code for use with dual mafs

[Yves]

Is there a code for dual maf use, where you can run one cylinder bank of one ve table and the other to another + 2 different widebands ?

[jsmcortina]

There's no support for dual MAFs.

There is "Dual Table" that runs the two batch-fire banks independently with a VE table and wideband per bank.

James

[Yves]

Just thinking out loud. Suppose you use 2 ms2's, connected thru can network, were one is master and the other is the slave. I suppose I can have 1 ecu run 1 bank and the other ecu the other with each it's specific maf sensor, correct ?

Can the info from the sensors be shared between them ?

How is the tuning then done ? Each ecu independantly ?

[ol boy]

There was a guy that ran 2 ms2 units to make a sequential V8 set up. This was way back before ms3 was an option. I suppose you could divide the motor into a pair of I4s and use dual MAF with 2 wbo2.

[dontz125]

I believe there were a few V12s set up the same way. The various ADCs could be shared via CAN, but each MS would need its own crank and cam sensors.

[dontz125]

Doing a bit of rummaging in TS, I don't see the ability to share MAT / TPS / etc via CAN. I withdraw my comment pending confirmation by someone who knows what they're talking about.

[Yves]

I think once you have a crank/cam sensor, adding another sensor for the second ECU would not be the biggest of problems. Having a double set of sensors on the other hand...

I know that sequential on a V8 would be possible that way, but what about individual coils in that case ?

Don,

I think one needs to be set to slave and one to master, but I'm not advanced enough to see if they can use the sensor info from eachother.

[jsmcortina]

There is no existing way to share the basic sensors over CAN. You would need to write it.

James

[ol boy]

http://www.msextra.com/forums/viewtopic ... 37#p205137

At the bottom of page 7 is where a member (JacoF) had a pair of ms2s wired together to run sequential on a sbford. I'm sure with some trickitry you could come up with a slick way to run the motor into separate V4's.

[Yves]

Thanks, that is interesting.

Funny reading this though :

As Jean said, with CAN comms you could share the inputs without the wiring (with a few code mods.)

James

I have no idea on how to deal with the code however. I assume some serious programming knowledge is required for that.

[Yves]

OK, I have pondered this some more. I think that the only extra sensor I would need is IAT and CLT. The TPS can be spliced to go to both ecu's I think and the ignition can be triggered by the main ecu. I can even use my non-used fidle to send a tach signal to the other ecu.

If I not mistaken with some expansion board I can even have 4 injector drivers per ecu. Would it be theoretically possible to drive each of those at a specifiek crank angle or not ?

[MS2tester]

would it not be time to upgrade to an ms3 with ms3x?

ms3 219$
ms3x 105$
ms3 casing 40$
import/taxes 120 euro?
life after that will be a lot simpler

[jsmcortina]

Running two MS2 ECUs does seem a very complicated and expensive way to configure this. Tuning would be twice as difficult too.

James

[dontz125]

I'm either blind or dense, but I don't see an option to run a second MAF with MS3, either.

[Yves]

MS3 doesn't run 2 mafs either.

MS2's can be had for 200-250 total.

I'm not convinced that the tuning would be a lot more difficult. If the maf curve is set right, there shouldn't be much to tune since the fuel is calculated from that. Maybe the warm up etc. but you could easily do it on one maf and keep the settings I assume.

I agree that 1 ecu with 2 mafs would be ideal. I still don't see why this hasn't been done before. Especially on itb'd engines it would be an advantage.
What megasquirt also lacks is additional analog inputs/outputs, like a motec does. I don't see the reasons either, but maybe it's just me.

[jsmcortina]

I still don't see why this hasn't been done before.

Because nobody has asked before and it seems like a tiny minority use case?

James

[seb209726]

Especially on itb'd engines it would be an advantage.

On most itb'd setups I've seen, there is still a common airbox, with a common air intake, which a single MAF can therefore monitor. Is there any specific reason why this is not possible in your case?
As for the I/O, you have several choices to pick from, the two first jumping to mind being jbperf's additional boards and the microsquirt with the I/O code.

[Yves]

In order to get a free flowing intake system I use 90 mm tubes on each side. If you want to combine those into 1 tube and have an equally free flowing tube that provides the air it would require a tube of 112 mm minimum. That's one hell of a big maf tube.

[elaw]

Here's an idea: how about putting two MS mainboards & processors in a single custom case, and sharing relevant signals between the two electrically?

For example for the VR sensor, just connect it to one mainboard, then route the VrOut signal from that mainboard to Tsel on both mainboards.

Likewise for shared analog sensors, connect the sensor to one mainboard, populate the pullup resistor on that mainboard but omit it on the other, then just route the signal to the 2nd mainboard via a wire. For example for CLT, connect the CLT sensor to mainboard #1 and on mainboard #1 populate R7. On mainboard #2, do not populate R7. Then run a wire from the R8/C6 junction on mainboard #1 to the same point on mainboard #2 and both will see the signal from the CLT sensor.

[jsmcortina]

I'd more likely use MS3 to give full sequential and trim. Plumb in two MAFs and connect both. Tuning would only use one MAF only but you could datalog the other to see how they compare.

James