[p057]

Related to my last thread, i am getting phantom knock at ~3000 rpm on map A (A/c off) vs Map B where i dont get knock at all.... so ive been driving with the a/c on pretty much all the time the car is on.

Anything easy I can basically copy over from one table to another to get rid of that crap? The map i use is basically the "stock" Stage 2 +TIH +SF 1.03a map.


Or if you can point me in the right direction I would be very appreciative!

 

[bova80]

if this is just cruising around there is nothing to worry about. if you are talking about your maf cal tables they should be the same anyways. there is nothing you can do to eliminate knock at part throttle cause its just the way the ecu is. and its not map a vs map b, they are tables, maps are the whole thing. unless you are trying to say its 2 maps.

i eliminated to part throttle knock by no longer monitoring anything while i'm daily driving. that way I don't have to see it.

 

[daztd]

What's your knocking range on part throttle....on the low side 1-2 or is it higher?

 

[MWSpeed6]

I stopped monitoring knock for DD as well. I wish the dashhawk allowed us to set a knock alert with additional conditions (e.g. RPM >= 3500 AND TPS >= 50 AND KR >= 1 or something like that) so we could monitor knock where it's more relevant. But we can't...

 

[TiGraySpeed6]

Along these "ghost knock" lines, Travis @Cobb posted the following not too long ago on the Cobb Forums while discussing random low load KR-

During normal driving, you will see more correction, but this can also be interpereted as timing adjustments and not nessecarily knock events. At lower cylinder pressures, this low-load high-knock count is normal and you shouldn't worry about it too much!

source thread from cobb forums:
New Logs. lots of knocking. Please need help


I too think it would be nifty if there was more of an event driven alarm set-up for the DH, but oh well. I do still monitor tho- have to while I'm still cleaning up some high load, foot to the floor KR numbers that appear from time to time (in the +4 to +6 range, 4th & 5th gear, WFO throttle - passing somebody for instance)

 

[p057]

whoops, sorry bova, you're right. not "maps" table A vs table B. And yes, i saw that both MAF tables were the same, you are correct.

As far as the knocking, i know its just a weird thing the ECU does, but the problem is the fact that it does it only when the A/C is OFF. if i turn it on, knock-be-gone.

I get the phantom knock at very light throttle at around 3k rpms. it doesnt go down, it starts going up, down, up, down, up up up, down down, up.... etc.

i think i've only heard my engine physically ping/knock twice since owning it. once because of crappy gas near my fiance's mom's place near pensacola ******* towns and recently because i over-loaded the engine at too high a gear stupidly.

I never hear/d knock otherwise.


anyway. i know i shouldnt care about it, but the fact that having the A/c on means that I dont get ANY "adjustments" means it must be a pretty solid table or configuration?

 

[laxplayermjd]

i was working hard to try and determine my phantom knock. i narrowed it light throttle 1500-4krpm from loads .7 and lower. all gears but 1-2.

ive changed timing for cl and part throttle ol. cant seem to resolve it and its fully random. sometimes wont see it for a month. values avg 1.8-2 degrees. but ive seend 6-7kr before

 

[daztd]

What is considered a safe KR range? Is 6 kr too high? I sometimes get 1.5 to 2.7

 

[bova80]

you are not going to solve part throttle knock...if you want it to appear less then just let it go and dont' take your foot off when you see it. your car needs to learn the timing for best gas mileage. at part throttle it can be anything really because there is no cylinder pressure there won't be any damage. At WOT you generally don't want it over 1, and if you see anything over 4 you'll probably be able to hear it and that's really not good, but this is WOT.

 

[p057]

i was working hard to try and determine my phantom knock. i narrowed it light throttle 1500-4krpm from loads .7 and lower. all gears but 1-2.

ive changed timing for cl and part throttle ol. cant seem to resolve it and its fully random. sometimes wont see it for a month. values avg 1.8-2 degrees. but ive seend 6-7kr before

This isn't about knock in general. this isnt a discussion about knock. i'm trying to find out why its occurring under only THESE conditions:

A/C off.
light gas at 3kRPM or at 80MPH.

Otherwise, there is no "knock".

If I have the A/c ON, i DO NOT RECEIVE "KNOCK" AT ALL.

THIS is where I'm confused. I read all the tech notes Cobb put out, i read all the info everyone and their mother has posted on this, I read that it shouldn't even really be noticed at all -- only when at WOT........BUT what I just only want to know is why the hell does having my A/c on prevent this condition from occurring in the first place?

you are not going to solve part throttle knock...if you want it to appear less then just let it go and dont' take your foot off when you see it. your car needs to learn the timing for best gas mileage. at part throttle it can be anything really because there is no cylinder pressure there won't be any damage. At WOT you generally don't want it over 1, and if you see anything over 4 you'll probably be able to hear it and that's really not good, but this is WOT.

 

[MWSpeed6]

This isn't about knock in general. this isnt a discussion about knock. i'm trying to find out why its occurring under only THESE conditions:

A/C off.
light gas at 3kRPM or at 80MPH.

Otherwise, there is no "knock".

If I have the A/c ON, i DO NOT RECEIVE "KNOCK" AT ALL.

THIS is where I'm confused. I read all the tech notes Cobb put out, i read all the info everyone and their mother has posted on this, I read that it shouldn't even really be noticed at all -- only when at WOT........BUT what I just only want to know is why the hell does having my A/c on prevent this condition from occurring in the first place?

I'm just speculating here... I know it is possible for the knock sensor to pick up other noise from the engine bay. Maybe there is something loose in your engine bay and somehow the A/C keeps it from rattling while on. When you turn off the A/C, this potentially loose part rattles within the right frequency range and is picked up by the sensor. Pretty far-fetched thought, but I just don't think this issue is related to (software) tuning at all.

 

[bova80]

because the load is different with the A/C so it is targeting a different timing number. just look at the timing for the 2 different loads and i'm sure that will tell you why it is happening.