Slammed'99

Hello, it's been awhile since I've been on here. Sold the '99.

Anyways, I've got a '03 1500HD with the 6.0L. As we know, these things suck on gas milage.

Any tips on getting better milage? Would a better flowing intake and filter help? Do you guys still like the UPD, or is there a better option?

Any other tips? Thanks

BigTex

iTrader: (16)

Intake and exhaust will help, as well as a good tune. I've seen my gas mileage change immediately after installing a good tune with more timing.

marc_w

I didn't like the off idle throttle responce with the UPD. I think it was giving up MPG. (up top it pulled hard, but down low it felt flat)

My favorite mods have been plug wires, exhast and simily tuning the part throttle fueling.

Duals aren't supposed to give better low end, but I was fortunate for going with the B&B. Low down torque is improved. Tuning easily gave me another 1.5-2mpg.

I regularily get MUCH better milage than I should be. 17.8 this last tank (a handfull of WOT runs to 60), and working on 19.5 this tank, with only a few spirited moments.

--

Tex, how did you go about throwing timing at your truck? Did you only do it after lowering the ECT?

I'm getting KR at 65-70mph, ~2000rpm when I lay into the pedal. I see my HO timing curves are "unnaturally lowered" in that area. They're lowered to the same as LO tables in the middle of this HOLE.

The rest of the HO (and LO) graphs flow nicely, except for this hole where I'm still getting knock.

........Because of this, I haven't even thought about adding timing yet.

FILE

iTrader: (5)

Don't Race.....

BigTex

iTrader: (16)

When I lay into the petal at 2000 rpms, it downshifts.

I do get KR when I'm at 65mph cruising along and it has to shift down from OD to 2nd gear for a WOT blast. If I'm manually in 2nd gear at 65 and punch it, it doesn't show KR. So my KR is more than likely due to some TM or trans shifting table. I just dont know how to correct it.

I added timing to the low MAF flow area, which are used for normal driving. This helped my mileage. The WOT sections of the tables have completely different values than the normal cruise cells.

marc_w

Okay... I need to look into this a lot further. I didn't realize timing was adjusted from the MAF tables. It must have been WOT I was looking at there...

By 'lay' into the pedal, I mean a healthy roll into the pedal... maybe about half throttle - enough to pass someone but not downshift.

I pretty much have all stock shifting tables/times/speeds.