New to tuning / HPT -- setting up a tow rig after cam install

I'll start with the HPT files that are always requested, although this is more of a 'question' thread than a 'problem' thread. My thanks to the people who have posted "how-to's" -- I used @Rinkrat456 's "Idle Tuning Guide" to start out with, and I think I've done well (so far).

Attachment 105339
Attachment 105340
Attachment 105341

(note: My channel config when I took this *did* have the fuel trim channels, so the data was / is (?) still in the logfile.)


I've also been reviewing the forum history, and finding a lot of info there -- maybe too much? :D So I'm at the point where I think I need to check in and ask a question or two, based on what I've seen / read.

The truck:
2003 Sierra 1500HD (Crew Cab) -- 2WD, 5800lb. LQ4, 4L80e, Dana 60 w/ 4.10 (it's a Quadrasteer truck, and yes, the QS works)
Rated at 12K; I'm towing about 7-8000 for now. Strong runner, even before I modified it. It's a dedicated tow, not a DD.
Have put a lot of mechanical TLC into it over the two years I've had it, and love the thing to death. (was towing with a 5.3L Envoy, previously)

Recently added a Comp Tow Cam (54-452-11), with the following specs:
212 / 216 duration, .052 / .052 lift; 115 LSA.
Calculated overlap is -16 (the stocker was -15.75)

Given the specs of a stock LQ4 cam, you can see that it's a pretty mild grind, and I know that made it easier to dial it in.

Along with the cam, I put fresh 317 heads in (stock height, no porting) with an all-new valvetrain, new oil pump, timing chain, replaced all sensors / gaskets, etc. Basically a top-end rebuild / freshening.

Bottom end is stock (but AFAIK is in great shape).

I had the truck down for awhile while I did the above, and the check valve in my fuel pump went bad, so I'm in the middle of replacing that. Got a Walbro E85-capable 450lph pump; eventually, I plan on adding the fuel composition sensor and being able to run E85. I like to travel west, and at elevation, they actually lower octane out there. At about 8mpg, I like to run the cheapest fuel I can get (while I'm willing to run mid-grade if absolutely recommended, I will *not* run 93).

My Knock Retard #s look good for now, IMHO. I did notice there was one point in the log where it pulled a bunch of timing out (it looks like after a gear shift occurred, and the truck was at about 4000rpm before the shift). Granted, I don't have a lot of seat time yet, as I'm doing the fuel pump, currently.

My STFT and LTFT looked really good, IMO (you may not see them in the logfile). My question revolves around Stoich - right now, 14.7 is commanded, and the reading I've done states that I'd probably want to richen that up a bit. I've also read that I shouldn't touch fueling without a wideband.


So... based on what's in my files... what are my next steps? Do I get the WB and start working with that? Or is that overkill for my application, which is towing @ 65mph max, and being able to get up the mountains at that same speed, when possible? IOW, WOT is not something you'll see me at often.
I worry that 14.7 is too lean (or will be, once I hook up the trailer and head up the mountains).

No, I haven't enabled PE, or disabled torque mgmt yet -- those things will come. I'll probably set up PE to kick in about 3000-3500 RPM.

Future plans include a TBSS intake w/ E85-capable injectors, something along the lines of a Airaid MIT tube, electric fans, and if I find I need it down the line -- a mild turbo setup (but that would be at least a year away, as I've not towed since putting the cam in). I want to pull like a Duramax, without getting a DMax (at my age, I don't have the time / patience to 'learn diesel').

I'll stop here and wait for any questions. Thanks for reading, if you got this far. :hi:

Be careful with that large fuel pump, you will likely over power the stock fuel pressure regulator and need to get an aftermarket regular or smaller pump like a 255lph so you don't peg the fuel pressure way past 60psi.

Stoich at 14.68 is fine for E0 fuels, if everything you have around you is E10 then just change the stoich to 14.1. It's not too lean to have stoich at this, all vehicles will be at 14.1 or 14.68. Even all the trucks with way more power than yours and that can haul 15,000lbs or more on a goose neck. Power enrichment is really delayed in these trucks and they still survive hundreds of thousands of miles on the road. Making it come in faster never hurts anything and often stop knock retard and make it pull smoother with a little more fuel when going up a hill or where higher rpm is needed. Outside of PE just cruising along it's just fine at stoich.

You should be logging your MAF, TPS, o2 sensors and fuel trims to really see how it's running. The oxygen sensors and fuel trims will really tell the story of how far the fueling is off. With a camshaft change you would ideally need a wideband to dial in fueling outside of closed loop, which would be for full throttle.

Appreciate the reply. Just some follow-up clarifications / info, while I finish the pump.

