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After you've modified the previous tables as show, you can eliminate the Misfire Diagnostics. I tackle this with a measure of redundancy. First, open each table in the Misfire section and increase all values to the maximum value as shown below. Next, you'll open up the DTC's section (you can see that tab in the menu next to Misfire) and deactivate the P0300 diagnostic routine. In fact, the best thing to do is slowly go down the entire list of DTC's and deactivate all tests that are unnecessary such as all Rear O2 codes (B1S2 and B2S2) as well as Rear O2 Heater tests, MAP/MAF correlation codes, Catalyst codes, etc.

NOTE: To use these values, ALL of the values in the AFR Correction, Gas and Alcohol tables MUST be set to 0! If you do not set those table values to 0 across the board and you run the timing advance values shown above, you will grenade your engine! That is a certainty, so don't forget to zero the AFR Correction tables out! If you take the shortcut by using the values from the table above (mapped using 93-octane pump gas) you should be quite close to an ideal spark map. Log the data from the dyno run or your track session to see if you experience any engine knock. If knock is present, address it as shown on the following page.

Once you've modified the Diagnostics, you're ready to start the engine. When working on your own beast, remember to break the new valve-train in properly according to the manufacturer's specs. While running the engine, use the HP Tuners Scanner software to monitor the engine vitals such as oil pressure, air/fuel ratio, temperatures, etc. Once you've broken in the valve-train, the real tuning work can begin.

To start off, you'll need a good batch of data to work with. If you read the previous article of our F.A.S.T. LSX intake manifold and tuning of this same car, you'll know how we dealt with the MAF transfer curve. If you haven't, take a look at it here as it will show you how to get your MAF table sorted out. In our case here with the new cam, we only required a very minor amount of correction to the MAF curve (less than 3% below 4,500 Hz and just over 4% above 6,500 Hz) as this cam didn't throw back so much intake air that it negatively affected the MAF sensor readings. If you install a far more radical cam (in terms of valve overlap), it may require much more work of re-mapping the MAF table as more intake reversion due to valve overlap can cause air flow to cross the MAF element multiple times at lower engine speeds or slow the mass of air in the intake down while the reversion occurs. At higher engine speeds during WOT, the MAF table (if previously mapped properly) should need very little adjustment. The E38 ECM is quite a neat little unit and so is the engine management software that it runs. The on-the-fly Speed/Density calculations the ECM performs takes care of the airflow modelling quite effectively when you map the MAF table correctly and put this system to work with most any of the mild to wild cams available on the market. If you install a cam with a huge amount of overlap, you have two options: i) set the ECM to run on MAF alone and ii) re-map the VE co-efficient tables. Neither of these are necessary with the cam we're using here (usually this stuff only applies to ridiculously large cams used by drag racers who need 8,500 RPM engines), so we won't go into this as it's beyond the scope of what we're doing here. An important point to consider, however, is how relatively straight-forward this all is. Remember that we tuned this car once for the cold-air intake and headers, then touched it up for the LSX intake manifold, and now only had to make a minor adjustment to the MAF table to suit the new cam. The Power Enrichment fueling will stay the same as we left it in the last article when we installed the F.A.S.T. LSX intake manifold, and this leaves us with tuning the spark timing to suit the new cam and the dynamic compression ratio changes it brings. The following table shows you what we came up with, and again will show you the difference between the new table and the stock OE calibration:


LS7 - CAM - Page 3