Discussion
I'm finally looping around to working on the SEAC. The 350i is running superbly on Megasquirt so I'm going to go that route on the SEAC. It took alot of time, money and grief to get the 350i working properly but I'm now in a good position to put all the knowledge gained to good use.
I bought a 'turn-key' kit for the 350i and it was a struggle all the way. I'm starting from scratch with the SEAC and have bought an un-built Megasquirt ECU from DIYAutoTune in the US. That way I can build the ECU to my own specification and have some faith in the unit and what it's doing.
So now I have a megasquirt ECU kit; a megasquirt 'stim' (for testing the ECU); A megasquirt relay board to simplify the wiring and house the fuses; an innovate WB oxygen sensor kit; A Volvo PWM idle speed control valve; Ford EDIS 8 ignition box (replaces the distributor); wasted spark coils and leads from a lateish Range Rover; and a Rover V8 specific trigger wheel.
I'll also need to buy a load of connectors/wiring to build the loom; I've got some of that already, left over from the 350i. I still need to get some intake trunking, an air filter and an air temp sensor to replace the Flapper unit itself.
Time to get soldering and build the ECU...
I bought a 'turn-key' kit for the 350i and it was a struggle all the way. I'm starting from scratch with the SEAC and have bought an un-built Megasquirt ECU from DIYAutoTune in the US. That way I can build the ECU to my own specification and have some faith in the unit and what it's doing.
So now I have a megasquirt ECU kit; a megasquirt 'stim' (for testing the ECU); A megasquirt relay board to simplify the wiring and house the fuses; an innovate WB oxygen sensor kit; A Volvo PWM idle speed control valve; Ford EDIS 8 ignition box (replaces the distributor); wasted spark coils and leads from a lateish Range Rover; and a Rover V8 specific trigger wheel.
I'll also need to buy a load of connectors/wiring to build the loom; I've got some of that already, left over from the 350i. I still need to get some intake trunking, an air filter and an air temp sensor to replace the Flapper unit itself.
Time to get soldering and build the ECU...
..So having control of these can only be a good thing...
Getting going on the ECU now; got the power circuitry in place and checked.
The ECU is the blue board; the green board is a clever piece of kit that they get you to build first. The green board simulates the car; it sends signals to the ECU (engine speed, TPS, coolant temp, air temp and exhaust oxygen sensor) and then reads back the ECU outputs (ignition pulses, fuel injector pulses, fuel pump activation and idle control valve signal). You can twiddle the knobs to vary the inputs and see what happens to the outputs; plus you can monitor it all with the tuning software on a laptop so you can familiarise yourself with that aspect too.
I also have the very big advantage of being able to plug the ECU I'm building onto the 350i, so I can be sure it's all OK before attempting to run the SEAC with it.
The ECU is the blue board; the green board is a clever piece of kit that they get you to build first. The green board simulates the car; it sends signals to the ECU (engine speed, TPS, coolant temp, air temp and exhaust oxygen sensor) and then reads back the ECU outputs (ignition pulses, fuel injector pulses, fuel pump activation and idle control valve signal). You can twiddle the knobs to vary the inputs and see what happens to the outputs; plus you can monitor it all with the tuning software on a laptop so you can familiarise yourself with that aspect too.
I also have the very big advantage of being able to plug the ECU I'm building onto the 350i, so I can be sure it's all OK before attempting to run the SEAC with it.
Getting there... the ECU is now finished:
and tested on the bench:
The gaps on the circuit board are meant for circuits I don't need; like the crankshaft trigger wheel sensor circuits and the coil drivers (both of which I'm handling with the Ford EDIS system).
Next step is to plug this ECU into the 350i that's already running Megasquirt and see how it behaves. The 350i was running MS1 and this new one is MS2 so there are differences; I've already noticed how much better the online documentation is for the MS2 which should help setting up and tuning.
and tested on the bench:
The gaps on the circuit board are meant for circuits I don't need; like the crankshaft trigger wheel sensor circuits and the coil drivers (both of which I'm handling with the Ford EDIS system).
Next step is to plug this ECU into the 350i that's already running Megasquirt and see how it behaves. The 350i was running MS1 and this new one is MS2 so there are differences; I've already noticed how much better the online documentation is for the MS2 which should help setting up and tuning.
The yellow wires are needed to add a beefed up transistor to the idle control circuit.
The standard board will run a stepper motor or an on/off idle valve through a relay. The transistor that is connected to the yellow wires will allow me to run a PWM idle valve in closed loop control - so I should be able to hold a desired idle speed under all conditions.
The standard board will run a stepper motor or an on/off idle valve through a relay. The transistor that is connected to the yellow wires will allow me to run a PWM idle valve in closed loop control - so I should be able to hold a desired idle speed under all conditions.
I've been running the MS2 on the 350i for the last couple on months; it's superb, much better than the MS1 I was running before. So much so, that I've decided to bin the 350i MS1 and build another MS2 so I can have the 350i and the SEAC both running the same ECU and tuning software.
So now at long last I'm getting back onto the SEAC. The megasquirt unit needs an inlet air temperature sensor which I've decided to put in the location vacated by the now redundant cold start injector. I don't want to do anything that would change the car and stop me returning it to a flapper configuration if I need/decide to, so I searched for an air temperature sensor that would fit through the small diameter hole that the cold start injector goes through. It's a BMW sensor, and I chose to make an adaptor piece so that I don't have to drill/tap the original SEAC plenum:
I now have to work out the calibration of the sensor so that the Megasquirt can convert the sensor output resistance to a temperature value - cue shannanigans with ice, boiling water and somewhere in between to get a three point approximation to the logarithmic curve of the sensor...
