Download Intercooler Spray Controller

MEARCAT
®
Intercooler Spray Controller
User/Installation Manual
July 2011 – Rev 2.3
Author & Copyright : Alan Mears
Contact Email : [email protected]
Website : www.mearcat.com.au
Mearcat is a registered trademark of Mearcat Auto Accessories © 2011
Table of Contents
Product Description / Features................................................................... 2
Installation .................................................................................................. 2
Calibration .................................................................................................. 6
Specifications ............................................................................................. 8
Suggestions ............................................................................................... 8
Warranty .................................................................................................... 8
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MEARCAT
®
Intercooler Spray Controller
Product Description / Features
The Mearcat Intercooler Spray Controller is a ‘smart logic’ controller which adaptively
monitors how hard the car is being driven to determine when the water spray directed at the
intercooler should be activated. It can be used on any turbocharged or supercharged cars
fitted with an intercooler and air flow meter (AFM or MAF), regardless of fuel delivery
system.
Unlike other intercooler spray controllers that are based solely on a simple Hobbs/boost,
throttle position sensor or RPM switch, the Mearcat Intercooler Spray Controller utilises
multiple inputs to determine when to activate the spray.
By measuring the temperature of the intercooler core or intake air temperature relative to
ambient temperature as well as the volume of air used by the engine, the controller
determines when to switch on the water pump. The pump is only activated when required
and water consumption can be drastically reduced, with no reduction in cooling
performance.
If the turbocharger or supercharger is producing boost but the intercooler/intake air
temperature is already cool enough, then no water is sprayed. If the spray is activated, then
it will continue between quick gearshifts and if the programmed logic determines the driver
has been pushing the car hard and the intercooler is still hot, it will continue to spray for a
pre-determined time (between 2-6 seconds) after you're off the throttle to attempt to further
reduce the intercooler temperature.
The controller will not aid in the reduction of the intercooler temperature when you are in
slow moving traffic or stationary, however the facility for an optional manual override switch
is included with the controller. It allows the driver at any point to override the controller logic
and force the spray to activate via a simple switch. This is particularly useful in cars with
top-mounted intercoolers such as the Subaru Impreza WRX.
The Mearcat Intercooler Spray Controller has been primarily designed for street use but can
also be used for any kind of track work. When used in a track environment, it is expected
that resultant water consumption will be less efficient when compared to street use. It would
also be expected that the spray would activate at more frequent intervals in cars with topmounted intercoolers (mounted above the engine) due to the heat from the engine bay that
can increase the temperature of the intercooler.
Installation
NOTE : Ensure that the car engine and all accessories are turned off before installation.
The unit is delivered fully assembled in a dust and moisture proof ABS plastic box. No
further assembly is required.
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User/Installation Manual
MEARCAT
®
Intercooler Spray Controller
Installation of the controller is a simple process for anyone with basic electrical knowledge.
The controller is to be connected to power and earth, air flow meter signal wire, two
thermistors (temperature sensors) and the water pump. The optional manual switch
(momentary or throw-type) can also be connected. Small holes are required to be drilled in
the side panel of the controller box to route the wiring to the terminals on the circuit board,
and it is recommended that rubber grommets is used to prevent penetration of dust and
moisture.
Power and Earth
12V power to the controller should be ignition switched type e.g. Cigarette lighter (which in
most cars are powered when the car ignition is turned on / not permanently powered).
Ensure a 0.5A fuse is installed between the power source and the controller. Earth
connection can be any chassis point of the car. Connect the power wire to the terminal
block labeled "12V" and the earth wire to the terminal block labeled "GND".
Note : The kit is not designed to have an inline switch installed from the 12V power source.
If the kit is powered down while the engine is running, the AFM signal wire voltage is
dropped to Zero volts and may cause engine an cut-out. However, an additional AFM signal
isolation module is supplied with the main kit and should be fitted when switched power to
the kit is used.
Air Flow Meter (AFM / MAF)
Refer to your car service manual to determine which wire is the signal voltage wire at either
ECU or at the actual Air Flow Meter. Alternatively, use a multimeter to probe each wire
leading from the meter to find the correct one. At idle, most airflow meters will produce a
signal of approx 1.0V and the voltage will rise as more air is used by the engine (when
engine is revved or under load). Tap into and solder to the AFM signal wire and connect to
the terminal block labeled "AFM" on the circuit board.
Note: In some vehicles, the kit may cause interference to the AFM voltage signal and
causes erratic or rough idle of the engine. In this case, the additional AFM signal isolation
module is supplied with the main kit and should be fitted to solve this issue.
Temperature Sensors
The two thermistors are pre-assembled so all that is required is to mount them. The two
sensors are identical so you can use either of them for measuring ambient or intercooler
temperatures. The ambient air temp sensor should be mounted so that it measures the
temperature of the outside air. In most cases mounting it in the lower area of the front
bumper (exposed to airflow) will be sufficient, but be careful not to mount it where it can be
affected by heat soak from the radiator, engine etc. Connect the ambient sensor wires to the
terminal block labeled "Amb" on the circuit board. If either of the sensors are not connected
to the circuit board properly, the red Temp Trip LED will flash continuously when the
controller is powered on.
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User/Installation Manual
MEARCAT
®
Intercooler Spray Controller
There are two mounting options for the second temperature sensor. It may be mounted on
the intercooler core or in the intake piping.
If mounted on the intercooler, the sensor must be mounted between the fins of intercooler at
the back of the intercooler core to prevent frontal airflow cooling the sensor and inaccurate
activating of the spray. Mounting it in the middle on the intercooler core (half way between
inlet and outlet end tanks) using a small amount of adhesive is advised. Be careful not to
cover the actual sensor with adhesive.
