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Discussion Starter · #1 ·
it has been almost a month now that i have been datalogging. I was concentrating on the fuel maps at wide open throttle. I came to a point that i brought the air fuel ratio from 4400 to redline around low 12s to low 13s. I feel this sufficient for right now because i am planing to get comptech race header in the near future so i dont wanna lean it out further more. Right now i dont have any knocks at wide open throttle. one or two shows up on very low voltage like 1s or 0.9s rarerly. I wanna concentrate on ignition timing now. I dont know a specific guideline to go doing this. Like i knew what the air fuel ratio had to be around when i was changing the fuel maps. Should i just advance timing slowly, through out the rpm range and stop when it starts knocking. Would this make more power. I cant think of any other way doing it except dyno tuning it which wont be hapenning pretty soon.

AK
 

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Discussion Starter · #3 ·
wdsonny said:
That is the problem alot of us are having. Start advancing slowly. Then when you get knocking retard it by .5. That should solve your problems.
i did all my runs at night because of air fuel ratio is leaner at nights, and car runs actually slightly richer day time due to less denser air. Should i do the ignition timing at night too?

AK
 

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REDLINE JUNKIE said:
it has been almost a month now that i have been datalogging. I was concentrating on the fuel maps at wide open throttle. I came to a point that i brought the air fuel ratio from 4400 to redline around low 12s to low 13s. I feel this sufficient for right now because i am planing to get comptech race header in the near future so i dont wanna lean it out further more. Right now i dont have any knocks at wide open throttle. one or two shows up on very low voltage like 1s or 0.9s rarerly. I wanna concentrate on ignition timing now. I dont know a specific guideline to go doing this. Like i knew what the air fuel ratio had to be around when i was changing the fuel maps. Should i just advance timing slowly, through out the rpm range and stop when it starts knocking. Would this make more power. I cant think of any other way doing it except dyno tuning it which wont be hapenning pretty soon.

AK
A lot of good questions and I sure wish, I really sure do wish, that there'd be a place where authoritative answers could be found.

By and large, there are only general rules on ignition timing. Like, the higher the rpm the more advance you need because it takes the piston less time to get to the top. And the higher the load, the less advance you need because a richer AF mixture burns more quickly. That's the general picture. Then you advance the ignition enough to get best power, but not so much that you run into knocking. There is a point where further advance will not bring extra power, even if there is no knocking. And it is said that the Type-S engine generally makes the most power within two degrees of knocking.

However, each car is different. Some will start knocking at a low advance, others will tolerate a very high advance and you could go even higher because the engine is not knocking, but it makes no sense as there is no extra power to be gained.

As for the knocking level, do not get hung up on the actual voltage. The voltage is just a relative value. It gets scaled up or down based on a number of variables and rules within the ECU. Next time you datalog, see how K.Threshold goes from max to min when you cross MAP = 40 unless vehicle load I also around 40. Or how the scaling totally changes when you cross 2,500 rpm. I could describe the rules i found in detail, but it suffices to say that they greatly affect K.Level and K.Threshold.

If I had to start from scratch, I honestly wouldn't know how to create a basic ignition advance table. I'd hope that someone somewhere had published a technical paper on how the K-Series likes its ignition. I'd start with that and then go on a series of dyno runs with fixed cam angles, adjusting timing at each part-load column until I am within a couple of degrees of knocking. That could take forever.

By now I have a pretty good idea of how to get rid of knocking by just looking at datalogs and figure out what the problem might be. I just wish there were more answers.
 

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wdsonny said:
That is the problem alot of us are having. Start advancing slowly. Then when you get knocking retard it by .5. That should solve your problems.

To a point. Knocking is most obvious on the low cam. On the high cam you can easily overadvance the ignition and have no knocking. You will loose power and put extra load on the engine though.

For a NA motor peak power is usually attained within about three degrees of the maps we ship.

I recommend you get it dyno tuned.

Doug
 

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Discussion Starter · #7 ·
Hondata said:
To a point. Knocking is most obvious on the low cam. On the high cam you can easily overadvance the ignition and have no knocking. You will loose power and put extra load on the engine though.

For a NA motor peak power is usually attained within about three degrees of the maps we ship.

I recommend you get it dyno tuned.

Doug
i see, i guess thats something i have to tune on the dyno. Otherwise, i would possibly over advance it and not even know about it. I am going to leave it the way its right now till i get the race header and, i will hit the dyno.

AK
 

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REDLINE JUNKIE said:
i see, i guess thats something i have to tune on the dyno. Otherwise, i would possibly over advance it and not even know about it. I am going to leave it the way its right now till i get the race header and, i will hit the dyno.

AK
I wouldn't give up just yet. Looks like you made some good progress. If you study the maps and all the info in the threads, you can definitely get your motor to not only be knock-free, but also set the A/F properly for most of the table (--> power). Then you can start smoothing out the curves, tweak the spots where the cam angle jumps too much during VTEC, smooth areas where ignition jumps too much, and generally tweak each individual curve. I am not sure there are too many tuners right now (except those who already have years of Hondata s-series experience) who'll be able to do much better.
 
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