Knock Levels On Safc Ii On An R33

[WogsRus]

Hi, i installed my SAFCII last night, no probs, last night after reconnecting the battery and everything, the knock level ( which i connected to knock 1 on the ECU) was 36 and 45. Now today after driving arround for the day and filling up on some BP ultimate, the car shows a knock level of 96 and 105.

So what is going on, is it because last night the car was only just after a reset, so the setting have changed.

ALso what is acceptable knock levels. I never bothered to do the test between wire 1 and two as the manual says, just connected to Knock 1. What do most people use, Knock 1 or Knock 2, sensor outputs that is.

Edited September 3, 2006 by WogsRus

[paulr33]

for the powerfc over 60 triggers the engine check light which is, "warning, get it checked by your tuner" the number represents the level of the knock, not knocks per second or amount of them, but how big it is. higher is worse

[(oo\__4Door__/oo)]

for the powerfc over 60 triggers the engine check light which is, "warning, get it checked by your tuner" the number represents the level of the knock, not knocks per second or amount of them, but how big it is. higher is worse

my safcII on my rb20 silver top shows 0 when its cold and can reach 35 on a hot day with the high octain fuel

[WogsRus]

ok So here is some more oddities.

When cold the knock is 35, after an hour, it shows 60, then after some more time 90. HOWEVER if you then turn the car off, wait 10 minuts, on a hot engine, and turn back on, the knock is back down to 35.

WHAT THE???? The car runs fine, don't sound like anything funny, no power deifferance between cold and hot, no drop off in performance.

NOTHING.

I am going to connect my knock sensor wire to my Knock No2 wire and see how that reacts.

What can couse such a weird veriation in knock levels.

ANYONE. WHAT knock sensor wire do you guys have it wired to????

[leech_]

i had the same problems with mine... in the cold it would run at like 40 on a hot day though it said like 80 - 110 i took it to get checked out he they said it was running fine and that the safc was reading wrong ??? i thought with them though you had to set a base level which was never done on mine.

[WogsRus]

Sorry, need to clarify, all the numbers are on base setting level. ( calibration screen)

So basicaly, this is where the raw data is from, i did my setting again, when cold, i presume that is better, as that is when the engine is less likely to knock.

So basicaly when it is callibrated to 35 and 40 it shows zero knock on the monitor screen. Once it gets to 90 on the setting callibration, it is only about 6 on the knock monitor screen.

The values that the SAFC II unses for knock are raw data, that is then interepereted to a value, so you do need to set it.

I just did not think, that having number like that all over the place was normal, but like i said the car runs fine, no problems, everything seams ok.

I am also going to change my O2 sensor, just to make sure, as the car has started to use a bit more fuel, mind you a heavy right foot don't help.

So what reading do most pople get?

ALSO THE MOST IMPORTANT. WHAT wire did you connect to knock sensor 1 or 2.

[SECURITY]

i connected mine to #1.

on idle on a cold day it'll read around 10-12. in the hottest day of summer it read 45 but it only reached that after giving it a hard time.

[WogsRus]

well not sure what is going on. Who knows, will know when something goes POP.

The reading you are getting, are they at the SETTINGS screen or the monitor, after they have been set up?

[Mr Italy!]

Mine sits around 10ish on a cold day after a bit of driving, but its been up to 35ish or so.

Are you running really advanced timing? if not, then i wouldnt worry.

[Busky2k]

Yeah the SAFC does show 'background noise' on a hot day. It did this on my old S14. My theory is that if it pings it'll be at least 60 points 'above' the background reading at idle. Cheers.

[WogsRus]

Well, basically if i set the number in th einital set, basiccaly, lets say 35 and 40 at corresponding rpm, then back at the monitor screen it will show 0 and maybe 10 once really hot.

However 10 on monitor screen is about 90 on the setup screen.

SO WHAT IS GOING ON.

Nope i have not changed the timming, as far as i know.

Will find out in a couple of weeks, once i get the tune.

