Ignition on a Mini-Turbo (No injectors)
Maximum planned boost is 0,8bar = 11,76PSI = 80Kpa, so max MAP reading will be 180KPa.
Planned rev limit is 7500 RPM
Project state
DONE
- connected all the wirings and sensors to the engine, diagram can be seen here: MartinFranck/Wiring
- document what is done - eg. trigger position and ignition channels
- complete config.txt
- have config.txt reviewed
- upload config.txt to GenBoard
- some table-testing wouldn't hurt (!)
- fire up the engine, whit succes 18/3-05 :)
TODO
- Check that the VR sensor position is correct.
- Calibrate the air temp
Sensors - already mounted:
- Knock-sensor
- Map-sensor (Ford cosworth, 2,5bar magneti/weber)
- TPS-sensor
- Water-temp
- Air-temp
- Coilpack (wasted spark) and Trigger sensor from the Ford EDIS system (not using the EDIS4 modul).
Idle air
- not under GenBoard control ?
Trigger
- 36-1 crankwheel (Home made one can be seen here MembersPage/MartinFranck)
- VR sensor(Placement of the sensor can be seen here: MartinFranck/Pictures).
The primary trigger input channel must be set up with the relevant jumper to VR-type input (so LM1815 is used).
I have uploaded new and better pictures of the board, they can be seen here: MartinFranck\Pictures
- you have to short SJ6 (right below LM1815) by soldering
- put a jumper (or rather solder, preferrably on bottom of the board) to short JP2 and JP7 : viewing from the "Top" side, connect the upper-middle pin to the upper-right pin of 3x2 pinheader (between the EC36 and the LM1815). Make sure you view the board in a good orientation, so econoseal points down and "Top" text is readable (not as on you pictures). If you view from the bottom (because soldering on the bottom), connect upper-middle to upper-left pin - obviously.
The other option would be HALL type: therefore this is only done before shipping when the user declares (eg. on project wiki page, or order note) that he needs VR type.
Ignition
Wasted spark: 2 channels for 4 cylinders.
- 1 and 4 fire together (PIN 34)
- 2 and 3 fire together (PIN 36)
I can´t figur it out with the starting dwell, I have looked on DummyIgnition. But if I start carefully with 2.5 msec, is´nt that okay too start with?
2.5 msec
x=2500/64 x=39 Hex(39)=27
so:
ign_dwelll4=27 # hex(27)=dec (39) ; 39 * 64 us = 2500 us dwell
Spark problems
I have tried to fire up the engine, but there isn’t any spark.
- trigger seems to be good: I can see on RPM scale in megatune when I am trying starting the engine, that the engine is taking 200 rpm.
- measured: the coil+ pin is on +12v
The English DTA controller has starting settings that controls how many RPM that the engine needs too take before the controller will allows any sparks.
No such parameter for GenBoard, the max position after the trigger is limited to 131msec (this means min 40..120 RPM depending on trigger and ignition advance setting).
It seems that some steps were skipped before cranking. Namely the mdn.. tests.
Very handy, because it allows testing spark infrastructure without cranking.
- check that the insulating material is under the IGBTs (IGBT must not touch Alubos directly)
- Make a sparkgap of reasonable length (not longer than 1.5 mm).
- the sparkplug works too (body touching engine), of course, or
- a wire in the sparkplug-wire boot, with other end very close to engine body
- mdn00 tests channel associated with element 0 of h[2] the configured dwell length of pulse will be fired
- mdn01 tests channel associated with element 1 of h[2] ...
- and so on
- Take care not to die from electric shock - don't touch it when ignition on
Good luck !
Pin connections and h[2] table
Pin connections can be seen here MartinFranck/Wiring
Some very important settings like
- h[] table, h[2] line. See GenBoard/Manual/Tables
- trigger_tooth
- the missing tooth are at the same mark as the top mark on the engine block and that is TDC point of Cyl 1-4, because they are in top position, this is 93 deg after the VR trigger.
- so isn't the missing tooth = trigger_tooth
- ign_tdcdelay (0xBA*0.5 = 93deg) is this correct?
will depend on
- which 2 ignition channels are used
- cyl1 and cyl4 or
- cyl2 and cyl3
This is of critical importance to document precisely.
... coming up
config.txt
http://www.vems.hu/files/MartinFranck/MFConfig.txt
- ign_tdcdelay=BA (to reflect the 93 deg. BTDC, which is 200 decimal because of 0.5 degree resolution. This is important.
- trigger_tooth=00 (0x00 means the missing tooth)
Ignition advance table
described in the n[ ] table (8x8 or 16x8)
Obviously, lower ignition advance is needed at highy MAP (> 100 kPa is possible because of the turbo). This means n[7] will hold lower values than n[0]
The following kpa and rpm ranges could be used (or other can be good too):
r[0] = 07 ... <5 RPM values of your choice> ... 40 48 (Also which format is the numbers)
k[0] = 18 40 64 90 B0 ... <2 values of your choice> .. FF (18 40 64 what is these numbers in e.g Hex ?)
You can take a look at my table file, it has plenty of hints should be enough to get you going:
http://vems.hu/files/DaveBrul/tables.txt - DB
You don't need too many bins initially, it just increases tuning time. For ignition during the 2nd phase (fine-tuning) you might find it a good idea to insert an rpm or kpa bin somewhere, so keep one "free" during the first round (spread your useful range across 7 bins and place the 8th somewhat beyond).
Question
Q: Have I understood it correctly, that if I want the ignition advance too be 30 deg, that i then should multiplicat with 2, so that I should write 60 deg = 3C (Is this correct)
A: That is incorrect, the timing unit of the ignition map (n) and ign_crank_advance is 0.25 degree. Therefore, 30 degrees = 30 x 4 = 120 = 0x78.
Q: I have tried to converts the config.txt to .mtt, by writhing make mtt in command promt and I gets this failure:
warning: variable "tooth_wheel_width2" in config_t not found
what can be the problem?
A: It probably means that you have a variable in in your config.txt that is not there in firmware config_t (names dont match or it is not there altogether)
Q: Is there anybody who has the Megatune 2.25, that could mail it to me, because the link on the site does'nt work.
My mail is: m_franck@webspeed.dk
Q: * Do I need too calibrate my map-sensor, I am using a 2bar Webber Marelli from a ford sierra cosworth.
2bar = 200 kPa so kpafac=64 (decimal 100) should be good.
No need to calibrate, IMHO, but you can checkout the local pressure in the radio/internet weather forecast or homepage of your airport. Adjust kpafac accordingly. You won't know exact kpaofs unless you have a calibrated vacuum source: so just guess kpaofs. Any kpaofs will work. After tuning the engine, don't change kpafac too much, because it will effect the tuning If you do, adjust req_fuel in the opposite direction.
Q: Tachometer problems, my tachometer does not showe the correct RPM because I am using wasted spark, can I connect the Tachometer to the V3-controller an get the correct RPM, ore are the other obsentions ?