Understand WhatEverYouDoYouDoItAtYourOwnRisk
7 cylinder engine is one I am building from drawing board up for an aircraft that I am also building.
hence the low rpm as it is direct drive.
- Static ground revs no more than 2700 other wise the propeller tips will break the sound barrier (inefficient)
- Propeller diameter 1.7m 2500 RPM most efficient rev
- we put as much pitch on prop as to limit revs
- also engine internals would not take high rpm (the internal forces go up by the square of the revs)
- legs out of bed in the sky causes one to sweat a bit , thats why we use the fan to keep us cool
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Injectors are out of a Nissan 280z are 2.6 ohms [ barbed tail, will consider changing ] and best idea of cc rate is 270.
- we do not recommend low-Z injectors even on ground.
Basic info
- 7 cylinders
- 4 stroke
- firing order: 1357246
- Injection firing 7246135
- naturally aspirated ?
trigger - HALL recommended
- primary trigger = HALL
- pattern= 7 crank teeth rising 38deg BTDC [ can shift if this is not early enough][ sensor gave a better signal on rising,[wide tooth]]
- secondary trigger cam= HALL
- pattern,= single tooth rising TDC number 1[was set up for VR]
For this (if there are 7 teeth on the crank!):
- then this is 14+1 type trigger (14 pulses per cam rev)
- very similar to 12+1 InputTrigger/MultiToothNoneMissing often used on Toyota and Nissan
- often referred to as "coil type" (not missingtooth aka "multitooth")
- next trigger tooth = 2
- tooth_width = 51.5 degrees. Since this is less than 64 degrees, early 1.1.x firmware (from around 1.1.12) can drive this, so 1.1.27 firmware seems to be an option
- the 5cyl audi 10+1 has tooth_width=72 (>64) so that requires newer firmware. That requirement does NOT apply.
When you confirm that 7 teeth are on the crank we give it some benchtesting.
There are 7 teeth on the crank.
Please name the falling - high to low going - edge of the crankpulse which is appr 45-96 degrees BTDC cyl1 as pulse0
- measure the falling and rising edge of campulse relative to this "pulse0"
- measure the duty (high to full ratio) of the cranksignal:
- Correct this sentence: example: 40% IFF the pulse is high for 21 crankdegrees and low for 31 crankdegrees
Cam pulse is somewhat before the "cyl1 crankpulse" I guess. (from now on use the pulse0 as reference) The chosen (rising or falling) campulse-edge MUST NOT race with the chosen edge of the primary trigger pulse. Min 15 degrees clearance recommended to allow cambelt sloppiness. Halfway (26 crankdegrees = 13 camdegrees clearance) between two primtrig pulses is best. We might choose the edges to allow higher clearance.
Ignition outputs
number,=7 stick coils, inductance [not known ]
Requires power IGBT output (not logiclevel) ?
The current(in function of dwell) measurement-series is required for any proper install (even though often jumped over during ground installs).
Recording
- VBATT
- RPM
- lambda (if not doing this in fresh air)
- dwell
- ignition coil (primary circuit) current
- scope is not essential, because the DC mean value is also useful reading for this
- it is best to measure all ignition transformers individually and find any outstanding values.
On ground we also decrease dwell to the point of misfire (often 1.2 .. 1.4msec). Finding dwell values from other applications (for same ignition transformers) can be reassuring.
Injectors =7 = 225cc High Z [ am expecting 130HP at 2500RPM can you advise on flow rate][Would like reliable idle]
Discussion
- Is there a manual directly relating to VemsTune 0.10.14 I am finding it impossible to go forward without better information.
- it has a help. It has many features, but the basic features are not hard to handle. Tutorial is in the works (separate manual other than the help is not planned: everything should be in the help).
You will not be able to set the parameters one-by-one. We will use a starting setup, and modify the bits according to your wiring. So:
Start by describing your system above, THEMATICALLY organized by subsystem. So we can help you get a starting setup. Note that even the cylinder count is missing !
Fill in this page above.
It now seems that the MAP guage on main screen is directly controlled by the movement of the throttle
The software is running alphaN, instead of speeddensity, that´s why the mapsignal is the same as TPS/skassa
- correct, if set in alpha-N mode (than rather "load")
You might want to setup a build page on the forum.
http://195.159.109.134/vemsuk/forum/index.php
In any case your alpha-n rpm must be 0 to the ecu to run
speed density.
You should find this in the Alpha-N/Speed density settings menu under the Base settings menu
Thanks sorted that bit, will consider forum idea
tested with the following two configs:
http://www.vems.hu/files/AllanFillery/v3.3_n001212-2010.02.08-14.01.12_14+1_1127.vemscfg
http://www.vems.hu/files/AllanFillery/v3.3_n001212-2010.02.08-14.10.40_14+1_1167.vemscfg
Now it needs more testing.
VemsTune Import values from vemscfg file feature:
- open the directory in windows that holds above vemscfg files (downloaded to local drive)
- in VemsTune open the reference tooth dialog
- to import values, drag vemscfg file and drop onto the dialog
- just imported the relevant values. Review values. Changed values appear in red. Send to ECU if you like them (or refresh from ECU if they seem bad). In this case these should be like:
12
10
8 6 4 2x (do not care)
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This is actually in the reference config.