Odd fire?

[GintsK]

Hello!
Does VEMS really support this kind of engine?

Currently 90° V6 Masseratti. 90°-150°-90°-150°-90°-150° firings.
Distributor cap for this cost same as VEMS unit 

60-2 and wasted spark in my mind.

Gints.

[rob@vems.co.uk]

That's really a Wiki question, I've puzzled over odd-fire for quite a while and decided to pretend that it didnt exist until I absolutely had to...
No idea how you'd configure the ignition offsets TBH.

[GintsK]

I want perform some bench tests.
1.1 branch have h[1] reference tooth table. 150°=25teeth 90°=15teeth. So 0-15-40-55-80-95.
In addition I have  o-scope with couple of channels for logic signals. Never try them before...

[rob@vems.co.uk]

dont forget to put the numbers in h[1] from the highest to lowest (to match the injector and ignition events)

Rob

[jonnyboost]

Hey GintsK, how are you getting on with your VEMS install? I have an oddfire engine I also want to run with VEMS but require guidance with the setup. I am interested in how you are doin.

Cheers John.

[rob@vems.co.uk]

Jonny, I havent forgotten about the answer, just trying to get a definate answer from the dev team.  All I've got so far is "it should be posssible" but they tend to like to see scope traces of the crank and cam signal before they'll suggest much.

[GintsK]

I was trying odd fire on the bench. Using 60-2 and camsync signal. It works only partly.
Main problem is lost of ignition when some level of dwell periods overlapping is reached.
Problem is dwell and rpm dependent. Less dwell time allow more rpms. But for reaching 7000 dwell becomes too short. When ignition cuts, nothing but restart helps.

Problem can be some misconfiguration - I can't found any documentation regarding odd-fire.
Odd fire selection do not change anything noticeable.

Ignition events and dwell times at normal operation looks perfect.

[rob@vems.co.uk]

Can you do some logs of this and we'll get an Odd fire page up on the Wiki and see if we can't prompt some cleverness.

The overlapping dwell code should take care of the collisions - I guess you're running 1.1 firmware - but which subversion?

Rob

[GintsK]

My tests was using 1.1.27.
No idea how to configure 1.0.73 for odd fire.

I have no log from it. Must repeat.  And I have msq only http://www.vems.hu/files/GintsK/odd_fire_test005.msq. But wiki issue reports must be with config and tables. Msq is using Megatune from this package.

During fail all injector channels still works, but no spark on all three  (wasted spark) chanels.

For full report need:
config
tables
camsync tooth
log file.

I will try to find some spare time to do it.

Glad for someone else interested!
Gints

[rob@vems.co.uk]

If you could repeat the test that would be cool, I hope to get some time over easter to experiment.
Forget all the wiki report stuff, I'll put the page together with the info, having the config and tables will be good, but the key bit is the datalog as I can then kick off a discussion behind the scenes.

Rob

[GintsK]

Before repeating: i do not understand CAM sync, engine phase at next primary trigger setting.

Lets say my missing gap on 60-2 is 16 teeth before TDC , trigger tooth 6 and cam signal rising edge is some teeth before missing gap. What value then must be CAM sync, engine phase at next primary trigger?

[rob@vems.co.uk]

Okay I'm planning on putting a couple of hours into this tonight
Looking at the http://www.vems.hu/wiki/index.php?page=GenBoard%2FUnderDevelopment%2FFirmwareChanges
It seems that the previous versions (after 1.1.18 had ignition faults that required a restart - which sounds similar to what you've said happened here) So I am wondering if we should try:
http://www.vems.hu/download/v3/firmware/v3_firmware_1.1.33.zip

I've asked what engine phase at next primary trigger means. I'll see if we get something that I can write-up in a sensible manner.

[jonnyboost]

Well im glad you both know what your talking about because I havent got a clue!! Im holding on for a version of VEMS to run rather than whats available as I like the concept. Hope its not too much of a pain in the ass to figure out. I'll be on here as often as possible checking any progress.

Cheers John.
 

[rob@vems.co.uk]

Don't worry mate, soon as anything good comes along I'll be letting you know

[GintsK]

Here is zipped folder with 1.1.33 msq, config.txt , tables.txt and log file: at beginning spark is at max rpm and later - no. http://www.vems.hu/files/GintsK/OddFire/OddFireIssue1.zip

In addition some observations:

with 3.71ms logged dwell ignition cuts
0° - 4200Rpm
30° - 3200Rpm
42° - 2600Rpm


with 2.43ms logged dwell ignition cuts
0° - 6800Rpm
30° - 4700Rpm
42° - 4000Rpm

Gints