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| GM 3.6 experts... Why the disparity between different LFX engines? (Page 6/7) |
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Joseph Upson
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SEP 29, 08:30 AM
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Found some far more detailed and impressive info on the 2016 upgrade motor I linked to on page 1 and had to bring this thread back. GM didn't lightly smooth over the newest version of this motor, they really went to work on it, so much so that it has two timing chains and 6 sprockets now instead of the previous 3 chains and 9 sprockets and does 335 hp and 284 lb/ft on regular unleaded gas! That suggests plenty of room for double digit boost and high compression, as far and likely even farther than I managed with the 3900. I'd love to get my hands on one of these right now. The torque is coming up nicely, still not where I'd like to see it but better.
Here's a link to a long list of improvements, some are preexisting attributes being relisted;
http://media.gm.com/media/u...20-cadillac-36l.html
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RacerX11
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SEP 30, 02:10 PM
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| quote | Originally posted by mender:
From my research (GM part numbers) the LFX cams are all the same. Intake manifold port shapes are different for RWD and FWD engines as are the head intake ports to match the manifold and probably account for about half the power difference. As mentioned earlier, the air filter/intake and exhaust system differences between the cars probably account for the rest.
You can see the Camaro vs Impala port shape here:
Some good info on the Impala LFX and mods here:
http://www.impalaforums.com...las-from-jacfab.html
Another one:
http://www.camaro5.com/foru...rumdisplay.php?f=148
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The intake manifold ports are different, but the head ports are the same between FWD and RWD engines. The LFX uses an aluminum lower spacer/adapter that goes between the heads and the plastic upper intake manifold:
The JacFab spacer you linked goes between the stock aluminum spacer/adapter and the intake manifold, so there are two versions depending on the intake port shape at the upper intake manifold.
Camaro head ports:
Impala head ports:
This makes the Camaro intake manifold a possibility on the FWD enignes.
Marty
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Raydar
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SEP 30, 08:17 PM
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| quote | Originally posted by RacerX11:
The intake manifold ports are different, but the head ports are the same between FWD and RWD engines.
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This makes the Camaro intake manifold a possibility on the FWD enignes.
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It also possibly means that an intake manifold could be fabricated, that would possibly outflow both intakes, if one were so inclined. 
This is encouraging.
Joseph Upson... That's good info, too. I wonder how much more difficult it would be to adapt the newer design.
Edit - I see that it also has AFM (cylinder deactivation.) While that's a good thing for economy, I'm not really interested in that for a performance engine.
At the risk of sounding like a Luddite, I think I would prefer something simpler. DI and VVT are complex enough.[This message has been edited by Raydar (edited 09-30-2016).]
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dobey
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OCT 01, 12:35 AM
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| quote | Originally posted by Raydar:
It also possibly means that an intake manifold could be fabricated, that would possibly outflow both intakes, if one were so inclined.
This is encouraging.
Joseph Upson... That's good info, too. I wonder how much more difficult it would be to adapt the newer design.
Edit - I see that it also has AFM (cylinder deactivation.) While that's a good thing for economy, I'm not really interested in that for a performance engine.
At the risk of sounding like a Luddite, I think I would prefer something simpler. DI and VVT are complex enough.
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AFM is simple enough, and trivial to remove from engine families where there are versions without it in production cars. The feature itself is not overly complex either, especially if using the factory ECU (which you currently need to do, to get working DI).
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Raydar
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OCT 01, 09:57 AM
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| quote | Originally posted by dobey:
AFM is simple enough, and trivial to remove from engine families where there are versions without it in production cars. The feature itself is not overly complex either, especially if using the factory ECU (which you currently need to do, to get working DI). |
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Perhaps. I wonder if the new ECU has been "cracked" yet. I'm certain that at least the 2012 Camaro LFX ECU (E39?) has been cracked. There are accounts all over the web of people running them stand-alone. Tunercat even has a definition file.
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mender
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OCT 02, 12:46 PM
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| quote | Originally posted by RacerX11:
The intake manifold ports are different, but the head ports are the same between FWD and RWD engines. |
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Hadn't checked images of the Camaro ports. Took off my Impala intake and confirmed that you are indeed correct.
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Raydar
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OCT 03, 06:09 PM
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| quote | Originally posted by mender:
Hadn't checked images of the Camaro ports. Took off my Impala intake and confirmed that you are indeed correct. |
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This is also encouraging.
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Will
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NOV 01, 01:19 PM
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| quote | Originally posted by Raydar:
Perhaps. I wonder if the new ECU has been "cracked" yet. I'm certain that at least the 2012 Camaro LFX ECU (E39?) has been cracked. There are accounts all over the web of people running them stand-alone. Tunercat even has a definition file. |
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Trifecta (and maybe others by now) can do stand-alone LLT's as far back as 2009.
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stickpony
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NOV 27, 10:30 PM
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| quote | Originally posted by Raydar:
Yeah. I know.
Except everything I've seen about the F40 is a complete pain in the ass. And would seem to require a lot more fabrication than I'm prepared (or skilled enough) to deal with. (I don't weld. Yet.) And that's aside from the initial cost of the oddball Saab F40.
If someone (Paul?) comes up with a kit that makes it a direct bolt in, then I might spring for it.
I am also quite familiar with the T-550. I have one (with the GM metric pattern) bolted to my 4.9. Since it's essentially a Getrag, it can use stock tranny mounts and axles. All I had to add was a clutch line adapter fitting (for the HTOB) and Rodney's FWD shift lever kit. Done deal. It does quite nicely, and I haven't broken anything, yet. (I try not to shock load it, but I am not averse to rolling along in gear with the clutch engaged, and then matting the right pedal.)
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why the saab F40, and not a GM F40? different gearing or something?>
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dobey
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NOV 27, 10:48 PM
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| quote | Originally posted by stickpony:
why the saab F40, and not a GM F40? different gearing or something?> |
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They are both "GM" in the sense that they were produced for GM cars. The trans is a Getrag.
The Saab is the only car with a High Feature V6 that came with a manual in transverse configuration. The G6 F40 is the wrong bell pattern. The Ecotec F40 is also yet another different bell pattern. The G6 also has some other differences from the HF/Ecotec versions. The gearing in the earlier Saab 2.8t F40 trans (at least, the FWD version, not sure about AWD) should be the same as the 2006 G6 F40.
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