To answer Chris' question, the MS2 will drive the hotwire stepper motor if so desired, but I'll be using a Volvo idle speed control valve made by Bosch.
So now at long last I'm getting back onto the SEAC. The megasquirt unit needs an inlet air temperature sensor which I've decided to put in the location vacated by the now redundant cold start injector. I don't want to do anything that would change the car and stop me returning it to a flapper configuration if I need/decide to, so I searched for an air temperature sensor that would fit through the small diameter hole that the cold start injector goes through. It's a BMW sensor, and I chose to make an adaptor piece so that I don't have to drill/tap the original SEAC plenum:
I now have to work out the calibration of the sensor so that the Megasquirt can convert the sensor output resistance to a temperature value - cue shannanigans with ice, boiling water and somewhere in between to get a three point approximation to the logarithmic curve of the sensor...
To answer Chris' question, the MS2 will drive the hotwire stepper motor if so desired, but I'll be using a Volvo idle speed control valve made by Bosch.
Hi Adam,
I can only go by my personal experiences and some people swear by MS1; my opinion of MS1 has been tarnished by buying a supposed 'turn-key' Rover V8 kit that was anything but. My opinion is that MS1 was originally designed as fuel-only (no spark control) where MS2 does both. I bought an MS1 that had been modifed internally (unbeknown to me at the time) such that it would control spark and fuel - and I had persistent problems with noise on the tach signal. If the engine speed is read incorrectly clearly the fueling will be way off, so I had regular hiccoughs. I spent ages working with various ways of getting rid of the noise (aided by people who really know their stuff) and got nowhere. When I ran MS2, built how B+G intended, the noise vanished.
It's now clear to me that MS1 is outdated technology, most of the documentation and forum advice out there relates to MS2 - I think that's because everyone's reached the conclusion that MS2 is far better! MS3 is generally for more modern engines with variable cam timing that could benefit from sequential fueling, there's little or no benefit in using MS3 on a 2 valve/cyl pushrod V8.
There's also microsquirt; but that was developed for snowmobiles and chainsaws and the like; I'm not sure of the wisdom of running a Rover V8 on one. In any case a microsquirt wouldn't run the 'flapper' injectors although it should be OK with hotwire (high impedence) ones.
It's also worth noting that contrary to some websites selling MS stuff, you NEED a wide band lambda sensor and you NEED to buy the tuning software to be able to tune the engine properly (ie better than 80% there). There are free versions of the software available but the free versions will severely limit your capability to tune.
I can only go by my personal experiences and some people swear by MS1; my opinion of MS1 has been tarnished by buying a supposed 'turn-key' Rover V8 kit that was anything but. My opinion is that MS1 was originally designed as fuel-only (no spark control) where MS2 does both. I bought an MS1 that had been modifed internally (unbeknown to me at the time) such that it would control spark and fuel - and I had persistent problems with noise on the tach signal. If the engine speed is read incorrectly clearly the fueling will be way off, so I had regular hiccoughs. I spent ages working with various ways of getting rid of the noise (aided by people who really know their stuff) and got nowhere. When I ran MS2, built how B+G intended, the noise vanished.
It's now clear to me that MS1 is outdated technology, most of the documentation and forum advice out there relates to MS2 - I think that's because everyone's reached the conclusion that MS2 is far better! MS3 is generally for more modern engines with variable cam timing that could benefit from sequential fueling, there's little or no benefit in using MS3 on a 2 valve/cyl pushrod V8.
There's also microsquirt; but that was developed for snowmobiles and chainsaws and the like; I'm not sure of the wisdom of running a Rover V8 on one. In any case a microsquirt wouldn't run the 'flapper' injectors although it should be OK with hotwire (high impedence) ones.
It's also worth noting that contrary to some websites selling MS stuff, you NEED a wide band lambda sensor and you NEED to buy the tuning software to be able to tune the engine properly (ie better than 80% there). There are free versions of the software available but the free versions will severely limit your capability to tune.
Hi Stewart,
I'm sure there's better qualified people to answer that question but I don't see why not. My engine is running a speed/density algorithm which may be problematic with one throttle per cylinder; but megasquirt can also run an 'alpha-n' algorithm where it just looks at throttle position and engine speed and calculates the fueling from that. I suspect it would run fine at high loads and sound fabulous, but not be so great at low revs/load.
MS can also run with an air flow sensor, but again that would be awkward and not very efficient with eight throttles...
I'm sure there's better qualified people to answer that question but I don't see why not. My engine is running a speed/density algorithm which may be problematic with one throttle per cylinder; but megasquirt can also run an 'alpha-n' algorithm where it just looks at throttle position and engine speed and calculates the fueling from that. I suspect it would run fine at high loads and sound fabulous, but not be so great at low revs/load.
MS can also run with an air flow sensor, but again that would be awkward and not very efficient with eight throttles...
mk1fan said:
Afternoon Martin,
You know, you really are not helping abate my V8 itch.
Given your field of knowledge on MS2, do you think it would work on a RV8 running Kawasonda throttle bodies?
The Honda ST1300 runs 4 TB's already set up in a V-formation; two sets of those and you'd be most of the way there You know, you really are not helping abate my V8 itch.
Given your field of knowledge on MS2, do you think it would work on a RV8 running Kawasonda throttle bodies?
The inlet is a really poor design so its hard to fit throttle bodies, esp on the middle 4.
No reason why TB's are any different from any other mapped system, hardest part is reading air temp.
also lots of people have had problems balancing them and setting up linkage. also I guess MS2 only has 1 TPS input. but with Lamda and TPS you can get a good map.
No reason why TB's are any different from any other mapped system, hardest part is reading air temp.
also lots of people have had problems balancing them and setting up linkage. also I guess MS2 only has 1 TPS input. but with Lamda and TPS you can get a good map.
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