Rotary Engine
Mazda Rotary Engine installation and tuning information
Engine Information
Identification
Only turbo models (other than RX8) have been covered.
12A Turbo
Available in the JDM RX7 Sereis 3 and some HB Cosmo models. This was a popular easy engine swap for all RX7 Series 1,2,3 models with it being a direct bolt in replacement engine. Easily identified by the orange hat on top of the carburettor-style throttle body. They have extremely small ports, small throttle, and as such make very little power. Distributor ignition with boost retard diaphram.
13BT Series 4
Found more commonly in the 1986-1988 RX7. Identified by the mechanical rod oil metering pump, twin scroll turbo with control diaphram, straight tube intercooler feed pipe, single TPS, 8.5:1 comp. Waste spark ignition with Toggle-style Trail igniter. This ignition runs the same as a Distributor but has a signal from the ECU to tell the igniter to alternate the output between two coils.
13BT Series 5
Found more commonly in the 1989-1991 RX7. Idenitifed by a stepper motor oil metering system, 2x TPS, larger turbo with no twin scroll, tapered intercooler feed pipe, 9.0:1 comp. Same ignition as Series 4
13B-RE Cosmo
Found only in the JC Cosmo. All were automatic transmissions. Very large end plate ports. Sequential Twin Turbos. Serpentine dirve belt. No inspection cover for flywheel on end plate.
13B-REW Series 6,7,8
Found in the FC RX7 Series 6,7,8. As per Cosmo engine with smaller end plate ports. Larger secondary injectors. Waste Spark Ignition.
13B-MSP
Found in the RX8. Exhaust ports moved from housing to end plates as per intake ports. DBW. Motor controlled port actuators. 10.0:1 compression. Naturally Aspirated. Direct Fire ignition. Manual transmission models have 3x injectors per rotor.
20B
Found only in the JC Cosmo with all having an automatic transmission. 3-rotor engine with Sequential Twin Turbos, specs otherwise similar to the 13B-RE. 2x Dual-Toggle igniters which run in the same way as Series 4/5 ignition but have 3x outputs fired in sequence. OEM igniters are NOT supported by Haltech ECU's.
R26B
Made famous from Mazda's win at Le Mans. Not available to the public. There are a number of 4-rotor kits that use custom crankshafts and end plates available on the market. 4-Rotor engines are supported via the Elite 2500 ECU model.
Displacement
Elite ECUs required the true displacement to be entered for VE tuning, as listed below.
Engine | Displacement |
|---|---|
| 10A 2-rotor | 982cc |
| 12A 2-rotor | 1146cc |
| 13B 2-rotor | 1308cc |
| 20B 3-rotor | 1962cc |
| 26B 4-rotor | 2616cc |
Firing Order
Engine | FIring Order |
|---|---|
| 10A | 1-2 |
| 12A | 1-2 |
| 13B | 1-2 |
| 20B | 1-2-3 |
| 26B | 1-3-2-4 |
Sensor Information
Crank Sensor
RX7 FC3S Series 4/5, Cosmo 13B and 20B
The FC3S has a distributor-like CAS (Crank Angle Sensor) unit with an easily removable inspection cover. Inside you will find a 24x trigger and a 2x home (sync) each with a reluctor sensor. Being a distributor type system it rotates at half of the crank RPM.
OEM Wiring
CAS Wiring | Description | Haltech Connection |
Red | NE+ 24x | Trigger + (Yellow in Trigger 4-core |
White | NE- 24x | Trigger - (Green in Trigger 4-core) |
Green | G+ 1x | Home + (Yellow in Home 4-core |
White/Black | G- 1x | Home - (Green in Home 4-core) |
RX7 FD3S Series 6/7/8
The FD3S has a crank mounted trigger system. It has an inner trigger with 12x teeth and an outer 1x tooth home trigger with both using reluctor sensors. This gives the same signal pattern as the FC3S CAS.
For this model, Mazda links both of the negative signals to each other in the factory wiring loom.
OEM Wiring | Description | Haltech Connection |
Black - Pin 2 - 12 tooth sensor | NE+ 12x | Trigger + (Yellow in Trigger 4-core) |
White - Pin 2 - 1 tooth sensor | G+ 1x | Home + (Yellow in Home 4-core) |
Red - Pin 1 both sensors | NE- & G- | Signal Ground (Blue in Trigger 4-core) |
Trigger and Home Ground Reference must both be set to Enabled for this wiring.
