active fuel mgmt

[gnshpr]

This active fuel mgmnt dropping cyls in town is making me nuts didnt notice it until new exhaust ,anyone else having this problem or is it something else not the AFM ???

[-Ray-]

Welcome to the wonderful world of magnified AFM.

[jmy]

Yes it's the AFM, I just experienced this morning on my way to work, put my Pypes axleback on last night....just think of it as now you know when your car is saving you $$$;) I believe if you put it over into sport mode it will deactivate the AFM if bothering you too much. Some are tuning it out altogether.

[gnshpr]

seems to do it in sport mode also what are some tuning options that work well ,tried flashpak its ok installed the jet maf getting ready to remove it after reading vectors post thanks

[solty]

Corsa!
It has been well documented in various threads that only the corsa would not drone when AFM kicks in. It is a bit pricier, but by the time you add resonators, straight pipes, and what not, you would have easily spent that money. I am still quite amazed that the other cat back vendors (magnaflow borla.....) still allow sales of these cat backs for the G8 GT knowing that the car will drone (GXPs are not impacted by this).
Free market going crazy:poof:


seems to do it in sport mode also what are some tuning options that work well ,tried flashpak its ok installed the jet maf getting ready to remove it after reading vectors post thanks

[mikesgt]

The AFM in my car is horrible. Sport mode will not get rid of it; only manual mode. The drone people talk about is not the AFM, just the frequency at certain rpm's. The exhaust could amplify the AFM some. To get rid of that POS AFM you'll need a tune, or live with it. Tuned mine and no more terrible vibration.

[gnshpr]

Yeah thanks for the reply dont have a problem with the drone or exhaust noise just that drop from the fuel mgmt feels like constant lock-up unlock what tune did you use to get rid of it

[SLVRG8GT]

Yeah thanks for the reply dont have a problem with the drone or exhaust noise just that drop from the fuel mgmt feels like constant lock-up unlock what tune did you use to get rid of it


Superchips cortex tuner allows you to turn off and on AFM on demand. Along with torque settings, 87-91-93 tunes. And soon to come CAI tunes.

[Panzer Leader]

What I find interesting is that when I go into the Engineering Mode on my V6, it shows that the AFM is active. I guess I go from 6 to 4 to 2 cylinders. At that point it must be in the New Dehli Taxi Mode .

['02 ws6]

Yeah thanks for the reply dont have a problem with the drone or exhaust noise just that drop from the fuel mgmt feels like constant lock-up unlock what tune did you use to get rid of it

VMS, New Era, Livernois, HPTuners by yourself, etc etc. Any of these shop's tunes or tuners can remove it.

[piecesparts]

I just call it a little "Burbble" in my pocket. I found that at the city speeds, the G8 will cruise around town in the 4 cylinder mode, all day. The axle backs did make it noticeable, but the application of undercoating and the accumat made it bearable. It is now just a little hum in the back. I can stand this, to get the loud response when you open it up. Actually I get more noise from the Vararam intake on acceleration.

[gearhead455]

Yes it's the AFM, I just experienced this morning on my way to work, put my Pypes axleback on last night....just think of it as now you know when your car is saving you $$$;) I believe if you put it over into sport mode it will deactivate the AFM if bothering you too much. Some are tuning it out altogether.


It is not active in manual mode.:)

[G8+6=fun]

I really like the sound of the Corsa exhaust, Price high but you pay to play.

[mikesgt]

Yeah thanks for the reply dont have a problem with the drone or exhaust noise just that drop from the fuel mgmt feels like constant lock-up unlock what tune did you use to get rid of it


I used the Cortex tune everyone else uses. Marylandspeed had the best price. I still can't believe it vibrated as horribly as it did when going into and out of AFM, which was constantly when diving between 30 and 50.

[johnbell2]

Another vote for DOD delete with Superchips. The difference in drivability is night and day.

Going to run another week or so w/ Superchips then do a write up in product review section.

[Camss57]

Another vote for DOD delete with Superchips. The difference in drivability is night and day.

Going to run another week or so w/ Superchips then do a write up in product review section.

I'll be looking forward to your write up. I'm thinking about getting a Cortex in a couple of months.

[johnbell2]

I'll be looking forward to your write up. I'm thinking about getting a Cortex in a couple of months.

My immediate recommendation is "do it" especially if you're going to stay relatively stock. The trans tune and DOD delete are worth the price alone, power is just gravy.

[edmanet]

This active fuel mgmnt dropping cyls in town is making me nuts didnt notice it until new exhaust ,anyone else having this problem or is it something else not the AFM ???

Turn it off or take it out.

[johnh]

The drone people talk about is not the AFM, just the frequency at certain rpm's. The exhaust could amplify the AFM some. To get rid of that POS AFM you'll need a tune, or live with it. Tuned mine and no more terrible vibration.

No its much, much worse because of AFM. It changes the tone and volume with my Pypes. I live with it, since I don't mind saving the gas and I can just turn up the radio.

[gnshpr]

turned off the AFM installed 87 octane tune took 500 mile hilly curvy trip average fuel mileage 24.7 and thats not driving consertive

[-Ray-]

No its much, much worse because of AFM. It changes the tone and volume with my Pypes. I live with it, since I don't mind saving the gas and I can just turn up the radio.

I've kept mine as well. I drove to the track and got 27.6 mpg. Then I ran it down the track and got 12.85 slip.

