When we tested Ducati’s Streetfighter S in 2009, we were so enamored with that naked superbike that we voted it Best Open Streetbike in our annual Ten Best Bikes of the Year awards. But shortly thereafter, we rode a base-model Streetfighter and were shocked to find that it had some bothersome fueling issues. The bike’s lean, emissions-appeasing fuel map caused a double-dip stumble at lower rpm, first as a sputter while pulling away from stops, then it would recover and stumble again at 3000 rpm; and during steady-state cruising, the Streetfighter would surge enough to be truly annoying. If the S-model we previously tested had acted this way, it would not have been a Ten Best winner.
Posts on a few Ducati web forums indicated that these same symptoms were a common complaint of numerous Streetfighter owners. The prescribed remedies were either a $3241 Ducati Accessories Termignoni full exhaust system that included a new ECU with a different fuel map, or an $1877 Termignoni slip-on mufflers/ECU combo. While both are reportedly an effective fix, they also are quite expensive. We had our hearts set on a more affordable aftermarket remedy.
Except that until just recently, lower-cost solutions were non-existent. Ducati had no other EFI options, and even Dynojet had never developed a Power Commander that was fully compatible with the Ducati’s closed-loop fuel-injection system.
Z-Fi main brains and O2 eliminators.
But now, Bazzaz Performance (www.bazzazperformance.com) has just begun offering its Z-Fi fuel control unit configured for the Streetfighter. The $399.95 package includes the Z-Fi controller itself, plus two O2 Eliminator modules and an adaptive wiring harness. The Eliminators plug into the stock wiring harness, bypassing the pair of lambda sensors in the Duc’s exhaust and enabling the Z-Fi module to communicate properly with the Ducati’s ECU. The Z-Fi comes preloaded with a fuel map configured for slip-on mufflers, but you can get a free stock-exhaust map from Bazzaz upon request and also upload custom fuel maps via a USB connection to a PC running the supplied Z-Fi Mapper software.
Once we installed the Z-Fi system with the stock-exhaust map, our Streetfighter’s fueling was vastly improved. The low-rpm stumbles were gone, and so was the steady-state cruising surge. Bazzaz’s maps don’t alter fuel-delivery values below 3000 rpm, but the O2 Eliminators fix most of that problem on the Streetfighter, and the end user is free to tinker with the mix throughout the entire rev range. We also found that the Z-Fi’s capability for on-the-fly toggling between two different maps proved very useful by allowing us to quickly and easily compare our own modified fuel values to the baseline settings.
In the end, our seat-of-the-pants experimentation determined that the provided map was sufficient to rid the Streetfighter of its fueling glitches. Even though stock vs. Z-Fi full-throttle pulls on the CW dyno produced equivalent peak output, the Bazzaz package provided exactly what we had hoped for: much smoother power delivery throughout the lower rev range and while cruising at smaller throttle openings. That’s of great importance, because even on a bike like the hyper-naked Streetfighter, the vast majority of real-world riding is done at very slight throttle openings.
So, problem solved—and rather inexpensively, too.
