NigeEss
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| posted on 19/11/13 at 12:37 AM |
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Megasquirt......on a diesel ????
Is it feasible ? Assuming a common rail application.
In my mind it will work, after all the principles are the same, injector timing and duration.
Discuss 
[Edited on 19/11/13 by NigeEss]
Time is an illusion. Lunchtime doubly so.................Douglas Adams.
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coyoteboy
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| posted on 19/11/13 at 01:42 AM |
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AFAIK, unless MS3 has changed it, megasquirt has no injection timing control? This makes it impossible to achieve diesel control, ESPECIALLY on a
commonrail where the injection timing is often 1 pilot injection followed by a second "full" injection.
Megasquirt does ignition timing and injects "whenever", or in sequential on the MS3 I think it has a "whenever, but approximately
here for each cyl". I'd have to check the manual.
This is because, on a petrol engine, injection timing is not particularly important, especially not at high load levels.
[Edited on 19/11/13 by coyoteboy]
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baz-R
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| posted on 19/11/13 at 02:42 AM |
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ms2 and 3 have injection timing control but this is aimed at petrol users and im not even sure it would work on GDI's yet but its possible that
even gdi petrol and diesel comon rail is in some form of alpha or beta firmware.
best place to look and ask is on msextra.com
also if you have no luck with megasquirt i have seen diesel engine control ecu's out there in the market
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MakeEverything
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| posted on 19/11/13 at 06:08 AM |
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IIRC, cant you select fuel type on megasquirt?
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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luke2152
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| posted on 19/11/13 at 07:34 AM |
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Megasquirt is not amywhere near fast enough for common rail diesel because fuel needs to be precisely injected at exact point btdc. On petrol
sequential injection timing need only be done on the correct stroke and even then only at low/mid rpm. So in a word, no. thereorically you could use
it on a rotary pump diesel to control the advance and fuel metering solanoids but all the calculations in tunerstudio are based on petrol and
injectors so would need serious amounts of trial and error to even get it running.
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ashg
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| posted on 19/11/13 at 07:59 AM |
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source code for ms3 is available, the processor has scope to do it, nothing is impossible.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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matt_gsxr
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| posted on 19/11/13 at 09:36 AM |
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just google it and you will find lots of good stuff
[Edited on 19/11/13 by matt_gsxr]
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luke2152
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| posted on 19/11/13 at 11:22 AM |
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quote:
Originally posted by ashg
source code for ms3 is available, the processor has scope to do it, nothing is impossible.
You could be right about the ms3 processor. When I asked similar question on forums couple of years ago the consensus seemed to be that the ms2
processor was too slow.
I think another big issue would be getting the seperate ms ignition and fuel outputs to control the timing and duration of the same injector.
Also I seem to remember common rail needing 5 injection events per cylinder per cycle (pre injection to reduce knock, then several normal injections
and a post injection to reduce emmisions). Not to say it wouldn't run ok with just one or two events if you could live with a bit of knock.
Maybe megasquirt could be used piggybacked onto original system fool the ecu that it needs to deliver more fuel under certain circumstances?
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coozer
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| posted on 19/11/13 at 12:47 PM |
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Thing with petrol injectors is they are quite slow. The time from valve open to closed is fast, much faster than injector opening time never mind the
full cycle. So petrol injectors spend most of the time injecting against a closed valve and thats why theres no point trying to make MS do it quicker
so wont be much use on a direct injection oil burner. Stick with the correct, supplied with the car, ECU.
1972 V8 Jago
1980 Z750
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DW100
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| posted on 19/11/13 at 01:05 PM |
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A few fundamental issues would need to be sorted.
1st, common rail diesel solenoid type injectors are fired using around 80volts
and 2nd desired fuel quantity is controlled as much by rail pressure as injector timing.
P.s I'm a mechanic and I do a lot of common rail diagnostic work and understand the systems very well.
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ashg
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| posted on 19/11/13 at 01:46 PM |
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it should be able to cope. ms3 can do windowed knock detection now so its already shown that it is capable of doing the processing. as for 80v
trigger thats easy to solve too. with regards to fuel rail pressure you can reassign the ignition control blocks to deal with that. its all possible
its just a lot of work.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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DW100
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| posted on 19/11/13 at 01:52 PM |
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Yes all do-able, but as the pioneer it'll be a huge learning curve.
It would definitely be easier to get the existing engine management system to run stand alone and chip it to whatever is required.
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ashg
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| posted on 19/11/13 at 03:49 PM |
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quote:
Originally posted by DW100
Yes all do-able, but as the pioneer it'll be a huge learning curve.
It would definitely be easier to get the existing engine management system to run stand alone and chip it to whatever is required.
oh yes most certainly.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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Simon
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| posted on 19/11/13 at 06:19 PM |
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There is an aftermarket diesel ecu out there, but iirc, it's about £2500 
I'm sure if they made it £700, they'd sell loads !
ATB
Simon
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coyoteboy
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| posted on 19/11/13 at 09:26 PM |
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quote:
source code for ms3 is available, the processor has scope to do it, nothing is impossible.
Aye but last time I checked you need a £k compiler and linker to compile changes as the"free" version is limited to compilations smaller
than the code requires.
You may also wish to check out the code license - IIRC the MS3 code is not licensed for use on non-MS mainboards which would hamper you.
[Edited on 19/11/13 by coyoteboy]
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