When wiring direct from a Haltech Elite ECU to the Crank Sensors. This is the preferred way to wire these sensors.
Trigger and Home Ground Reference must both be set to Disabled for this wiring.
OEM Wiring | Description | Haltech Connection |
Black - Pin 2 - 12 tooth sensor | NE+ 12x | Trigger + (Yellow in Trigger 4-core) |
Green - Pin 1 - 12 tooth sensor | NE- 12x | Trigger - (Green in Trigger 4-core) |
White - Pin 2 - 1 tooth sensor | G+ 1x | Home + (Yellow in Home 4-core) |
Red - Pin 1 - 1 tooth sensor | G- 1x | Home - (Green in Home 4-core) |
Trigger Wiring Sheet
All Mazda rotary engines use Reluctor sensors, and when wired correctly use a Falling edge
Crank Trigger Configuration
Trigger Type | TDC Angle | TDC Offset Angle Table Required | Trigger Sensor Type | Trigger Sensor Edge | Trigger Filter Level | Trigger Pull-up | Trigger Ground Ref | Home Sensor Type | Home Sensor Edge | Home Filter Level | Home Pull-up | Home Ground Ref | Home Min RPM | Quick Start | Ignition Mode | Ignition Edge | Ignition Dwell Mode |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mazda - 13B RX-7 FC3S | 5 | Yes | Reluctor | Falling | 0 | - | Disabled | Reluctor | Falling | 0 | - | Disabled | - | Disabled | OEM IGNITORS NOT SUPPORTED | - | - |
| Mazda - 13B RX-7 FD3S | 5 | Yes | Reluctor | Falling | 0 | - | Enabled | Reluctor | Falling | 0 | - | Enabled | - | Disabled | Waste Spark | Falling | Constant Charge |
| Mazda - 20B Cosmo FC | 5 | Yes | Reluctor | Falling | 0 | - | Disabled | Reluctor | Falling | 0 | - | Disabled | - | Disabled | Direct Fire Only. OEM IGNITORS NOT SUPPORTED | ||
| Mazda - RX-8 | 35 (unverified) | Yes | Reluctor | Falling | 0 | - | Disabled | - | - | - | - | - | - | Disabled | Direct Fire | Falling | Constant Charge |
Ignition Wiring
LEAD are the bottom spark plugs and the housing are marked with an "L" to show this.
TRAIL are the top spark plugs and the housings are marked with a "T" to show this.
Haltech treat the rotary engine ignition as if, for example, a 2-rotor was the same as a 2-cylinder with just one spark plug per cylinder. So when wiring the ignition the Lead spark is wired first, and the Trail is treated as an auxiliary ignition. So they are wired in the follow orders:
2-Rotor Direct Fire (10A / 12A / 13B)
Function
Haltech Output
Haltech Wiring Colour
Elite 550/750 ECU Pin
Elite 1000/1500/2000/2500 ECU Pin
LEAD 1
Ignition Output #1
Yellow/Black
3
A3
LEAD 2
Ignition Output #2
Yellow/Red
4
A4
TRAIL 1
Ignition Output #3
Yellow/Orange
5
A5
TRAIL 2
Ignition Output #4
Yellow/Green
6
A6
Function
Haltech Output
Haltech Wiring Colour
Elite 550/750 ECU Pin
Elite 1000/1500/2000/2500 ECU Pin
LEAD 1
Ignition Output #1
3
A3
LEAD 2
Ignition Output #2
Yellow/Red
4
A4
TRAIL 1
Ignition Output #3
Yellow/Orange
5
A5
TRAIL 2
Ignition Output #4
Yellow/Green
6
A6
2-Rotor Waste Spark (10A / 12A / 13B)
Function
Haltech Output
Haltech Wiring Colour
Elite 550/750 ECU Pin
Elite 1000/1500/2000/2500 ECU Pin
LEAD
Ignition Output #1
Yellow/Black
3
A3
TRAIL 1
Ignition Output #3
Yellow/Orange
5
A5
TRAIL 2
Ignition Output #4
Yellow/Green
6
A6
3-Rotor Direct Fire (20B)
| Function | Haltech Output | Haltech Wiring Colour | Elite 2000/2500 ECU Pin |
| LEAD 1 | Ignition Output #1 | Yellow/Black | A3 |
| LEAD 2 | Ignition Output #2 | Yellow/Red | A4 |
| LEAD 3 | Ignition Output #3 | Yellow/Orange | A5 |
| TRAIL 1 | Ignition Output #4 | Yellow/Green | A6 |
