Anybody tweak your truck with HPtuners?

[Sweet Chops]

I always thought that was the torque management.
I can step on mine from a dig....it will toss you back real good, then fall on it's face until about 3K.

My tuner has said with just a 50% reduction in TM, a little more fuel, and some light changes in the timing the TBSS's really wake up.
Of course, going to be differences there between the 5.3/6.0 and the LS2.

I would like to see better mileage out of my rig, but until the LS1 fans are in, I think I am stuck looking at 17.5MPG on the highway. Damn the 4.10's.

I put them in my 08 Saab 97x Aero, it did clean up the engine bay but I didn't see much MPG increase. The MPG increase was the main reason I did it. I see 16.5-17mpg mostly city. I'm just waiting for the warranty to end then im going to do a full street tune on that.

[Firebirdjones]

I put them in my 08 Saab 97x Aero, it did clean up the engine bay but I didn't see much MPG increase. The MPG increase was the main reason I did it. I see 16.5-17mpg mostly city. I'm just waiting for the warranty to end then im going to do a full street tune on that.

Clutch fans are the most efficient mechanical driven fans you can use. So the gain wouldn't be great with an electric fan swap. Not to mention GM uses a plastic fan now which is lighter than the old steel or aluminum clutch fans of years past.

However anytime you can remove any parasitic drag there should be some gain. On the dyno removing a clutch driven fan shows a 12 HP gain at the flywheel when we used an old style steel fan with a clutch. That's at higher rpms though on a BBC.

I removed the clutch fan on my 6.0 for several reasons. This was a retro swap in a 72 blazer and I was moving the engine forward for the longer overdrive trans. I wanted to free up some room in front of the engine. I also wanted the cleaner look without the HUGE 72 truck fan shroud up there so it's much easier to work on. I also liked the idea of running both fans while the AC was one, since I'm using 134 freon in the old style single pass condensor, I need all the help I can get to cool the condensor. And last but not least, I'll take any HP and mileage advantage as a small bonus.
I don't think this 6.0 getting over 19 mpg highway is no accident. Considering I haven't tuned any fueling tables yet, and it's running in a boxy 4600 lbs. blazer with 33" tires, I'm pretty happy with it.

There is definately more fuel mileage to be found in these things. I think my free flowing exhaust helps with a real dual 2 1/2 inch system as well as the 4" air intake. The engine isn't choked down.

[Mr. Luos]

I keep reading about guys saying 10HP and 1MPG. For $275 or whatever, worth it even if it is half of that.
Time will tell. Mine won't be going on until Feb/March.

Oh, and I will not use anything else. This is my second set (first on the T/A)....

[Cutlass]

Well I haven't been driving my truck much lately so I don't have mileage numbers yet. But today I spent a couple hours today "tuning" my friends '06 1500HD 6.0 4L80e. He has a cold air intake and dual exhaust. He has a weird hesitation at WOT, second gear, around 60mph, and 3800ish rpm. So we practiced using the scanner and histograms and determined its getting a bunch of spark knock around that point. The ign timing is far from aggressive around that point so we were pretty sure it was lean. We checked the fuel trim histogram to kinda confirm our suspicions and yep...a bunch of positive LTFTs. So I totally hacked away at the tune adding to the VE table in that area. we keep adding and adding but it never went away and it actually started knocking at other rpms and shifting super hard (somehow the VE table must be linked to shift pressure??)
Well we knew we weren't getting anywhere and in fact were maybe making things worse. So we stopped for lunch and did some thinking. We came up with the ideas that:
1st we weren't tuning the VEs properly since we didn't fail the MAF and
2nd maybe the cold air intake was skewing how air flowed through the MAF and skewing its readings.
So we flashed the stock VE table back in and scaled the MAF up 10% across the board(again just randomly hacking away/experimenting). A couple blasts down the highway and we found out our changes made a big difference. now the cruise and low rpm fuel trims were negative and the WOT problem areas were about 4 points closer to zero than before. the hesitation was barely there and only .5 deg of knock retard was showing.
But we ran out of time to further mess around. But now we know that a proper MAF calibration should solve this lean condition. So I might have to get a wide band so we can do this properly.

[Firebirdjones]

I'm pretty sure that shift pressures do work off the MAF to some degree, so that may be why you experienced some hard shifting.

Sounds like you started heading in the right direction. It takes some getting used to doesn't it? I'm no expert myself, and it's probably taken me alot longer than most to figure some of this stuff out.

You'll probably need that wideband to simplify things. I tuned via fuel trims on my first tuning experience, and it worked but took me a very long time to dial in the VE tables. I also ramped up the MAF tables in that car, but I found that I had WOT too rich in the upper rpm ranges, because GM already has them rich, and I just made that worse. Other than that it was successfull.

Orion then helped me setup my wideband with HPtuner after I upgraded to pro. Sooooo much better. I did the VE tables on my wifes 4th gen within 3-4 hours of street driving, stuck with a speed density tune, and commanded a 12.7 AFR and it was nearly spot on throughout an entire rpm sweep. It runs better than it ever has.

