Perfect Power XMS4A User manual

XMS4A
LetRipp II
Engine Management System
DIY MANUAL
Version 2.1

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PERFECT POWER XMS4A – Engine Management System DIY MANUAL V2.1
TableofContents: Pageno:
1. INTRODUCTION.................................................................................................1
2. PARTS SUPPLIED IN THE KIT...............................................................................1
3. WHY SHOULD YOU READ THIS MANUAL?...............................................................1
4. EXPLANATION OF XMS4 UNITS AVAILABLE............................................................2
5. TECHNICAL DETAILS ..........................................................................................3
5.1 FUEL INJECTION.............................................................................................3
5.2 IGNITION ......................................................................................................3
5.3 ACCELERATION ENRICHMENT...........................................................................4
5.4 INJECTOR/ENGINE PRIMING.............................................................................4
5.5 TRIGGER INPUTS............................................................................................4
5.6 BOOST CONTROL............................................................................................4
5.7 PRIME (FUEL).................................................................................................4
5.8 IDLE CONTROL...............................................................................................4
5.9 SETPOINT CONTROL .......................................................................................4
6. FEATURE EXPLANATION......................................................................................5
6.1 LAUNCH CONTROL..........................................................................................5
6.2 EXTERNAL SUPPLY TO SENSORS.......................................................................5
6.3 MAPS A / B ....................................................................................................5
6.4 CALIBRATION.................................................................................................5
6.5 FUEL INJECTION MAP......................................................................................5
6.6 IGNITION MAP ...............................................................................................5
6.7 COMPENSATION MAP ......................................................................................5
6.8 BOOST CONTROL............................................................................................6
6.9 SETPOINT......................................................................................................6
6.10 MAXIMUM RECORDINGS..................................................................................6
6.11 ONBOARD LOGGING (COMING SOON)...............................................................6
6.12 COMMUNICATION CONNECTION .......................................................................6
6.13 USB DRIVERS SETUP.......................................................................................7
7. COMPUTER REQUIREMENTS ................................................................................7
8. PIN OUTS OF XMS4A UNIT ..................................................................................8
8.1 XMS4A PIN-OUT TABLE....................................................................................8
8.1.1 XMS4A IGNITION PIN-OUT CONNECTOR (6 PIN)..............................................8
8.1.2 XMS 4A INJECTION PIN-OUT CONNECTOR (8 PIN) ...........................................8
8.1.3 XMS 4A AUXILIARY CONNECTOR (4 PIN) ........................................................9
8.1.4 XMS 4A MAIN CONNECTOR (22 PIN) ..............................................................9
9. ASSESSING YOUR CAR’S FUEL SYSTEM...............................................................10
9.1 IS YOUR CAR READY FOR FUEL INJECTION?.....................................................10
9.2 HOW TO MAKE YOUR CAR READY FOR FUEL INJECTION .....................................10
9.3 CONCLUSION...............................................................................................11
10. ASSESSING YOUR ENGINE ................................................................................11
10.1 COMPATIBLE TRIGGER WHEEL........................................................................11
10.2 CAMSHAFT SENSOR......................................................................................12
10.3 HOW TO INSTALL A COMPATIBLE WHEEL AND PICKUP SENSOR ..........................12
10.4 WHICH SENSORS ARE MISSING?....................................................................13
10.5 INJECTOR RESISTANCE .................................................................................13
10.6 MAKE SURE THE ENGINE HAS THE BASICS.......................................................14
10.7 CONCLUSION...............................................................................................14
11. WHERE TO FIT YOUR XMS4A?............................................................................14
11.1 SUITABLE PLACES ........................................................................................14
11.2 UNSUITABLE PLACES ....................................................................................15
11.3 CONCLUSION...............................................................................................15
12. WHERE TO FIT THE IGNITION AMPLIFIER? ..........................................................15
12.1 SUITABLE PLACES ........................................................................................15
12.2 UNSUITABLE PLACES ....................................................................................16
12.3 CONCLUSION...............................................................................................16
13. SCREENED CABLE............................................................................................16
13.1 WHAT IS A SCREENED CABLE? .......................................................................17

