LLT to VF LFX engine swap requirements?

[LachieKb]

By "earlier models" I thought you meant pre-SIDI, which nobody does.

Ah, yeah nah just the LLT. Do you think this crate motor would be a suitable swap for an LLT? Or better off trying to find a Commodore sourced LFX to get all the extra parts with it?

 

[someguy360]

I was always under the impression that the LFX ECU was different to the LLT.

 

[_R_J_K_]

I was always under the impression that the LFX ECU was different to the LLT.

Correcto, ebay is always helpful:
VE LLT: https://i.ebayimg.com/images/g/RaIAAOSwOyBjvXqA/s-l1600.jpg
VE LFX: https://i.ebayimg.com/images/g/o-0AAOSwyKNjsuzg/s-l1600.jpg
VF LFX: https://i.ebayimg.com/images/g/WEUAAOSwpddjqbcc/s-l1600.jpg
VF LFX: https://i.ebayimg.com/images/g/c-IAAOSwhA9jlfSg/s-l1600.jpg

Just based on the looms alone this is another reason why I think whatever aforementioned shop is just running an LFX on the LLT ECU. Or they're flashing the ECU to run without VATS (not good), or they've worked out their own tuning as they seem to offer manual conversions as well (guessing this is GC Cars Nerang?)

 

[LachieKb]

Correcto, ebay is always helpful:
VE LLT: https://i.ebayimg.com/images/g/RaIAAOSwOyBjvXqA/s-l1600.jpg
VE LFX: https://i.ebayimg.com/images/g/o-0AAOSwyKNjsuzg/s-l1600.jpg
VF LFX: https://i.ebayimg.com/images/g/WEUAAOSwpddjqbcc/s-l1600.jpg
Possibly VF LFX too: https://i.ebayimg.com/images/g/c-IAAOSwhA9jlfSg/s-l1600.jpg

Just based on the looms alone this is another reason why I think whatever aforementioned shop is just running an LFX on the LLT ECU.

Right, so I will have to source an LFX ecu and probably wiring loom too in that case. Not sure if the rest of the hardware (sump, intake manifold) will swap from the LLT to the LFX or that LFX crate motor

 

[_R_J_K_]

Right, so I will have to source an LFX ecu and probably wiring loom too in that case.

The ECU and loom won't plug into the rest of the car, neither of the plugs between the two are similar whatsoever.

 

[LachieKb]

The ECU and loom won't plug into the rest of the car, neither of the plugs between the two are similar whatsoever.

Well it must be possible somehow because multiple people have done it. I’m just trying to figure out exactly what I’d need to do

 

[_R_J_K_]

Well it must be possible somehow because multiple people have done it. I’m just trying to figure out exactly what I’d need to do

Sure, it's possible, but like I said there's every chance that they just used the LLT ECU - there's no reason they have to use an LFX ECU. They may physically be different but they still run extremely similar Bosch systems on extremely similar engines. Do you know if they used the LFX ECU? Are they just slapping in the LFX ECU with no Vehicle Security Signal? Are they repinning plugs? Are they retuning at all?

There's a multitude of ways (including bad ways) to skin this cat, but they're all complicated. It's also likely whichever shop this is also has a diagnostics and programming tool with some pretty advanced GM specific features if they can chop and change like this, along with the experience to go with it.

 

[_R_J_K_]

For all intents and purposes the engine is just a big dumb lump of metal. If that lump of metal is so similar to another dumb lump of metal that it can be run by some other system within its parameters, then to that ECU it's not a different engine and should run correctly.

I'd throw the LFX in on the LLT ECU and see what happens. If it doesn't like it, swap the LLT heads and top end onto the LFX block, the blocks and displacement are the same and you'll get a bees dick of improvement in compression that would be well within the limits of the LLT ECUs knock control.

 

[vywgn]

You will need loom to suit VE, ecu, cat converters and to swap the sump. Ecu will need to be programmed to suit your vin

 

[LachieKb]

You will need loom to suit VE, ecu, cat converters and to swap the sump. Ecu will need to be programmed to suit your vin

So will my original VE LLT loom, ECU and sump work? Or will I have to source those from a VE II LFX?