I just hope that my blazer is that easy. I'm going to keep the MAF on that one for now, so after I do the VE tables first, I'm going to attempt to tune the MAF using the wideband, I haven't done an MAF table like that yet. I'm not even sure I have a histogram setup for it. I may just have to park it and drive something else for a couple days so I can get started on tuning the fuel tables. I'm getting anxious to get started.

[Mr. Luos]

How far off do you guys think the LT's will throw the tune on the TBSS??
I don't want to tune it until the warranty is up, but having these headers sitting here is killing me.

[pajeff02]

Just check your trims after running around for a bit and see what they look like.

[Firebirdjones]

Can you log it now Luos for a "before and after" check? So you can do what Jeff says and see how much it changed.....then go from there.

I'm sure it's going to be different, not sure if it's enough to worry about tuning it right away though. With your own software, you could always quickly flash in the stock tune for warranty purposes if that concerns you. Would having the headers on anyway raise an eyebrow at the dealer??

[Cutlass]

With your own software, you could always quickly flash in the stock tune for warranty purposes if that concerns you. Would having the headers on anyway raise an eyebrow at the dealer??

They check for that now. At least they do for engine, transmission, and driveline components. Dealers are required take a digital picture of the Tech 2 of the Calibration IDs and Verification Numbers. The computer saves the last 8 or so calibrations.

[Firebirdjones]

They check for that now. At least they do for engine, transmission, and driveline components. Dealers are required take a digital picture of the Tech 2 of the Calibration IDs and Verification Numbers. The computer saves the last 8 or so calibrations.

Ah, I've also seen these new vehicles that come with On Star, they can tell when you do something to the vehicle and notify you as such. Friend of mine has a new duramax diesel truck, and he installed a bully dog tune. He got a letter in the mail a week later that GM was aware he had tampered with the tune and it would void his warranty. He told me it was through his On Star system or something like that. Ain't that the shits?
It seems the man is always watching you

[Mr. Luos]

From my understanding....if it gets plugged in, it can be shown to the dealer.

Just wondering if I should hold off on install, don't think it would be too far off, and the original manifolds could easily go back on if need be.

[Cutlass]

Ah, I've also seen these new vehicles that come with On Star, they can tell when you do something to the vehicle and notify you as such. Friend of mine has a new duramax diesel truck, and he installed a bully dog tune. He got a letter in the mail a week later that GM was aware he had tampered with the tune and it would void his warranty. He told me it was through his On Star system or something like that. Ain't that the shits?
It seems the man is always watching you

Now thats some shady crap there. But I know this all started with the Diesel power up tuners...now they've updated that to include gas V8s. But it doesn't say anything about 4 or 6 cylinders...so if you have one...mod away

[Cutlass]

Just filled up...14.6mpg. I'm not too impressed. But I may have had a heavy foot while butt dyno'ing/tuning on the first half of the this tank of gas. I guess I run another tank through doing my normal daily driving routine and see.

[Firebirdjones]

Just filled up...14.6mpg. I'm not too impressed. But I may have had a heavy foot while butt dyno'ing/tuning on the first half of the this tank of gas. I guess I run another tank through doing my normal daily driving routine and see.

Ya the good ole' butt dyno I just filled mine yesterday, all around town driving, alot of stop and go in 25-35 mph zones and got 15.73 mpg. Not my best but not horrible I guess.
I'm setting it up to do some VE tuning Friday morning. Once I get the fuel spot on, I can log some timing runs and see what I have for knock, maybe get more aggressive with timing.

I beleive the stock tunes are based off of sea level, but I'm at 5,000 feet. So I know the fuel trims are hunting around, not to mention the commanded 11.7 AFR is pig rich up this high . I'm looking for this thing to get even better mileage and have some more get up and go with the ole' butt dyno

[Cutlass]

yeah, I'm actually happy with 14.6 because that 1 mpg better then the Jeep it replaced!!

[Firebirdjones]

Some other interesting things I've found.

"PE delay RPM" It reads that if the rpm is below this amount PE will be delayed. Well my factory tune has 5500 rpms in there
So basically I'm never going to hit PE??? Pfffff!!!

I checked my 4th gen tune and it has "0" So that's what I put in the truck tune. We'll see what happens, but if I'm thinking right, my truck was still trying to command a stoich AFR at wide open throttle unless I got above 5500??? I should feel a "seat of the pants" difference with that change.

Another one that isn't in the 4th gen tunes......

"cylinder charge temperature" This looks like another useless table that is taking ECT and IAT temps and using them to modify the airflow tables. It says if disabled it reverts to just using the IAT temps and is good if relocating the IAT sensor and/or using a forced induction setup.
Sounds to me that disabling this feature just dummies down the tables a bit to a simplified IAT only table. Anything dummied down is good in my book

Another one under PE that simply floors me...

