Freedom computer control

All the Freedom controls purchased from Maruha are being administrated by a serial number. We respond to any questions and it is possible to consult us if you have any troubles.
However, we cannot respond to questions concerning Freedom controls that were not purchased through Maruha.

Dr. M’s report Vol.1

This time I’d like to talk about ignition timing, especially about the carburetor’s ignition control.
First of all, the reason for setting ignition timing at the BTCD is that the combustion takes time and we expect the best position for the explosion energy at around 10 degrees of ATDC.
I will talk about this later, now just let me say that the combustion time differs accordingly to the engine spec and the driving conditions.
If setting ignition timing with computer control, we have to keep in mind 4 main points.

  1. water temperature sensor
    E/G cranking time, idling time, lag correction etc.
  2. sensor
    switching between idling control and map control
  3. airflow meter
    intake air amount / air mass
  4. engine rpm

If the airflow meter has been removed from the carburetor, in the case of B6 the intake amount and in the case of BP the mass information don’t get into the computer, that’s why we cannot control them properly. By adjusting the crank sensor we can decide the proper position however, we have to note that it is just a compromised adjusting without computer control. If we remove the airflow meter from BP it cannot be backed up by the computer and there is no advance.
At Maruha, for the carburetor we set up an ignition control computer (ROM) at the engine rpm. This has brought a very good result.
The engine’s maximum power doesn’t change much. However, especially at medium speed both the torque and horsepower become clearly better.
This time we used BP engine with FCR carburetor and we set up a throttle position sensor and tried a 3D control by throttle opening and engine rpm. First of all let’s take a look at the graph below.

Red line: control by genuine ECU

Green line: Adding throttle position sensor to the FCR and control by Freedom ECU
The BP engine: processing of the port and the combustion chamber; level up of the compression ratio thanks to the head grinding; Maruha’s 246 camshaft normal skid base; universal head tuning.
It is a test performed with air cleaner, for this reason we can see some loss in the power, but the 170ps test ride impression is fast.
We can predict that in the case of BP this kind of head machining and carburetor with a 4-throttle injection is going to become the main stream.
In the case of a carburetor used together with a fully computer controlled 3D the ignition can be controlled better.
One of it is the control of idle time. The idle time advances when A/C is being used however, it doesn’t reach better idling. As we can see on the graph, the main points are better power and response from low speed to middle speed.
On high locations and the corners of mini circuits the torque right after slowing down and then starting again is better at 40 degrees of ignition timing rather than on 30. However, don’t think that it’s enough to set higher ignition timing. Sometimes even lag is necessary.
You have to be especially careful in the case of a tuned engine. Only with 3 degrees the air-fuel ratio changes.

About Freedom ECU

We use with our 4-injection throttle system the Freedom computer of the company E&E. It is an excellent system.

  1. 16bit full computer system
  2. the coupler is connected (there is no need of wire processing)
  3. both throttle style and vacuum style control is possible
  4. there is a model designed for Miata/MX-5
  5. it is cheap

These are the main points.
As a company, our most important aim was a low price.
Other universal full computer controls are expensive and even if one is interested in them, one cannot afford to buy them.
And even the wiring is very difficult and quite poor.
After all these reasons you can see that it’s a good idea to use our Freedom control.
If you program it efficiently, you can get the expected results.
It has been backed up by E&E System, that’s why our customers can get the latest informations and advices. To users who are programming by themselves, we can offer data that can help with the backup.

D-Jetro change

You can change to D-Jetro by using Freedom ECU.
In other words, it is a vacuum control, but except the 4-throttle injection system, it is possible to get a system without airflow meter, too.
The big throttle and the funnel can be controlled by this system.

Control of the throttle position

It is possible to control the throttle position.
In contrast to the vacuum control the accelerator throttle’s movement responds linearly, that’s why the operability of acceleration and deceleration is good, however, on the other hand idling control becomes difficult.
Even in the case of conversion if we set up a throttle position sensor at the carburetor, an effective 3D control becomes possible.
3D is a control, that’s base lies in the combination of ignition timing, engine revolution and throttle opening control.
It is possible to use it also for the 16 bit NA8C (Sr.2) Miata/MX-5 through a variable coupler.
The basis is the D-Jetro change, for this reason it is not an easy setup, however in the case of tuning it is a very convenient ECU.
NA8C is a hot wire type and there is no flap unlike in the case of NA6CE.


Maruha Motors Co., Ltd.
Ushizuma 2095-6, Aoi-Ward
421- 2106 Shizuoka city, Shizuoka prefecture
TEL: 0081-54-294-0076
FAX: 0081-54-294-1312