Zipper's Performance 109-214 - Manual (Page 6)

Tuning Strategies and Suggestions for Modified Engines
Your first objective is to make sure you have large enough injectors selected for your application. Your
injectors must be able to supply the proper amount of fuel required with nitrous so engine damage does
not occur when nitrous is activated. The factory injectors have only enough capacity to operate safely on
stock 96 or 103” applications with nitrous; larger injectors will be required for modified 96 or 103” engines,
and any engine larger than 103
”. Select an oversize injector and first develop a map for proper engine
operation with the new injectors without nitrous activation.
1) Select and install the proper sized injector for the engine. You need enough capacity to cover the
engine at peak torque (max cylinder fill) plus enough capacity for an additional 15-25% fuel
override when spraying. Once you have determined the size of the oversize injector required for
your application, install the injectors then develop the map for proper operation on gasoline only.
2) Make sure the fuel system is equipped with a new fuel filter, fuel line and fuel pressure is proper
(58-62psi) before you start the mapping operation.
3) Update your software, make sure you are using the TunerPlus (advanced) version of the software
(dark blue screen with right click functions).
The following are the tuning steps required to develop a custom map for a ThunderMax-equipped nitrous
system engine (these steps are for creation and stabilization of a map without nitrous activation, in
preparation for use with nitrous activation):
1) Select a map with closest match to the injector flow rate and key engine parts like cam timing and
compression (pumping pressures) of the engine.
2) Review the map ’s air/fuel target pages to make sure they are compatible with the desired target
you want for your engine. Revise the targets as required for your application. Displayed air/fuel
targets are for normal engine operation on gasoline. Nitrous override percentage will richen these
targets (20% is usually a good amount of enrichment from a 13:1 AFR target at WFO under
normal engine operation without nitrous).
3) We have found ideal target air/fuel ratio while
spraying nitrous is between 11:1 to 11.75:1, which
is achieved by the Fuel Enrichment value entered
in the Nitrous Setup window. This fuel override is
activated when the system is armed and the
motorcycle has met the additional presets of
[Engine RPM] and [Vehicle Speed] - once
roughly 70% throttle is reached (this setting is not
adjustable). Note- Fuel and spark overrides are
not active unless system is armed and presets
have been reached, therefore the same map for
general engine operation is used with and without
spraying nitrous.
4) Once injectors and map have been selected, if the
engine is unstable with the first start up (rich or
lean) you can globally adjust the map fuel flow either way to obtain stability. In the TunerPlus tool
bar labeled [Tools], use [Injector Size Compensation] to adjust fuel flow (we suggest entering a
value of no more than +/- 10% at a time, check results).