Dod and tunes
 

Sierras with dod. Has anyone ever tuned them? What are the gains?

Also another question with exhaust. Does it get aggervating when it switches to 4cyl?

People do them all the time. Great results. And I have 2 1/2 true duals from the cats back with a 3 1/2 inch ss tip at a 45 and the only time it annoyed me was when I was cruisin down the interstate or pullin a trailer cause it exaggerates the 4cyl tone. I ended up turning off the dod and my mileage didn't change.

If you tune it to stay on longer, you will see increases. I had mine where it would stay on for 10 minutes at a time, overpasses and everything.

i tuned mine out. love it.. runs like a damn truck now.. i hated the 4 cyl mode wasnt worth shit imo..

First I got turned off with the tune and milage didn't change,now I did it mechanicly.

The DOD is an amazing feature and I don't see a benefit to turning it off "just cause." I can see it if guys are running huge cams and are worried about the DOD lifters failing. If you like driving 80 mph all the time, ya, it's not gonna save you any gas, cause it's not active! The 4 cylinder mode only turns on when you're under 6% TPS. I'm learning how to tune, and I have my DOD TPS raised up to 12%. Highway mileage went from 19 to 22, at about 65 mph. If you don't like the sound in 4 cylinder mode, just turn up the stereo.

what about the surge in power? and the delay of getting out of 4cyl mode back to 8 cyl... very annoying... maybe for a mid size car. but a truck na... i guess if you can stand the in and out of the dod mode good for u. but most of us can not.. lol...i also think its an amazing feature, but not in my truck. :drive:

When I was doing my "intelligence gathering" before buying my truck, I have to admit I was really surprised to find out they didn't put the DOD on the 6.2. That puzzled me because I figured the bigger motor had more to gain from cutting displacement at cruise or when creeping around in bad traffic. I finally decided (based on hunch, not facts) that either something must not have worked out right with it on the bigger motor, OR GM decided that guys buying the hot-rod motor wouldn't give a shit. If anybody knows more than that, I'd love to hear it.

Even stranger, they have DoD in the SUVs with the 6.2..... I'll admit, I had to talk myself out of using the DoD parts from my 5.3 and putting them in my 6.2. The 6.2 could cruise with 4 cylinders quite a bit with the extra balls it has. But the VVT by itself actually seems to make a good difference.

I never had problems with surging or delays. I also had stock exhaust on it so I didn't hear anything annoying. It was not noticeable in my truck, when I needed power, all 8 cylinders fired.

The VVT is supposed to help and that is why the 5.3s also have it now. I knew the SUV 6.2s kept DOD through '11 but am unsure if the early truck 6.2s ever had it.

I've read that DOD was available on the 6.0 in trucks, and then starting in 2010 they added it to the 6.2 in SUVs. (And actually GM is now calling it Active Fuel Management.)

yea a guy on another site has the 09' 6.0 with dod. he says he hardly feels it at all.. i guess different trucks act different. lol..

My '09 5.3 had it and I never noticed it either. If you so much as touched the throttle it was gone anyway. With the way the freeways are constructed here you are almost always on a grade going up or down so it was pretty useless since it was never able to stay on. It was pretty much a non factor and I don't miss it on my 6.2 but if it was there it wouldn't bother me.

I never felt it on mine. I even had a flowmaster 40 series on back in the day and the difference in tone wasn't bad at all. Transition from 4 to 8 was quick and seamless. It's a good idea if you live in an area with lots of 55-65mph speed limits. That's where it makes the best gains. But for 75mph interstates, the 4 cylinders just don't put down enough torque to overcome wind resistance. 6.2 might be a different story...

Hmmm......... what year you working on ......... never seen a new truck with DBW TB have a TPS % rate any lower than 15% at idle ??? or are you monitoring a different parameter my V4 mode varies but will hold til about 34% TPS under most conditions ....... have you increased the timing in V4 mode ??

