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Advance timing light question

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Old 05-12-2007, 06:55 PM
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Question Advance timing light question

background:

since my WBo2 died it threw my tune off sooo bad when i put it on the dyno...where I thought I was at 12.5:1, it was reading past 10:1 on the dyno (the richest it will display). Fix that. but still had no power.

I basically put 8° back into the entire spark map im running. this got me close to my last dyno numbers.

This had me thinking. if I had the timing set to 10°, and I basically had to advance the map 10° throughout to gain back power, one would assume that maybe i had the thing retarded 10°

here's the timing light question:

I have a digital advance timing light. this means that i can dial in the advance on the timing light. I was under the impression that if I set the light to 10° (megasquirt set to a fixed 10°) that I would put the mark on TDC. When I set the light to 0 this would display 10° on the pulley mark. Is this correct? Cause that's what I did...

so

I had no signs of knock and probably could have advanced it more to get more closer to my prior dyno plots...I basically gained 20rwhp/20rwtq by adding the 8°, which put me 10rwhp/10rwtq lower than I should be...think if i add another 2° I would have been very close to my previous numbers. I was also richer than I should have, but without a WBo2 log it was hard to tune...anyways, whatcha think?
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Old 05-12-2007, 07:10 PM
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Don't you have to set the advance to 20 because of the wasted spark setup? When you put the clamp on plug #1 it will be firing 2X as much right?

Maybe I'm on crack. I have an advance timing light but I just used the 10* mark and set the light to 0.

Wonder what EGT looked like??
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Old 05-12-2007, 07:25 PM
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no damnit you are right!!!! totally forgot about that.....

no EGT gauge...probably 2000000°
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Old 05-12-2007, 09:36 PM
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Originally Posted by Braineack
background:

since my WBo2 died it threw my tune off sooo bad when i put it on the dyno...where I thought I was at 12.5:1, it was reading past 10:1 on the dyno (the richest it will display). Fix that. but still had no power.
What's your WBo2 doing? I think my LC1 may be funked up as well.
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Old 05-12-2007, 09:42 PM
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dude i think if my replaced LC1 doesnt work right ill go through DIY autotune. no more ebay wb02 for me :(
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Old 05-12-2007, 09:48 PM
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How many LC-1's have failed in the past week? Did they build in a self destruct timer or something?
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Old 05-13-2007, 12:52 AM
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Scott, I could smell your car every time you accelerated
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Old 05-13-2007, 01:46 PM
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Originally Posted by jayc72
Don't you have to set the advance to 20 because of the wasted spark setup? When you put the clamp on plug #1 it will be firing 2X as much right?
No, wasted spark should not change the advance setting. The only thing it might change is if you have a timing light with a rpm reading from the pickup, you would have to divide the rpm number by two.

Think about it, let's say coil #1 is for cylinders 1 & 2 and timing is set to 10 degrees advance of TDC. So when cylinder 1 is at ten degrees and the spark fires, the timing light fires and the mark on the pulley should line up with the 10 degree mark on the plastic thing. When cylinder 2 is at ten degrees and the spark goes off, cylinder #1 is on the opposite side so at 190 degrees, and the timing light fires and the mark on the pulley is on the other side so you wouldn't even see the mark.
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Old 05-13-2007, 02:22 PM
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Originally Posted by y8s
Scott, I could smell your car every time you accelerated

you think'd running at > 10:1 would do that wouldn't you....
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Old 05-13-2007, 04:18 PM
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I wish I had bought my lc-1 through diy, instead of bell.

I'm confused, and I thought setting timing was simple. Don't you just set the mechanical timing to tdc, the timing light to 0, set the CAS to 10*, then set MS to 0*?

Its not like it matters since I ******* blew up a clutch today and won't be able to tune ms for a month.
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Old 05-13-2007, 04:21 PM
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my timing light defaults to 10....so it's just easier that way, i'm pretty sure im doing it right....light says 10, mark hits 0; light says 0, mark hits 10.

the main reason I question it was my power was only 140rwhp at 12.5psi until I increased my spark table about 8* advanced....
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Old 05-13-2007, 04:23 PM
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You don't have to adjust the mechanical timing at all. Just leave it how it is. Then adjust the timing angle to synch the engines timing with the static timing value you set in MS.
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Old 05-13-2007, 04:25 PM
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That's interesting that his map could be that retarded. I don't think Al messed with timing much seeing how he doesn't have a knock sensor and wanted to keep it conservative.
I'm also running that map and I've been told that the 1.6 map is pretty shitty when run on a 1.8.
Anyone know where to get FM's 1.8 link spark map?
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Old 05-13-2007, 04:30 PM
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Originally Posted by cjernigan
You don't have to adjust the mechanical timing at all. Just leave it how it is. Then adjust the timing angle to synch the engines timing with the static timing value you set in MS.
so in ms is static timing "0" or "10" if I set the CAS at 10*?
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Old 05-13-2007, 04:53 PM
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From DIY:
MegaTune Configuration

You need to use a timing light to calibrate the MS's timing to the Miata's timing. To do this, run "fixed angle" of 10-15 degrees and adjust the "trigger angle" until the timing light flashes while the motor is on the same 10-15 degree mark on the crankshaft, this needs to be spot-on. This way, whatever timing Megasquirt is commanding is actually happening.


You don't have to adjust the CAS at all. Just leave it where it is. That's just part of the ease of going MS.
The fixed angle is what i meant when saying static. For MS to adjust timing that value must be returned to -10 for MS to use your timing/spark map.
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Old 05-13-2007, 05:02 PM
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Originally Posted by cjernigan
From DIY:
MegaTune Configuration

You need to use a timing light to calibrate the MS's timing to the Miata's timing. To do this, run "fixed angle" of 10-15 degrees and adjust the "trigger angle" until the timing light flashes while the motor is on the same 10-15 degree mark on the crankshaft, this needs to be spot-on. This way, whatever timing Megasquirt is commanding is actually happening.


You don't have to adjust the CAS at all. Just leave it where it is. That's just part of the ease of going MS.
The fixed angle is what i meant when saying static. For MS to adjust timing that value must be returned to -10 for MS to use your timing/spark map.
thanks, that makes sense.
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Old 05-13-2007, 09:28 PM
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flyin miatas tables are here: http://www.flyinmiata.com/support/defaults.php

select your engine. I believe their targets are 220 180 140 100 60 20, in reverse order of MS, so 20kPA is on top 220kPa on the bottom...not sure about the rpm....then take the numbers and divide by 4. however, someone with a link might know better.
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Old 05-13-2007, 09:55 PM
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Originally Posted by Braineack
flyin miatas tables are here: http://www.flyinmiata.com/support/defaults.php

select your engine. I believe their targets are 220 180 140 100 60 20, in reverse order of MS, so 20kPA is on top 220kPa on the bottom...not sure about the rpm....then take the numbers and divide by 4. however, someone with a link might know better.
awesome link, thanks.
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Old 08-13-2010, 03:39 PM
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Sorry to hijack. If my 1.8 motor came without a CAS fitted and I went straight to Megasquirt how do I set the timing? Do i set trigger angle to 65 and advance to fixed 10 use my timing light and adjust the CAS to show 10 on the crank?

I just ask as I'm wondering whether to adjust the CAS or the trigger angle in MS?

Thanks
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Old 08-13-2010, 03:55 PM
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If you don't have a CAS, how can you adjust it?




Let that sink in for awhile.
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