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13.2 WHY SHOULD I USE A SCREENED CABLE?........................................................17
13.3 WHAT SHOULD YOU USE A SCREENED CABLE ON? ............................................17
14. CRANK SIGNALS - WHAT DO THEY LOOK LIKE?....................................................17
14.1 POSITIVE EDGE............................................................................................17
14.2 NEGATIVE EDGE...........................................................................................18
14.3 MAGNETIC...................................................................................................18
14.4 DIGITAL/HALL EFFECT...................................................................................18
15. TYPICAL SENSORS USED AND HOW TO WIRE THEM..............................................18
15.1 AMP............................................................................................................19
15.2 ENGINE TEMP...............................................................................................19
15.3 AIR TEMP ....................................................................................................20
15.4 THROTTLE POSITION ....................................................................................21
15.5 CRANK ANGLE SENSOR .................................................................................21
15.6 CAMSHAFT SENSOR......................................................................................22
15.7 CONCLUSION...............................................................................................22
16. TYPICAL DEVICES DRIVEN BY THE XMS4A...........................................................23
16.1 BOOST SOLENOID ........................................................................................23
16.2 FUEL PUMP RELAY.........................................................................................23
16.3 FAN RELAY...................................................................................................24
16.4 2 WIRE IDLE CONTROL MOTOR.......................................................................24
16.5 SHIFT LIGHTS..............................................................................................25
16.6 REV COUNTER..............................................................................................25
16.7 INJECTORS..................................................................................................25
16.8 IGNITION AMPLIFIERS...................................................................................26
17. IDLE CONTROL – IN MORE DETAIL .....................................................................27
17.1 TWO WIRE IDLE – SOFTWARE SETUP ..............................................................27
17.1.1 F3 – TWO WIRE IDLE FOR XMS4A.............................................................28
17.1.2 SHIFT F2 – SYSTEM DEF .........................................................................28
17.1.3 IDLE RPM TARGET..................................................................................29
17.1.4 SHIFT/F11 – 2WIRE IDLE ........................................................................29
17.1.5 SETTING UP THE IDLE ............................................................................30
18. DWELL TIME....................................................................................................30
18.1 WHAT IS DWELL? .........................................................................................30
18.2 CAN IT DAMAGE YOUR COIL? .........................................................................30
18.3 DWELL SETUP VIA SOFTWARE........................................................................31
19. SETTING UP PARAMETERS.................................................................................32
20. SYSTEM DEFINITION........................................................................................33
21. SET POINTS ....................................................................................................34
21.1 USES ..........................................................................................................34
21.2 WIRING.......................................................................................................34
21.3 SETUP VIA SOFTWARE ..................................................................................35
22. CALIBRATION OF SENSORS...............................................................................35
22.1 AMP............................................................................................................36
22.2 ENGINE TEMP...............................................................................................36
22.3 AIR TEMP ....................................................................................................37
22.4 THROTTLE POSITION ....................................................................................37
22.5 CONCLUSION...............................................................................................37
23. RPM...............................................................................................................38
23.1 SETUP AND CALIBRATION VIA SOFTWARE .......................................................38
23.2 LIMIT..........................................................................................................38
23.3 CONCLUSION...............................................................................................39
24. WHAT TO DO BEFORE TRYING TO START THE ENGINE ..........................................39
24.1 IGNITION SETUP WITH TIMING MARKS AND TIMING LIGHT................................39
24.2 IGNITION ADJUSTMENT VIA SOFTWARE ..........................................................40
25. TIME TO START THE ENGINE .............................................................................40
25.1 FIRST THINGS TO DO WHEN CRANKING THE ENGINE........................................40
25.2 FIRST THINGS TO DISABLE WHEN THE MOTOR IS RUNNING ..............................40
25.3 IDLE SETUP .................................................................................................41
25.4 FUEL SETUP WITH AMP..................................................................................41

