Hydra Nemesis 2 Plug and Play Installation Instructions
Nemesis Tuning Primer
Boost Control Installation
Before starting the process of installing your Hydra Nemesis 2 plug and
play system, disconnect the negative battery cable from the battery and
push it aside so that it cannot make contact with the battery post during
Open the trunk and using the tip of your key push in the middle buttons on
the four fasteners holding the top of the trunk liner against the firewall
separating the engine bay from the trunk. The fasteners should easily pull
out. Peel back the trunk liner to expose the ECU on the left side of the
car. Using a 10mm wrench, remove the three bolts holding the ECU to the
firewall. Screw these back in a couple of turns when you remove the ECU
because you will be using them later to bolt the Hydra Nemesis system to
the firewall. To the left of the location where the ECU was bolted, there
is a large hole covered by a grommet with a wiring harness passing through
it. Just below and a little to the left of this large grommet is a smaller
hole covered with a rubber cover just over 1/2" in diameter. Using a
small flat-bladed screwdriver, gently pry off the cover and replace it with
the grommet provided with the Nemesis.
Using a flat-bladed screwdriver, carefully pull up the plastic step cover
running along the lower part of the left door sill. You do not have to
remove it completely, just loosen it so that the trim panel it touches on
the rear side of the passenger cabin can be removed. Inside the passenger
cabin, move the left side seat forward to permit you to access the rear
carpet covering the firewall. If you are storing your T-tops here, remove
them from the passenger cabin until the installation is complete.
Use a #2 Phillips screwdriver to unscrew the screw holding the plastic
trim behind the engine lid opening lever and carefully pull it out.
Pull the lid covering the step behind the seat up and pry the plastic
fasteners holding the lower side pillar cover to the lip of the step
cavity. Unscrew the lid hinge and put the lid aside.
Grab the edge of the lower side pillar cover and carefully pull it away
from the frame and set it aside.
Carefully pull the lower right corner of the carpet back enough to expose
the grommet covering the hole through which the main wiring harness passes
to the engine bay. Unplug the two ends of the serial cable from each at the
audio-style plugs found near one end of the serial cable. Put the very short
end in the trunk and bring the long end with you into the passenger cabin.
Using a Phillips screwdriver, carefully poke a small hole in the grommet
and push the audio-style plug on the long end of the laptop cable through
the hole to the engine bay. From the engine bay, carefully pull the serial
cable out and feed it past the gas fuel filler pipe, under the air intake,
the charcoal canister and the fuse box through the new grommet and into the
trunk. If you find it hard to work your hand down to feed the cable into the
hole, use a coat hanger or a length of wire fed in from the trunk side and
electrical tape to secure the serial cable and carefully pull it through.
You may also find it easier to temporarily remove the 1/2" grommet
from the hole as you will be able to work it back on later when the serial
cable, MAT sensor cable and vacuum line have been routed through the hole.
Plug the short end of the serial cable back on. Snap the lower side pillar
cover back in place arranging the laptop cable so that it easily reaches
to the passenger seat and is not pinched by the plastic trim pieces. Push
the fasteners back in place and screw the lid back on and snap it shut.
Carefully work the trim piece back behind the engine lid opening latch and
screw it into place.
If you are installing the Hydra Nemesis 2 on a gen3 engine with a gen3
engine harness, do not install the provided MAT sensor. You should skip
past the next series of steps that describe the installation of the MAT
sensor for the gen2 engine.
Loosen the hose clamps holding the intercooler to throttle inlet pipe and
work the pipe off. Using a 12mm socket, take off the throttle body inlet
and the two bolts holding the throttle body brace between the throttle body
and the valve cover. Take off the two bolts holding the accelerator cable
bracket and detach the cable from the throttle. Use a 10mm socket to remove
the two bolts holding the valve cover side of the bracket and remove the
bracket. Pull off one side of the little hose running between the valve
cover and the throttle body.
Using a 12mm socket, remove the four bolts holding the throttle body to the
intake manifold taking note of the fact that the two lower bolts are longer
than the upper ones. Unplug the connector going to the throttle position
sensor (four pins) and pull the throttle away from the intake manifold so
that you can access and pull off the connector to the idle speed valve
(three pins) under the throttle body. Do not detach the hoses connected to
the idle speed control valve but gently move the throttle body out of the
way so that you can access the cold start injector underneath the throttle
body attachment point on the intake manifold.