[Busky2k]

Yeah but the setup doesnt get you to set the knock sensor level at idle IIRC. So yeah just take my advice, as it was the best way to see if you were detting. I had experimented extensively with that darn SAFC II.

[WogsRus]

so the knock level you are talking about, is that on the setup screen or on the Monitor screen.

Dam this thing is confusing, i just don't see how the number could actually be as high as it states. I mean, if it was getting above 90, the dam thing would have poped by now.

So whould i worry or what, should i bother about connecting to wire number 2?

HELP

[Busky2k]

I'm referring to the monitor knock value. So lets say its a super hot day and at idle its showing 40. No need to worry there, its just noise. After a boosting session the peak recall is about 55. The difference is 15, so therefore you aren't pinging. If the peak recall was 110, then yes the motor was pinging because the difference is 70. So just subtract the idle # from the peak # and go from there.

Its unfortunate the SAFC II does not let you set up the background noise "knock value" at idle.

[Mr Italy!]

^ So can it be knocking at idle at all?

Why does the background noise increase on a hot day and when engine is warm?

[paulr33]

it certainly is possible but highly unlikely

[leech_]

Can others confirm this ??? if thats the case that would make sence as my knock sensor didnt show anything on the monitor screen... ever... but in the diagnostics it showed up noramlly about 60 driving around and as i said on a hot day with a fang like 90 - 110... if thats the case does that mean i am really just getting a knock reading of like 0 - 20 ???

as i said i have never heard my car knocking and the workshops i have taken it too also have not ever heard any knocking... i think my safc (that was stoeln) was possibly a little faulty

However 10 on monitor screen is about 90 on the setup screen.

[Busky2k]

I don't know why the readings go higher when the car is hot. but its not vehicle specific. It happens on SR20s, your RBs obviously and even 4G63s (EVOs). Once I even unplugged the darn knock sensor and it still showed a value on idle. Weird shit indeed.

What I have found is when its a hot day, rerun the knock calibration. Esp when the values in the monitor are high on idle. This helps lower the number a bit. But as I mentioned, the *difference* between the values on monitor whilst idling and peak recall is how to determine if your car pings.

[Sydneykid]

Hi, i installed my SAFCII last night, no probs, last night after reconnecting the battery and everything, the knock level ( which i connected to knock 1 on the ECU) was 36 and 45. Now today after driving arround for the day and filling up on some BP ultimate, the car shows a knock level of 96 and 105.

So what is going on, is it because last night the car was only just after a reset, so the setting have changed.

ALso what is acceptable knock levels. I never bothered to do the test between wire 1 and two as the manual says, just connected to Knock 1. What do most people use, Knock 1 or Knock 2, sensor outputs that is.

Where do you have the SAFC knock sensor wiring connected?

At the sensor?

OR

At the ECU plug?

Either way, the problem is cross talk getting into the SAFC knock amp. That’s why you need “trim” out the background noise. Then you will see only true knock readings.

cheers

[WogsRus]

Allright then, alot of stuff has just been said, and i can't make any sense.

IF my car is Stone cold, in the SETUP(SETTINGS) screen, it will show 35 at idel 35 at 1500 and 45 at 3750 rpm.

This sets the knock to ZERO at the MONITOR screen

Ofter driving round, and having some fun. The reeding in the SETUP (SETTING) screen can show 90, but that is only 10 on the MONITOR SCREEN.

I turn the car off, leave for 10 minutes, come back start, and the setting in the MONITOR is back to zero.

And slowly works it's way up.

SO does the engine knock show in the MONITOR or SETUP screen, I torght that the Knock is in the MONITOR scrren, as the SETUP screen is just for calibration. So basicaly get the engine to temperature and then set the knock at correcponding rpm when hot.

Is that correct.

Can somone tell me how else to tell if engine is knocking?????

What is the deal with teh knock setting, if it's so inconsistant, what's the use of it?

The knock is taken from Output 1 or 2 for the knock sensors

Edited September 5, 2006 by WogsRus