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PERFECT POWER XMS4A – Engine Management System DIY MANUAL V2.1
25.5 CONCLUSION...............................................................................................43
26. LOOK HERE IF IT DOESN’T START......................................................................43
26.1 POSSIBLE REASONS AND COMMON CHECKS ....................................................43
27. TUNING YOUR XMS4A FOR THE FIRST TIME.........................................................44
27.1 OPTIONS.....................................................................................................44
27.2 TOOLS NEEDED............................................................................................44
27.3 FUEL TUNING...............................................................................................44
CO MEASUREMENTS.........................................................................................44
4 GAS ANALYSER.............................................................................................45
27.4 IGNITION TUNING ........................................................................................47
28. COLD START MAP.............................................................................................48
29. ACCELERATION ENRICHMENT............................................................................49
30. SETTING THE BOOST CONTROL UP.....................................................................49
30.1 CLOSED LOOP..............................................................................................49
30.2 VIA PWM .....................................................................................................50
31. LAUNCH CONTROL ...........................................................................................50
31.1 USES ..........................................................................................................50
31.2 SETUP VIA SOFTWARE ..................................................................................51
31.3 CONCLUSION...............................................................................................51
32. TROUBLESHOOTING.........................................................................................51
32.1 FUEL...........................................................................................................51
32.2 PRESSURE...................................................................................................51
32.3 IGNITION ....................................................................................................51
32.4 SPARK PLUGS ..............................................................................................52
32.5 COIL...........................................................................................................52
32.6 TWO WIRE COIL...........................................................................................52
32.7 THREE WIRE COIL ........................................................................................52
32.8 FOUR WIRE COIL:.........................................................................................53
32.9 TRIGGER WHEEL ..........................................................................................53
32.10 TRIGGER SENSOR .....................................................................................53
32.11 ENGINE FAILURE, NO COMPRESSION...........................................................54
33. BASIC XMS4A-2A WIRING DIAGRAM...................................................................55
34. BASIC XMS4A-4A WIRING DIAGRAM...................................................................56
TableofFigures: Pageno:
FIGURE 1. FUEL SYSTEM LAYOUT.................................................................................10
FIGURE 2. ENLARGED VIEW OF SURGE TANK.................................................................11
FIGURE 3. CRANK PULLEY...........................................................................................12
FIGURE 4. 60 – 2 TOOTH WHEEL SETUP........................................................................13
FIGURE 5. TYPICAL “UNDER THE DASHBOARD” INSTALLATION ........................................14
FIGURE 6. 4 WIRE PLUS SCREEN FOIL..........................................................................17
FIGURE 7. WIRING OF PERFECT POWER AMP SENSOR ....................................................19
FIGURE 8. WIRING OF PERFECT POWER ENGINE TEMP SENSOR .......................................20
FIGURE 9. WIRING OF PERFECT POWER AIR TEMP SENSOR.............................................20
FIGURE 10. WIRING OF THROTTLE POSITION SENSOR ...................................................21
FIGURE 11. WIRING OF MAGNETIC ..............................................................................21
FIGURE 12. WIRING OF HALL EFFECT...........................................................................22

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PERFECT POWER XMS4A – Engine Management System DIY MANUAL V2.1
1. INTRODUCTION
Congratulations on the purchase of your first XMS4A engine management system. This
product is a leader in aftermarket engine management systems and it uses the latest 16bit
technology.
The XMS4A series is a result of many years of development. What started in 1986 as a hobby
has turned into a company that thrives on innovation and performance. With the latest
technology backing our products and new features continuously being added the XMS4A
surpasses any price or performance comparison.
The XMS4A uses “LETRIPP TECHNOLOGY” and thus can be tuned by the LETRIPP WINDOWS
TUNING SOFTWARE. The new XMS4A product range will undergo extensive modifications and
upgrading over the next few years. Please make sure you have the latest software version
which can be downloaded from our website www.perfectpower.com.
2. PARTS SUPPLIED IN THE KIT
For your XMS4A to function correctly it is essential to confirm that all the necessary items
have been supplied.
The standard items supplied in the XMS4A kit include:
1 x XMS4A unit
1 x XMS4A harness
1 x Software CD that includes manuals and USB drivers.
1 x USB tuning cable
If you don’t have all of the above items please contact us immediately either via
www.perfectpower.com or [email protected].
The use of a suitable dual channel ignition amplifier is required for all installations of the
XMS4A product. We do supply a product with the required specifications called the Blue-Fire,
however you are welcome to make use of a different manufacturer (as long as the specs are
the same).
3. WHY SHOULD YOU READ THIS MANUAL?
The XMS4A standalone engine management system has a lot of features and even more wires,
which can be quite daunting. However this manual will guide you through the different stages
of installing the unit and finally tuning the engine.
To unlock or use the XMS4A to its full potential this manual MUST be read – even if you are a
novice or a professional at installing systems. If this is your first time installing an XMS4A,
then the manual will explain how to do things and things to avoid. Our goal is to get the
installation up and running with the least amount of time and problems as possible. As with
most manuals you may be reading this one because you are stuck or something isn’t working
and you need assistance.

