LLT TO LFX ENGINE CONVERSION

48319 Views 51 Replies 13 Participants Last post by CamaroPA, 4 mo ago

monty

Discussion Starter · Aug 12, 2015 (Edited)

I own a 2010 LLT Sequential Twin Turbo V-6, Automatic. My shop engineered, fabricated and installed the entire system. Vince at Trifecta did the tuning, which was great and still using today. He did a wonderful job and the car runs spectacular. It is a daily driver and I have driven 30,000 miles to date with no issues. As most LLT owners know, computer programming has limitations due to the Bosh ECM and very difficult to tune for maximum efficiency. In 2012, GM introduced the LFX engine, which is a much stronger engine and has higher horsepower capabilities. It uses a Delphi ECM, making it easy to tune by most tuners and more HP can be extracted through these tuning capabilities.

With LLT's now getting higher mileage on them and possibly needing new engines, my thoughts are to transplant a LFX engine with the Delphi ECM into the LLT. After much research over the past year, I purchased an LFX engine assembly, complete with wiring and ECM. It is in my shop on an engine stand and I have been evaluating feasibility.

So far, I have verified that the physical engine bolts right in with very few issues except for exhaust connections and very minor plumbing hook ups. Really easy. The in-tank fuel pumps on LLT'S and LFX's are the same, so no issue there. All other mechanical hook ups are the same. There are (2) body plugs that come off the engine wiring harnesses of both the LLT and the LFX's. After carefully looking at them, both of the physical plugs are the same. The pin outs of these (2) plugs are the same, as well, with the exception that one of the LFX engine side plugs have (4) additional pin outs and the LLT has (1) additional pin out in the fuse block plug. I feel pretty confident that these are for later model Camaro's that GM added features to.

My thoughts are that I could install the LFX complete engine/ECM assembly into my LLT, hook up the exhausts and minor cooling connections, etc. and plug the (2) body plugs into the existing mating body plugs on the vehicle and it should work. The extra pin outs on the LFX body plugs would simply terminate at the plugs and do nothing. I can't imagine GM changed anything that would not allow this to be done. Most everything is the same on the Camaro's from 2010 to 2015. Just additional options and features as the years progressed.

I need someone to chime in on the feasibility of this conversion concerning the extra pin outs on the LFX harness and help me further understand the compatibility. I am 95% verified on everything else. So darned close. If this works, this opens up the many, many LLT's that would qualify for this major improvement in a transplant. LFX engines are plentiful and cheap and the engine is a refined unit with much stronger internals, larger valves and better breathing characteristics for those who want more HP. Let's get our heads together to make this happen. I'm ready to do a transplant just as soon as I get my ducks in a row.

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monty

Discussion Starter · #41 · Apr 14, 2016 (Edited)

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. $$$$

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monty

Discussion Starter · #42 · Apr 19, 2016

Here is a video of the completed engine and transmission, 100% done and ready for install as soon as we can work out the electronics!! And that's the hard part, for sure. Very slow progress but still optimistic.

https://youtu.be/btWy5Y_CfRk

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SC2150

· #43 · Apr 20, 2016

Love the video Monty......everything is quality second to none.

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monty

Discussion Starter · #44 · May 26, 2016

Just received a new ECM from Vince at Trifecta. He loaded a 2014 base program, Vin matched my LLT and disabled VATS. He is the only programmer I know who has been able to successfully do this without ODB2 access, which will not work from the LLT due to VIN/YEAR difference, thus, server locks out the ability to download a different program from the one allowed for that year and model Camaro.

This has been a long journey getting to this point. Vince was the original tuner for my twin turbo LLT way back in 2010. He is one of the most knowledgeable tuners I have talked to. We have been collaborating about this project for some time now and he told me he was able to do what others have not been able to do. He indicated that theoretically, I should be able to roll the LFX engine/transmission along side my LLT and plug it in and it should start the engine. Once we confirm that this step in the process can be accomplished, we can evaluate any other glitches and/or codes/incompatibilities and move on from that point. As Vince pointed out, even if it starts, we may still not be out of the woods until we know that all the BCM's are happy in the vehicle and proper communications are confirmed. Vince's main concern is the ECBM compatibility with this conversion, so we will see.

Vince is working with me on this project and I feel confident that if this transplant is possible, he will be the genius that makes it happen. He has done programming for me in the past and has always succeeded in dialing things in. I believe that he was the first programmer to crack the LLT/Bosch encrypted ECM and successfully manipulate programming. My twin turbo project was one of the first in 2010 and the program he supplied has flawlessly worked since. Driving on it everyday.

Because a holiday is coming up and my business workload is heavy, my plan is to attempt to give this a try in several weeks. It has taken me almost a year to get to this point so I am not going to rush this. Haste makes waste! I plan to video tape the trail attempt and record data to send back to Vince for evaluation. As Vince indicated, this is a first for a LLT/LFX transplant and uncharted territory for sure, so at this point we can only try it and see what happens. I can't thank Vince enough for taking on this project. In my opinion, if he can't make it work, nobody can!

I am so excited to have arrived at this point. I will keep everyone updated.

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monty

Discussion Starter · #45 · Jun 19, 2016

Well guys!!! Did the first critical test!!! Plugged the LFX engine into the LLT, connected the fuel and charcoal canister from the LLT to the LFX engine, installed the ECM from Vince at Trifecta and BINGO, got in the car, turned the key and it started and ran perfectly! No major DIC's, no issues other than a few minor ones. This was a total success! Everything performed as Vince had stated. This is a major accomplishment and proves that this transplant is feasible. I will be passing on more information when I get time to compile it. It works!! I will also be posting a video of the actual test in a couple days. Stay tuned. Talk about a HAPPY CAMPER!!!!

