Scrub

iTrader: (25)

Can someone tell me what could be causing this? I will get a reading of 103 sometimes and even higher. I was told it could be engine noise, I could be running too rich and it could be the timing is off. Whe I was putting the belt back on the alternator pulley I turned the eccentric shaft pulley by accident, could that be the problem? I don't think it is but I could be wrong. Also I will be getting my car tuned next week sometime, im guessing that will eliminate the high knock readings by getting better air fuel ratios. I just wanted a second opinion on what this could be from. My guess is it's running too rich. Anyone else?

Thanks,
Dan

Badog

Knock is relative.

Normal knock for me is 100. For someone else it could be 10. So if I see 175, my eyes perk up.

What is your "normal" or average knock and what is the degree of deviation?

Who is tuning your car? Make sure they log and work off the logs rather then watching a display and tune from it.

Do yourself a favor and make sure you car is in tip-top shape before taking it the the tuner. Put fresh plugs in there, change out the wires if you have now, and make sure everything is in good working order...like the brakes and tires if road tuning.

Do you know where your peak knock is? What RPM range or cell if you have a datalogit? If you're running any mods and using a base map I can tell you that you have a whole section of the "map" that is lean, right about 4000rpm and up to about 7psi boost. I won't be specific since each car is different to each ECU and map on it.

List out your mods and I'll PM you with where you will be lean, and you can double check your tuner's results with it and tell me if I win anything!

Tony

cewrx7r1

iTrader: (2)

Mine reads low while accelerating under full boost, but as soom as I shift or let off the pedal, the knock sometimes will jump to over 70. Mine is drivetrain noise.
When I went to coil overs and solid sway bar end links, my noise levels also went up higher.

Take you car out for a spin with a knowledgeable PFC
observer on board. A datalogic would give you exact data.

jeff48

As usual I am in agreement with Chuck and Tony.
MY normal knock levels are below 30 and 90 percent of the time below 15, but I get peaks of up to 180 or 190 on the Commander's peak hold feature. Those numbers used to scare the hell out of me.

It turns out that after buying a datalogit and logging the runs, the scary peaks occured for under 300 milliseconds in duration and SECONDS AFTER the throttle was released. No chance of the knock being related to detonation. Although I have never been able to accurately determine the cause (could be backfires, drivetrain noise, whatever) I am not concerned about the engine anymore (at least in reference to these numbers)

To accurately determine the meaning of the knock reading, you must have good data about when the spikes occur and what the other engine functions are doing. Get a datalogit or at least have a co-pilot telling you when the peaks occur and the approximate time period of duration.

radkins

Wow, Jeff you are always full of good information. I was wondering about that myself, because I always see high knock readings when shifting. I have seen knock go high during slight backfires when letting off the gas.

rotorbrain

my knock readings seem to move up with rpms. no matter what i do. . . its always there. the readings are jumpy when im cruising and the such. its hard to just dismiss that damned thing, ya know. haha.

paul

DavidDeco

Mine too but the peak is at the 6-9 columns mostly and then go back down. I replaced the knock sensor just to be sure ...same thing. I have a WB linked to a datalogits and I have plenty of fuel in those cells with high knock.

Now that my car has been completley reconstructed I will find out how is now but Knock readings seem to only be useful in a relative context....

rynberg

When I first installed the PFC, I was getting knock near 100 in 3rd and 4th gear pulls. I reinitialized and reinstalled it (don't ask) and let it learn everything again. Since then, I haven't had a knock value over 50, even when shifting or letting off the gas.....hmmm....

ZeroBanger

my knock would on a regular basis be 175 or so on my power FC on my old engine. It has never gone above 15-25 on my new one.

One of my motor mounts was broken, my mechanic blames that for the high readings before.

dunno.

wave65

I have another weird question to ask. If anyone have the answer, pls let me know. I went out just now and logging the knocking in my labtop. It was showing maximum at 15, but in the same time it was shown 22 - 28 on my commander. After I turn off my labtop, under the same conditions, knocking was gone up to 68. Then I was logging on again, same result as the first time, only 15 on labtop and 28 on commander. I checked a few times and I still got the same result. Do anyone know what going on? Which ones should I believe? Logging or Commander? Thanks in adv.

twokrx7

iTrader: (1)

Sorry if this is not applicable to your situation but be careful when using the Datalogit software ... when I start up the latest version it defaults to a maximum displayed value of 15 in Mapwatch mode. I have to change it every time. I always keep the monitor mode screen up on the laptop which displays maximums.

jeff48

Generally, (not always but most times) when the datlogit is recording, the commander freezes. This is normal so I would not count on any consistency between peak hold numbers on the commander and the datalogit file.
Twokrx7 is also correct about the Max value limitation. You should reset it for each parameter. I believe the reason for the 15 default is that AFRs over 15 will screw up the average and are usually indicative of "throttle off" conditions no matter where in the map they occur. Reset the max to 200 for knock and hope you don't see anything that high.

BATMAN

I get 120 most of the time.

But I have good ears and can actually hear the "nuts" bouncing around in the engine-sound when it;s knocking.

Until i have time to get Excess Eng. to tune the car I would say that i'll ease off on the BNR on stock maps. They definatelty flow more air.

TwinTriangles

Mine usually reads between 15-20 on acceleration hard or slow but like most of you said it will jump to about 50 when shifting but never seen above 50...

GoodfellaFD3S

iTrader: (213)

You're playing with fire, Mr. Wayne......

Power_Put

i have the same problem my gose up to 60 - 70 and even on neutral it nocks but i think we have **** fuel in Europe i hope its the fuel anyway??????

damian

iTrader: (2)

hmm, i logged at the track today, it was very hot day and I was on normal pump gas, 12psi, knock never went above 20....

AUS-FD3S

i know this is old but any way...

Before my re build i read between 2 and 5 knock

AST blew and shat the motor, i registered 65 knock

After rebuild, moved t warmer climate, now reads no more the 3 knock

Seems like we need a better method of recording knock.... if i saw anything as high as 10 it would scare me enough to pull over.