To start off, we strapped it to the dyno for a baseline pull and baseline scan. After a couple baselines, we set out to tune for maximum performance. By looking at our baseline pulls, we logged a peak spark timing of 23 degrees at WOT--not bad for a stocker, but definitely not optimal. From past experience, we know LS1s equipped like this perform best with nominally 27 degrees of timing, give or take a few tenths depending on knock aggression. Capitalizing on the bi-directional controls, we set up the absolute spark control for 27 degrees, started the pull and toggled on the timing lock around 3500 rpm. We picked up 8 ponies at the wheels.
Scan logs showed a touch of light knock, indicating we should tap down the timing a touch, especially since we planned to lean it out a little. The air/fuel ratio on the baseline was the factory-typical pig-rich, high 11s. Next we leaned out the AFR with an experience-based target of about 12.9:1. We started with the bi-directional control approach again, but found the resulting fuel delivery still not what we called for. There are several possibilities for the discrepant AFR, such as COT enriching, slow O2 response, slower O2 response due to their relocation from the addition of headers, inaccurate switching type O2s, etc. Fuel tuning is always more tedious than spark, simply by nature. Our scan logs allowed us to track all fuel enrichment parameters and search for those contributing to the resultant delivery--this is necessary to decide which tables will be due for tuning changes. Since fuel delivery is based on the sum of various adders from various tables, it is necessary to study them all, and how they interact and contribute to the final sum.
The same 'sum of base tune plus adders' process is used for spark delivery. Figuring out what comprises the final fuel and spark commands and how they interact is critical. For instance, if we simply went to the high-octane spark table and set the peak timing for 27 degrees, we'd end up in trouble. We have to consider all tables that contribute adders to the final spark delivery parameter. Base spark timing is increased (or added to) depending on the equivalency ratio (AFR), as defined by the table that calls for additional timing based on the instantaneous AFR. Basically, the delivered spark timing is lame until it sees a richer AFR, safe enough to add more aggressive timing. So if we set the high octane table to bold 27 degrees and walked away, the PCM would be taking 27 degrees and adding up to 4 degrees from the enrichment table for a total of 31 degrees! 31 degrees would be disastrous, sending knock sensors through the roof and cutting gobs of power. Some tuners chose to simply zero out all conditional 'adder' tables and work only with the base tables. This may work for some isolated applications (such as full blown racing), but for street/strip use we like the idea of utilizing all the goodies the factory PCM allows. Obviously, keeping all the tables in the works will require more extensive effort and more trials to get it right. After a few hours of testing and tweaking, we settled on a WOT AFR of 12.8:1, and WOT spark timing of 26.5 degrees. Our car was fairly prone to knock activity, thus the slightly richer AFR and less than 27 degree timing.
To finish up the tune, we hit all the basics: we increased the rev limiter by 200 rpm, dropped the fan on request temperatures, and shut off CAGS. Our final tune netted 370.9 SAE rwhp and 382.8 SAE rwlb.-ft, up from a baseline average of 358.1 SAE rwhp and 372.7 rwlb.-ft. These were welcomed peak gains, but the real party was at mid-range rpm where we enjoyed torque gains in the 20 lb.-ft. range, as evident in the dyno charts. Albeit, we set out to tune a stock cammed and stock displacement, naturally aspirated LS1. If we added a cam, a few cubes, or a blower, we could really spread our wings and complete a full-blown remapping of the PCM. That is where drivability and part throttle tuning really come into play, and where HUGE performance gains are made over stock tunes.We didn't do much to the transmission beyond disabling the skip shift and its accompanying light, obviously due to the manual box. With a slush box and extra slippery converter we could spend another article coving the transmission tuning, as EFILive's trans scanning and tuning capabilities are just as elaborate as the engine section. In summary, EFILive V7/FlashScan is worlds ahead of its still good early versions, and its one helluva professional scanning and tuning tool.
The speed of USB communication is phenomenal. We read the PCM tune in less than two minutes. | 
Its tuning capabilities are exhausting--an example of scalar parameters is shown here for the cooling fans. In all, over 350 engine parameters can be adjusted. | 
The tuning software is very user-friendly and almost entirely point-and-click. The shown spark map is an example of a table. Each parameter includes a description block (upper right), a tabular chart (bottom), and a full color plot (upper left). Highlighted cells in the chart automatically show highlighted in the plot. The three-dimensional surface plots are interactive and can be resized and rotated infinitely. All this and we still haven't touched the keyboard. |
Correlating scan log data to a tune map is outstanding. In the shown window, we highlighted a section of the dyno pull using the mouse (the white section of the rolling scan on the left), and the corresponding cells of the volumetric efficiency table are automatically shown highlighted on the right. | 
EFILive V7 allows a tuner to compare two files at the same time. The shown plot is a 'difference' plot showing the net changes made to spark advance between the tuned file and the stock file. Again, we highlighted 6400 and 6800 in the table and we see the corresponding section of the plot highlighted to match. The user can toggle back and forth between two loaded tunes. | 
Tuning a two-dimensional map can be done with the mouse, by point-click-drag. The shown MAF plot has clearly been modified at the high frequencies. |
The tuning software has built-in algorithms for smoothing and blending. The 'rough' changes made to the MAF table in the previous screen have been 'smoothed' using the built in blend/smooth tool. The smoothing takes a matter of clicks (seconds). Smoothing this map cell-by-cell, number-by-number with the keyboard would take 15 minutes. So you don't like the smoothing results we just clicked on? No problem, because EFILive has a built-in UNDO/REDO option. Simply click UNDO and you're back where you started. | 
Smoothing and blending applies to surface plots, or three-dimensional charts as well. You can even apply it to stock tables, with no other changes. The high-octane spark map is shown here. Note the rough terrain in the center of the plot. | 
To smooth or blend the desired section, we simply highlighted the desired cells and selected the size, axis, and algorithms desired for altering the area. |
A few clicks of the mouse and we have a smooth and blended plot. Total time necessary for the changes: 30 seconds. | 
In comparison, you can adjust downshifts as well. Shown is the 4-3 shift speed table. Factory downshifts are typically ultra-sluggish, so you'll spend time on these tables for sure. We only scratched the surface on the trans, but all the expected tables and parameters do exist for tuning. | 
Our C5 tester is strapped to the dyno. We put down a very respectable 358.1 SAE rwhp with the stock tune. After adding our custom tune using EFILive V7, we jumped to a Z06-blasting 370.9 at the wheels. |
On the SLP dyno we captured before and after tune data. The mid-range torque pickup, around 20 foot-pounds, was outstanding. | | |