Using a small flat-bladed screwdriver, pry the retaining clip off the
cold start injector connector. It is not easy to do, but there is a small
notch on the very top of the edge facing towards the front of the car that
you can use to pry the clip out. When the clip is out, the connector will
slide out easily. Use a little electrical tape to wrap the cold start
connector so that it does not make contact with anything and short the
electrical system. Use a 10mm closed-end wrench to pull off the two bolts
holding the cold start injector to the intake manifold. Pull off the cold
start injector and remove and clean the gasket behind it. If it is broken
and not reusable, obtain a new gasket from your Toyota dealer before
proceeding to prevent boost leaks. Using a 10mm wrench, unbolt the union
bolt holding the cold start fuel line to the fuel rail. Prepare a small
container or rag to catch the fuel that will run out of the cold start
injector fuel line when you pull it from the fuel rail. Save and clean off
the seal washer on the union bolt.
Use the original seal washer and the 8x1mm bolt supplied with the Hydra
Nemesis 2 to plug up the fuel rail. Do not torque the plug over 10 ft/lbs.
Locate the manifold temperature sensor and the mounting plate provided
with the Hydra Nemesis 2 and screw the sensor snuggly into the plate.
Using the bolts and the gasket originally on the cold start injector, bolt
the mounting plate onto the intake manifold with the measuring tip of the
sensor pointing up into the manifold. You should see the tip poking out of
the hole in the bottom of the manifold when the plate is firmly reattached.
Do not torque the bolts over 10 ft/lbs. Locate the temperature sensor cable
provided with the Hydra Nemesis 2, snap the connector on the cable onto the
manifold temperature sensor and snake it under the fuse box and through the
hole with the new grommet into the trunk. Wrap electrical tape over the
cold start injector connector to prevent it from shorting against the
throttle body or valve cover and potentially blowing a fuse.
Line up the throttle body back on the intake manifold first reconnecting
the idle speed valve connector (three pins) and the throttle speed sensor
connector (four pins) and placing the gasket that goes between the throttle
body and the intake manifold back in place. Put the four bolts that hold
the throttle body back in place (the longer ones go an the bottom) and
torque them to 13 ft/lbs. Push the little hose that goes between the
throttle body and the valve cover back into place. Put the bracket that
secures the throttle body against the top of the valve cover back on and
torque the 12mm bolts to 13 ft/lbs. and the 10mm bolts to 8 ft/lbs. Put the
throttle body inlet back on remembering the gasket between the throttle
body and the inlet and torque the four bolts to 13 ft/lbs. Reattach the
throttle cable and bolt the throttle cable bracket onto the throttle body.
Torque the two bolts holding the throttle cable bracket to 13 ft/lbs. Work
the intercooler to throttle body inlet pipe back in place and tighten the
clamps properly so that they do not pop off the next time you boost.
The plug and play box comes programmed for the type of engine that you
indicated you had when you ordered the unit. If you suspect that the box
is not properly configured, open the box by unscrewing the four larger
screws on the base of the board.
Carefully pull the top of the plug and play box forwards to clear the main
connector and then upwards to pull it away from the base. Grab the wire
bundle coming out of the hole on the side of the plug and play box and
gently push inward to give the wires extra slack to allow the top to be
moved upward enough to expose the entire circuit board inside. The
configuration jumpers are now exposed and can be easily set by pulling
each jumper off and reinserting it in the position shown
Inside the engine bay, locate a small black box attached to the same
bracket holding the connector labeled "Diagnosis." There is a
short 4mm inner diameter hose connecting this small box to a vacuum port
on the intake manifold. On the 91 and 92 MR2s, cut this hose and reconnect
it together using using the 4mm tee provided with the Hydra Nemesis 2.