Its always been called AFM (from 07 brochure). Dodge called it dod. In my truck with stock exhaust can't hear it unless its really windy pushing you for some reason (perhaps it changes things enough muffler doesn't work properly to change the tone), can't feel it, doesn't surge so no idea where all that comes from. I do have a RCSB though, so that helps, as don't have the extra 500-800 lbs of a ext/crew cab.

I do know the aluminum block versions in the early years had issues as those cylinders would cool off too fast or something like that, causing sticking rings and oil use. Its pretty much useless on the highway too I have found unless going downhill.

For a while the 6.2 was the only engine with the 6 speed auto and they were having issues with the trucksgetting that combo tuned in v4 so simply skipped it. I think they got it sorted out now though (haven't looked for a while).

Maybe its our roads or our altitude but it works wicked here. Speed limit on many of our roads are 50mph and with all the cameras you don't go much over that in those sections (not for long anyway), it will sit in v4 for a long time... I'd post my mileage but people just get mad and call me a BS'er so screw it. Works good for me though, and yes I check real mileage, not just using dash readout for avg fuel economy.

Whether you want it or use it or not is fine, but just remember GM gets points for putting it in and that allows them to keep making big monster engines we all like so that is good. One of these days I will get my 6.2L/6 speed into this thing and I won't be bothering with AFM when I do that!

Really? I read about it on the hpt board, Some folks said they raised it from 6% to 20, and an experienced tuner said 12 was the magic number. 34? Serious? Haven't touched timing yet. And my truck is an 08.

I do believe the DoD TPS reading is NOT the same as the TPS, read this:

http://www.hptuners.com/forum/showthread.php?t=10993

So the 6% (my stock tune has this figure as well) would be actual, whereas the 18% my truck idles at would be GM using the voltage of the sensor again (in the same way you only get 87-88% TPS reading at full throttle even though you are wide open).

i'm not much of a teacher, sorry.

Also, when I was playing with AFM don't forget you have to modify the vacuum tables under "vacuum thresholds", it all works together.

OK that makes sense .......based on voltage my truck idles at 15% TPS and yes WOT 88% ......... My AFM works fine seamless in and out .......but of course does not stay in long enough to be a real benefit ..............since I went to 4.11 rear gear it comes in alot sooner and I now can actually cruise at 60/65 without it kicking out for the slightest incline ..........the 4.11 gear alows less throttle position to move this truck stop and go city mileage has improved alot ....... I dont have a tune yet trying to gather as much info on how AFM working in my truck for my tuner .it appears to me vacuum and TPS effect it the most and pbly "load" ( although that rate is pbly a calc of vacumm and tps ??) Some have added a bit of timing to the V4 mode to made more power in V4 .....appreciate the info

AAAAAAAAAAAAAAAAAAA-MEN, brother! :cheers:

Did some scanning today, and ya, the V4 mode stays on til around 36% tps. Added some timing across the board too without any KR. Cool. Getting closer to 20mpg imperial!

Good info Thanks
So did you make a change in the TPS setting for V4 or just timing so far
How much timing 4* or less ?? have you changed anything in the vacuum tables as suggested by other poster ??

I've touched on the timing and the V4 TPS so far. Haven't touched the vacuum yet. I'm JUST learning this stuff, and I've been reading up on it for 4 years now!

Thanks I'm just starting to understand this AFM tuning ........

Going slow and making small changes, one at a time, is the smart way to do it. I'd have to look at my tune but on the vac tables I dropped it about 25% in the rpm range where you wan to hold it the best. A bit more timing, bit more tps allowed, makes a big difference.

One other thing to be careful of here is that you can't use other peoples numbers, plug them in and expect the same results. Different altitudes, truck weights, gearing, terrain, all plays a part.