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Reactions: 1

tookold96

· #46 · Sep 24, 2016

monty said:
We are 95% there on confirmation of a successful conversion but we have a few pin outs yet to identify. This is tricky stuff but it looks very promising. I have a brand new LFX engine waiting on a stand for my transplant when I am sure it will work. Note that if you have an automatic transmission, you will have to use the transmission that is same year as the LFX. Can't use the LLT, period, due to communication differences between the Delphi computer to the TCU.

Everything mechanically bolts up except a modification needs to be made to marry the exhaust pipes to the LFX heads, which is silly simple. In tank fuel pumps are the same on all Camaros, so no issue there. The (2) body plugs are the same, as well and will plug right in, so no issue there. We are trying to identify a few additional pin outs to be sure nothing will interfere with this transplant but it sure is looking very promising.

You will use the LFX engine wiring harness complete with it's computer and MAF. A few changes in hose connections and should be good to go with programming IF we confirm just a few remaining pin outs on the LFX harness. I am very excited about this and if it works, this is the only way to go if LLT engines should ever need replacing for any reason. LFX is a much stronger and advanced engine and can be precisely tuned for more power.

If anyone out there wants to try it, we have brought the level of feasibility up to 95% certainty. Will keep you informed. Please keep me informed of anyone that can add to the information on this potentially beautiful transplant.

Monty

so you cant use the transmission out of a 2011 camaro with the lfx swapp?

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RICHARD

· #47 · Nov 13, 2017

HI I have a 2010 camaro 3.6 and a 2014 3.6 engine,transmmition and pcm WITH THE HARNESS to swap do I NEED TO REPROGAM THE VIN INTO THE 2014 PCM OR NO

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RICHARD

· #48 · Nov 13, 2017

HI I HAVE A 2014 CAMARO AUTO 3.6 ENGINE,TRANY,PCM AND HARNESS GOING INTO A 2010 3.6 CAMARO AUTO DO I NEED TO REPROGRAM THE VIN FROM 2010 INTO THE 2014 PCM?

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[email protected]

· #49 · Aug 8, 2019

I just did a 2011 to 2015 llt to lfx conversion. I swapped heads and timing and oil pan basic just using 2015 short block. Everything else 2011 except crank pistions and block. It starts and runs ok until it warms up and then it runs like out of time. If I try to restart it cranks very hard still run but like a dog. Anyone have any thought on how to fix. Or any experience

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BillieBobbieNorton

· #50 · Oct 12, 2020 (Edited)

monty said:
Well guys!!! Did the first critical test!!! Plugged the LFX engine into the LLT, connected the fuel and charcoal canister from the LLT to the LFX engine, installed the ECM from Vince at Trifecta and BINGO, got in the car, turned the key and it started and ran perfectly! No major DIC's, no issues other than a few minor ones. This was a total success! Everything performed as Vince had stated. This is a major accomplishment and proves that this transplant is feasible. I will be passing on more information when I get time to compile it. It works!! I will also be posting a video of the actual test in a couple days. Stay tuned. Talk about a HAPPY CAMPER!!!!

Well what happened? What were the minor issues?? Does "feasible" mean it worked and it's driveable???? Where is the video????
DID IT BLOW UP??? Don't leave us hanging for 4 years!!!!!!!!

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ads103

· #51 · Nov 21, 2021

monty said:
Well guys!!! Did the first critical test!!! Plugged the LFX engine into the LLT, connected the fuel and charcoal canister from the LLT to the LFX engine, installed the ECM from Vince at Trifecta and BINGO, got in the car, turned the key and it started and ran perfectly! No major DIC's, no issues other than a few minor ones. This was a total success! Everything performed as Vince had stated. This is a major accomplishment and proves that this transplant is feasible. I will be passing on more information when I get time to compile it. It works!! I will also be posting a video of the actual test in a couple days. Stay tuned. Talk about a HAPPY CAMPER!!!!

Hey, Monty! I'm interested in replicating your replacement on a 2011 Cadillac STS which, to my understanding, is very similar to the Camaro of the same year. My STS's LLT is starting to get rather tired, and I'd love to wake the car up a little with a fresher LFX. It's been a while since you shared your success with the forum... Do you have any additional information you can share to help a newbie get started on this project? Did you get all your BCM issues sorted?

Being a newbie with more book knowledge than experience, I still have a lot to learn before actually attempting the transplant, but I'd be grateful for any insight you can provide. For instance, what kind of tool is needed to flash the VIN to the new Delphi ECM? And what is VATS?

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CamaroPA

· #52 · 4 mo ago

The bottom end of the LFX (short block) will be a direct swap, using the LLT heads, fuel injectors, intake, and HPFP. You keep your ECU. You do not need to do anything with the timing area, or the oil pan. Just make sure the timing is on, and it is a two stage process.

The LFX long block can also run off the Bosch ECU, but you still need to use the LLT HPFP, and injectors. There is a sensor on the LFX intake manifold that will not be wired, but you leave it in. There are some small routing changes with the vacuum pump, and PCV, but you can use the LLT tubing.

The car will run rich with the LFX HPFP and Injectors, using the Bosch ECU. Using the Delphi ECU requires more work, mostly programming.

This has been done now, and it all works out.

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LLT TO LFX ENGINE CONVERSION

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