Arduino as ECU?
#423
In my opinion, the best setup is something like a 36-1 wheel on the crank and a single cam pulse. That gives you everything fast sync for starting, full sequential and good timing accuracy. It is a pain to get a 36-1 wheel onto the crank on these engines though, so I haven't seen a lot of MX5s/Miatas go that route (It's a VERY common setup on other vehicles though and very well tested with Speeduino).
It does for fuel (The California models run sequential as standard) and these boards have the drivers there already for it. You just need to cut 2 traces, which are designed for this.
Ignition is trickier though as there wasn't ever a version of these that had 4 drivers from the factory. These PNP Speeduino boards only have 2 ignition drivers on them, so they're limited to wasted spark, which is what the car is wired for. The generic v0.4 Speeduinos have 4 ignition outputs, but aren't as straightforward to wire in as the PNPs.
It does for fuel (The California models run sequential as standard) and these boards have the drivers there already for it. You just need to cut 2 traces, which are designed for this.
Ignition is trickier though as there wasn't ever a version of these that had 4 drivers from the factory. These PNP Speeduino boards only have 2 ignition drivers on them, so they're limited to wasted spark, which is what the car is wired for. The generic v0.4 Speeduinos have 4 ignition outputs, but aren't as straightforward to wire in as the PNPs.
#426
Alternatively, will I be able to just run a wasted spark coil on/near plug setup? Is that a thing?
#427
This is the real question
Some people like to keep it there initially when they do the switchover, just incase they need to go back to the stock ECU. In those cases I generally recommend disconnecting it so that the fuel pump control and things don't interfere with the control from the ECU etc. It's not mandatory, but it's how I suggest people run it whilst it's still there.
Some people like to keep it there initially when they do the switchover, just incase they need to go back to the stock ECU. In those cases I generally recommend disconnecting it so that the fuel pump control and things don't interfere with the control from the ECU etc. It's not mandatory, but it's how I suggest people run it whilst it's still there.
#430
Yeah you can certainly go that path. I ran mine like this for quite a while and made an adapter board for the v0.4 to interface with the 48 pin connector.
It's definitely a thing. Practically every COP/CNP conversion I've ever seen on these cars has still been wasted spark. Unless you're running crazy high rpm (Think 10k+) or using coils with extremely long dwell time requirements, then there's no real reason you need to run sequential ignition.
It's definitely a thing. Practically every COP/CNP conversion I've ever seen on these cars has still been wasted spark. Unless you're running crazy high rpm (Think 10k+) or using coils with extremely long dwell time requirements, then there's no real reason you need to run sequential ignition.
#432
Small update on things.
The initial PNP units have all seemed to be pretty successful. Most people who have them seem to be up and running and I haven't heard any major issues back
A small design revision (v1.1) has been finalised now and is going out for manufacture within the next 1-2 weeks. This mostly addresses some compatibility issues with various later year / Euro spec models and things like A/C. There are no feature differences for those with working setups now (Apart from possibly the A/C), just further compatibility.
The list of changes for these are:
The initial PNP units have all seemed to be pretty successful. Most people who have them seem to be up and running and I haven't heard any major issues back
A small design revision (v1.1) has been finalised now and is going out for manufacture within the next 1-2 weeks. This mostly addresses some compatibility issues with various later year / Euro spec models and things like A/C. There are no feature differences for those with working setups now (Apart from possibly the A/C), just further compatibility.
The list of changes for these are:
- The Cam signal is now duplicated onto pin 2F. Some of the later Euro spec model used this pin rather than 2G for this signal
- Tacho output added on pin 2I for the later model years. This is also useful if you replace the stock coils with COPs and the tacho stops.
- A diode has been added onto the idle output to quieten up the idle valve a little. No change in functionality, but improves the signal a little.
- Pins 2O and 2T are now joined for fuel pump control on the '94 and '95 1.8 models
- Pins 1Q and 1J are joined to enable the A/C. This was missed on the original units as none of the test cars had A/C :(
#433
Small update on things.
The initial PNP units have all seemed to be pretty successful. Most people who have them seem to be up and running and I haven't heard any major issues back
A small design revision (v1.1) has been finalised now and is going out for manufacture within the next 1-2 weeks. This mostly addresses some compatibility issues with various later year / Euro spec models and things like A/C. There are no feature differences for those with working setups now (Apart from possibly the A/C), just further compatibility.
The list of changes for these are:
The initial PNP units have all seemed to be pretty successful. Most people who have them seem to be up and running and I haven't heard any major issues back
A small design revision (v1.1) has been finalised now and is going out for manufacture within the next 1-2 weeks. This mostly addresses some compatibility issues with various later year / Euro spec models and things like A/C. There are no feature differences for those with working setups now (Apart from possibly the A/C), just further compatibility.
The list of changes for these are:
- The Cam signal is now duplicated onto pin 2F. Some of the later Euro spec model used this pin rather than 2G for this signal
- Tacho output added on pin 2I for the later model years. This is also useful if you replace the stock coils with COPs and the tacho stops.
- A diode has been added onto the idle output to quieten up the idle valve a little. No change in functionality, but improves the signal a little.
- Pins 2O and 2T are now joined for fuel pump control on the '94 and '95 1.8 models
- Pins 1Q and 1J are joined to enable the A/C. This was missed on the original units as none of the test cars had A/C :(
#438
They're not far away, I promise!
The order size for these is growing with each batch, but the factory has completed the first test unit of this run, which usually means the full run isn't far behind. Hopefully just a few weeks before they're back in the store.
In terms of volume, there's somewhere around 120 of these PNP units out there already, which simply blows my mind, so a big thanks to all those who have shown interest in the project!
The order size for these is growing with each batch, but the factory has completed the first test unit of this run, which usually means the full run isn't far behind. Hopefully just a few weeks before they're back in the store.
In terms of volume, there's somewhere around 120 of these PNP units out there already, which simply blows my mind, so a big thanks to all those who have shown interest in the project!
#440
There's open loop VVT there already, but closed loop on the 99+ trigger should certainly be possible though and is part of a larger piece of work.
Step 1 is in incorporating cam angles (as opposed to just crank angles) and there is some early code for this already, but it's definitely a WIP
Step 1 is in incorporating cam angles (as opposed to just crank angles) and there is some early code for this already, but it's definitely a WIP