Attach one end of the 4' long 4mm hose provided with the Hydra Nemesis 2
to the third end of the tee. On the 93-95 MR2s, pull off the short
4mm hose that goes from a 4mm tee to the small vacuum actuator on the
throttle cable linkage and attach the 4' long 4mm hose provided with the
Hydra Nemesis 2 to the 4mm tee. Feed the hose around the back of the intake
manifold and under the fuse box and feed it through the hole with the new
grommet into the trunk. You may need to temporarily slide the 1/2"
grommet off the sheet metal to give the hole a little more room to squeeze
the hose through with the serial cable and MAT cable already there.
Insure that the three connectors on the plug and play box are securely
connected to the corresponding connectors on the Hydra Nemesis 2. Note
that the two smaller connectors are identical except for their color and
that they must be plugged into the matching color connector on the Hydra
Nemesis 2 unit. Lay the Hydra Nemesis 2 face down on the bottom of the
trunk and connect the three stock connectors that used to plug into the
stock ECU into the main connector on the end of the plug and play box.
For the Hydra Nemesis 2.1 and 2.5 systens, partly screw in the two bolts
on the left side of the firewall that originally held the stock ECU and
slide the two tabs of the bracket underneath the heads and washers of
these bolts. Insert the last bolt that held the stock ECU into the
remaining bolt hole and tighten all three bolts with an open-end 10mm
wrench. For the Hydra Nemesis 2.6 system, pull the unit off the bracket
which is secured with Velcro and you will be eble to easily access the
bolts and tighten then with a 10mm socket.
Push the 4mm hose from the intake manifold into the vacuum port on the
Hydra Nemesis 2. You can carefully trim off any excess length from this
hose before doing so to keep it from kinking or tangling. Connect the
manifold temperature sensor cable to the connector labeled 'MAT' on the
plug and play board. Connect the serial cable to the Hydra Nemesis 2 and
secure it with the two small screws on the serial connector. Position
the switch on the left side of the plug and play box with the labels
'Test' and 'Race' to its center position. On newer plug and play boxes
there is no 'Test' label because this function is selected by putting a
jumper across T and E1 in the diagnosis connector just as you would if
you had a stock ECU. In this case, the switch just has two positions and
you should set it to the one pointing away from the 'Race' label.
Double check all connections to insure that they are tight and all
screws and bolts are securely tightened. Reconnect the battery. Using
a bent paper clip, connect the +B and Fp terminals in the 'Diagnosis'
box and turn the ignition key to 'ON' without attempting to start the
engine. The fuel pump will run and the fuel system will pressurize. Use
your nose and a flashlight to insure that the cold start fuel feed plug
inserted in the fuel rail is not leaking. If you smell or see any
gasoline, quickly turn off the ignition and fix the cause of the leak.
Do not continue until the leak is fixed. Turn the ignition key to 'OFF'
and pull out the paper clip.
Insert the software CD provided with the Hydra Nemesis 2 in your laptop's
CD-ROM drive. At this time you may want to read the User's Manual provided
as a PDF file on the CD and familiarize yourself with the basic features
and navigation of the laptop software. Then, run the installer (the file
named 'Setup.exe') to install the Nemesis program on your laptop. You can
also download the latest installer
Connect the serial cable in the passenger cabin to the laptop computer.
Note that it is strongly recommended that you either use a laptop computer
with a built-in serial connector or that you purchase a PCMCIA serial
interface to connect to the Hydra Nemesis 2.1 or 2.5 systems. The Hydra
Nemesis 2.6 system comes with a USB to Serial converter that has been
tested and known to work with the system. Other USB to serial interfaces
may not work or require that you spend a lot of time playing with the
advanced setup features of the interface to find a combination of settings
that sometimes work. Use these interfaces at your own peril.
VERY IMPORTANT: DO NOT use the version 2.1 or 2.5 download button
or the version 2.6 'File->save to ECU' menu item on the laptop software
to send a new set of maps to the Hydra Nemesis 2 unit until you have
managed to upload the maps that where shipped with the Hydra Nemesis 2
unit and saved them on your laptop. Most of the cases where the Hydra
Nemesis 2 unit fails to start the motor are a result of doing a download
with an improperly configured serial interface that is unable to do a
successful upload much less have a chance of doing anything except
downloading complete and total junk to the Hydra Nemesis 2 unit that may
require you to send back your unit to us to get it fixed.
