ProECU Tuning Guide
Introduction
The Skyactive engine platform found in the ND MX-5 vehicles is a particularly complex system. Throughout our development we’ve made an effort to balance our efforts in simplifying the tuning system, as well as offering RaceROM features in the limited free space available to us in the ROM. This means our RaceROM offerings are slightly different than in other platforms as there are either simplified forms being used, or something altogether unique.
With a framework for the platform in place, we’ll be working with our dealers in order to balance the features for this platform, with the practical limits of the ECU.
The Platform
The Mazda Mx-5 SkyactivG cars use a high compression (14.0:1) 1.8L or 2.0L 4 cylinder engine utilising direct injection with a high degree of freedom of cam timing on both inlet and exhaust cams. This allows the engine to use many complex strategies to deliver high power and high efficiency for such a small capacity. The control system components are as below.
Mazda have employed ion sensing technology to model per cylinder detonation, pre ignition and air fuel ratio and uses these in many of the airflow and ignition timing strategies to preserve reliability while maintaining a high as possible performance and low emissions.
Ion sensing involves measuring the electrical current flow after the spark initially bridges the gap between the center electrode of the sparkplug and the ground strap. In the event of a misfire, no current flow can be easily detected, making it a fairly stable and accurate method of measuring misfires.
Supplemental Content
Platform Specific
General
Table of Contents
The 4-2-1 type exhaust pipes have been adopted for the exhaust manifold to create an engine with a high compression ratio.
Two types of load and airflow estimation have been adopted for the intake air amount measurement to achieve stable combustion free from abnormal combustion.
- L-jetronic (The intake air amount is directly detected by measuring the amount of intake air flow using the MAF sensor.) MAF sensor adopted
- D-jetronic (The intake air amount is detected indirectly by measuring the intake manifold pressure (pressure between downstream of the throttle valve and intake manifold) using the MAP sensor.) MAP sensor adopted
- IAT sensor No.1 and No.2 adopted
To improve the fuel economy and emission performance, an electric variable valve timing control has been adopted for the intake side, and a hydraulic variable valve timing control for the exhaust side. The electric type is adopted for the intake side to achieve expanded valve overlap and delayed closing of the intake valve (enlarged intake valve opening angle). The Hydraulic Lash Adjuster (HLA) has been adopted to achieve the maintenance-free valve clearance.
- Intake side: Electric variable valve timing control with independent CMP sensor
- Electric variable valve timing motor/driver
- Electric variable valve timing relay
- Exhaust side: Hydraulic variable valve timing control with independent CMP sensor
Engine hydraulic pressure switching control (using Engine oil solenoid valve) has been adopted to reduce the oil pump operation load on the engine.
To improve engine reliability, an ion sensor has been adopted which detects pre-ignition.
Some other features Mazda have listed as advances with their SkyActiv technology are.
Sliding resistance reduction
- Rocker arm (with built-in needle roller bearing) adopted for cam-contact area
- Reduced valve spring load
- Narrowed down crankshaft journal
- Optimized piston skirt shape
- Lowered piston ring tension
- Lowered drive belt tension
- Suppressed chain tensioner load by stabilized timing chain behaviour
- Oil shower pipe adopted
Mechanical resistance loss reduction
- Optimized oil passage
- Optimized oil pump shape
- Engine oil control adopted
Cooling loss reduction in early stage of combustion
- Piston cavity adopted
Pumping loss reduction
- Variable valve timing mechanism adopted on both intake and exhaust sides for fine control of exhaust amount and internal EGR volume
Cooling efficiency improvement
- Air seal cowl and flaps adopted
- Optimized cooling fan shape
- Optimized engine coolant passage
- Optimized water pump impeller shape
Combustion efficiency improvement
- Multiple hole-type fuel injectors
- High-pressure fuel pump
Accelerator
Map List
Live Data Parameters
Boost Control
Map List
Live Data Parameters
Camshaft Timing
Mazda utilise an electronic Intake Cam VVT actuator to allow quick and precise wide range of movement. With a maximum overlap from intake open to exhaust close is 92° allowing for huge amounts of blow through if not correctly calibrated. In addition to using the cam timing for EGR duties, it allows the system to enact the “Mazda Miller Cycle at low loads. This cycle allows the intake valve to stay open beyond the bottom of the travel and into the compression stroke causing a slight amount of the air fuel mixture to go back into the intake manifold during the initial ~20% of the piston’s compression stroke. The benefit being a slight reduction of the effective compression ratio. They also utilise a hydraulic exhaust cam VVT actuator to allow for maximised. The basic outline of the cams and how it related to crank angle and injection period is shown below.