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PERFECT POWER XMS4A – Engine Management System DIY MANUAL V2.1
4. EXPLANATION OF XMS4 UNITS AVAILABLE
There are 6 different versions of the XMS4 unit available, and in this section we explain each
version available.
Hardware
Type Part Number Details
A XMS4A-2A
2 Injection and Ignition Outputs, 4 Cylinder Batch Injection with
installed AMP sensor
A XMS4A-4A
4 Injection and Ignition Outputs, 4 Cylinder Sequential Injection.
4 Set points with installed AMP sensor.
B XMS4B-4A
4 Injection and Ignition Outputs, Wideband lambda controller. 4
Set points, with installed AMP sensor.
B XMS4B-8A
8 Injection and Ignition Outputs, Wideband lambda controller. 4
Set points, with installed AMP sensor.
C XMS4C-4A
4 Injection and Ignition Outputs, ETC, Wideband lambda
Controller. 8 Set points, with installed AMP sensor.
C XMS4C-8A
8 Injection and Ignition Outputs, ETC, Wideband lambda
Controller. 8 Set points, with installed AMP sensor.

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5. TECHNICAL DETAILS
The following features are that of an XMS4A.
5.1 FUEL INJECTION
•3-Ampere injector drives : 2, 4
•Injection : Batch, Sequential
•Injector trimming : Yes
•Main map sites : 384
•Manifold pressure map sites : 24
•Engine temperature map sites : 24
•Air Temperature map sites : 24
•Max duty cycle : 100%
•Peak and Hold : No
•Injection length resolution : 0.01Ms
Total injection length is calculated as follows:
+Mainmapentry
+ Air temperature entry
+ Engine temperature entry
+ Acceleration enrichment
+ AFR Short term loop adjustment
+ AFR Long term trim
+ Manifold pressure entry
+ Fuel range
Other fuel components:
+ Priming
+Idlecontrol
+ Set point control Soft/Hard fuel cut
5.2 IGNITION
Cylinders : 2, 3, 4, 6, 8
Ignition : Sequential: 2, 3, 4 Cylinders
Ignition outputs : 2, 4, 8
Directdrive :NO
Output polarity : Positive
Main map sites : 384
Manifold pressure map sites : 24
Engine temperature map sites : 24
Air temperature map sites : 24
Dwell length map sites : 24
Total ignition angle is calculated as follows:
+- Main map entry
+- Manifold pressure
+- Engine temperature entry
+- Air temperature entry
Other ignition components:
Launch control retard
Dwell

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5.3 ACCELERATION ENRICHMENT
Acceleration RPM Enrichmentmapsites: 24
Acceleration Air Temperature enrichment map sites: 24
Acceleration initial injection map sites: 24
5.4 INJECTOR/ENGINE PRIMING
Prime Engine temperature sites: 24
5.5 TRIGGER INPUTS
Balanced CRANK input YES
Balanced CAM input YES
Triggers on logic signal YES
User selectable CRANK polarity YES
User selectable CRANK trigger level YES
User selectable CAM trigger level YES
CAM on/off option YES
5.6 BOOST CONTROL
For Turbo waste gate control YES
PWM bleed Air temp. map sites 24
PWM sites for cruising 24
PWM sites for full power 24
Target boost map sites 24
PIDloopgain YES
5.7 PRIME (FUEL)
24 Map sites accessed by the engine temperature, allow extra fuel during starting.
5.8 IDLE CONTROL
Target RPM map sites via temperature 16
For 2 wire idle motors YES
PID control YES
Integration time adjust YES
Loop gain adjust YES
5.9 SETPOINT CONTROL
Number of set-point functions 16
Number of assigned relay outputs 4
Output drives 0.5A
High/Low limit setting YES
Soft fuel limit YES
Hard fuel cut YES
“OR”function YES
“AND” function YES
Map switching YES
Output short circuit protection YES
Over-temperature protection YES

