Fuel Injection Kits
Starting from $1025
on kit designed for an Isuzu G series SOHC engine (G161, G180, G200) within a
Holden Gemini, models TX-TG, but could easily be used in the engine bays of a Jackaroo, Rodeo, etc. Obviously, it will also bolt onto 4Z series engines.
inlet manifold used is a factory Isuzu manifold as fitted to 2.6 litre engines
and is modified
to bolt onto a G series SOHC engine. The manifolds do not simply bolt up
to a G series engine without modifications.
kits come with everything needed - it is a complete bolt on kit designed to
include every component needed to fit the EFI manifold to the engine and
install the complete fuel injection system minus the EFI computer. The kit
comes will all the little parts like gaskets, hose clamps,
studs, etc. There is no fabrication necessary, it is truly a bolt on EFI
kit. The only extra work required is to hook up an air filter, wire up an EFI computer and
to suit your engine.
The kit consists of:
EFI manifold is quite large, using 36mm ID inlet runners, and approx. 2 litre plenum.
can flow enough air to support well over 450 horsepower. The injector size is the only limiting factor, but bigger injectors are easily installed.
The manifold is larger internally and can flow more air than a standard Piazza
manifold is modified to directly bolt onto the Gemini cylinder head. All unnecessary
ports are plugged, while a few are left available for things like MAP
sensor, brake booster and boost gauge connection.
Depending on type of manifold purchased, either
an oval shaped twin butterfly TB is used, or a big single butterfly Hitachi throttle body, 60mm
in diameter. Throttle position sensors (TPS) with switches for closed
throttle, open throttle, and wide open throttle are included with either TB
INJECTORS & FUEL PRESSURE REGULATOR
manifolds are fitted with fairly big
Nippon Denso injectors.
TB EFI kits are fitted with 300cc injectors.
TB EFI kits are fitted with 330cc injectors.
are sonically cleaned and flow tested, so you will get a set of matching flow
an example, the 330cc injectors are rated at 44psi fuel pressure with the standard
regulator. 330cc will be enough fuel delivery for around 240hp.
Upping the fuel pressure to 59psi (4bar) would make the injectors flow more like
390cc and be capable of handling around 280hp.
Even bigger injectors such as 550cc Mazda
13BT units can be installed very easily to the manifold, and I have done this
conversion myself several times. The manifold can flow enough air to support
around 400-500hp, so if you plan massive power for the future, all that would
need upgrading is the injectors, the rest of the manifold assembly would still
handle the power.
fuel pressure regulator also works very well as a boost referenced regulator for
turbo applications, as I am using the stock regulator on my turbo engine.
The regulator gives a 1:1 rate of fuel pressure rise, so approximately 1psi of fuel pressure increase for every 1psi
of turbo boost pressure. A common misconception is that you need a rising
rate regulator for a turbo engine, this is not the case. A rising rate
regulator may actually be costing you horsepower if its stressing your fuel pump
& WIRING LOOM
standard sensors include the throttle position sensor (TPS) and the water temp
sensor designed for use with an EFI computer. The TPS has the typical
closed and open throttle switches, and also has a wide open
throttle feature, great for water injection, a boost solenoid, NOS, intercooler
spray, etc. Whatever you can think of.
wiring loom provided has the 4 Denso injector plugs, the TPS plug and the water
temp Bosch style plug, all on a short (0.5m) flying loom ready to hook up to the EFI
computer of your choice.
fuel system included a BRAND NEW Bosch style external EFI fuel pump. The fuel pump
is a Bosch 070 VL turbo spec pump. The pumps can
handle around 350hp worth of fuel delivery, so should exceed your engine output
with standard injectors,
with a bit left up its sleeve. Included are adaptors required to connect
from the stock Gemini electric fuel pump and from the stock steel fuel line to
the inlet of the manifold fuel rail.
pressure hose is included to connect from the pump to the stock steel fuel
lines. Wherever there is low pressure hose from the stock carby system
that now has high pressure fuel in it gets replaced by the high pressure
hose. Enough hose is included to do the whole car, along with all the
required hose clamps. Included high pressure hoses to join stock Gemini pump
outlet to fuel line adaptors, then to EFI pump, hose to replace low pressure hose under
car/over diff, and to connect fuel supply and return lines of EFI manifold and
fuel filter in
new EFI filter is also included to keep the injectors and the rest of the fuel
system clean from debris. You cannot use the standard carby filter due to
the higher pressure of the EFI system.
KIT & GASKETS
fitting kit consists of an accelerator cable which is another part that's often overlooked when
people buy standard manifolds and try to adapt them to the Gemini. The
accelerator cable is modified to fit into the Gemini firewall and attach to the
hose joiners and extra heater hose is included to bypass the inlet manifold self
heating system and to maintain correct operation of the Gemini coolant and
gaskets are also provided to bolt the inlet manifold onto the Gemini cylinder
So in summary, each kit option comes with the following hardware/accessories
assembled ready for use:
Complete & assembled EFI manifold with 36mm inlet runners.
Big 60mm throttle body (optional oval twin butterfly TB).
Large plenum chamber with all unnecessary ports blocked.
300cc or 330cc fuel injectors - sonically cleaned and match flowed (optional 300cc injectors or 460cc injectors)
rail and boost/vacuum referenced fuel pressure regulator.
position sensor including wide open throttle switch, EFI water temp sensor.
loom for all sensors and injectors.
cable to suit EFI manifold into Gemini engine bay.
inlet manifold gaskets.
hose joiner kit for manifold to heater hose connection
New Bosch 070 VL Turbo spec EFI fuel pump, capable of supporting over 350hp.
New brass adaptors from stock Gemini fuel hoses to fuel pump inlet/outlet.
New brass adaptors from stock Gemini hoses to high pressure fuel line.
New EFI fuel filter.
high pressure fuel lines and hose clamps required to fit up high pressure fuel
system to whole car.
to follow fitting instructions that guide you through the installation.
Note: The manifold is supplied assembled and ready to bolt on.
Instructions cover fit up of fuel lines, heater hoses, and also the electrical
connection of the wiring loom.
is $1025.00 plus postage - Oval twin butterfly throttle body
is $1095.00 plus postage - 60mm single butterfly round throttle body
us with your post code for a postage quote. Also ask for pricing on
460cc or 550cc Mazda RX7 fuel injector upgrade. If you want any more
info feel free to ask questions at email@example.com
can be seen in the photos, we piece these kits together ourselves and know the
condition of all components. Where possible, components have been disassembled, inspected,
cleaned, and then reassembled. The
injectors are sonically cleaned and flow benched so you get a set of matched
EFI manifolds are usually filthy when we get them and many hours are spent stripping and cleaning
everything and modifying the manifolds so they slip
straight on. When we're finished,
they are in near new condition. Usually
the manifolds show either zero or very minor corrosion in
the water cooling galleries.
following photos show the components in the kit, and one of the manifolds fitted to an
engine to show how it all fits together.