Don't have access to laptop right now, but CDN SS if you are interested I can send you a copy of my tune for V4, pretty sure I kept a change log too (been a while). Because of your gearing and better mechanical advantage, you should be able to run a bit more v4 than most. I found I could not keep my V4 engaged on the highway at 125km/hr, and it was jerking going in and coming out so that can't be good and backed off at that point. We ARE pushing barn doors through the atmosphere after all. Its also good to know that the v4 mode disengages the lockup converter, goes into v4, then re-engages the lockup..same coming out..it also opens the throttle more (without any feedback to you) when in v4...plus the flapper in the muffler, all designed to make it seamless.

If you go onto HPTuners website and search dod, afm, there are some good threads on there too.

^Interesting. Didn't realize the muffler had a flapper valve. Is the vacuum table you adjusted in Engine>Fuel COT Lean Cruise>Vacuum Thresholds>Enable Vac?

CDN SS, you aren't planning on keeping AFM with the blower are you?

Hey Jake ...... this AFM deal intriques me, it really working well since I installed the headers & 4.11's ..... curious to see how good I can get it to work ..........pbly wont get the blower on for a month or so so for now tuning the truck the way it is ............... assume AFM wont like boost in the "shutdown" cylinders

Lower gearing is gonna bring out the best of DOD because of the mechanical advantage, like stated above. With stock settings, boost won't be able to get into the "shutdown" cylinders because the blower would still be in bypass long after the TPS increased and trigged DOD to deactivate (assuming the settings weren't tweaked enough to allow enabled DOD and boost to overlap). My issue is I don't trust DOD so much... A few years ago after only about a year of having the truck, the DOD would get stuck on, as in it wouldn't come out of 4 cylinder mode at all. Even started up with 4 cylinders... Sucked at the time, and I eventually just turned it off to avoid it happening again. Problem is, you throw a blower into the mix and that happens, you're gonna see double boost instantaneously if it ever has a hiccup like that. :bomb:
There's a fine line between good mileage daily driver and a tough towing truck...you have to decide where you wanna draw that line. Of course you could always buy a diesel :)

There's a fine line between good mileage daily driver and a tough towing truck...you have to decide where you wanna draw that line. Of course you could always buy a diesel

I know I know ...... I want my cake and eat it too ......and yes should have bot a diesel ...but that would be too easy LOL ........ Did not intend to leave AFM enabled but kinda interesting how its working now, thanks for heads up , good points re blower and AFM re TPS/ vacuum settings etc "if" I keep AFM when blower goes on I will proceed with caution re non stock settings

Yes, in the enable section went from 45 to about 33 and blended it a bit, in the disable section went from 3 to 2. TPS from 6% to 15%, timing have to look at a bit to see but bumped it up overall, also getting rid of all negative values made it much more responsive off idle (nothing to do with afm just thought I'd throw it in there).

One of the biggest complaints GM had with the old caddy v8/6/4 system was the sound of the exhaust (when it worked). That is a prime example of how technology had to catch up before an idea could be effectively put into action...so not sure exactly how it works, but under the lower airflow for the v4 mode there is a pressure loaded door or some crazy thing like that which moves and changes the sound so the exhaust sounds normal in v4. That is why aftermarket mufflers sound stupid in V4, they don't compensate for the 4 cylinders not firing.

They did put some thought into it. Interesting article:

http://www.enginebuildermag.com/Arti...ve_timing.aspx

Appreciate all the info , Thank-you .......whether I can keep AFM enabled when I finally get around to installing my Blower remains to be seen but I am very interested in this ..........a copy would be great
wmwaters@mymts.net

I do understand every vehicle is different and will make small changes as I go .........the unfortunate part of this whole technology is the reliability of the collapsing EATON lifters !!! Sure would be nice if a way to know if my motor has the "good" Delphi ones I only have about 8000 miles on my truck so listening for the clatter every day

FWIW ...... the exhaust note in V4 is barely noticlble .I have a CC ....... headers .no cats .... 3" magnaflow single pipe cat back uses the 22" muff ........ plus I added a 24" magnaflow bullet in front of the main muff once I added the headrs and removed cat ( got drone) ......... with added bullet no drone sounds great at wot and cruises nice

Copy of tune is on the way. Use the info at your own risk! A work in progress.