| TRAIL 2 | Ignition Output #5 | Yellow/Brown | A7 |
| TRAIL 3 | Ignition Output #6 | Yellow/Blue | A8 |
4-Rotor Direct Fire (26B)
Function
Haltech Output
Haltech Wiring Colour
Elite 2000/2500 ECU Pin
LEAD 1
Ignition Output #1
Yellow/Black
A3
LEAD 2
Ignition Output #2
Yellow/Red
A4
LEAD 3
Ignition Output #3
Yellow/Orange
A5
LEAD 4
Ignition Output #4
Yellow/Green
A6
TRAIL 1
Ignition Output #5
Yellow/Brown
A7
TRAIL 2
Ignition Output #6
Yellow/Blue
A8
TRAIL 3
Ignition Output #7
Yellow/Violet
B17
TRAIL 4
Ignition Output #8
Yellow/Grey
B18
Function
Haltech Output
Haltech Wiring Colour
Elite 2000/2500 ECU Pin
LEAD 1
Ignition Output #1
Yellow/Black
A3
LEAD 2
Ignition Output #2
Yellow/Red
A4
LEAD 3
Ignition Output #3
Yellow/Orange
A5
LEAD 4
Ignition Output #4
Yellow/Green
A6
TRAIL 1
Ignition Output #5
Yellow/Brown
A7
TRAIL 2
Ignition Output #6
Yellow/Blue
A8
TRAIL 3
Ignition Output #7
Yellow/Violet
B17
TRAIL 4
Ignition Output #8
Yellow/Grey
B18
OEM Ignition Coils
FC3S Ignition Coils
The FC3S Lead coil assembly includes a dual-post coil for the Lead spark with an attached single channel igniter module that fires in Waste Spark. The Trail coil assembly includes 2x single output coils attached to a unique igniter module. Both igniters ground through the body of the module so they must be connected to chassis ground. The Trail igniter has what is known as a "Toggle" system. There is one timed input from the ECU to the igniter, and a second signal that is sent by the ECU to determine which coil is to be fired. This ignition system was supported on all Haltech ECU models up until the Elite Series. The Elite Series will NOT work with the Trail igniter.
The Ignition Mode must be set to DISTRIBUTOR and NOT Waste Spark for these coils. Constant Charge with a Falling edge and 5.0ms dwell.
Lead Coil (NOT FOR ELITE. Wiring for Sport Series or older)
Trail Coils (NOT FOR ELITE. Wiring for Sport Series or older)
Dwell
Wire Colour | Description | Haltech Connection |
Tan | 12V+ Swtiched | --- |
Pink | ECU Signal | Ignition Output 1 |
Trail Coils (NOT FOR ELITE. Wiring for Sport Series or older)
Wire Colour | Description | Haltech Connection |
Tan | 12V+ Swtiched | --- |
Pink | ECU Signal | Ignition Output 2 |
White | Toggle Signal | Ignition Output 3 |
Yellow | Tacho Output | --- |
Grey | No Connection | --- |
Dwell
FD3S Ignition Coils
The FD3S changed to Waste Spark ignition with the ignition coils mounted under the intake manifold and the 3x channel igniter module mounted on the inner guard. The Lead coil is a dual-post fired in Waste Spark, and the Trail has 2x separate coils. They should be configured as Waste Spark with a Contant Charge and Falling edge output.
| Pin and Wire Colour | Description | Haltech Connection |
1 - No Connection | --- | --- |
2 - Light Green/Black | Coil- Lead | --- |
3 - Light Green | ECU Signal Lead | Ignition Output 1 (Yellow/Black) |
4 - Light Green/White | Coil- Trail 2 | --- |
5 - Black/White | 12V+ Switched | --- |
6 - Brown/Black | ECU Signal Trail 2 | Ignition Output 4 (Yellow/Green) |
7 - Light Green/Red | Coil- Trail 1 | --- |
8 - Brown | ECU Signal Trail 1 | Ignition Output 3 (Yellow/Orange) |
Dwell
RX8 Ignition Coils
The 13B-MSP engine has 4x ignition coils and uses Direct Fire ignition. They have an internal igniter module and as such can be wired directly to the Haltech ECU. They use Direct Fire mode and Constant Charge with a Falling edge.
