Forget needles, jets and carburetors—this...
Forget needles, jets and carburetors—this is the new age of fueling. A laptop and sophisticated software will lead to internally-combusted perfection.
The fact that modern sportbikes push the performance envelope beyond what was once considered possible while remaining emissions compliant is simply astonishing. Passing sound and emissions laws isn’t easy as these regulations require bikes be quiet yet clean, and none of the sanctions consider the performance sacrifices their regulations impose.
Since the manufacturers have to dial back performance to meet emissions, it means the aftermarket can address these concessions in pursuit of maximum performance. Take our 2009 GSX-R1000 for instance; a few issues ago we ditched the heavy stock pipes and catalytic converter for a Two Brothers single system and cat-delete. The free-flowing pipe uncorked the exhaust to the tune of nearly 5 HP, but there was still power left on the table since the stringent stock fuel curve was lean down low and rich up top. Lean partial throttle mapping hurts throttle response and increases heat, while the rich condition robbed horsepower.
To remedy our fueling quibbles we paid a visit to Bazzaz Performance and decided a Z-Fi fueling computer would fix the issues. The box comes equipped with two preloaded fuel maps (stock/slip-ons), but one can visit a dyno operator for a custom map to maximize performance–and this is exactly what we did, but with a twist.

That’s more tech than a Microsoft...

That’s more tech than a Microsoft convention and it’s as user-friendly as it is effective thanks to the fuel injection maestros at Bazzaz.

Trying to save time by leaving...

Trying to save time by leaving the tank in place will only cost you twice as much in the long run. After removing the tank, lay the Bazzaz harness in the correct orientation to get a better idea where all of the plugs go and how best to route the wires.

Most of the plugs are easy...

Most of the plugs are easy to access—save for one. The TPS sensor on the main throttle bodies is best reached by removing the regulator/rectifier (which means the right-side fairing comes off as well). Don’t make the mistake of plugging into the upper secondary throttle body TPS (don’t ask us how we know).
With hopes of higher horsepower in sight we decided to dyno test the bike with a zero map against the Bazzaz maps. From there we had our resident dyno dude, Gene Thomason, create a custom map for max power.
The end result showed that the preloaded Bazzaz maps bested the baseline by 1.6 HP and just under 1 LB-FT, while our custom dyno tune pushed that number up another 4.8 HP and 1.7 LB-FT for a total gain of 6.4 HP and 4.4 LB-FT over the stock map.
The Bazzaz Z-AFM uses a traditional...
The Bazzaz Z-AFM uses a traditional oxygen sensor (O2) that’s much larger than the factory unit. We opted to weld the Bazzaz O2 bung next to the stock one (as opposed to replacing it) in case we ever want to return the bike to stock.
To sweeten the pot we also tested the Bazzaz Z-AFM. This add-on is a self-mapping unit and proved to be quite handy. The Z-AFM allows a user to set a desired air-fuel ratio (AFR) and the Bazzaz will automatically build the ideal fueling map for your setup. Simply plug the self-mapping box into the Z-Fi, select the target AFR and ask the unit to capture the data. From there a simple test loop, whether on track or the street is all that’s needed. When back from the ride the captured data from the Z-AFM is loaded into the Z-Fi and you have yourself a custom map.
The Z-AFM is also useful for mapping the ever-elusive partial throttle portions of the map. “It usually takes just as much time, if not more, to map the low RPM partial throttle areas since it can be tricky getting it right,” Thomason said. “With the Z-AFM it took 15 minutes, where normally it’ll take me an hour if I’m building the map myself.”
Don't forget a solid connection...
Don't forget a solid connection to the power source. Bazzaz recommends tapping power off the diagnostic plug under the tail.
With that said, you’ll need to know the ideal AFR settings to achieve the most power, but according to Thomason, oftentimes getting it close to perfect isn’t too hard with the self mapper.
“As a rule, a 13.0-13.5 AFR on a naturally aspirated bike will get you close to peak power, from there a dyno session will really tell you where maximum power is, since some bikes like 12.85 and others like 13.75, depending on RPM.”
The Z-AFM self mapper also comes in handy if you ride in varying weather and geographical conditions since despite extreme changes, the unit will hold the target AFR no matter if you’re in the mountains of Aspen or the flatlands of Death Valley.
The Bazzaz map improved on the baseline by 1.6 HP, while the custom map with the Z-AFM was worth an extra 4.8 HP. Our findings show that a DIY tuner could simply plug in the Z-AFM, set an AFR range and have a "custom map" that would be very close to the map that you'd spend an entire day on the dyno with a tuner to achieve.
The bike started out strong but finished even better thanks to some fueling tweaks that all modern sportbikes can stand to benefit from. If all of these fueling bits seem expensive, there is solace in the fact that Bazzaz allows users to bundle their products or buy them piecemeal. Start with the Z-Fi and use the included maps for some nice gains. When budget allows, add the Z-AFM and set your target AFR as mentioned for even greater gains. If that’s still not enough, take your Bazzaz wizardry to a dyno shop and completely maximize the setup. Here’s a word to the wise though, once you start fiddling with the Bazzaz software and self-mapper it can get addicting. If you find yourself up at night wondering if a few more tweaks can get you more power, don’t say we didn’t warn you. SSB
6.4 Horsepower gained over stock Fueling
Thomasonracing
(310) 618-1908
Next Month: Simple mods for a big impact.