A blower and afm seem to be mutually exclusive, I would think the risk is not worth the reward (couple mpg's) should something go wrong, but if you could make it work that would be excellent.

Don't drive yourself nuts listening at the engine. If it happens you will know...:) The design seems rather flimsy I thought, so I could see there being issues in the future. If I have any issues at all, they are out of there, and afm will be disabled, done. Meanwhile, Amsoil 5-30 every 5000km along wiht new filter is about all I can do to keep it happy.

Located where you are, have you looked into the effects of cold on a blower setup?? I drive my truck daily, and it sits outside so I would be curious at -30 C starts if that has any effect on the things...I have heard some superchargers will lock up at those temps.

Let us know how you make out.

A blower and afm seem to be mutually exclusive, I would think the risk is not worth the reward (couple mpg's) should something go wrong, but if you could make it work that would be excellent.

Yep I agree ....but interesting to try to make it work .......I will proceed with caution :) Thanks for your help

Cold weather and a bower .......I bot a GTP with eaton blower new in 98 ...very heavily mod'd sold it in 2009 ran 12.3's all day long ........was my DD always sat outside all year ( toys in garage) started fine in -30 never had an issue I dont expect an issue withe maggie in cold weather .

The stockers are engineered for that but I had a friend with a dodge truck and he was basically told the supercharger he was looking at (will have to ask him) was not recommended for -20C or colder due to clearance issues. Its the only time I have heard of that and my truck does sit outside all the time (same deal, toys are in the garage) so it would have to deal with temps like that in the winter months...

Anyway, let me know how things go...we seem to have our own set of special issues up here in Canada...:)

HMMM interesting .........may have to connect one of those circulating heaters that go inline the heater hoses ..pump hot water thru it or a battery blanket around the blower housing :)

I drove an AFM truck with some wicked sounding exhaust... Wish I remembered what it was... But it IS possible to have it sound good...
Well... If you like the way a Subaru sounds... It sounded like a very large Subaru, in 4 cyl mode, lmao



Also, a bypass for the intercooler will be a good plan.

Not that anyone cares, but I have a Dual Flowmaster 10 Series setup out the side in front of the rear tire. They cut out my resonator as well, and it causes almost a crackling noise going into 8 cyl. The 4 cyl. mode is not bad, but it is the transistion that kills me. SOunds like someone with a cough that has a lot of phlegm coming up (sorry for the graphic display, but this is pretty accurate).

I have a 2010 also my AFM transistion has always been smooth with no odd noises ......now with headers and Magnaflow single exit 3" cat back ( no cats) plus added a 24" magnaflow bullet muffler to system yes it does sound different in V4 but nothing objectionable and no odd noise at transistion

UPDATE....... just got my tune installed with AFM tweaks :) Thanks to all on here you shared there AFM tuning details helped alot !!!.............. working great ....
....I can see under some conditions ( going into the wind ) when in V4 cruising at 70mph @2100(4.11's) TPS @37 the mileage in V4 is not dramatically better than V8 ....... drop back to 66mph and it really bumps the mileage up :) I realize at some point V4 wont cut it ...EG. when TPS at 40% it still stays in V4 but it is working hard and mileage drops off ...... betwen the 4. 11's & the tune it really is worthwhile function now. usefull at normal highway speeds 60-70mph ....... I am amost always in V4 in the city 30-50mph ..........get on it good from a stop then roll back on the throttle lightly and V4 kicks in & stays and yet still alows you to acclerate lightly if traffic changes or small hills ........

PM me all your AFM settings you tuned in, please :)

I know some of them won't work as well because I have the 4 speed instead of the 6, but still... :)