Muscle Mustangs & Fast FordsHow To Engine
Nitrous Oxide Injection - Go With The Flow
Adding Nitrous To Your Three-Valve Mod Motor Is Easy And Effective.
Carlson used SCT Live Wire to log and manipulate the ECU tune, which he had modified when the shop added a Steeda cold-air kit to our test subject. He said this about the tune on the nitrous, "the jets supplied by Nitrous Pro Flow were well matched. The low and mid-range rpm was a little lean and the top-end was a little rich. It would be fine as is, but I am picky so I changed the base fuel table in the tune. I richened the low-end and mid-range and got the air/fuel ratio to run consistently in the 11.5:1 to 11:1 range." The car was tuned for premium fuel, in addition to the Steeda cold-air kit, so Carlson removed a few degrees of timing to keep it safe.
On the 100-shot, three more degrees of timing were removed for a conservative overall timing package, due to the stock spark plugs. Carlson did inform us he modified the top-end timing table due to the nitrous flow. "When the system was activated, it was displacing some of the fresh incoming air through the MAF with force fed nitrous. The MAF counts (mass airflow meter voltage) actually dropped a little with the nitrous on. This caused the engine load, which is calculated by the ECU, to be reduced. The engine load calculation was reduced to the point where it dropped down to the next row on the spark table. At that lower engine load, the computer tune calls for several more degrees of spark advance," he states. Carlson used SCT Live Wire to data-log the runs, identify this problem, and solve it.
In just one day, the '08 was more than capable of going deep into the 12s and take on the latest street machines like the Challenger and forthcoming '10 Camaro--due out by the time you read this issue.