Looking for some help on cam/headers tune LM7 5.3L (mostly spark)

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Originally Posted by LastCall

Calc.vet calculates the VE and corrects the maf. You had those two switched. I would verify you your selben is getting correction values.

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LastCall, what would I need to do to verify that my selben is getting correction?

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Originally Posted by ScarabEpic22

I was thinking about this last night and again this morning, Im frankly surprised your MAF correction was 1 across the board. IMHO, it shouldnt be unless you're running SD... Per Joe's description, Calc.VET calculates the MAF and corrects VE. How your MAF is the same as a stock tune when you used that data to calculate a correct VE...something's not adding up. It would explain the bog you get as well (experienced it on my own vehicles).
...
...Let me do a quick trans tune for you as well, should firm the shifts a bit and make them crisper without hurting trans life. In my experience, a tuned trans lasts longer than a stock one because with stock tune the clutches burn out due to slow shifts.

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Well, i'm getting close to the final hour....Will be on the dyno tomorrow from 11am to 3-4pm. Odd circumstances, but it's a pretty cool opportunity to get total access to a dyno for 4-5 hours free of charge. I just hope I'm prepared to make good use of it, but I am feeling a ton better with how the truck is running right now.

1. Joecar and scarabepic22, you both mentioned transmission tuning. What are the goals/aims you had in mind, or what parameters/tables should I be concerned with? Are there any tutorials, references, or stickies you know off the top of your head that would bring me up to speed before tomorrow?

2. Also, as far as I know, the long term fuel trims are at 0.0 in my logging. At this point I am planning on setting up an AutoVE tune to double/cross check the fueling, but yeah I am really confused about the 1.00 MAF multipliers resulting from CALC.VET.

3. What should (how do I figure out) my PE commanded EQR be? i.e. How rich is too rich? / Do I just need to guess and check with the dyno until I find peak tq?

4. Is it possible to use DVT controls WHILE logging data? For instance, I'm guessing I am going to want to activate DVT so I can enable 3rd Gear Hold. But it seems like every time I have every tried activating the DVT in the Scan Tool during logging, it comes back with "No Response" . Also, when I am on the dyno, I should be in 3rd gear (auto) with TCC locked, correct?

5. Again, with the DVT, I was hoping to be able to hold the engine steady at various loads and speeds, and use DVT to make adjustments to find optimum/max advance without KR. Is this a good or bad idea?

If anyone has time to look over my latest (short) log, maybe you'd be able to see what's going on with CALC.VET and anything else I may be missing. I can post it in like 30 mins.

Transmission tune:
1. increase shift pressure tables (reach 96 psi at around 300 ftlb, linearize from zero).
2. set shift desired time table to 0.2 to 0.3 s.
3. reduce shift torque reduction tables some.
4. set throttle kickdown tables to 100% TP (allows PT upshift/downshift tables to work properly).
5. make sure WOT downshift MPH's are below their corresponding WOT upshift MPH's (at least 5 mph difference).
6. make sure the PT upshift/down shift curves do not cross each other anywhere (dump them all into the same xls spreadsheet).

If MAF/VE are correct, then PE set to EQR 1.175 is just right for NA... this can be fine tuned (a little richer at peak TQ, a little leaner at peak HP).

Connect scantool to vehicle, then goto DVT tab and activate the control you need, then start logging.

Yes, 3rd gear, TCC locked.

Where is your short log...?

Joecar et. al.,

Thanks for the tips. Sorry I didn't get back sooner, I left the charger to my Windows laptop in my buddy's truck on Saturday at the dyno shop, so I can't post the logs or tune until I get it back from him tomorrow.

However, the dyno experience went well, I think. I did figure out that enabling 3rd gear lock PRIOR to logging was the trick. The truck made 317hp on the initial baseline pull! Not bad for a tune made from only a few hours of street logging. And the shop owner pretty much came clean and apologized and basically admitted he just didn't put any time into tuning it, and also said that he sort of misunderstood the situation. Okay, yeah right, whatever... He did make it right though, all money was refunded AND he gave me 3-4 hours access to the dyno.

