LSx swap with AFM?

[Butch]

If I swap a 5.3, in place of my L31, that was originally equipped with Active Fuel Management (AFM) as long as I do a 0411 pcm swap would there anything else I would need to make it work?

Edit: As these only came on Gen IV motors how much more work is that over the Gen IIIs?

 

[eck95z71]

I would also like to know this answer. I have a 5.3 out of an 02 ready for the swap.

 

[Aloicious]

you may need to swap to the PCM for the AFM engine, I don't know if the 512k 411 supports it or not, you may need the 1m PCM. it wouldn't be that hard to put in though. is the engine you're looking at a 24x or a 58x engine? if you know. (I think most gen IV's are 58x but I could be wrong.)

 

[Butch]

I'm not looking at specific motors yet but I'd like to get this swap started by spring. If you think the PCM is the only extra thing I'll need for this over the Gen IIIs then I'll keep that option open and hopefully find a block that'll work for me, within budget of course.

 

[Aloicious]

I've never done a gen III or IV swap, so I don't know what kind of adapting is needed for things like the Trans and motor mounts, etc, but as far as the electronics are concerned, I think the PCM for the AFM might be an issue, but it wouldn't be hard to change to something other than the 411 if you're running a gen III or IV motor. if its a gen IV, you may have to swap to drive by wire, I don't know if the 58x PCMs support cable driven TB's, but that wouldn't be too hard either, you'd just need the correct TB, TAC, and pedal, IIRC.

 

[CodyB]

I would try to get a whole truck that was wrecked to do the swap from, or if using a salvage yard try to make a deal to have first pick at all the parts from that truck. If its a craigslist buy this would probably be easier. If you buy the whole truck swap all you need and then sell it to a scrap yard possibly with your old engine to make it easier on the pocket book. This could make the swap easier having parts you may have not foreseen needing, eliminating a bunch of parts runs that would add up quick, as a bonus you would only have one truck year to remember when you needed parts in the future.

Just tossing my thoughts into the mix.

 

[DRAGGIN95]

I would try to get a whole truck that was wrecked to do the swap from, or if using a salvage yard try to make a deal to have first pick at all the parts from that truck. If its a craigslist buy this would probably be easier. If you buy the whole truck swap all you need and then sell it to a scrap yard possibly with your old engine to make it easier on the pocket book. This could make the swap easier having parts you may have not foreseen needing, eliminating a bunch of parts runs that would add up quick, as a bonus you would only have one truck year to remember when you needed parts in the future.

Just tossing my thoughts into the mix.

Yeah if you can pick up one complete you will save yourself a lot of trouble, and I am also unsure about the 58x working with a cable TB, but it would be cool to have the AFM working.

 

[jcro61]

the way gas is these days that is probably the best feature of doin the swap

 

[300King]

AFM is overrated in these GenIV motors, IMO. The fuel savings is minimal and good luck trying to get an exhaust setup that sounds decent when AFM is active. These things drone like a **** if your exhaust isn't tuned properly. I know a lot of G8 owners that have eliminated AFM and not seen any change in fuel mileage. In many cases mileage improves with the addition of a CAI and a tune. I would suggest going with the GENIII for your swap. That is what I plan on doing down the road.

 

[Aloicious]

AFM is overrated in these GenIV motors, IMO. The fuel savings is minimal and good luck trying to get an exhaust setup that sounds decent when AFM is active. These things drone like a **** if your exhaust isn't tuned properly. I know a lot of G8 owners that have eliminated AFM and not seen any change in fuel mileage. In many cases mileage improves with the addition of a CAI and a tune. I would suggest going with the GENIII for your swap. That is what I plan on doing down the road.

yeah, fuel mileage has more to do with driving style and a proper setup than gadgets. although as a science geek, I like the gadgets and AFM is a pretty interesting setup.

for example, bone stock (stock L31, stock 4L60e, open carrier 3.73, stock 29" tires) my truck would get and average of ~16mpg peaking around 18mpg, thats 100% bone stock...
added shorty headers, a CAI, truetrac posi, ZZ4 cam, custom external MPFI manifold sporting 24# injectors, 411PCM, and starting doing some tuning on 'er, now averaging ~15mpg peaking around 17mpg...
later swapped to a T56 6 speed trans (double overdrive FYI), gearing still at the stock 3.73, removed the CAI and put the stock air box back in, more tuning, now hanging out at ~12mpg peaking aroung 15mpg...
Changed heads, added supercharger at 6psi, changed injectors to 40#ers, pulled shorty headers and replaced with full length headers, full 3" true dual exhaust, removed distributor for 24x setup with LS2 coils, more tuning, steady at ~11mpg peaking at 13mpg...
regeared to 4.88 (still with the same trutrac still with 29" tires), more tuning...back up to ~15-16mpg, peaking in the high 17mpg's...

this is all over the course of 3-4 years on my daily driven truck, with the MPG's calculated at every fillup and maintained in my mpg spreadsheet. most fillups were done at the same station, and using the same pump as well.

IMO my results show that a proper setup and driving style have WAY more to do than mods when it comes to fuel efficiency. after all, I went from bone stock, to a highly modified supercharged setup, and didn't even lose 1 full mpg in my daily driving. sure there was a time in there where I lost a decent amount and only averaged around 11-12mpg, but my gearing setup wasn't correct for my trans, and once that was corrected, the fuel efficiency came back up.

I doubt AFM would affect it that much if I were able to add it, MAYBE 1mpg on the highway only. but its not like we'll ever know on my setup at least since there is no real feasable way to add AFM to a SBC.

if someone wanted to do a motor swap with AFM because the setup is interesting and science is fun, then I'd say go for it, learn and have fun. but if someone was wanting AFM simply to gain MPG's I'd say look elsewhere for something more worth your money.