Ignition TIming, for the last time I hope.
 

Ok I´ve read through near on every thread in the section regarding how to set your ignition timing.

Some people say remark the pulley, some say put the CAS in so it lines up with the 5deg. ATDC mark and set the static value to 5deg.

Now I was just thinking about this....
Wouldn´t you want to set the Timing Trim value to +5deg. NOT the static value?

It was my understanding that the static value set the minimum possible timing value and didn´t actually have bugger all to do with telling the motor where TDC was?
I thought that was Timing Trim´s job?

Either way I´ve set mine so its at 5deg ATDC and then +5deg in the static section.

Works alright so far...

Is this right or wrong? Or does no one actually know?

Obviously marking the pulley would be the best bet if you could do it acuratly enough..

There's no right or wrong way. It's just what you prefer. That said, marking your pulley can be accurate if you measure it correctly.

I guess what I was trying to get at Infini IV, is not just the difference between marking your pulley vs not marking your pulley.

But rather when setting your timing off the 5deg. ATDC crank mark, putting +5deg in the Opt TIMtrim var as opposed to setting +5deg in Opt Static.
If you did the static option, it is my understanding that the engine would never run 'under' 0deg. (ie, TDC) now you might want to run it at the stock setting of 5deg. ATDC at idle, you can't do this if you set +5deg in Static.

But you can if you set it in TIMtrim.

Just a thought I had today whilst mucking around with my ignition system...... :)

static is the value that you can st base timing to, not advance. so you can advance it past the static value, you just cant set the basic vlue any lower. so you idle value cant be less than 5 ATDC, but your high rpm advanced values can. i think that is how it goes.

pat

Yes that is what im trying to get at patman..

I'll try and reword this so it's a bit more coherant....


First let me say that this only applies if you 'zero' your timing on the microtech by aligning the crank pully yellow mark (5deg ATDC) with the pointer.

If you have re-marked the pulley it does not affect you.

Now if you line up the 5deg ATDC mark with the pointer and then set the static value to +5deg like alot of people here seem to do, then no matter what you can do the most retarded you can ever get your timing is right at TDC. This is because 0deg on the microtech is actually 5deg ATDC, but +5deg in static brings it back to TDC.

It is well known around here that rotaries tend to like to idle at the stock setting of 5deg ATDC.

You can only get this to happen if you either re-mark the pulley, OR instead of mucking around with the static option you line up the 5deg ATDC mark with the pointer, like normal. However, instead of setting the static option you set the TIMtrim option to +5deg. Because 0deg on the microtech = 5deg ATDC, this is why you need to add 5deg.
It can then still be retared back to 5deg ATDC at idle.


Is there anything wrong with my thinking here?
My car certainly seems to run good like this.

static is what it 'sees' when it is zeroed. in other words, it is like...you are setting it to 5* on the pulley, so you have to 'tell' the microtech that that's where it is, rather than 0. that is all static means.

No, not at all patman, thats not what the 'static' option is for.

It is to set the minimum permissable timing value.

If you set the timing using the 5deg ATDC mark on the pulley and set +5deg in static, then you will be firing _AT_ TDC.
Not 5deg after like stock, and as you've said in other threads IIRC, that firing _AT_ TDC isn't the best value for a rotor.......

Therefor you can never get to 5deg ATDC if you set +5deg in the static value.
You can however if you set it in the TIMtrim option and leave static as Zero.

If you could set -5deg in the static you'd be laughing, but you can't.

ok, so are you telling me that my car never advances past 5*? ever? no way. it would barely run at high rpms.

heres some proof for you:

with my timing set at the 5* mark on the pulley, and static at 5*, i fire at 5*. no question about it, its been checked with a timing gun. also, i advance past 5* when i rev. also been checked. in short, with the setup above, my timing, basic and advance, works exactly as it should.

pat

No, I said nothing about not advancing.

I said not retarding. Ie, minium permisible value.

5deg ATDC is retarded. Not advanced. :)

I find it strange you car runs like that in that you have +5deg in the static option yet it fires at 5deg ATDC, ie, retarded like stock. Mine does the opposite, like I was describing above...


I have also put a timing gun on mine many times and it behaves rather differently to yours.

yes i know that 5 ATDC is retarded. but why would you want to retard it any more than that? as far as where your car fires at...well...i dunno. all i know is that that is how microtech says to do it, and i did it, and it works. there really arent any definitions of the functions, but what i said above is what i'm convinced the static function does.

maybe i have -5 in the static box?

i dunno.

i'll check it all out next time i drive somewhere...see if i can see any reason that yours might work differently.

pat

Please do check it out, i'm very interested.

If you do have -5deg in static that would explain a little bit.
Point being on my microtech, and presumably many others, you can't put a negative value in there.


Anyhow, as I understand it the Static option does not advance timing across the board, it only sets the minimum timing value...

The TIMtrim option however does advance the values across the board.
This is the one you want to use.


I'd like to hear someone on here that knows alot about microtechs to chime in, this microtech I have wasn't 'setup' for a rotor. So it _may_ be different.
However I can't see the integral functions like the static and TIMtrim functions differing just because mine was setup for a 4cyl.

Also another thing i'm interested in, you said before that yours fires at 5deg ATDC, what value does the microtech show on the handset?
Does it show -5deg? or does it show 5deg, like it would a normal BTDC value?
Just curious...