If mounted in the intake air stream the sensor should be mounted within the intake piping
after the intercooler, as this will indicate whether the intercooler has become heat soaked or
not. A hole will need to be drilled into the intake piping, the sensor inserted into the pipe and
an adequate seal around the wiring provided to stop any air leaks while the engine is
running.
Once mounted, connect the sensor wires to the terminal block labeled "Core" on the circuit
board.
Pump / Relay
The onboard 12V relay is capable of activating a pump that draws up to 10 Amps of current.
Connect the pump to the terminal block labeled "Pump" on the circuit board as per Fig. 1
below. Note : Check the rating of the pump you will be using and ensure that it is not rated
at more than 10 Amps.
Manual Override Switch (optional)
Any momentary or throw switch can be connected to the terminal block on the circuit board
labeled "Switch" to allow the driver to override the controller and force the spray to activate.
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User/Installation Manual
MEARCAT
®
Intercooler Spray Controller
12V
Ground
Air Flow Meter
Reset Switch
Ambient Sensor
AFM Threshold Trimpot
Intercooler /
Intake Air Sensor
12V Pump
Terminal Block
Manual Switch
Terminal Block
Figure 1. Terminal Block Locations
12V Source
Pump Terminal Block
Pump
Manual Override Terminal Block
Pump
Ground
(0V)
Switch
Figure 2. Pump & Manual Override Switch Connections
Spray Assembly
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User/Installation Manual
MEARCAT
®
Intercooler Spray Controller
The water pump, nozzle, check valve and hosing are not included in this kit but will need to
be installed so that the water spray will spray in an even fashion across the intercooler. It is
highly recommended that an atomising nozzle that sprays water in a fine mist is used to
increase the effectiveness of the controller.
Calibration
Although there are only two thresholds that need to be set, the controller is very flexible and
allows for a temperature difference threshold as small as 5°C or as high as 30°C (in 5°C
increments), and an air flow meter voltage threshold of anywhere between 0-5V. The
position that these threshold values are set will depend on a wide range of factors but the
most effective way to set the values is on a trial-and-error basis.
Temperature Threshold Adjustment
The temperature difference threshold (temperature difference between ambient and
intercooler, or temperature difference between ambient and intake air) is easily set by a
single jumper on the circuit board. Decide how much hotter the intercooler core than
ambient (or intake air than ambient) must be when the spray is activated and place the
single jumper on the appropriate pins (5, 10, 15, ... 30°C). If the jumper position is changed
while the car ignition is switched on, the "Reset" button on the controller circuit board must
be pressed momentarily. If no jumper is fitted, the controller defaults to 5°C. When the
intercooler/intake air reaches the selected temperature difference, the red “Temp Trip” LED
will turn ON. See Fig. 3 below for location of the temperature threshold jumper pins.
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User/Installation Manual
MEARCAT
®
Intercooler Spray Controller
Temperature
Threshold
Jumpers
Figure 3. Temperature Threshold Jumper Pins
Air Flow Meter Threshold Adjustment
Initially, turn the trimpot labeled "VR1" (see Fig. 1) fully counterclockwise and the red “AFM
Trip” LED should turn on as soon as you start the car. Turn the trimpot approx 45° clockwise
so that the LED turns off. Take the car for a quick drive and monitor when the LED turns
on/off. If the LED turns on under an engine load which is too low, turn it a small amount
clockwise (the trimpot is quite sensitive) and go for another quick drive. The “Reset” button
does not have be pressed when making these adjustments. Repeat this procedure until the
trimpot is set at an appropriate engine load. A recommended threshold point to set is when
the red “AFM Trip” LED turns on as the turbo starts producing boost.
Pump / Water Spray Activation
Once both temperature and AFM thresholds are reached (both Temp Trip & AFM Trip LEDs
turn on), the controller will activate the pump relay (the red “Pump On” LED will also turn on)
and start spraying water onto the intercooler. The controller will continue to keep the pump
on (even between quick gearshifts) while both thresholds have been exceeded. If either of
the two signals drop below the configured threshold, the controller will continue to spray for
between 2-6 seconds longer – the exact time will depend on how much hotter the
intercooler/intake temperature is in relation to the temperature threshold, and the amount of
time the thresholds have been exceeded for.
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User/Installation Manual
MEARCAT
®
Intercooler Spray Controller
Specifications
Power Requirements : 10-15V DC
Required Air Flow Meter voltage : 0-5V (~1.0V at idle and rises with air flow)
Controller Box Dimensions : 92mm x 66mm x 28mm
Suggestions
Should you have any suggestions for this unit, please feel free to send me any comments /
bug reports or suggestions for modifications via email.
While the details contained in this manual are intended to be as accurate as possible, any
details are subject to change without notice.
Warranty
All Products manufactured or distributed by Mearcat Auto Accessories are subject to the
following warranty, and no others:
The warranty period begins on the date of shipment and extends for a period of 6 months
from and after that date. Electronics warranties and guarantees only to the original
purchaser/user that such a product will be free from defects of material and workmanship in
the manufacturing process. Mearcat Auto Accessories, at its own discretion, shall choose to
repair or replace the defective product. This warranty shall be inapplicable to any product
not properly installed and properly used by the purchaser/user or to any product damaged
or impaired be external forces. This is the extent of warranty available on this product.
Mearcat Auto Accessories shall have no liability whatsoever for consequential damages
following from the use of any defective product, by reason the failure of any product or
driver failing to monitor temperatures, distraction from the road or relying on the display to
determine eg. Warm-up times, overheating levels, after-run/cool-down times. Mearcat Auto
Accessories specifically disclaims and disavows all other warranties, express or implied
including, without limitation, all Warranties of fitness for a particular propose, Warranties of
Description, Warranties of Merchantability, Trade Usage or Warranties of Trade Usage.
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User/Installation Manual