New Nissan triggering idea

[rob@vems.co.uk]

Most of the popular japanese cars have a 24tooth engine speed trigger with 1, 2, or 4 tooth synchronisation trigger.
As these are camshaft mounted you effectively get 12 engine speed pulses per RPM.
The single tooth sync trigger gives fully sequential timing (one sync for two RPM), the 2 tooth gives semi-sequential and the 4 tooth gives only enough info for batch fire with a distributor.
We decided to call this the Oceanic standard.

The nice thing about 12 pulses is that you can run a 4, 6 or 8 cylinder car using it, and as theres a lot of 4 and 6 cylinder Nissans about I decided it would be a good idea for a one trigger disk fits all solution.

Thanks to Damo_S13 and his Dad we've got some to play with

These are very much experimental at the moment, I should be able to get one tested by the end of this week on the test bench and hopefully onto a car after that.

[dnb]

Looks good!  Makes me wish I had a Nissan to play with   (But I don't have time)

[200KriSX]

Most of the popular japanese cars have a 24tooth engine speed trigger with 1, 2, or 4 tooth synchronisation trigger.
As these are camshaft mounted you effectively get 12 engine speed pulses per RPM.
The single tooth sync trigger gives fully sequential timing (one sync for two RPM), the 2 tooth gives semi-sequential and the 4 tooth gives only enough info for batch fire with a distributor.
We decided to call this the Oceanic standard.

The nice thing about 12 pulses is that you can run a 4, 6 or 8 cylinder car using it, and as theres a lot of 4 and 6 cylinder Nissans about I decided it would be a good idea for a one trigger disk fits all solution.

Thanks to Damo_S13 and his Dad we've got some to play with

These are very much experimental at the moment, I should be able to get one tested by the end of this week on the test bench and hopefully onto a car after that.

Its good seeing them in the flesh after seeing the plans Hope all testing goes well so my name can be on one of them lol.

Kris

[rob@vems.co.uk]

RESULT

I've just been testing the trigger on the VEMS UK Patent Trigger tester (my old drill press), and it worked like a dream.
I tested using the same settings as were used to get a Toyota Supra running.

So it seems that the unit I've been using to test the Toyota sensor is a bit ropey, not a suprise really as it is my "Donkey" unit its been sat on, reconfigured and generally messed around with

The config.txt settings (don't worry if you don't understand, you either will or won't need to) used were:

primary_trigger=07    # coil type, filtering, rising edge. 06 would work for HALL.
secondary_trigger=19    # camsync, rising edge; alternatively 1d is same, but with filtering
tooth_wheel=18    # decimal 24 tooth (between cam pulses)
trigger_tooth=01    # or upto 03
another_trigger_tooth=06    # 24 tooth / n cylinders
ign_tdcdelay=10    # 10 crankdegrees
tooth_wheel_twidth1=78    # decimal 120, that is 30 crankdeg per tooth
tooth_wheel_twidth2=00
alternate=15    # injgroups 5 .. 0 (fire all banks during cranking)
ignchmax=05    # ignition 5..0
reset_engphase_after=40    # since camsync is used

And the h[] entries in the tables.txt

# h[1]=00 14 10 0C 08 04 .. ..
# h[2]=10 60 50 40 30 20 .. ..

[sm]

Makes no sense to me :p

However nice to know that its tested & works

[damo_S13]

glad to see you like em and have it sorted bud

i new i should have got one more made for me  lol never mind im sure the old disc will be ok as its in my cas all ready and waiting

damo

[rob@vems.co.uk]

Well the reason I wanted to use these was so that I could threaten Skyline people
I will be using a Four slot on my car should it ever get finished.

Rob

[damo_S13]

cool. im happy with what i've got well would like to change from cop tho

hope you get on with your s14 soon, i had a little set back on mine as my dads gone and got a cbx750 bike at weekend so did no work on my engine will be in this week tho been promised

damo

[rob@vems.co.uk]

A change from COP to coil packs is quite simple and will work with the four slot trigger disk you have

[damo_S13]

  just need the funds to do it lol will try to transfer to it in the summer got to get her running asap

damo

[Mr Bizzle]

Rob,
Do you think this will work with my VH45DE V8 engine?
It seems to have a single cas sensor that looks *from the outside* to be very similar to the SR20DET one.
Im going to post a thread in a moment. Im very new to the whole idea of a vems and stand alone systems. I am going to use the VEMS ecu on the project (as you know Mr Robbbboooo ) however i need more information about it

Chaaaarrrsss!

Chris

[rob@vems.co.uk]

I've seen a picture of the innards of a Skyline RB26 CAS and its pretty much the same as the SR20 (and the RB25 is similar to the CA18)
So I am expecting a disk with 8 inner slots of varying size.  One of the reasons I went for the 24tooth one is because it works for 4, 6 and 8 cylinders in a nice fashion.

Looking forward to seeing the post on the engine build

[dundersmurfen]

This seems like the place for me to post my annoying thoughts 

triggering at tooth 0 or using tooth 0 makes me nervous... as i see it tooth 0 dont exist, other than in theory, when sync signal is recieved primary trigger counter resets (tooth 0) wich is between tooth 24 and 1. using tooth 1 makes more sense?