Saturday, November 28, 2009

MaxPowerCMD

Since my old Caponord need some "power injection" and that in any case the Traction Control need engine power adaptation, I thought is time to design my own Power Cmd.

The basic idea is to build up an electronic system to be connected at ECU inputs (trottle position, engine RPM, engine speed, ...) and outputs (injector driving signals, ...) so to change the injections maps during engine operation.

To clarify my initial ideas, I draw this:


So, let's try to explayin (and clarify myself also):
- on the left there is the original Motorbyke ECU, one Injector channel is drawn only. The Aprilia Caponord ECU drives the 4 Injectors exactly in such way: each Injector is connectd to +12V and the low side is switched by ECU (most likely using a power N-MOS), this is what I found from original Aprilia manual:


- between the fuel Injector (drawn on top right) a "fake injector" is inserted: this is needed to scope the Injector signal and to make sure that the ECU sense something and believes that Injector is still connected and working as expected:


- some logic gates must be inserted so to be able to replicate the original ECU signal as it is or to modify it:


- the last blocks is the MaxPowerCMD CPU itself, so the XE164:
.

How it works?
The basic idea is the following:
1- MaxPowerCMD has to sense the time when the motorbyke ECU would like to start an Injection sequence
2- MaxPowerCMD has to sense the Injector ON time at every revolution
==> with all information from 1 and 2, MaxPowerCMD would be able to reproduce the same Injection pulse as the motorbyke ECU would do
3- MaxPowerCMD has to measure the engine RPM
4- MaxPowerCMD has to measure the trottle position
==> with all information from 3 and 4, MaxPowerCMD would be able to access to a new Injection MAP as:

(rows: trottle position; columns: engine RPM speed)

==> the Injection MAP will have to be designed in % way, so 100% would indicate that the MaxPowerCMD will not change the motorbyke Injector pulse width. 50% would indicate a 50% shorter pulse and 150% an 1+1/2 pulse lenght. From this last requirement is now easy to understand why I have designed the logic gate block
to èermit to create an output signal that is shorter or longer then the ECU's imposed. The logic gate implementation also simplify the need to sincronize the MaxPowerCMD with the ECU signals since the MaxPowerCMD will simply impose the BYPASS mode just before any new injection sequence.
Before proceeding with the MaxPowerCMD I think is better to acquire more information about the Aprilia Caponord electronic injection system.



Injectors Test:
Aprilia indicated that a working Injector should have a resistence of about: 11,5 - 13 Ω at 20 °C (68 °F):

1 comment:

Unknown said...

Good day I have a 2006 aprillia rsv factory 1000 mille I get fuel to my injectors but not spraying I then tested my injectors it works fine I then checked a power there is power but when tested for a earth on the injector wires non found I then gave it a direct earth from the frame then my injectors started spraying..... Iv ran a dainostic test it shows open cercuit could that be my loom(wiring harness) as my ecu is perfect iv tested it in two other aprillias please assist