[piecesparts]

turned off the AFM installed 87 octane tune took 500 mile hilly curvy trip average fuel mileage 24.7 and thats not driving consertive

Which Company's tune did you use?

[Night Train]

The AFM doesn't bother me that much. I appreciate having the opportunity to get decent gas mileage but still have fantastic performance.

[hchiava1]

I received a copy of this from the dealer. Evidently they are working on a solution to the AFM Vivration

#P1P4691: Phasing Vibration In Drivers Seat And Steering
Wheel - Under Investigation - keywords BQMI - (Aug 27,2OO9)
Subject: Phasing Vibration in Driver's Seat and Steering Wheel - Under
Investigation
Models:2OO8-2OO9 Pontiac G8 with 6.OL Engine (RPO L76)
and 6 Speed Automatic Transmission (RPO MYC)

Conndition/Concern:
Some customers may complain of a phasing vibration in the driver's seat and steering wheel while cruising at a steady speed. Generally this is most pronounced around 65-70 MPH (97 KPH) but some customers who are tuned into it may be able to detect it at other speeds as well. This may be a result of active fuel management (AFM - V4 Mode), tire or tire imbalance, or a driveline concern.

Recommendation/Instructions: If SI diagnosis does not isolate the cause of this concern, pedorm the steps below to determine if this is related to AFM:

If this concern only occurs in V4 mode, no repairs should be peformed at this time. This concern is under investigation with a correction being developed. Once a correction is available, this PI will be updated with additional details.

[gearhead455]

Yes it's the AFM, I just experienced this morning on my way to work, put my Pypes axleback on last night....just think of it as now you know when your car is saving you $$$;) I believe if you put it over into sport mode it will deactivate the AFM if bothering you too much. Some are tuning it out altogether.



In manual mode only,it is deactivated.

[Patrick G]

My G8 spends 90% of its time in AFM. I did the opposite of most of you and I made AFM much more aggressive. I can cruise 75-80mph in 4 cylinder mode in 6th gear or I can cruise through a 20mph school zone in 4th gear 4 cylinder mode. So I'm either barking gears in 8 cylinder mode or sipping fuel in 4 cylinder mode. I'm embracing the technology, not running from it. My fuel economy is excellent!

[gearhead455]

My G8 spends 90% of its time in AFM. I did the opposite of most of you and I made AFM much more aggressive. I can cruise 75-80mph in 4 cylinder mode in 6th gear or I can cruise through a 20mph school zone in 4th gear 4 cylinder mode. So I'm either barking gears in 8 cylinder mode or sipping fuel in 4 cylinder mode. I'm embracing the technology, not running from it. My fuel economy is excellent!


How good is it?


I got 22.988 mpg average on my 6000 mile trip, that's with 3 adults and a very full trunk and cruise set at 90 mph most of the time.

[polo]

How good is it?


I got 22.988 mpg average on my 6000 mile trip, that's with 3 adults and a very full trunk and cruise set at 90 mph most of the time.

I think I remember reading he gets like 50-55 mpg...

j/k :)

[johnbell2]

My G8 spends 90% of its time in AFM. I did the opposite of most of you and I made AFM much more aggressive. I can cruise 75-80mph in 4 cylinder mode in 6th gear or I can cruise through a 20mph school zone in 4th gear 4 cylinder mode. So I'm either barking gears in 8 cylinder mode or sipping fuel in 4 cylinder mode. I'm embracing the technology, not running from it. My fuel economy is excellent!

I really need to see about sending some business your way for a tune one of these days... Superchips has been fun but I'd like something less generic.

[mikesgt]

I received a copy of this from the dealer. Evidently they are working on a solution to the AFM Vivration

#P1P4691: Phasing Vibration In Drivers Seat And Steering
Wheel - Under Investigation - keywords BQMI - (Aug 27,2OO9)
Subject: Phasing Vibration in Driver's Seat and Steering Wheel - Under
Investigation
Models:2OO8-2OO9 Pontiac G8 with 6.OL Engine (RPO L76)
and 6 Speed Automatic Transmission (RPO MYC)

Conndition/Concern:
Some customers may complain of a phasing vibration in the driver's seat and steering wheel while cruising at a steady speed. Generally this is most pronounced around 65-70 MPH (97 KPH) but some customers who are tuned into it may be able to detect it at other speeds as well. This may be a result of active fuel management (AFM - V4 Mode), tire or tire imbalance, or a driveline concern.

Recommendation/Instructions: If SI diagnosis does not isolate the cause of this concern, pedorm the steps below to determine if this is related to AFM:

If this concern only occurs in V4 mode, no repairs should be peformed at this time. This concern is under investigation with a correction being developed. Once a correction is available, this PI will be updated with additional details.


Man I hope they find a fix for it. They can use my car as a test vechicle if they want.

[SRG963]

My G8 spends 90% of its time in AFM. I did the opposite of most of you and I made AFM much more aggressive. I can cruise 75-80mph in 4 cylinder mode in 6th gear or I can cruise through a 20mph school zone in 4th gear 4 cylinder mode. So I'm either barking gears in 8 cylinder mode or sipping fuel in 4 cylinder mode. I'm embracing the technology, not running from it. My fuel economy is excellent!

Hi Patrick, can you elaborate some? Average MPG's?

Sounds like something GM should have done to begin with :nud: