what is going on and why we can't load a engine computer program. Our best guess is that we are not getting a computer wake up signal from possibly, the fuel pump control module. For now, more schematic brainstorming is needed. Will keep you posted. Positive progress!

Will you have a list of what is needed to complete the swap? got a blown LLT and all I want is to replace it with a LFX.

Question this is a manual transmission. Will I have to replace the Trans with a newer Trans or will the current trans work?

Can't say for sure about the manual tranny but I believe you will be able to use your tranny. As far as I know at this point, the manuals are not prioritized for this conversion but let's wait to see if I can get the LFX ECU to accept a stock program download. The Automatic transmission took the program download when plugged into the vehicle body harnesses, which is encouraging but had issues with the engine side. Ran out of time and plan on trying again this next week.

Thanks

Anything more with this build?

Was out of the country for a while. Just got back and I will be getting back on this project in about a week or two. I am still optimistic at this point. I am building a stand on rollers that will allow me to set the engine and transmission on, bolted together so I can start the engine/transmission assembly for short durations of time and evaluate any codes that set. Of course, that's assuming I get past the programming of the LFX ECU. I'm hoping!

:pop2:

Yes, I understand that this is taking a long time. There is a lot involved in working out issues in a conversion like this. It's unknown territory, for sure. Page after page of schematics that must be compared and understood, especially when all of the body control modules are different in the vehicle. Time, time, time. And, of course, I am still a working man and have to run my machine shop and pay bills, so I'm taking my time. I feel like within the next 6-8 weeks, I should be able to confirm this will work or not work. I will keep you posted for sure. Sorry for the slow progress.

Today I constructed the roller platform for the engine/transmission assembly. Turned out great. I will install downpipes and hook everything up for a trail run, when that time comes. So, making progress but again, very slow. Get more popcorn!!

Any update
 

Any new updates on this project?

Ran into a stupid issue. Purchased (1) new ECM for the 2014 LFX. We had a heck of a time figuring out why we couldn't communicate with it from the laptop!! After weeks of time delays, we tried communicating with the ECM on the bench, to eliminate the vehicle in the loop. Much to our surprise, it would not. Defective computer!! Ordered another, waited, more delay and it, too was defective. Purchased from Source One, which is usually pretty good about having good parts. At the suggestion of my programmer, I purchased a new ECM directly from GM. Checked it on the bench, first and finally established communication!!!!

So, we hooked everything up through the vehicle. Established communication perfectly. Tried to download the 2014 program data from the GM server and a pop up window appeared for security! (mismatched VIN's) Had to stop. Programmer took the ECM and is working on a solution. We will have to disable VATS on the vehicle for sure. Currently in process of working that issue out. I am still forging ahead but lost several months due to bad ECM's right out of the box. Who was to guess this could happen? Learned to only purchase ECM's directly from GM, NO AFTERMARKET! Very frustrating and came close to giving up.

The going is slow at this point but still hopeful. Making snails pace progress. Probably will be several more weeks before next update, hang tight.

:popcorn:
Glad to hear your still moving forward.

Got to figure out how to disable VATS on the vehicle!! Can't move forward until this obstacle is resolved. GM began Global A electrical architecture in 2010 on the Camaros and it looks at all the body control modules to be sure all conditions are met before allowing the vehicle to start and run. A very complex security system, to say the least. Every module must meet identification codes. Someone help!! We have almost resolved this transplant. I can find no information anywhere on how to overcome this issue and disable VATS on these 5th Gen Camaros.

I think it was the Diablo Sports techs that got the hellcat engine to run stand alone for GMG.
https://www.holley.com/blog/post/dia...cat_swap_car_/
Might be worth checking into I believe HP could not get it running if I remember right.

I am still waiting on a couple responses from a couple knowledgeable tuners, concerning next steps in tackling these unknown procedural steps forward. As of today, one possibility is to find a 2014 Camaro LFX and temporarily remove it's factory ECM, install my new 2014 GM, unprogrammed ECM and have my mobile programmer load a base 2014 program into it, along with the 2014 VIN.

Next step would be to have a performance tuner take the 2014 ECM and disable VATS and change the 2014 VIN number to my 2010 LLT VIN number but it needs to be DONE ON THE BENCH AND NOT IN THE CAR. (Still haven't verified that disabling VATS and changing the VIN can be done on the bench, as suggested)

Final step (hopefully) would be to roll the 2014 LFX engine/transmission up, next to my LLT, remove the (2) LLT engine harness plugs and plug in the LFX engine harness and see what happens. Obviously, from the pictures in the previous posts, I have the ability to do this without installing the engine in my LLT and if necessary have provided a way to even start and run the LFX on the stand. Codes and communications can then be verified and then proceed to resolve any issues that might remain. This is my daily driver vehicle and I cannot risk down time to install an engine that we don't know will even work in this LLT. This is why I am doing this project the way I am.

If anyone has any further input on this conversion/transplant project, PLEASE feel free to comment and/or assist. This is a FIRST of this kind in the 5th Gen Camaros. Uncharted territory. Hopefully, I will have more information in the coming days/weeks, as to if this is the correct procedure to follow or if another procedure should be tried first.

Footnote: As far as Global A, GM electrical architecture is concerned, it is generally agreed that this should not be of concern (although not written in stone) on this transplant. Global A began in 2010 to date on all Camaros. Google it to see what GM is up to. You will be totally amazed! This technology throws a monkey wrench into people changing and installing used body control modules in their vehicles in an attempt to repair issue themselves. You are at the mercy of the dealer!!!!! If attempted, the secret ID numbers in all the modules from the factory will default the vehicle useless and will not start until the car is taken to a dealer for proper repair. $$$$

Alice, glad you havnt given up like myself.

This car truly annoys me and gives me grief. Its a love hate relationship. Mines been sitting for almost 2 months now with engine potentially blown.

I don't understand how SS guys can change their motors all day but we cant on our LLT