[cjperformance]

I noticed that the Procharger tune has disabled the DOD/AFM on my 2017 SS.

I never really had any problems with the DOD/AFM when it was N/A, the extra MPG was nice. I understand the system can cause issues long term as the system wears, but curious if DOD/AFM is just incompatible with blowers in general?

I think the LT4's in the ZL1 come w/o DOD from the start... so just curious more than anything if anyone is using DOD w/ a blower and what the experience is like.

[SSUNDVL]

buys v8 and supercharges it, worried about mpg... this post makes me chuckle but i get what your saying.

[wolfdog]

scary thing to me is the mechanical transition between DOD actuation/deactivation when applying power...sure these systems are meticulously tested but it is a system of added variables that will be put to the test when going for aftermarket power.

GM disables DOD on the SS 1LE and it is NA...figuring that a 1LE owner will put it through its paces more so than a standard SS...but its not even supercharged. Something to think about when adding even more HP.

[wnta1ss]

Originally Posted by wolfdog

GM disables DOD on the SS 1LE and it is NA...figuring that a 1LE owner will put it through its paces more so than a standard SS...but its not even supercharged. Something to think about when adding even more HP.

Not just the 1LE, it's ALL of the M6 SS/LT1 engines that have DOD disabled. The lifters are still the same ones as the auto car (DOD), but the feature is not enabled in the computer.

[arpad_m]

In addition to the mechanical aspects, in supercharged applications there is the added complexity of managing V8/V4 transitions coupled with the blower bypass.

Say, when the car is in V4 mode and the driver applies more throttle, the computer sees it can satisfy torque demand by switching back to V8 mode, but by then the bypass may close and suddenly there is positive boost, which throws the whole calculation off, potentially making the ECM think it can safely go back to V4 (and vice versa when getting off the throttle). Who knows if this doesn't result in a weird flip-flopping of V4/V8 transitions and the supercharger bypass competing with each other, or seeing "supercharged V4" operation.

This may be why AFM is off on the ZL1 as well, and if GM didn't think or want to manage this on a factory configuration, I sure wouldn't want to be a guinea pig with my supercharger.

[cjperformance]

I agree with all the above. I intend to leave it off. Was genuinely curious more than anything. I wasn't aware it was turned off on so many other applications. I can't keep from mashing the gas pedal to the floor for long enough to get an accurate mpg since I supercharged it.

With periodic pedal-mashing, I'm still averaging 23 with about 60% highway usage and the other 40% being backroads and such.

I always enjoyed bragging that my 455 HP car could get as good mileage highway as some of those 4 and 6 cyl cars. Usually on all highway, 31 MPG was normal.

[Staves]

Originally Posted by cjperformance

I always enjoyed bragging that my 455 HP car could get as good mileage highway as some of those 4 and 6 cyl cars. Usually on all highway, 31 MPG was normal.

Bragging be tacky, bra.

[s346k]

if you done it, it ain't bragging

[cjperformance]

Well.... you gotta brag without bragging... like just slide it in to normal conversation.

Person: Oh, just bought a new car!
Me: Nice... what'd you buy?
Person: Oh this <insert boring car name here>
Me: Cool how do you like it so far?
Person: Oh, it's great it really sporty and gets good gas milage.
Me: Oh? What kind of milage does it get.
Person: about 35 MPG highway
Me: And what engine?
Person: The 3.whatever. It's got 285 horsepower!
Me: I see. I get about 31 MPG highway in mine.
Person: what kinda car do you drive
Me: Camaro SS
Person: oh the 8 cylinder? How much horsepower?
Me: 455
Person: <looks embarrased that he bought a lesser vehicle>

[laynlo15]

I ran 10.00@139 with a Magnuson 2300 with dod, afm on my 16 SS. Lucky I didn't break any spring/lifters as they made it thru 18 lbs of boost on occassion. However after 180 passes I did break a couple ring lands on the stock motor.

[Corbu]

Are there any tuners that can safely leave the DOD actuation/deactivation enabled with a supercharger? I am in the planning stages for a Magnusson 2650 with low boost, but I would actually like to retain the awesome fuel efficiency that I get on the highway once it swtiches to V4 mode. From my observations, during highway driving, the motor is in V4 mode at least 90% of the time if not more.

[KingLT1]

Did/AFM does very little for fuel mileage.

[arpad_m]

Originally Posted by KingLT1

Did/AFM does very little for fuel mileage.

I can second that. Since I knew I was going to get it tuned out with the Maggie, I did some before and after measurements on the same routes, the difference was a mere ~0.5 mpg. Of course, this isn't fully scientific, as I can't guarantee that I drove the exact same way twice, plus traffic, although similar, wasn't identical either, but the difference still seems to be barely above the noise threshold.

I'd be more worried about uneven wear and potential lifter failures with DoD than the minuscule gain in fuel economy it provides.

[Joshinator99]

Originally Posted by KingLT1

Did/AFM does very little for fuel mileage.

Originally Posted by arpad_m

I can second that. Since I knew I was going to get it tuned out with the Maggie, I did some before and after measurements on the same routes, the difference was a mere ~0.5 mpg. Of course, this isn't fully scientific, as I can't guarantee that I drove the exact same way twice, plus traffic, although similar, wasn't identical either, but the difference still seems to be barely above the noise threshold.

I'd be more worried about uneven wear and potential lifter failures with DoD than the minuscule gain in fuel economy it provides.

Agree with these fellas. Also of note is AFM activation causes your TCM to command a decent amount of torque converter slippage...not good. Now you can tune that out in the TCM, but just something else to keep in mind.