Wheel Decoder

[Jag]

Just a quick question.

I have been away for a fair while and not following the extra code development as much as I would have like to be.

Does the wheel decoder code now support a 6-1 (5 teeth and one missing) for 6 cylinder wasted spark setup? Or is it still necessary to use a second trigger for to achieve this?

If the code does now support a 6-1 setup, which code version and MT version is stable for this purpose?


cheers,

Jeff

[KGB]

That's just a normal -1 wheel, unless there's too few teeth

[jsmcortina]

6-1 has been supported since 021t or thereabouts.

However for decent dwell you should probably fetch the latest alpha code 029j1
Under Advanced Code options use the 024s9 wheel decoder.
(I think I'm going to remove the 025 style routine)

James

[raku]

6-1 has been supported since 021t or thereabouts.

However for decent dwell you should probably fetch the latest alpha code 029j1
Under Advanced Code options use the 024s9 wheel decoder.
(I think I'm going to remove the 025 style routine)

James

is there a reason why the 025 routine should be removed, atleast my 12-1 cam setup with dual-dizy for dualcoil setup dont work with the 024 routine, it backfires if i try to start it.
with the 025 it works nicely

[KGB]

Just went and checked - found out that it really only affects missing teeth routine. Makes no difference if I don't have a wheel with missing teeth

[jsmcortina]

6-1 has been supported since 021t or thereabouts.

However for decent dwell you should probably fetch the latest alpha code 029j1
Under Advanced Code options use the 024s9 wheel decoder.
(I think I'm going to remove the 025 style routine)

James

is there a reason why the 025 routine should be removed, atleast my 12-1 cam setup with dual-dizy for dualcoil setup dont work with the 024 routine, it backfires if i try to start it.
with the 025 it works nicely :D

OK, sounds like a good reason to leave it in there. Great to hear that you are using the dual-dizzy setup - I wasn't aware of anyone running it yet.
I think I'll make the 024s9 type the default though.

James

[Jag]

James,

As always you are a mine of information, thank you.

Just to make sure I have my head around this, 6-1 wheel is five equidistantly spaced teeth and the sixth tooth missing right?

So for a six cylinder running three wasted spark coils, teeth spaced 60 degrees apart (if using the crank as the wheel reference). The inductive pickup placed at 70degs btdc.

So if a second trigger is not used what signals the return trigger return?


Seems almost too easy?

cheers,

Jeff

[jsmcortina]

So for a six cylinder running three wasted spark coils, teeth spaced 60 degrees apart (if using the crank as the wheel reference). The inductive pickup placed at 70degs btdc.

So if a second trigger is not used what signals the return trigger return?

You have to use timebased.
This setup is what one of the first wheel decoder and dwell users, RyanPzz, used on his V6 probe.

James

[Jag]

Hi all,

Again I have been away from all of the developments and have sort of lost touch with the state of play.

I had originally setup up to use two inputs (both crank) for a 6 cylinder wasted spark situation. One crank wheel having 6 teeth and a second trigger off the flywheel for trigger return.

It seems now that I can do this without the second trigger and use a 6-1 (five tooth wheel and one missing) to achieve the same thing.

My question is if my actual inductive pickup is placed at 70degs btdc, does it matter where on the wheel (in relation to TDC) the missing tooth is?

How would one set the spark settings in MT for this type arrangement? would I need to employ dwell control in MT ( i am planning on 3 vb921 for ignitors in conjunction with 3 double ended coil packs) and if so what are typical settings?

Lastly can I use the stim for wheel option to test this setup on the bench?

I know I should go back through all the posts and do the research however I am at a point where I am so far behind the current information that it would take me forever to catch up.


cheers,

Jeff

[boost junkie]

It took me a while to understand the "missing tooth" role in the whole decoder scheme. All the missing tooth does is reset the tooth counter. It doesn't matter where it is in in relation to TDC. The trigger points are simply which tooth is at what crank degree. For example, lets say tooth 6 is at 60 degrees. When the software gets to tooth 6 in the count, it knows its at 60 degrees then branches off into the part of the code that sets up the spark timing.