Members Page/Skassa Trigger Subaru - VEMS wiki www.vems.hu

MembersPage/SkassaTriggerSubaru (2015-01-01 07:00:00)

Strobe shows different angle than what we expect

with (InputTrigger/ShortGapTrigger) InputTrigger/SubaruTrigger :

I downloaded the config from one subaru
uploaded to another
ign advance is off, just like it was also off on the other Subaru
- just to clarify: the ignadv is displayed OK in megatune, (and on LCD mlp00 bottom right corner), but the strobe shows the ignadv changes half angle of what it should.
Yep, what is written in megatune sparktable, is what is showed on display,and megatune.

It is the strobe that shows half of what´s written

can it be that the advance is calculated from the cam ,and not the cas?? so it´s every time the 3tooth is passing??

I was tuning the car last night, and the advance seems to be off:

strobed at 10degrees, so this is right
if I write 40 degrees in the megatune sparktable

it changes only +15 crankdegree (to 25 BTDC), not +30 crankdegree (to 40 deg BTDC) as it should

measured on the crank, of course (not on cam)

some smart strobes are confused by the wasted spark ignition, this actually happens quite often.

Can you do measurements the 40deg and 10 deg with same strobe settings (or a dumb strobe, and see angle difference on engine ?)

40deg is 25deg measured, and 10deg is 10deg measured

Can you describe the strobe and its usage in great detail ?

type
switches
what knobs
display
...
- the timinggun is about the oldest that can be had, there is no buttons on it, i will check if i can see a name on it, but i think it´s around 20-25years old.

there is just 2wires for power and gound, and a 3rd with the inductive feeler to put on the ignitionwire.

if it lights up at the time of spark (seems likely if it has no buttons) and you read from the rotating crankshaft, than the chance of getting it measured wrong is minimal indeed.

Want to test with Sami's 1.0.77 compile that Jorgen drove for quite a while now and found good. Anyone have that firmware image ?

yes i will give it a try, anything to make it work:)

This way earliest is 37.5 crankdegrees BTDC (max commanded ignadv is 63.75 degrees.

This is from the helpful [VEMS FORUM]

There are trigger errors when cranking, though the wiring seems OK

and i cant seem to find any info, regarding the "advanced filtering" settings, if that maybe can help filtering that out
- GenBoard/UnderDevelopment/FirmwareChanges, (toothrel_normal and toothrel_missing ) multitooth advanced filtering so thresholds can be set for what is considered as long-gap (eg. 125-420%, in actuality 60/30 and 90/60), and what is short (eg. 16-100%, in actuality 30/90 ).
car will sometimes backfire when cranking
on the MS site, i asked a guy who run there subaru trigger,he had the same cranking problem and that was fixed with software,as he is able to see in megatune,that it was caused

by the ecu going in and out sync.

Could this maybe also be the problem here??

the "crank minimum usec" shouldn't cause that (you can set it to 370 usec, that is 20 degrees at 9000RPM, or you can even try 0). If it's too high, high-RPM triggerinput will not be believed

Link to some info to how ms extra does subaru, can any of you see what the vems is missing to filter the noise, if this ms extra setup works, interesting that they trigger on raising egde

http://www.msextra.com/ms2extra/MS2-Extra_Subaru.htm

Another link with a sulution to ms setup with the exact same symtems as i got when cranking.

http://www.msextra.com/viewtopic.php?f=91&t=28092

We scoped the oe dwell time, and that is 3ms.