rich knock or lean knock

[d_tsiawd]

i have a1g with a 2gmas and my afc settings are pretty up there i was wondering does rich knocking and lean knocking do they have similar characteristics? how can someone tell if it is rich knocking or lean knocking? here is a graph of my last night about 90% throttle im trying to figure out if im lean knocking or rich knocking.

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[kpt4321]

I honestly don't think rich knock exists.

I need more information (more datalogged parameters, mod list, boost level, etc) before I can tell you much more.

 

[HighPSI TSi Guy]

Originally posted by kpt4321
I honestly don't think rich knock exists.

uuhh... are yuo drunk? i know you know enough about tuning to know that rich knock very much exists..

they way you tell if it is rich knock or lean knock is by adding/subtracting fuel to see if it goes away, looking at EGT or O2 volts, or using a wideband

 

[Tyler_Baker]

What are you corrections on the SAFC? How many lbs are you running? With 9:1 Compression, I am thinking that is lean knock.

 

[d_tsiawd]

look in my profile for mods. im at like +45% correction acreoss the board and my egt stayts around 400-600 C hmm thanks for the response i'll try messing with afc again

 

[jdmawd]

I have been as rich as 10.8:1 when i first installed my 720's with no tuning. The logger never registered knock at that a/f ratio. If your motor is knocking its lean.

 

[nine5raptor]

Originally posted by d_tsiawd
look in my profile for mods. im at like +45% correction acreoss the board and my egt stayts around 400-600 C hmm thanks for the response i'll try messing with afc again

+45% wowzers

why so rich? Are you still using the 1g mas? Why not start at about -10% and lean out from there?

Are your fuel trims pegged at 80%? 02 voltage ever make it below 1.00V?

 

[kpt4321]

Originally posted by HighPSI TSi Guy
uuhh... are yuo drunk? i know you know enough about tuning to know that rich knock very much exists..

Originally posted by jdmawd
I have been as rich as 10.8:1 when i first installed my 720's with no tuning. The logger never registered knock at that a/f ratio.

There you go.

I've been even richer than that, without seeing knock.

Rich knock might exist, but I've had the car so rich it sputters and misfires, without the knock sensor picking up anything.

Maybe it is possible, but you need to be richer than shit to do it.

 

[kpt4321]

Chris is on the right track, you seriously need to work on your tuning.

 

[HighPSI TSi Guy]

Originally posted by kpt4321
There you go.

I've been even richer than that, without seeing knock.

Rich knock might exist, but I've had the car so rich it sputters and misfires, without the knock sensor picking up anything.

Maybe it is possible, but you need to be richer than shit to do it.

maybe a 1G knock sensor can't pick it up or something.. rich knock is different than lean knock, but still bad.. we were able to see it on my buddy's car using a EMS w/ 2G knock sensor.. that is the only time i've personally witnessed it however i've heard of it on other occasions.. load, etc, would play into effect too

back off your base timing.. and start at 0 on the AFC and lean it out from there.. also turn down the boost to a moderate level

 

[Tyler_Baker]

Originally posted by d_tsiawd
look in my profile for mods. im at like +45% correction acreoss the board and my egt stayts around 400-600 C hmm thanks for the response i'll try messing with afc again

It doesn't say how much boost your running in your profile. Also, are you running 7ES spark plugs? With that much compression and a bigger turbo, you definetly want to run a colder plug.

 

[Bohrn]

my car will definately rich knock. When I put my 625's in, I left it at the same settings (SAFC) as my 450's. It ran almost 2 seconds slower and had tons of knock. I took out 15% across the board and it went a full 2 seconds faster, and had almost no knock(except heat soak, stock IC type knock)

I guess each car is different.

 

[d_tsiawd]

well i dropped the corection to around 30 im runnig stock boost oas of now i was wondering sometimes im cruising in like 5th gear around 2200-2500 rpm and im knocking then i let go of gas and press again and it goes away.. weird anyways my fuel trims are not pegged at 80 and my o2 does read less than 1.0v my o2 seems to be reading incorrectly the o2 voltage goes to 0 when i drive

 

[thejeebus]

Log your fuel trims, 02 trim, and inj. duty cycle. Post them up so we can give you a better idea.

scott