I've already got the intake; just haven't put it on yet. Along with that goes a C5 Vette FPR; it plumbs in nicely with the returnless / FPR-less TBSS intake. And I'll hook up a gauge on the test port to make sure it continues to maintain 58psi, as well.

Got new injectors, too (L33-spec; rated at 50lb / E85). I did track my duty cycle, since the stock injectors were said to be so marginal (25lb) - when I playback the file with the duty cycle added in, the absolute max for that log I posted was momentarily at about 65%; most of the time, it was loafing at under 10% (and I'm thinking the new pump may change that, as well). Although I'm not starving it of fuel, or I'm sure I'd notice KR and drivability issues.

I wanted a baseline established before I swapped out the intake, as I didn't have one prior to the swap, plus I figured it would be easier to manage the tune at first, keeping changes to a minimum (my original plan was to have someone do the tune, but I found a nice deal during the project on an unused MVPI, and decided I'd take a stab at tuning things myself.)


I had been logging the O2 sensors previously, but took them out of the channel config, as they looked so normal, and I started removing things from the channel listings, both because I try to monitor every piece of data in R/T (parked), and once you get past 3-4 items in a chart group, things start getting really busy (I know how to split the charting into multiple groups, as well.)

As part of the cam swap, I replaced the B1S1 sensor, as my previous scanner was showing it was a bit 'lazy' compared to B2S1 (but not enough to throw codes). Now B1 and B2 primaries mirror each other perfectly in R/T.

Once I get the pump finished, I'll add those things back into my channel listings and cut another log for review with the items you mentioned. The complete fuel modules have been out of stock, so I'm taking a stab at modifying my existing module / bucket to accommodate the Walbro pump (and that was the lowest rated pump I saw that reported E85 capability, IIRC). I'm not a 'fan' of E-anything, but I'm future- / disaster-proofing, plus I know there's an octane boost with E85, so it's nice to have the ability to flex and not have to worry about E15 killing my fuel system.

I live in a major metro, so we do have E10 (and E15) to contend with, and I see it most places I go out of state with the truck, as well. It's been a long, long time since I've seen E0 available, outside of a road course.

WRT the wideband, I see how often those things update, and to be honest, I'd find it a bit distracting to have it permanently mounted, as I know I'd be watching it.) Apparently, one doesn't have to leave the thing continuously connected, and the sensors have a finite service life, as well, so I *could* disco it after everything's dialed in. If its only benefit is for WOT fueling, I do wonder how useful it'll really be for me, to be honest. We'll see.

I bet if the PE was setup more like a 4.8/5.3 where it doesn't have so a long delay for enrichment your injector duty cycle would shoot up another 20% because it would be adding in more fuel as the commanded AFR drops.

I tend to have my foot control PE to make it easy. I would lower the pedal enable to maybe like 70%. Lower the rpm delay to 3000-3500 like you are talking about, zero out the time delay so it doesn't need to wait 60 seconds. Then raise the MAP kpa enable to 80-85kpa. It should roll into PE nicely and only when your foot is far enough into it. Check your duty cycle after that and o2 sensor readings at full throttle to see how they are doing.

Just updating this thread quickly, as it's been awhile (so this is just 'FYI'). Posted in someone else's thread, and decided to update this one. No addn'l tunes to evaluate, for now.

- I took 5FDP's advice and swapped from a 450lph pump down to a 340lph. Had some issues with the exchange / vendor, but the new pump is in.

- I took the truck out for another run (still haven't touched PE, etc.) -- and got the injector duty cycle up to 97% at ~ 5200 RPM.
Definitely felt the 5800lb truck get up and go in the midrange. Still got a long way to go to finish.

Reverted to stock for the time being, as I'm going to put the TBSS intake on that I've had stashed away, along with a set of new L92 FF injectors (# 12613412), rated at about 50lb @ 58psi, if I looked up the info correctly. Gathered flow data from a few sources as well as the .xls worksheet to incorporate them into tune, once installed.

Went shopping on Craigs for an AFR gauge / kit. Picked up a NIB Holley analog gauge / sensor kit; it came as part of an STS rear-mount turbo system (also NIB); with the AFR gauge, I got the whole ball of wax for $1400 total (couldn't resist). Won't install the turbo until next fall at the earliest; looking to run a small / minimal amount of boost (8-9lb), just to make it easier to get up the mountain ranges with the trailer. Picked up a MIG welder in another transaction, so I'll be 'rolling my own' exhaust, when the time comes.

Once I get the TBSS intake / injectors on (working on another car right now), I'll start modifying the truck's tune again, and will post back here. But I think that catches things up with this truck / thread.

1. what valve spring are you using - how much seat and open pressure?