Pin | Function | Haltech Connection |
| A | Signal | Ignition Output |
| B | Ground to Rotor Housing | --- |
| C | 12V+ | --- |
Dwell
Injection System
Injector Wiring
2-Rotor (10A / 12A / 13B / RX8 13B Auto Trans)
| Function | Haltech Output | Haltech Wiring Colour | Elite 2000/2500 ECU Pin |
| Primary 1 | Injector Output#1 | Blue | A19 |
| Primary 2 | Injector Output#2 | Blue/Black | A20 |
| Secondary 1 | Injector Output#3 | Blue/Brown | A21 |
| Secondary 2 | Injector Output#4 | Blue/Red | A22 |
2-Rotor (*RX8 13B-MSP Manual Transmission)
| Function | Haltech Output | Haltech Wiring Colour | Elite 2000/2500 ECU Pin |
| Primary 1 Front Rotor | Injector Output#1 (Stage 1) | Blue | A19 |
| Primary 1 Rear Rotor | Injector Output#2 (Stage 1) | Blue/Black | A20 |
| Primary 2 Front Rotor | Injector Output#3 (Stage 2) | Blue/Brown | A21 |
| Primary 2 Rear Rotor | Injector Output#4 (Stage 2) | Blue/Red | A22 |
| Secondary Front Rotor | Injector Output#5 (Stage 3) | Blue/Orange | A27 |
| Secondary Rear Rotor | Injector Output#6 (Stage 3) | Blue/Yellow | A28 |
* These engines have a total of 6x injectors i.e. 3x injector per rotor using 3x stages. The OEM (Mazda) calls first stage Primary 1, the second stage as Primary 2, and the third stage as Secondary.
3-Rotor (20B)
| Function | Haltech Output | Haltech Wiring Colour | Elite 2000/2500 ECU Pin |
| Primary 1 | Injector Output#1 | Blue | A19 |
| Primary 2 | Injector Output#2 | Blue/Black | A20 |
| Primary 3 | Injector Output#3 | Blue/Brown | A21 |
| Secondary 1 | Injector Output#4 | Blue/Red | A22 |
| Secondary 2 | Injector Output#5 | Blue/Orange | A27 |
| Secondary 3 | Injector Output#6 | Blue/Yellow | A28 |
4-Rotor (26B)
Function
Haltech Output
Haltech Wiring Colour
Elite 2000/2500 ECU Pin
Primary 1
Injector Output#1
Blue
A19
Primary 2
Injector Output#2
Blue/Black
A20
Primary 3
Injector Output#3
Blue/Brown
A21
Primary 4
Injector Output#4
Blue/Red
A22
Secondary 1
Injector Output#5
Blue/Orange
A27
Secondary 2
Injector Output#6
Blue/Yellow
A28
Secondary 3
Injector Output#7
Blue/Green
B29
Secondary 4
Injector Output#8
Blue/Violet
B30
Function
Haltech Output
Haltech Wiring Colour
Elite 2000/2500 ECU Pin
Primary 1
Injector Output#1
Blue
A19
Primary 2
Injector Output#2
Blue/Black
A20
Primary 3
Injector Output#3
Blue/Brown
A21
Primary 4
Injector Output#4
Blue/Red
A22
Secondary 1
Injector Output#5
Blue/Orange
A27
Secondary 2
Injector Output#6
Blue/Yellow
A28
Secondary 3
Injector Output#7
Blue/Green
B29
Secondary 4
Injector Output#8
Blue/Violet
B30
OEM Injector Flow Rates
ENGINE | Primary | Secondary | Tertiary |
|---|---|---|---|
| 12A Turbo SA22C Savanna (RX7 Series 3 JDM - 1st Gen) | 800cc | - | - |
| 13B-RE EGI 6-Port Non Turbo FB (RX7 Series 3 USDM - 1st Gen) | 720cc | - | - |
| 13B-RE DEI 6-Port Non Turbo FC3S (RX7 Series 4 and 5 - 2nd Gen) | 430cc | 430cc | - |
| 13B-RE Turbo FC3S (RX7 Series 4 and 5 - 2nd Gen) | 550cc | 550cc | - |
| 13B-RE Turbo JC (Cosmo) | 550cc | 550cc | - |
| 13B-RE Turbo FD3S (RX7 Series 6,7 and 8 - 3rd Gen) | 550cc | 850cc | - |
| 13B-MSP RX8 Manual Transmission | 290cc | 380cc | 380cc |
| 13B-MSP RX8 Automatic Transmission | 290cc | 480cc | - |
| 20B-REW JC (Cosmo) | 550cc | 550cc | - |
Throttle Position Sensor
Series 4
The Series 4 TPS can be identified by there being only a single sensor.
