PDA

View Full Version : spark tables



ZL1Killa
November 17th, 2005, 06:42 AM
I'm using the run spark table estimate on efi live and plotting rpm vs grams/cylinder like the actual spark table has and in some places up high i'm getting 45 degrees

is that too much? or i guess what I"m saying is that I'm using to seeing as high as 40 at most, so would 45 be too high to run?

ZL1Killa
November 17th, 2005, 07:11 PM
.........so these values are ok?

GMPX
November 17th, 2005, 07:24 PM
WAY too high under load, off throttle coasting that would be O.K.

Cheers,
Ross

ZL1Killa
November 17th, 2005, 07:34 PM
now let me say that I'm using the estimation of the run spark in efi live and logging if versus grams/cylinder

so its the EST_Run_dma

should i be using that to get my spark table values? (I'm in SD mode so high octane is low octane)

or should i be using idle spark or base spark

caver
November 17th, 2005, 11:16 PM
I use SAE.SPARKADV
Timing for cyl 1.

Max adv at full throttle runs 22 to 25 deg.

ZL1Killa
November 18th, 2005, 01:38 AM
basically i want to dial in what my spark tables should be. and i thought that using the run spark estimation with grams/cylinder would tell me what i should be running. Am I going about this wrong? should i be making the plot for the SAE.SPARKADV Timing for cyl 1??

ZL1Killa
November 18th, 2005, 09:50 AM
ok...to simplify things...


I want to dial in my spark tables...using the *.map ability in efi live I want to dial in my spark tables(similar to the ben factor) do I use the RUN SPARK estimation? if not what do I use.

the timing for cylinder 1?

the numbers that i'm getting now are ranging from about 4 degrees to as high as 38 or so

caver
November 19th, 2005, 09:22 PM
At light throttle you will see numbers like that but at wot the numbers will be much lower.

I have made a map using SAE.Sparkadv RPM and Cylair so I can see the actual timing the motor is getting.

I have a similar map for KR so I can see where the knock retard is active and by how much.
And I have the same for IAT spark so I can see how much that is affecting the timing will probably do one for ECT as well.

ringram
November 20th, 2005, 12:14 AM
Yes, estimated spark is close to the actual spark that carver is logging. If you log both you will see they are close to the same. I think if you want to do a map you will need to figure out the "ideal" advance and then the difference between "ideal" and estimated or sae.sparkadv should be taken off, or added to your high octane table.
Im currently trying to figure mine out at present I was running about 30deg spark under load. I understand 26 or so is about right.
I just put a known good baseline in there and will probably tweak that.
You really wont know what "ideal" is unless you dyno the car. VE is a little easier to figure out I think.

caver
November 20th, 2005, 12:39 AM
Easiest way without a dyno is to adv timing in 2deg encrement untill you start getting knock and then back it off so that there is very little.
Monitor GM.Aspark to see what the spark scaler is doing after you enable the low octane table again and you should be done.

Blacky
November 20th, 2005, 10:37 AM
The EST in the PID names: {GM.EST_xxx_DMA} stands for Electronic Spark Timing. There is nothing "estimated" about these spark values. They are very much *real* spark values.

Sorry, it took me a while to figure out why I was reading "estimated" spark. I thought maybe I missed some new table Ross had added.

Regards
Paul

ZL1Killa
November 20th, 2005, 11:46 AM
so blacky what would be a good way to find your "Best" spark values ?? or is there really one?

MCG
November 20th, 2005, 12:47 PM
A good way to analyze your spark effeciency is to use a 5 gas analyzer. If you have access to one, they are great to work with. Watch you CO and NOx counts. When they cross, you should be right at peak combustion chamber effeciency. We've done that on several cars, and it makes them very crisp in responsiveness and picks up on gas mileage. The bad news is that they aren't cheap. Decent 5 gas analyzers start at around $3000US.

Blacky
November 20th, 2005, 02:08 PM
so blacky what would be a good way to find your "Best" spark values ?? or is there really one?

Nothing in EFILive will tell you the "best" spark - its all in the art of tuning, and looking at external inputs like the 5-gas.

I am not a tuner, but the following two points are sometimes overlooked:

Don't run spark too close to KR, because as you get KR the spark will retard back below where it would have been had it not been set so close to detonation.

Don't use extra fuel to prevent detonation that could just as easily be fixed by retarding the spark a few degrees with no loss of power, especially on turbo/supercharged cars.

Regards
Paul

ZL1Killa
November 24th, 2005, 04:40 PM
gotcha on that one. I'm going to be playing around with these numbers for a while. I still have my stock tune and I notice that my spark tables in the stock tune have a huge curve climbing to pretty much 42 degrees at high rpm but other than that the values are pretty much in the green.

I will be playing with these numbers....don't see how some people say 35+ degrees is too much....especially if the stock tune calls for up to 40, but then again thats up high in the rpm

caver
November 24th, 2005, 06:25 PM
gotcha on that one. I'm going to be playing around with these numbers for a while. I still have my stock tune and I notice that my spark tables in the stock tune have a huge curve climbing to pretty much 42 degrees at high rpm but other than that the values are pretty much in the green.


You have to differentiate at what airflow you are seeing 40 plus degrees.Those numbers are all on the left hand side of the table which is light throttle low airflow. at Wot you should see over .68 g/s which should be between 18 and 25 deg depending on exact airflow and rpm.

If have 35+ deg at the high airflow numbers then you have a huge problem.