Project GD STI: Getting More Power with Precision Turbo and Cobb Tuning! – Part 1


With the car making sort of okay boost, we then brought it to Cobb Tuning So Cal to do some ECU recalibration for the new intake and turbo.  Cobb has one of the best AWD dynos in the area with a super nice dyno cell.
Huge roof mounted fans move a lot of air through the cell and these huge fans are linked to the dyno to vary flow with changes in road speed. This allows driving speed conditions to be simulated. We like these fans because they allow for more consistent dyno testing and can come closer to actual on the road conditions than any other dyno we have access to. 
A wide band AFR meter hooks to the dyno.
To tune our car, Cobb's R&D calibrator, Mitch McKee first updates our V2 access port. Mitch downloaded the new features like a launch control mode and a no lift to shift program.  They work really well. Our car previously had an older version of no lift to shift and the newer version works better and keeps the boost higher.
With our Access Port updated, Mitch spent a long time working on the driveability parts of our fuel and spark maps.  With part throttle, the tuning is more critical than wide open throttle due to lower injector pulse widths. Many tuners are just shooting for sexy power numbers and don't take their time tuning the conditions where the car spends most of its time operating. 
Mitch found that our fuel trims were correcting a lot to richen the fuel mix up, probably due to the larger intake tube.  He worked on the MAF correction table until our long and short term trims were centered.

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