Cobb AccessPort for 370Z!

Denny McLain

To be absolutely honest, did not purchase the car for gas mileage and really never check it. It was basically an accident that I discovered it on an impromptu unplanned urgent family business trip. So when did it start?? Damned if I know, but I downloaded updated software and checked it again to verify what was going on.

Not a professional tuner, but I used to hang around a bunch who were to the point where I'm pretty confident doing basic tuning by all means. When the car was tuned at Cobb I spoke extensively with Calvin whom does their tuning on what tables they use and what parameters they look for. Everything he said was consistent with what I've seen in the past and basic tuning 101.

Calvin recommended for open loop conditions (WOT) the primary fuel table be adjusted and for finer tuning where the primary fuel table is not adequate, tweaking the MAF tables. In my experience the MAF tables can be very tricky plus the primary fuel tables seemed to give the desired effect so the MAF tables that can effect drivability and fuel economy, were not touched.

This comes directly out of the Cobb AcessTUNER tuning manual:

"Primary Fuel"

This table is referenced by RPM and Theoretical Pulsewidth (Engine Load) The tables values represent the A/F ratio you wish to run during open loop conditions. Doing so will normally not result in an appreciable decrease in fuel economy since these conditions are only met only when driving the car aggressively.

During idle and cruising, the ECU uses a Closed Loop strategy designed to optimize fuel economy, not power."

The only other tables that were touched were primary ignition A and B which I found from logging did not like adjustments more than 1 or 2 degrees. This also has no effect on fuel economy.

In my experience basic bolt on moded cars do not need drivability tuning. When you get into more radical cams and high compressions, playing with timing segments and driving A/F tables can smooth out driveability plus help pass emissions tests. Basic bolt on cars.....no fricky way do you need to.

So.....you tell me what magic does Cobb have that you think I don't I have? How would you tune the car?