molecular bob

I am looking at what i would need from an ECU to control a stock 6 port RX8 engine transplanted into a Caterham 7. I want to retain the stock lower manifold and if there is enough space the upper manifold as well. I would be replacing the flybywire throttle with a fabricated manual body.

My first (of many)questions are:

1. How are the intake valves controlled? Are they simple switches or do they require PWM.

2. How is the oil metering controlled?

3. How is the air pump controlled?

Is there anything else on this engine that needs ECU control such as the thermostat?

I'm really just trying to figure out how many PWM channels and switched outputs i will need.

vansickey

SDAIS
I was just flipping through some Mazda docs...
SSV solenoid valve

• Turns on at the same time as the injection timing of the secondary injector. Due to this, the intake manifold vacuum is fed to the SSV actuator allowing intake air from secondary port which is opened by the SSV valve.

VFAD solenoid valve (13B-MSP (High Power))

• At an engine speed of less than 5,500 rpm, the VFAD solenoid valve turns off and feeds intake manifold vacuum to the actuator (valve closes).

• At an engine speed of approx. 5,500 rpm or more, the VFAD solenoid valve turns on and feeds BARO to the actuator (valve opens).


APV motor (13B-MSP (High Power))

• When the following conditions are met, a duty signal is sent to the APV motor, the APV gradually opens. If an APV-open condition is not met, a minus duty signal is sent to the APV motor, reversing the motor and closing the APV.

APV-open condition
– Engine speed: Approx. 6,250 rpm or more
– ECT: Approx. 20°C {68°F} or more
• The APV motor has a built-in APV position sensor that monitors the APV position.

• When the opening conditions are not met, the APV sends a reverse duty signal while the APV opens.

VDI solenoid valve

• At a VDI valve operation engine speed or more, the VDI solenoid valve turns on and feeds intake manifold vacuum to the actuator (valve opens).

The OMP

Outline
• Controls the amount of plunger stroke which determines the amount of oil delivery through the stepping motor according to the engine operation conditions.

• The plunger opens and closes by the stepping motor in the metering oil pump.

• The PCM determines the target step number of the stepping motor from input signals for engine speed, charging efficiency and ECT, and sends an operation signal to the stepping motor. For the construction and operation of the metering oil pump, refer to metering oil pump construction/operation.


Regular Drive Function
• The PCM always calculates the optimum target step number according to the engine operation conditions, and controls the stepping motor step number so that it is close to the actual step number in reference to the target.

oh, and the thermostat is mechanical, but the cooling fans are relayed through some logic, low speed, and high speed operation depending on demand and temperature.


Hope that answers a couple of questions.

dannobre

iTrader: (3)

The only thing that is difficult to control is the APV.

The valves that are vac solenoid controlled are easy to do. ( VDI, SSV, VFAD)

The APV needs a +/- voltage signal with control logic. The Motec can do it..and the Bosch..most others can't.

OMP is relatively easy as well. Don't need the air pump?..

I am in the finishing stages of installing a Haltech E8.....it has more than enough in/out to run everything...and I have a turbo application so the APV has been blocked open full time

molecular bob

Thanks for the replies, clears up a lot of things. Do any of the ECU suppliers have a ready to go solution for a stock engine? The on off valves don't look like a problem, but getting PWM and feed back controls right could take an age.

Would really like to go ITB, but i haven't seen anyone offering anything that could be used.

zoom44

Star Mazda cars use Motec M800. It can control drive by wire throttles and even handles traction control