TunerZine's VIP Honda Fit project gets fitted with ZEX™ Nitrous Kit
As we come to an end with out Project Honda Fit, we looked for a quick and safe way to gain some extra horsepower to our project. After doing some research and considering the supercharger from Jackson Racing, we decided a nitrous kit from ZEX™ would be a better "fit" to our project. Nitrous installs are one of the most common applications for a quick gain in horsepower and given that many Fit owners are on a budget we believed that the ZEX™ nitrous kit would be more beneficial to our readers.
Take a look at our in depth step by step photos and install details as we set our Fit up for some extra horsepower at a push of a button! Many thanks to ZEX™ for sponsoring our Honda Fit. For more information on ZEX™ Nitrous Kits, visit their
website.
 1 We start by laying out the kit and making sure we have all the
parts necessary to start our install |
 2 A shot of our Fit engine bay minus the Nitrous |
 3 First we need to remove the filter, using a philips screw driver we
remove the clamp holding our intake to the throttle body
and the air breather |
 4 Locate a spot where you would like to install the ZEX™ Nitrous
Management Unit. We chose to attach it to the plastic battery shield. |
 5 Use the supplied tapping screws, to attach the unit in place |
 6 Once we have the unit safely mounted we attach the fittings to
both nitrous in and fuel in connections on the management unit |
 7 Connect the long hose assembly to the nitrous in connection |
 8 We routed our nitrous hose under the car. Make sure to use
supplied zip tie's to keep everything nice and secure and away
from moving parts that can damage the hose. |
 9 We found a whole with a rubber stopper that allowed us to snake
the hose through to our trunk area. No drilling required! |
 10 Next, we locate a spot in the trunk to mount the bottle |
 11 Drill and attach brackets with tapping screws |
 12 Here's our bottle mounted and ready to go |
 13 Attach the hose assemble from step 8 |
 14 Next we move on to the fuel supply, locate the stock fuel hose
which connects to the fuel rail. This will be located right under the
throttle body. The fuel connector uses a clip which disconnects
easily. Be sure to have a rags handy to catch spill from excess fuel |
 15 ZEX™ provides all connections to make our adapter which will make
it a snap tapping into the fuel system without cutting any stock fuel lines |
 16 Using the the quick connects and adapters,
we put together our adapter |
 17 To demonstrate the connection on the right we have a stock fuel
hose to show how the connection goes together |
 18 Back into the engine bay we connect the hose which will supply
fuel to the managment system |
 19 Connect the hose from the where we tapped into the fuel line to
the back of the management system to the fuel out connector |
 20 Next snap the stock fuel hose into our adapter piece |
 21 For our Jets, we decide on a conservative 45hp Shot, so we're
using a 17 jet for our fuel and 28 for nitrous, for a proper mix |
 22 Attach both fuel supply and nitrous supply hose from the
management unit to the ZEX™ Nozzle |
 23 Now lets move on to the electrical side of the install. We will need
to locate a throttle signal for our management unit. On the fit there will
be a large connector that attaches to the throttle body. Within that
harness we will need to tap into the red wire (first one on the connector) |
 24 Throttle-by-wire systems are VERY sensitive to any load on the
TPS signal line, so ZEX™ supplies us with a resistor that isolates
the Nitrous Management Unit further to prevent issues
with check engine lights, etc. |
 25 Using the supplied electrical connectors we make our adapter that
contains the resistor in line |
 26 Plug the connector into the red wire on the connector that we
located in step 23 |
 27 Wiring from the management unit. white - TPS signal, black - ground,
red - power connected to switch |
 28 Next, we will need to ground the system, we found a great spot
on the driver side frame rail |
 29 With our power switch we router the wire next to the firewall all the way
to the passenger side where we were able to snake it through a wire grommet |
 30 Zex supplies all the wiring and necessary switch to install
inside the cabin |
 31 Now that all connections are done, check to make sure everything is
connected properly. We install our intake back in reverse order. |
 32 A shot of the ZEX™ nitrous system installed |
 33 Now that you have completed the nitrous install, the next step is to
program the Activation Switch. (Please follow included install manual
for more information on this process) |
 34 We have the green light indicating that the system is ready to go! |
 35 But before we go and run our system, we install a set of colder
ZEX™ spark plugs |
 36 A comparison of stock and ZEX™'s colder plugs |
 37 Once everything is connected up, we head over to Velocity Trends
for dyno runs. Make sure to fill up with high octane fuel and Top off
the nitrous and your ready to roll. |
 38 Here's our dyno run, and after couple runs we netted a solid
33hp gain at the wheels on a 45hp shot! Just be careful,
Nitrous can be addicting!!! |
Text & photos courtesy of
tunerzine.com 
Honda Fit ZEX™ Nitrous Install 
Linear Mode
