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.