squealingtires

iTrader: (14)

I've been learning my new tuning software with my 2000 T/A and the first thing I did was to download the existing tune on the car. This tune was a mail order deal (previous owner) from Street & Performance in Mena, AR for a 402ci running an '04 LS6 camshaft, CNC'd revalved heads, shorty headers, stock y-pipe, exaust, Wieand intake and SLP 39lb injectors, 85mm MAF.

Then out of curiosity I compared this tune to a stock tune for a 2000 LS1 and didn't see much of a difference. There were only a few parameters that seemed to have been changed and these changes wern't in any of the Air or fuel or spark tables

The car runs good, surges while cold, and seems to overfuel at low rpms and then comes to life all of a sudden (whiplash style) also gets 22mpg at 70mph. So anyways, I've got a cam swap lined up for warmer weather but I'd like to get a handle on some tuning basics first.

Does this mail order tune seem odd? Is it possible to increase the displacement and increase the injector size but leave the tune pretty much stock?

foff667

iTrader: (2)

odd, no...but this is the reason not to do a mail order tune in most cases lol, its hard to nail one off type of setups such as a 402 with an LS6 cam, shorty headers with stock ypipe, weiand intake & 85mm maf...that combo is about as one off as it gets lol so there's only so much you can guess at really without really f'ing something up.

squealingtires

iTrader: (14)

I guess through this experience I'm gaining a better understanding of how broad of a spectrum the stock PCM tune can cover. This also had my curiosity a while back when I was considering a supercharger which I would install and then drive about 2hrs to get it tuned. The shop which I would purchase the charger and the tuning from said the drive wouldn't be a problem as long as I didnt go WOT. Before hand I thought that was a horrible idea. Thanks for the info foff667

foff667

iTrader: (2)

if you just slapped a blower on the maf/o2's will compensate just fine at part throttle to keep your a/f in check so it would be fine

WOT would be a whole different story though.

chrisj6

Yeah some mail order guys change so little its unreal. Some just feel more comfortable changing some things than others. A/f and spark are two main things that need to be changed IMO for the engine to make the most power.

squealingtires

iTrader: (14)

This software is sweet. I just found out that the software will do a comparison between tunes and figure out what the differences are and list them. I've been clicking on each fuction one by one between the two tunes, then looking at the tables for differences. Awesome! So here is what changed from stock to the mail order tune.

Spark IAT Table -14%
Burst Knock Min Coolant Temp -6%
Adaptive Spark Min MAP -14%
Knock Retart Limit Not in PE Mode +6%
Knock Sensor Multiplier B (Cylinder Mode) -37%
Torque Loss from Spark Retard
Engine DTC stuff
shift speeds
TCC stuff
Fan settings

I hope the guy who paid for this service didn't pay too much! But the car does run well so maybe that's all he was after