EFI Live Programmer - Brainwashed
One of the keys to auto VE...
One of the keys to auto VE tuning is the scan log mapping function. These maps organize scan logs into a functional and easy-to-read format. They quickly 'average' data scanned at the same operating point over the entire course of a scan log. Speed density tuning is based on the BEN data, as organized by rpm and MAP. EFI Live's instructions include a step-by-step procedure for setting up auto VE tuning--details on how to configure data maps can be found there.
Speed density tuning requires...
Speed density tuning requires good scan logs. Scan logs must capture data at as many engine operating points as possible. The scanning can be done either while driving on roads, tracks, or dynos. Each offers some advantages, so a little experimentation may be necessary to figure which will work best. If scanning while driving, getting a buddy to help will go a long way, as trying to juggle the responsibility of driving and watching a logger is somewhat challenging (and dangerous).
Stand-alone scanning (with...
Stand-alone scanning (with no laptop) is scheduled to be a future upgrade for EFI Live's V2. At the time we did this tune, a laptop was still required for scan logging. Running the laptop in the car isn't a bad idea anyway, as by watching the map cells counts (number of data points at any particular operating point) as you work, it's possible to see where to target operation to build necessary scan data.
When scanning, it's important...
When scanning, it's important to capture data at all relevant operating points. This is easier said than done, especially off the dyno. Cruise points are easy to capture, while predominately transient points are often challenging to hit. EFI Live's scan maps can be viewed in a 'cell count' format. This format will show the total number of data points captured for each operating point. In the shown map, it's obvious to see most 'cruising' was done in the high cell count areas (around 1500 data points per cell), 55-60 kPa MAP, and 2000 rpm. By comparison, the 85 kPa MAP and 2800 rpm area has less than 10 points per cell. The vehicle's tremendous torque doesn't allow the engine to spend much time here--acceleration of the car from this point is simply too quick. This where a dyno's 'controllable' load pays dividends.
The data of concern is the...
The data of concern is the BEN number itself. The shown map shows a scan from a nearly finished tune. The BEN numbers hover around 99 percent--which means the engine is receiving around 1 percent more fuel than commanded. We target to stay on the lesser side (richer) of 100 percent, rather than on the lean side of over 100. Initial maps (prior to any tuning) may be off by over 20 percent, depending how radical the needs and how far off the base tune is.
Scan maps can be tailored...
Scan maps can be tailored and filtered to suit various needs. Usually, low cell count data should be discarded. To 'hide' data in cells with low counts, the map properties (as shown) can be adjusted accordingly.
The shown map has been 'filtered'...
The shown map has been 'filtered' to only show cells with counts over 50. In other words, the shown BEN factors are the average of at least 50 data samples.
The BEN factor recorded in...
The BEN factor recorded in scan maps is used to directly adjust the VE table. To capture the filtered scan data to apply to the VE table, the entire map is 'highlighted' and the data is 'copied' by clicking "Copy with labels." Once it has been copied, it's on the computer's 'clipboard'--aka buffer, and is ready to apply to the tune file map.
After logging and applying...
After logging and applying a couple BEN factor corrections, the logged AFR values should start to mimic those you defined originally in the "Commanded Fuel vs. rpm (Normal)" (B3647) table. Any areas that appear radically out of line with the commanded numbers will require further tuning.
Scan data maps are very useful...
Scan data maps are very useful beyond auto VE tuning. Additional scan maps can be made by copying the BEN map, and adjusting the data parameter in the map properties window. The shown map has been reconfigured to show average spark advance, resolved by MAP and rpm.
Scan maps can be used to resolve...
Scan maps can be used to resolve other operating conditions, not 'defined' or 'mapped' by MAP and rpm. Knock retard is an excellent example. The shown knock map shows we've only encountered a touch of minor knock retard around 4800 rpm and 100 kPa MAP. Tracking down trouble operating points can be easy using the scan maps.
The Obrizok's T/A responded...
The Obrizok's T/A responded remarkably to the installation and tuning of EFI Live's Custom Operating system, version 03. Its well-behaved low-speed manners are a tribute to the gains made possible with a properly tuned custom operating system. The proof was at the track, as they say. In this case, it was a late November trip to Atco Raceway (in full street trim, complete with woofer box, cats, muffler, and street tires) that resulted in a best effort of 10.97 at 127.1 mph. The unassuming T/A is only given away by its instigating license plate, which is appropriately customized to read "455 LS1."
3400 Democrat Road Suite 110 Dept. GMHTP