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PERFECT POWER XMS4A – Engine Management System DIY MANUAL V2.1
6. FEATURE EXPLANATION
6.1 LAUNCH CONTROL
The Launch Control is for turbo cars where “spooling up” of the turbo is required on the start
line. It is an extra switch input. The Launch Control is affected and works in the following way:
Proportional retard above a settable launch RPM limit. When the clutch is depressed (pushing
a switch) the ignition is retarded when a specified RPM is exceeded and advanced back to
normal when the clutch is released.
The Launch Control feature can also be used for “Flat-foot-shifting” in non-turbocharged
engines. This restricts the RPM to a specified level while the clutch is pressed and the
accelerator is pressed down.
6.2 EXTERNAL SUPPLY TO SENSORS
A separate +5 Volt output (pin 9 of 22) is available to power manifold pressure and TPS
sensors.
6.3 MAPS A / B
The XMS4A has two complete maps for all tuning data. Maps can be switched while driving.
The two maps can hold different tuning for weather, fuel grade or performance requirements.
The maps can be switched from a manual input, or automatically via the SETPOINT procedure
in the LetRipp Software.
6.4 CALIBRATION
All inputs can be calibrated to suit your existing sensors of your engine. Calibration is
performed for two reasons:
A) So that the XMS4A interprets the sensor readings correctly.
B) So that the Tuner (you) can read the data in engineering units (Bar/PSI,
Fahrenheit/Degree C, other).
6.5 FUEL INJECTION MAP
This map controls the fuel injection. The amount of fuel injected can be mapped on 384 sites
(main map) and the output of the three possible side maps can modify the main map value.
The entry is in counts, 100 counts = 1.00mS.
6.6 IGNITION MAP
This map controls the ignition. The ignition angle in degrees is from the 384 main map sites
and is further modified in the possible three side tables of 24 map sites each.
6.7 COMPENSATION MAP
This map contains various items:
•Acceleration enrichment
•Dwell time specification
•Priming
•Idle target control

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6.8 BOOST CONTROL
Boost Control is for turbo installations where the boost must be controlled:
•To avoid knocking on an engine, OR
•To avoid damaging a motor that is not designed for boost above a certain pressure, OR
•When the boost is increased at high RPM.
The boost level can be specified for each of the possible 24-RPM map sites. The XMS4A will
operate a “bleed” valve with the specified PWM values. The BOOST control loop can be
operated as an “open” loop by setting the required bleed PWM or as a “closed” loop PID
controller with target and gain adjustment.
NOTE: DO NOT use a solenoid with less than 13 ohm.
6.9 SETPOINT
The XMS4A has 4 set point outputs, which can be activated from 16 different signal sources.
This is for the implementation of fan control, gearshift lights, RPM limits, soft fuel cut and all
other small jobs around the engine and cockpit. All functions can be combined in a logical
AND/OR fashion, and polarity selection is possible.
6.10 MAXIMUM RECORDINGS
The units recorded are:
•Max RPM
•Max Engine temperature
•Max Air temperature
•Max Manifold pressure (AMP)
The maximum recordings can be retrieved and cleared by using a computer only.
6.11 ONBOARD LOGGING (COMING SOON)
All units have a very large memory for logging 64000 data points. This converts to:
•5 Data channels, 12800 recordings OR 8 Data channels, 8000 recordings.
The amount of channels can be stipulated. The recording frequency ranges from:
•200 records per second, 5ms TO 1 record per second, 1000ms
This means that 5 channel data can be recorded for 64 seconds at 5ms intervals, or for 213
minutes at 1 second intervals.
More to come later!
6.12 COMMUNICATION CONNECTION
All variations in the XMS4A product range have a USB 2.0 communication connector. It is best
to use the supplied cable to connect the XMS4A unit to your computer. If any communication
problems are encountered, (e.g. the PC hangs and must be restarted), then a “FERRITE”
interference eliminator must be used on the cable!
It is critical to follow the exact procedures for installing the USB drivers in the order indicated
in the Auto start on the CD supplied with the kit.