On the last pull, the truck put down 323hp and 319tq at about .82EQR PE. Much much better than the 295hp and 284tq it put down after his "tune".

I will post up tomorrow AM with all the current stuff and the dyno graphs as well. I still need to take care of the transmission stuff and back the timing off a bit in few places.

Thanks as always.

***EDIT: I think I meant to say .82λ, not .82EQR (I mean to say richer than stoich)

Good job :cheers:

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Originally Posted by LastCall

Calc.vet calculates the VE and corrects the maf. You had those two switched. I would verify you your selben is getting correction values.

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Doh, updated my last post. Thanks for sanity checking me! :D

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Originally Posted by 96SWB

ScarabEpic22,

Yeah I was always a bit confused at how values derived from instrument measurement could work out to be exactly 100.00% correct on the first time. I kind of poked around to see what might have been wrong, but I eventually dismissed it, figuring that, "Well, the MAF is stock, so who am I to argue with the GM calibration engineers?"

As an aside, last night I decided to completely start over with a clean sheet on Spark segment. Starting with {B5913} H. Oct. Spark, I actually printed out the tables from a factory 2002 LS1 calibrations, the factory 2002 Silverado LM7, and from a couple of other forum member's custom tunes who had camshafts. I did that because I'm a Mac guy, so I only have a little netbook to run EfiLive on, and its tough to look at multiple data sets on this 11 or-whatever-inch screen.

So, I spent a lot of time carefully making a "hybrid" of the different maps, probably giving the factory F-body tune the greatest weight, but also narrowing the band of "heat"
down a good little bit, and just generally doing my best to reconcile my common sense and grasp of the 220R cam vs the LS1 cam, and looking at other tables in the tune.

The result? Unbelievable! A short drive late last night blew me away. There are 2 little spots where the table is still too hot (around at 2600rpm/.44g/cyl), and I saw that I got into a little KR, but it always was brief and decayed out quick. So I have to touch that up here and there. But even with some KR the truck is pulling SO much harder at any RPM and just generally feels and sounds SO much healthier it was shocking. I also undid every single thing the dyno shop did to it, because none of them made any sense and the truck ran like absolutely turd on that guy's tune.

Additionally, I extrapolated/guesstimated some more air into {B101} Base VE above 4400.

I'm not exaggerating when I say it felt like I downloaded another 50hp into it with that one tune. I had it up in the mountains last night on the highway and did a 3rd gear roll starting at about 60, and it was up to 115 just about as fast as a pickup needs to do.

I have a couple more questions to ask in a bit I got to run 4 a minute..

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Your LTFTs should never be 0.0...I think LastCall has it right, you're not getting the proper data to have the MAF calculated in your SELBEN.

Glad to hear it pulls harder, sometimes it's just going back to square one and starting with a blank slate and it clicks.

Start with Joe's advice on trans tuning and put your shift points into the shift point calculator on here, that's really what Ive found "cleans" up shift feel and times.

I just wanted to follow up with you guys

So as it turns out, the issue with the MAF corrections coming out as 0.000'ed (and also the LTFT's being 0.0'ed) was that there was only one front narrowband O2 sensor connected the whole time I was tuning it. The truck's owner removed one of the front NBO2's and put the WBO2 in it's place. The whole time I had assumed that he had welded up a third bung in front of the cats and installed the WBO2 there; not so.

More-or-less satisfied with how the truck running/performing, he has since removed the WBO2 altogether, and put the NBO2 back in place. He said that he didn't notice a change in how the truck runs since he hooked it back in, but I'm curious what it means that I did all the VE mapping (using calc.vet) with only one factory narrowband? Does it just mean that the {B5001} table is wrong and needs correction (obviously still factory-tune values since they were only ever *'d by 0.00); OR, does it mean that the entire {B0101} VE table is also somehow wrong or skewed?