They allow a wide range of movement (roughly 74deg), where the target position in the map is the advance or retard from the base stop position. The VVT has different target modes, for idle, cold start and normal operating temperature and the switch point between the modes is not known yet.
| Item | Specification | |||
|---|---|---|---|---|
| Valve Timing | IN | Open | (°) | BTDC 420ATDC 32 |
| Close | (°) | ABDC 36-ABDC 110 | ||
| EX | Open | (°) | BBDC 56-BBDC 11 | |
| Close | (°) | ATDC 5-ATDC 50 | ||
Map List
Live Data Parameters
- VVT Intake Actual - Actual intake variable valve timing control - Advance amount from max retard position °(deg)
- VVT Intake Desired - Target intake variable valve timing control - Advance amount from max retard position °(deg)
- VVT Exhaust Desired - Target exhaust variable valve timing control - Retard amount from max advance position °(deg)
- VVT Exhaust Actual - Actual exhaust variable valve timing control - Retard amount from max advance position °(deg)
Cam Timing Exhaust #1 & 2 (hot/cold)
These are standard maps that set a desired exhaust cam angle for different speeds and loads. The output values are the amount of retard from the base position (most advanced angle 56deg BBDC). Maps one and two are believed to be high and low temperature, testing can be done on the dyno to see which one is used when.
It is believed that the large amount retard used at low loads on the exhaust cam is used to promote Exhaust gas recirculation through the manifold. When back pressure is significantly different due to higher airflow or exhaust blockages (like turbocharger turbines) significant changes may be required to these maps. Especially as the load values with force induction will be exceeded even at low pedal % and engine speeds.
In the EcuTek Turbo charged Forced Induction example ROM the load axis was rescaled to allow it to compensate for the higher cylinder fill appropriately and more retard was used at higher RPM and loads to try get more out of the power stroke. The tuned profile looks like Below, testing should be done to confirm that the vehicle you are tuning responds in the same way.
Cam Timing Intake - Hot / Cold
These maps set the target intake cam angle. Mazda have calibrated them to match the exhaust cam mapping and create the Mazda Miller Cycle
When forced induction is involved the profile of these maps will need to be altered significantly as the available airflow characteristics are vastly different. Tuning these maps for forced induction requires load axis changes and significant modification to the higher RPM and load cells, deceasing intake advance at lower RPM high loads and increasing the advance at high RPM high and low loads.
Fuelling
Map List
Live Data Parameters
Idle
Map List
Live Data Parameters
Ignition
map list
Live Data Parameters
Limiters
map list
Live Data Parameters
Load
map list
Live Data Parameters
Sensor Scaling
map list
Live Data Parameters
Torque
map list
Live Data Parameters
Misc.
map list
Live Data Parameters
EcuTek ProECU tuning tools tools should only be used by experienced tuners who understand the product and engine calibration.
If you do not fully understand this product then you WILL damage your engine, ECU or your vehicle.
Please ensure you fully read all EcuTek manuals BEFORE attempting to use ProECU with your laptop or your vehicle.
Use with extreme caution and understanding at all times, if in doubt then do not proceed.
EcuTek accepts no responsibility for any damage to the engine, ECU or any part of the vehicle that results directly or indirectly from using the product.
** If you are in any doubt that you do NOT have the experienced required to use this product then you should NOT USE IT **
Retail customers
** If you have any doubt that you do NOT have the experienced required to use this product then you should NOT USE IT, you should simply contact your EcuTek Master Tuner shown clearly on the top of your Programming Kit or visit your preferred tuning shop to have a professional tuner to use it for you **