"Enrichment Rate" The description states this tables dictates how fast the commanded PE ratio comes in. The higher the number, the faster you reach your desired PE, the lower the number, the slower it reacts. A peak number is 4.0
Mine had .0125 in there stock. What's up with that?? At that slow of a rate I could be through most of first gear before it decided to do something. When you whack the throttle you want instant PE, that's my thinking. Why the hell would you want your AFR delayed under 100% load?? That just invites detonation if you ask me. I bumped that to half of the allowed number (2.0) which should be a big change from .0125

I also checked two other PE mode enable tables. One that uses KPA from the VE tables and the other that uses throttle position %.

My KPA was factory set at 55 KPA, which seems high. My 4th gen has a factory 15 KPA in the tune. I'll leave that alone for now until I get some other things ironed out.
My throttle position % to enable PE was set at 90% accross the board. This seems a bit extreme to me. My 4th gen starts off around 50% and tapers down to the 20% range as rpm increases,,,,,which makes more sense to me.
I'm going to drop this percent down on the truck a tad and go from there.

[Firebirdjones]

I finally went out and made a few log runs to see where timing was at and my shift points.

Cutlass, I can see now why your truck was commanding those timing numbers of 28-30. Those are the stock timing tables up in the 52-56 g/cell rows.
I logged mine and I was surprised to see that big 6.0 only running in the 52-60 g/cell rows of the timing table. I was seeing the same timing numbers you were.
I made all my WOT timing changes in the 64 and up g/cell timing rows, and I never saw those changes when I logged, the engine doesn't run up that far.

That surprised me because our 4th gen runs up around the 76-80 g/cell range.

Anyway, with 28-30 degrees of timing, I didn't see any knock what so ever. I went ahead and tamed it down to 27-28 in that area since I don't have the fueling done yet, and I'm sure it's running fat.

Another thing I noticed is that my IAT temps jumped to over 100 degrees rather quickly after a bone cold start, and then settled around 115-117 degrees and stayed there no matter what I was doing, idling or driving at 55 mph. That IAT integrated into the MAF is a bad idea.
In any event, I had already zero'd the IAT tables that pull timing at higher temps anyway, so it's not doing anything. Seems I didn't need it anyway because I saw no detonation at all running 91 octane and ambient temps are 87 degrees at the moment.

[Cutlass]

My friends 6.0 runs in the 68 to 76 range at WOT and sometimes higher than that. My 5.3 truck runs in the 56 to 68 range WOT.
Also I'm right there with on the PE and Enrichment tables. Those things surprised me also I a made similar changes like you did.

[Firebirdjones]

I spent 4 hours tuning the VE and WOT on mine today.
I noticed on the VE table it would get up to the 80 g/cel range but on the timing table it would only hit the 62-64 rows.

Anyway I was shocked at what I found. Anyone that thinks the stock tune is fine might want to take a look.

Before I changed any fueling at all, I logged with the wideband with the MAF working and then disabled the MAF and logged with the wideband using only the VE tables (speed density).

With the MAF working it's the primary source for fueling, and it was much too rich, nowhere near stoich (14.7) It was running in the 13.5 range with huge fluctuations, sometimes I would see 14.x for a split second but that was it. That thing was really hunting for fuel. I'm surprised this thing even got 16 mpg city and 19 mpg highway.

I then logged the VE tables in SD (disabled the maf). Again no changes yet. Now the truck was running way too lean with AFR's in the 15.5 to 15.7 range. What I did notice is that the AFR was much more stable and not hunting around, it was just too lean. Another benefit I noticed is that my idle instantly became rock steady the moment I started the truck in SD. No more flare up upon startup, settles to a nice steady idle, and my throttle response was crisp.

So with that said I had made my mind up that the MAF had to go. I'm running the truck in SD from here on out. Which is exactly what I did with my wifes 4th gen with similar results.

So on to tuning. I spent 4 hours driving around and dialing in the VE tables. Eventually I got everything showing 14.6 to 14.8 AFR. Very solid AFR readings at all cruise ranges, so I expect another bump in gas mileage readings as it's no longer hunting all over the place.
I got the WOT dialed in with a 12.8-12.9 AFR up through 6,000 rpms, and now this thing pulls and runs like it should, I'm very pleased with the power it's making considering it has no gear, it shits and gits now

In any event, I'm buying the IAT relocation kit so I can completely remove the MAF. I'm done with that piece of junk. Right now it's still resting in the air intake track but it's inoperable. Only the IAT part of the sensor is working.

I filled up with gas after I was done and got 16.4 mpg on that tank. Not sure how I did that with about 6 full throttle runs to 100 mph, not to mention all the part throttle driving in various gears to hit all the lower cells.
I'll fill up again on Wednesday or Thursday and see what the MPG is with the new tune. I'm hoping for another 1-2 mpg bump.

[pajeff02]

Are any of you guys playing with DOD engines?