There are several unconnected wires attached to the plug and play box
with blade connectors. Do not remove the blade cap to any of these wires
unless you are going to connect the connector to another wire or solenoid
as some of these wires could cause problems if they were to short against
each other or against the chassis. The solid red wire is switched power
and supplies 12 volts when the ignition key is 'ON.' Do not use this wire
to power any accessory as it is connected to the Hydra Nemesis 2 power
supply and is only intended for use in powering relays to switch on larger
amounts of current such as to power water injection pumps or cooling fans.
The white wire with a yellow stripe or red wire with a yellow stripe is
unswitched power and is used by the optional turbo timer kit.
Start the laptop software and turn the ignition key to 'ON.' The check
engine light on the dashboard should light up. If it does not, verify
that the Hydra Nemesis 2 unit is getting power by checking the EFI fuse
in the engine bay fuse box. Use the 'Upload' button in version 2.1 and 2.5
or the 'File->Load from ECU' menu item in version 2.6 to load the base
program stored in the Hydra Nemesis 2 unit to the laptop. Use the 'Maps'
button in version 2.1 and 2.5 to enter the map adjustment portion of the
program. On the front panel, locate the 'BATT,' 'AIR' and 'COOL' values,
which indicate the battery voltage, intake air temperature and coolant
temperature, respectively. Verify that these values are reasonable. In
particular battery voltage should be near 12 volts for a healthy battery
and the air and coolant temperatures should be close to the ambient
temperature (unless the engine is still warm from having been operated
before you began the installation). Use the 'Select->Settings' menu
item in version 2.1 and 2.5 and the Map Group->Settings 1 menu item in
version 2.6 to bring up the settings panel. Click on the 'THROTTLE' button
to select the throttle settings panel in version 2.1 and 2.5 or select
the Tools->TPS/PPS calibrate menu item in version 2.6. Click on the
'calibrate zero' to set the closed throttle position. Press the gas pedal
down all the way and keep it there. Click on the 'calibrate WOT' button
to set the open throttle position. Close the settings panel by pressing
the 'Ok' button. Locate the 'TSP' value on the front panel and verify
that it goes from 0 to 100 as you move the throttle. Select 'Maps->Save'
in version 2.1 and 2.5 and 'File->Save to file' in version 2.6 to save
the base map to a file.
If you purchased the wideband feature, follow the directions in the
wideband installation section at this time.
The Hydra Nemesis 2 unit is capable of operating low impedance fuel
injectors directly without a fuel injector resistor pack. When using
large injectors, it is particularly important to actually eliminate
the fuel injector resistor pack. Keep in mind that if you eliminate
the fuel injector resistor pack you must never try to run the car with
a stock ECU unless you replace the resistor pack as doing so will damage
the stock ECU and the injectors. You can eliminate the resistor pack by
unplugging the pack which is bolted to the rear firewall from the engine
harness. This pack is the one that has five wires going to it. Using
a pair of diagonal cutters, cut off the plug from the resistor pack
leaving about two inches of wire connected to the connector. Strip off
about 1/2" of insulation off the end of each of the five wires
connected to the connector and twist all five wires together to make good
contact. Use a soldering iron and solder to solder these five wires
together. Wrap the exposed solder connection with electrical tape or
heat some shrink tubing over it to cover it completely. Plug the connector
back into the engine harness. You have now electrically eliminated the
fuel injector resistor pack.
At this point, you should load the appropriate injector response curve
into your Nemesis map. Turn the ignition to 'OFF' and load the map file
that you saved from the Nemesis using the 'File->Open' menu item. Click
the 'Maps' button and then 'OK' when the laptop program tells you that the
ECU is not connected. Go to 'Tools->Load injector response.' If you are
running the Hydra Nemesis 2 with the fuel injector pack still in the car
using either stock or Supra injectors, select '8 OHM INJECTOR' and click
the 'Load' button. If you are running without the fuel injector pack, use
an ohmmeter to measure the resistance in ohms across the two terminals of
any one of your fuel injectors then select the value from the panel that
most closely matches the resistance you measured and click the 'Load'
button. Once you have done so, select 'Maps->Exit' to go back to the
laptop program entry screen. Use 'File->Save' to save the maps with the
proper injector response curve. Turn the ignition key to 'ON' to power up
the Hydra Nemesis 2 unit and then click the 'Download to ecu' button and
'Download' to load the new injector response curve into the unit. Switch
the ignition key to 'OFF' when the download completes. Note that if you
reload the map and go into the load injector response panel again, that
it will always have the 16 ohm option selected. This is normal regardless
of which option you loaded last.
