Opinions on a 'mystery tune' VE table

[AngelMarc]

Customer came in for a fuel filter because their tahoe (or suburban, whatever SUV it was).
Didn't seem like fuel flow problem, but we did it anyway because that's what they wanted.
I couldn't help but think the vehicle had something more suspicious going on, so I read entire and glossed over it.

CustomersVE.png

Does this look familiar to anybody? A popular base tune available online, stock corvette VE? Half ass cam swap tune?
Seems like a high torque peak, that goes into a flat-line. Supposedly it had a 'tune up' somewhere else, then wasn't running right because "it needs a fuel filter".

VEReference.png

This is what I'm use to seeing on the ECUs I've read.
Peaks earlier, then falls off.

[antus]

Have a look a the protection settings too. See if things like speed limiter, torque limiters, enrichment have changed. I bet they have. Not too familiar with UP but can you get it to show you a list of differences side by side? Or being that its OSID '2088 which is a major one there should be well defined XDFs for it around then you can do the side by side compare in tunerpro.

[AngelMarc]

Added bin file to 1st post.
you can do side by side compare.
I checked spark timing, seems like ordinary truck timings. Rev limiters aren't raised.
Most sensible theory I have is, shady "mechanic" made it run poorly, then they would do the filter and flash it back to stock to make it look like they new what they were doing recommending the filter. Second best guess, bullshit customer.
I was also expecting to see MAF setting/DTCs to be fucked with at 1st, but no. There is a disabled "MAP sensor range/performance" code that seems... not stock.
There's also a "retarded mechanic" theory. "I'll make it run so good, they'll think I performed magic. Corvette tune! Fuck yeah."... then "hmm, why isn't it running right?... Higher performance needs more fuel, maybe they need a new filter." That's the most charitable theory. That last one could have involved AI advice.

[AngelMarc]

I probably should have put this in the general tuning section. Can you move it there? Thanks.

[antus]

Moved the topic.

The tune doesn't look too far off. I have this file archived, so I did a compare. Similar platform, same OS, so not identical and did expect some differences. There are few settings slightly different, including 0.5-1% variance in the VE. But that is not massive. Most the changes are only small, like what might be expected evolution of a calibration for a new platform in 2000 from the factory calibrators on the LS1 platform. What jumped out was changes to DTCs to do with electronic throttle errors and TAC, but then I realised that one of them probably has electronic throttle and one of them does not, so that would explain all of those changes. I don't think there is anything sus in your bin, it's just an early tune in the generation that GM improved from in later years.

[AngelMarc]

I compared this electronic throttle, to a cable throttle, noticed some similar things.
With my understanding of VE tables and torque peaks, I find it hard to believe it's just old vs new. Unless older engines just had more aggressive cams because emissions and CAFE standards weren't too strict yet or something.
The flat line beyond stock rev limiter makes enough sense, vs stock P59 tunes I've looked at; that's an old vs new difference, sure.

[vlad01]

Not experienced in LS or anything like that, but well versed in tuning custom engine/cam combos. That looks way too diff to be a factory option and too wrong to be a real engine? my guess is some generic bogus tune made by a kid on ebay. The thing with those is people just copy and pass them around, so there is no way of confirming where it cam from or what it was for originally, if it was at all. As I said, lots of Dunning Kruger tuners out there that think upping things in the ECU = more power, whist completely ignoring the obvious description of the job in the title "tuning"

The way that map looks, it would be quite a radical cam change, and assuming what you have implied is that it's a stock engine?

[vlad01]

Also, VE tables do not change in a "tube up", only maybe a tickle to spark if required and very rarely, a tweak to the AFR tables. VE is the model of the engine to the ECU, if you change it willy nilly, the engine will run like shit, if at all if the changes are too big, any deviation from original tuned VE will only = losses, there are zero gains, only losses to be had with this approach. Of course, if there have been physical changes like long headers, a different cam for example, then yes, the VE will change accordingly and it must be dialed in to get the performance that is there. Can't just change it because one thinks it's a good idea.

[antus]

Well, heres the difference between the two tunes VE as a percentage, same os, same engine, different throttle, different vehicles. It's there but it's not triggering alarm bells for me.

That 400 rpm row maybe, but the engine is not operating there.

[AngelMarc]

Well, heres the difference between the two tunes VE as a percentage, same os, same engine, different throttle, different vehicles. It's there but it's not triggering alarm bells for me.

That 400 rpm row maybe, but the engine is not operating there.

Where did you get that reference tune?