spacemanspif

iTrader: (5)

Hi all,

I just picked up HPTuners (non-pro version) with 6 available credits off craigslist. Lots of research still to be done but thought I'd see what other, smarter, people think of the tune on my car. This is a generic bench tune that was loaded on when I sent my comp and harness out to be modded for my swap. Car has been running fine for the last 3 years but I always wondered about the tune that was put on the computer. Now that I can see the tune, there are a couple basic things that have me scratching my head but I'm also totally lost at this point on the more "heavy" aspects of fuel and spark. I've attached the tune file for the car for review if you care to take a peek. Any and all info. you are willing to provide will be greatly appreciated.

Car is 1987 Monte Carlo SS. 2004 5.3 (flex fuel from the PN of the injectors) and 2003 4L80E. 3.73 rear gear and only modification is Mid-length headers; bone stock everything else. Car has run 13.67@104 in the 1/4 on 87 octane gas. MPG is 18 no matter how I drive.

I'm hoping that other HPT users can see the tune. Like I said, totally new to this stuff...

Thanks,

mrvedit

I spend just a minute looking at it...

The VE table looks smooth.
However the spark tables have the lowest advance #s I have ever seen at high throttle - 8 degrees at 3200 rpm and a max of 12 at 4800. And that is the high octane table!
Was this designed to run on cheap wine or something?

Also, the Injector Flow rate table has all equal values (33). That means the pressure regulator needs to be vacuum controlled. If yours is not, you need to change that table.

2xLS1

iTrader: (25)

Its a stock truck timing table. They add spark with AFR correction. Wont see much more than .68 g/cyl at WOT. Timing is a little higher in those rows. VE is stock too. And FF trucks use return fuel systems so the IFR table is correct for a FF vehicle. Comparing it to a stock 04 FF 5.3 tune not much was changed. It is for the most part a stock tune with The FF switch was disabled, Tq management disabled. The file I used for compare had a 4L60 so couldn't do a proper trans comparison.

mrvedit

Thanks for the explanation 2xLS1. I've obviously never looked at truck tunes.
I'm still learning how to look at and diagnose other people's tunes.

Since this is swap into a (lighter) car, I suspect the OP wants to get more performance out of it and won't be towing with it.
Since swaps often change how the fuel system is plumbed and regulated, it is important to know how the type of pressure regulator affect the injector flow rate table (IFR).

spacemanspif

iTrader: (5)

Thanks for the insights guys. Yes my engine has the stock fuel pressure regulator on the rail with the vacuum line hooked up. Fuel system is -6AN lines all the way back to the in-tank walbro255 pump.

mrvedit is correct, I would like to optimize the system mostly for power but also would like to squeeze out more MPG. As he said, the car is lighter (stock is ~3800lbs) than the truck it originally came from and won't see the hauling/towing that it was tuned for.

2xLS1: thank you for checking the tune against a stock one. Did you find it on the repository or is it one you have saved to your computer? I'd like to see it too if it wouldn't be too much to ask you to upload it. Things that have me wondering about what they did are DFCO basically disabled as well as lean cruise. Are they set that way from the factory or did the tuner change the settings to cancel them out? Lean cruise would bump my MPG for sure because most of the time I'm on the highway with the car.

Some of the settings in the trans look a little weird too. Like why is 1-2 shift set to super hard at low and high RPM but soft in the middle?

Reading up on this stuff continues...

Thanks for the help,

2xLS1

iTrader: (25)

Here is what you've got the best I can tell. It looks like they took a 2004 GMC Sierra 3/4T 6.0L VIN U truck file probably for the 4L80 segments then converted all the engine tune parameters to match a 04 5.3L L59 FF vehicle, then disabled the FF option. The 04 GMC 6.0L file I'm comparing the segments to is in Tunercat format so it is a little difficult to do a direct compare to your file to look at the trans parameters. I just used a 04 Tahoe 5.3L L59 FF file to compare the engine cal to yours and like I said it is pretty much stock. The Tahoe would have had a 4L60. If I have time later I'll try and load the Tunercat file I have into a PCM and then read it out with HP Tuners for a better comparison of the trans segments.

2xLS1

iTrader: (25)

Here are a couple of files you can use to compare what was done to yours. They may not be the exact files used to create yours but they are close enough to use to see what was changed from stock. Use the Tahoe file to compare the engine part of your tune and the GMC file to compare the Trans part of the tune. Be aware that some of what will show as differences in the trans tune are because of the different rear gear ratio and tire size you are using vs what the truck used. Mainly the shift and converter lock up tables.

And Lean Cruise can only be enabled with hex editing the file or some other tuning software than HP Tuners. There is one out there that lets it be enabled quite easily. Even if you populate the tables with HP Tuners they will not be used. It is an EPA thing that HP Tuners chose not to violate.

spacemanspif

iTrader: (5)

Thanks a million for the effort and those files!! Seeing stock tunes shows just how stock my tune is. Hopefully I get a couple more ponies out of this thing and maybe pick up some time at the track too. I'm sure there is a lot to play with once I understand it all and start datalogging.

Neat little fact on the lean cruise, guess I'm stuck with 18mpg for a while

ctd

iTrader: (1)

There are things you can work to improve performance & don't fret the lean cruise. I'm sure it i will respond nicely with timing & how your Power Enrichment PE is enabled, you may find your mileage will suffer while you are working these tables Rather than enabling your lean cruise you can work on the O2 RL switch point tables & Mode vs Airflow table & lean your AFR mixture that way.

spacemanspif

iTrader: (5)

Thanks for the insight. Looking through things I can see how I can lean things out while cruising. Still need to do a lot more reading before I'm willing to click the button that'll actually change the tune in the computer lol.