Why does my Advance Multiplier keep dropping?

[steve99]

Originally Posted by LucasFT86

@steve99 @jamesm @Shiv@Openflash

So a month after switching back from E85 tune to stage 1 tune, I decided to plug in my OFT and noticed my adv multiplier was down from 1 to 0.80 . It's pretty much always been at 1 even when I was running E85 on the stage 2 tune. I took a short datalog with a decently hard pull and adv multiplier increased by .01 after the pull. Heres the link to datazap:

http://www.datazap.me/u/lucasft86/lo...-9-10-12-13-14

any ideas why its down to 0.8?

No knock correction in that log and flkc is returning timing arround 3000 rpm area,and iam is 0.8, knock must have occurred prior to that log, you will need to log some more.

try some light partial throttle runs 3000 to 6000 to get the iam back to 1 then some full throttle runs and some driving in the 1500 to 4000 rpm area in high gear high load and se if it knocks.

might have been a bad batch of fuel.

[LucasFT86]

Originally Posted by steve99

No knock correction in that log and flkc is returning timing arround 3000 rpm area,and iam is 0.8, knock must have occurred prior to that log, you will need to log some more.

try some light partial throttle runs 3000 to 6000 to get the iam back to 1 then some full throttle runs and some driving in the 1500 to 4000 rpm area in high gear high load and se if it knocks.

might have been a bad batch of fuel.

ok thanks, I'll do another log and get back to you.

[JB86'd]

So if your IAM is at 1, can FLKC still be stored so even though you're at IAM 1, timing is being pulled in certain spots?

[steve99]

Originally Posted by JB86'd

So if your IAM is at 1, can FLKC still be stored so even though you're at IAM 1, timing is being pulled in certain spots?

Its fairly complex see here this was for 16 bit ecu but appears similar to our 32 bit ecu nore their iam was 0 to 16 where ours 0 to 1 and our correction value is 0.35 not 1 or two degrees ( oft tunes changes values from stock)
http://www.romraider.com/forum/topic1840.html

If IAM is 1 then flkc can only be negitive, if iam is less than one it can be positive or negitive.Appears when your iam increments or decrements then flkc table is cleared.
Dont worry i had to read it ten times bgefore it started to make sense

[Kodename47]

Originally Posted by JB86'd

So if your IAM is at 1, can FLKC still be stored so even though you're at IAM 1, timing is being pulled in certain spots?

Yes. It's because of consistent FLKC or FBKC that will cause the IAM to reduce.

[JB86'd]

Originally Posted by Kodename47

Yes. It's because of consistent FLKC or FBKC that will cause the IAM to reduce.

So what I'm trying to get at is, even if your IAM is 1 (ECU is making no changes over entire timing table), your ECU can still be pulling timing in certain ranges due to stored FLKC, and add the timing back if it sees fit at some point, all without IAM changing? In simpler terms, if your IAM is 1 it doesn't mean you're 100% knock free?

[steve99]

Originally Posted by JB86'd

So what I'm trying to get at is, even if your IAM is 1 (ECU is making no changes over entire timing table), your ECU can still be pulling timing in certain ranges due to stored FLKC, and add the timing back if it sees fit at some point, all without IAM changing? In simpler terms, if your IAM is 1 it doesn't mean you're 100% knock free?

Yes even if iam is 1 flkc can still be active as can fbkc.

you can have low levels of either type of knock detection occasionally and iam will say at one. The ecu has some weird algorythm where if it sees certian levels of knock in a certian period it will decrement iam, if knock is under these levels of size duration and frequency then iam is not decremented, conversly if it sees levels of knock below these thresholds it will try to increment the iam if it is less than 1

[LucasFT86]

UPDATE: So I got the adv multiplier up to 1.0 shown in log 1 with partial throttle pulls. In log 2 I was commuting to school attempting to cause knock not sure if it knocked at all. Log 3 was during my commute from school to work. I noticed adv multiplier started to drop while on the highway. It went down as low as 0.64

log 1: http://www.datazap.me/u/lucasft86/lo...10-11-12-13-14

log 2: http://www.datazap.me/u/lucasft86/lo...10-11-12-13-14

log 3: http://www.datazap.me/u/lucasft86/lo...10-11-12-13-14

@steve99 @Shiv@Openflash @jamesm

[steve99]

Originally Posted by LucasFT86

UPDATE: So I got the adv multiplier up to 1.0 shown in log 1 with partial throttle pulls. In log 2 I was commuting to school attempting to cause knock not sure if it knocked at all. Log 3 was during my commute from school to work. I noticed adv multiplier started to drop while on the highway. It went down as low as 0.64

log 1: http://www.datazap.me/u/lucasft86/lo...10-11-12-13-14

log 2: http://www.datazap.me/u/lucasft86/lo...10-11-12-13-14

log 3: http://www.datazap.me/u/lucasft86/lo...10-11-12-13-14

@steve99 @Shiv@Openflash @jamesm

Ok what happening is pretty normal on 91 fuel, some brands are better or worse but if you want to fix it either

A ask one of the california guys for a copy of their modded 91 rom or Base Timing B changes

B read the knock correctio links below
from a quick look if you pull about 1 degree from your Base Timing B table , rpms from 2600 to 3400 and loads 0.8 to 1.4 should fix it.

[LucasFT86]

Originally Posted by steve99

Ok what happening is pretty normal on 91 fuel, some brands are better or worse but if you want to fix it either

A ask one of the california guys for a copy of their modded 91 rom or Base Timing B changes

B read the knock correctio links below
from a quick look if you pull about 1 degree from your Base Timing B table , rpms from 2600 to 3400 and loads 0.8 to 1.4 should fix it.

I only use 93 octane since day one

[LucasFT86]

@steve99 now that I think about it I usually use Shell 93 and I think I'm running Sunoco 93 right now. I'll fill up with Shell and see if it goes away.

[wparsons]

I get more knock on a 91 octane tune with 91 octane gas commuting on the highway than I do beating on it on a track. It's the light-mid load lowish rpm range that's the worst, right about where the RPM's sit at highway speeds.

I don't find I'm getting anywhere near as much knock on a 93 octane tune with 94 octane under the same driving conditions.

[steve99]

Originally Posted by wparsons

I get more knock on a 91 octane tune with 91 octane gas commuting on the highway than I do beating on it on a track. It's the light-mid load lowish rpm range that's the worst, right about where the RPM's sit at highway speeds.

I don't find I'm getting anywhere near as much knock on a 93 octane tune with 94 octane under the same driving conditions.

Correct as 91 &93 tunes are same except for timing above 5000 rpm. So below 5000 it same tune your running on 91 vs 94 octane

[LucasFT86]

@steve99 I just put in a K&N drop in filter today and idle afr switches from 14.7 to 14.8. Am I running a tiny bit lean? Should I reflash the stage 1 tune?