Turn the ignition key to 'ON' and attempt to start the engine. If it
starts and settles into an idle, you have a big smile on your face and
you can go on to the next paragraph. If it starts and stalls, try again
a couple of times. If it idles after one or two tries, you most likely
just need to adjust the cold start parameters a little bit. If it
continues to stall, try giving it a little gas after it starts and see
if you can keep it going. If you can, then most likely your idle map is
a little too lean for your engine or your idle screw needs adjustment to
give the engine enough air to keep it running. If it doesn't start or
won't keep running even with some gas, you need to go to the
After you get the engine to start and run, let it warm up and bring it
to a stable idle between 800-1200 RPMs. At this point, verify your
ignition timing before you proceed with tuning the Hydra Nemesis 2. The
process of checking the ignition timing is very similar to what you do
to check ignition timing with the stock ECU except that instead of
putting a jumper in the 'Diagnosis' connector, you need to flip the switch
on the left side of the plug and play enclosure upwards to the 'Test'
position to get the base map to select a timing of 10 degrees BTDC. On
newer plug and play boxes, there is no 'Test' label on the switch and if
this is the case, then use a jumper between the 'TE1' and the 'E1' pins
in the 'Diagnosis' connector to check the base timing just as you would
in the with the stock ECU in place. With the engine running and warm, the
right side trim plate removed and a timing light connected, flip the
switch to 'Test' or put the jumper in place and verify on the main software
panel that the 'ADV' value is 10 (hit the 'Mode' button to switch to
digital mode if the 'ADV' box shows a bar instead of a number). If 'ADV'
is not 10, then you have either modified the base map timing maps so that
they no longer gives 10 degrees of timing when you switch to test mode or
maybe the engine has not yet reached an operating temperature between
80-100 degrees Celsius. Whatever the 'ADV' number is (assuming that it is
stable), that is the amount of advance that you should read when you point
the timing light at the crankshaft pulley. If it is off, loosen the
distributor and turn it clockwise to advance and counterclockwise to
retard the timing mark until the reading on the pulley matches the value
in the 'ADV' box. Once you have a match between the timing light reading
and the laptop screen ADV number, tighten down the distributor and move
the switch on the plug and play box back to the center position or pull
the jumper out.
If you have the boost controller feature, follow the directions in the
boost control installation
section at this time to install the boost controller and program it.
If you have an aftermarket MSD ignition system or purchased the direct
fire ignition option, follow the directions in the
section at this time to connect the ignition system.
If you have the launch control cable, follow the directions in the
launch control section
at this time to set up your launch control system.
If you have the turbo timer option, follow the directions in the
turbo timer section
at this time to set up your turbo timer.
At this point, you are ready to tune your car for best drivability and
power. You can learn more about this in the
Nemesis tuning primer.
When you are finished tuning the car, you should remove the black wire
going to the B10 pin on the small blue connector on the Hydra Nemesis 2
unit. Only older version 2.1 units had this feature. This will prevent
the Hydra Nemesis 2 unit from being programmed on the fly and enable the
backup spark map when the knock detection system parameters instruct the
unit to fall back to the backup spark map. Turn the ignition key to 'OFF.'
Carefully unplug the three connectors from the right side of the Hydra
Nemesis 2 unit. On the small blue connector, look at the back where the
wires come out and locate the markings on the corners that distinguish
row A from B and the B1 pin from the B12 pin. The B10 pin is the third
pin from the pin labeled B12 which is a solid black wire. Use a small
flat-baded screwdriver to pull off the plastic retaining clip on that row
of pins. Then, use a straightened out paper clip or a small jeweler's
screwdriver on the large hole in the front of the connector for B10 to
carefully push back the locking tab for the B10 wire while tugging gently
on the black wire to release it. Use a little bit of electrical tape to
prevent this pin from contacting anything.