notgetleft

I can't imagine that AFM will be something you can beat by pulling a fuse or installing a resistor in the connectors. Unlike CAGs or other simple solenoid operated systems, AFM not only is turning off lifters, but it also shuts off fuel to the deactivated cylinders. If you just disconnect the oil diverter solenoids (or whatever the hell they are), the ECM will still cut fuel and the car will still be running on 4 cylinders, only even less efficiently since it will be pumping air through the holes. This would also then no doubt **** off the ECM which would see all that extra air in the exhaust and assume the car was way lean.


What's funny is it seems so many are worried about sound and the 'inconvenience' of having to get a tune to get rid of AFM to fix it.. What i think most of you are totally forgetting it torque managment. All 05+ LSx (auto and manual) applications have HORRENDOUS torque management built in that holds back the car's performance and make it inconsistent as hell. A tune should be a MANDATORY mod for any real performance enthusiasts with a modern car.

JakeRobb

What exactly is torque management anyway? How does it work?

Also, just for clarification: Does the C6 Z06 have it?

notgetleft

Torque management pulls timing and closes the throttle blades slightly (on cars with ETC) to reduce torque during upshifts, off the line, etc to reduce shock on the drivetrain, wear on the clutches, etc.

I can't say for sure how bad the C6 ZO6 has it, but i'd bet it does since the regular C6s are completely hamstrung by it.

slayerxxx213

If I can't be allowed to turn the DOD on and off then I wouldn't want it at all...That's all we need is a bunch of Camaros running around that sound like oversized Civics

loki993

does anybody have a clip of a DOD car in 4 cylinder mode or one going from 4 cylinder mode to 8 cylinder mode, id like to hear it for myself.

CamaroBoy96Z28

I dont think the sound will be a huge issue for me. It'll be my DD and at best it'll get full bolt-ons and tune. Considering most driving conditions, AFM wont kick in unless its freeway driving and trace amounts of city cruising unless the engineers/programmers make the system slightly more aggressive. As it sits, the system doesnt make that much of an impact in real world driving from the studies I've read, testimonies and the nature of its criteria to engage, cutting the cylinders. AFM may hardly even get used which I hope is not the case...

MagnaPilot

I have yet to see one myself... If I had a way to hang the camera out of the trunk I would record one for you, but I don't feel like taking a chance of droping my $600 camera while driving 45mph.



I really wish people would understand that the V4 does mode not in any way sound like a civic or any other Inline 4 cyl engine. Not even remotely. It likens to a (horizantally apposed 4 cly engine) like those in the WRX and Porsche cars. Though its still not the same, as the actual tone... or frequency is lower than. There is nothing quite like it really. But thats as close as it gets.... it in no way sounds tinny, or raspy or anything else for that matter... it sounds like a V8 skipping every other cylinder (but not in a bad way).

The current '05 and '06 LS4 motors use a sort of patchwork ECU at the moment, the '07s are supposed to be able to use AFM more often as well as log pretty much everything you do with the car.... and I mean everything due to a much more powerful ECU. The AFM code in the old ECU is supposedly currently inside of tables that were not designed for AFM... the new ECU was probably made specifically for that purpose, perhaps with the newer ecu's, they'll be able to program out AFM, or worse, not program at all. I haven't heard if the '07 LS4's are getting better mileage yet, or actually use AFM more. There aren't many on forums yet.

Thats all the crap I can think of at the moment. If I can find a wired mic maybe I'll take the laptop out and get a recording for you guys.

CLEAN

I have no idea how it'd react to a catback, but honestly, with the stock exhaust, the sound is so similar, you really don't notice it. It may be just a hair quieter, but to my ears, the tone is more or less the same as it is when running on 8.

AdioSS

How about video from the inside? Have a friend ride in the trunk recording?

I believe that the AFM equipped SUVs have mufflers that are tuned to mask the change in tone when going into 4 cylinder mode. I'm sure GM's engineers will do a good job with the exhaust sound. Stock V8 camaros have always sounded good.

Buttercup

Give me AFM for sure. Better fuel economy and quieter cruise, what's not to like?

People who think this sounds like an I4 with a coffee can exhaust are thinking way too simplistic. The number of cylinders is only a small part of what defines an exhaust note. Will you notice a difference in exhaust note when AFM activates? Of course! If you're listening for this and already have it in your head that AFM is somehow an evil performance killer than you'll think it sounds bad.

Every other physical characteristic that defines an engine's exhaust note is in place in V4 mode. It sounds more quiet and like running at half the actual RPM. Does your V8 sound like crap at 800 RPM but great at 1600???

I haven't heard an AFM equiped car with an aftermarket exhaust but I have ran my LT1 on 4 cylinders for s$!ts and giggles. With a cam and full exhaust, including the true duals with x-pipe, it still has the same exhaust tones just at half the intervals. Granted I, unfortunately, can't completely close off 4 cylinders so I ran on 4 active cylinders with 4 just pumping air but IMO it's a good indicator. I showed it off for a few other enthusiasts and they were surprised at how good and smooth it sounded on "only" 4 cylinders.

People say the Subarus are the only good sounding 4-bangers out there. That's why some people are describing the sound as such. It really doesn't sound bad, in fact it sounds good, like these V8's do. They just don't like the AFM for some reason.

If I could add AFM to my LT1 at reasonable cost I would!!! At WOT I want great performance and a wild exhaust note. At cruise I want fuel economy and quiet. Why wouldn't you?

kertong

It's not about volume - it's about tone.

Andy30thZ

I agree if AFM gave great gains in fuel mileage. But the reality is 12% increase on the highway is the norm that I have read, provided you are going slow enough. (which equals 3.6mpg from a car getting 30mpg) I'm not sure I'm all that worried about another 3.6 mpg from a 30mpg car. (provided the Camaro can get 30mpg) Also, I thought LS4 owners are not seeing the fuel mileage as advertised. So I'm not sure that I want the added complexity (cam swap?)and 4 cylinder sound on my new Camaro that will be a fair weather summer driver.

CLEAN

Anybody who has concerns on this, go drive an SS w/ DOD, and de-select the DOD mode from the DIC, so you don't see when its on 4 or 8, then try to figure when its on 4cyl mode. I will all but guarantee you wont be able to tell from the exhaust or driving feedback. And also, this hasn't been addressed, but the SS ALWAYS idles on 8cyl, so theres no need to worry about that.

MagnaPilot

I could give it a shot, never been in my trunk to see how it sounds, but from the cabin, it's rather hard to hear at driving speeds. I'll try a slow roll, I generally can get it going at 20mph... maybe you could hear it then.

MagnaPilot

So far there hasn't been reason to believe that a cam swap would be a huge issue. I believe the current limitation is of Cams that have .590 lift or less... don't qoute me on that number though. I haven't heard of anyone doing it yet, they are all under warranty.

Remember, if the Camaro comes out tilting the scale at 3700 lbs or more, it could very well not get 30mpg like the 4th gens did. My Impy SS tilts the scale at the weight, probably around 3900 with a load... with AFM and a good road condition I can pull 28mpg easy. If I go a little slower, which I do sometimes I'll hit 30. I've hit over 32 mpg in the right trip, but I've also only got 22mpg before as well (crossing west texas at 85 mph) GM will need this more for their trucks, and large cars, but I sure wouldn't want to pay a gas guzzler tax on a new camaro if we can help it.