OEM Diagram | OEM ECU Pin and Wiring Loom Information | Direct Sensor Wiring Information |
|---|---|---|
2A = 5 Volt (Brown/White) 2C = Ground (Brown/Black) Some are plain Black 2G = Signal (Green) Some are Green/Red | Orange = 5V+ Black/Red = Ground Green/Red = Signal |
Note: Series 4 TPS do not operate over the full range of throttle movement. They read 100% by around 30% actual throttle opening and are as such not suitable for accurate Haltech ECU tuning. It is advised to change to the Series 5 throttle body or sensor arrangement.
Series 5
The Series 5 TPS can be identified be there being two position sensors. One is a full range sensor and one is the same as the Series 4 sensor. The full range sensor was added for engines having an electronic oil metering system.
OEM Diagram | OEM ECU Pin and Wiring Loom Information | Direct Sensor Wiring Information |
|---|---|---|
2i = 5V (Brown/White) 3D = Ground (Brown/Black) 2F = Short Range TPS (Green/Red) 2G = Full Range TPS (Black/Green) | Sensor 1 Red = 5V+ Blue = Ground Yellow = Full Range Signal Sensor 2 Orange = 5V+ Black/Red = Ground Green/Red = Short Range Signal |
Only the full range sensor should be wired to your Haltech ECU.
Series 6,7,8
OEM Diagram | OEM ECU Pin and Wiring Information | TPS Direct Connection |
|---|---|---|
3f = TPS Signal (Green/Red) 3g = Idle Switch (Black/Green) NOT USED 3i = 5V+ (Brown/White) 4d = Signal Ground (Brown/Black) | Orange = 5V+ White = Signal |
Cosmo 13B and 20B
Please excuse the hand drawn old diagram. Finding info on these vehicles is near impossible.
MAP Sensor
Series 4,5
It is recommended to use the internal Haltech MAP sensor for these vehicles.
Series 6,7,8
It is recommended to use the internal Haltech MAP sensor however the OEM unit can be used if preferred.
OEM Diagram | OEM ECU Pin and Wiring Information |
|---|---|
1o = MAP Signal (Grey/Yellow) 3i = 5V+ (Brown/White) 4d = Signal Ground (Black/LightGreen) |
OEM Oil Metering Pump
Old diagram but will be updated shortly
PDF
Related Articles
Rotor Phasing Secrets
Even though modern engines don’t rely on distributors anymore, there are still plenty of race and historic engines that do. What is a distributor? Before individual coil on plug ignition systems, engines used to have a single coil and a mechanically ...10 Things You Need To Know About Rotary Tuning
Are you a piston guy or a rotor guy? If the former applies to you then you might find this article irrelevant and rather boring. However, if you identify with the latter then this might well be the most important article you’ll ever read. Right from ...Distributor Rotor Phasing
This article is about why we need to check the rotor phasing, and how to set the mechanical location of the rotor button inside the distributor when EFI is being used. For training purposes Elite ECU terminology has been used but the same process ...Honda / Acura B Series Engine
The B-Series engine was offered in Integras, Civics, Preludes, Accords, CRXs, Del Sols and CRVs. This engine had 28 different engine codes. The letter B is normally followed by two numbers to designate the displacement of the engine, another letter, ...Ignition Tuning
Ignition Tuning Ignition Angle Lock Mode Allows the ignition advance to be fixed at a determined value to allow calibration of the TDC Offset. All ignition tables and corrections are ignored when this is active, and the ignition advance will not ...