2. E85 will reduce economy significantly. The fuel is cheaper but its energy content is far less than gasoline so even though you pay less per gallon you will get much fewer miles per gallon making the switch not worth any economy at all.

So if your goal is to use the cheapest fuel for economy, 87 octane is king by a fairly wide margin.
Ethanol is a racing fuel, it will cool down the intake and trash thermal energy savings which adds to the fuel cost of economy cruise.
E85 is also famous for bio-debris, read this announcement from Aeromotive:

Quote:

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WARNING: If you plan to run E85 fuel you must be prepared to install proper filtration, and maintain it as frequently as every 10 run-hours. If not, Aeromotive does NOT recommend you the use of E85 with the 340 Stealth Fuel Pump. Aeromotive’s new product warranty assures the purchaser their 340 Stealth Pump will be free from defects in material and workmanship for one year from the date of purchase. Fuel pump failure caused by clogged/blocked fuel filters is not the result of any defect in the pump itself, and is not covered under this warranty.

For a detailed look at post-pump filter options and what a good one should be like, please see Aeromotive Tech Bulletin: Post-Pump Fuel Filtration TB-102 here:

https://aeromotiveinc.com/post-pump-fuel-filtration/

For a specific example of the issues related to a clogged post-pump filter, please take a moment to see the Case History File embedded in TB-102 here:

https://aeromotiveinc.com/wp-content...-Case-File.pdf

---

https://aeromotiveinc.com/tech-help/...th-fuel-pumps/

3. If you really want to achieve the highest mileage you will need a wideband. Factory narrowband can only maintain 14.7:1 air fuel ratios, whereas true highest peak economy is maintained near 15.5:1 air fuel ratios sometimes leaner 16.2:1. You will need to experiment at those ratios during a steady state cruise, using cruise control, and filling the tank -> Drive X miles -> Refill the tank the same way and calculate economy. It may only be worth less than 1mpg in your application so this isn't a recommendation, only an idea.

Improve economy cruise to consider soon:
A. Rotating weight: Get a low stall, lightweight 9.5" Lockup converter for the 4l80e is ideal. YANK makes the best unit in my experience.
This will reduce rotating weight at the engine, similar to lightening the crankshaft but without the potential for ruining the balance of the engine internals the way the factory intended it to be. SFI flexplate is obvious. Check the converter spacing (pullout) while in there.
Use the lightest tires, and lightweight wheels, rotors, driveshaft, etc... Light weight rotating parts free up economy.

B. Tune up, clean paper air filter and iridium ngk spark plugs, don't gap them down too far, keep the gap as large as possible for best economy cruise. It should be fine near .032" to 0.038" if just using low < 10psi of boost.

Thanks for the detailed info -- appreciated. I'll reference your questions / items in order...

1. They're the LS6 blue beehives. Seat s/b 90# @ 1.800?; Open 280# @ 1.250?
Comp recommended these or their own similar, with the cam. Also has the LS6 titanium retainers & locks, and the valve seats are the 'hat' type, also new.

2. E85 -- I'm not building compatibility for fuel economy, but for future mandated changes (if E15 goes to E20, etc...), the octane boost that comes with using it, and potential scarcity, if I'm traveling (the truck is a dedicated tow). The only time I'd use 100% E85 is if regular gasoline wasn't available. If I were to experience detonation, I'd experiment with ratios of E85 / gasoline. But other than those things... I'm fine with RON 87 gasoline, alone. At 8mpg with the trailer, fuel economy kinda goes out the window. What I should look for is one of those larger fuel tanks that can be retrofitted to increase range (26gal @ 8mpg is gone, quick).

I was actually wondering why you thought I was going for FE with E85, and then I saw one of your older posts -- so I understand. I'd love to get to 10mpg towing, but that's a 20% increase; I just don't see it happening, TBH. Unloaded, I can beat the highway EPA #s pretty easily. My problem is the trailer -- because it's effectively a big sail, increasing wind resistance.

3. Wideband - I have it now, and will tune with it, going forward. Since it appears that it's not required to be permanently installed, I plan to remove it once the tune is set, as I know I'd be distracted by looking at its constant movement, installed in a gauge pod.

Torque converter / flexplate -- On the converter, I had contacted a well-regarded vendor / owner, thinking that I'd be able to increase my tow weights if I purchased a performance converter. But he told me that I should stick with the stocker, if that was my goal. I'll have to do some research on the type of converter you're referencing, for its towing compatibility.
On the flexplate... that sounds like a good option, and will likely pursue it.

Misc items: GM actually backspec's platinum plugs for this engine, vs. iridium. The truck had Bosch platinums from the PO, before I tore the motor down; it now has the spec'd AC Delco platinums at stock gapping. It's not a hardship for me to replace the plugs more often, due to wear. And all the filters, etc., are brand new.