Jump to content
SAU Community

Recommended Posts

I did the whole set up step of the knocking levels, was getting about 80 at 1,600rpm & 92-100 at 3,500rpm (in set up screen - not monitor)

so then I put it in monitor mode and it says around 4 while idling but then drops to 0 whenever the throttle is open..

I set it up once the car was warm & took it for a drive once the car was also warm & that's the reading I got..

(I've got an R34 with 35,000kms on the clock)

Ideas as to why it drops to 0?

Link to comment
https://www.sau.com.au/forums/topic/163747-safc-2-knock-level/
Share on other sites

i just bought an safc2 myself (havent installed it yet)

but as i understand it - you are meant to subtract the "stock" knock figures from the "tune" knock figures... no?

since it's a microphone you'd get knock anyway - but since the "stock" knock figures are normal, you would ultimately make that zero?

what the ?

the knock display on the powerfc is bar chart and digital counter output which goes up as the knock is larger

ie: knock 0 means no knocking. knock 40 is mild, knock 60 is warning, knock 100 is bad etc etc..

normal driving should be 0 or very very low

what the ?

the knock display on the powerfc is bar chart and digital counter output which goes up as the knock is larger

ie: knock 0 means no knocking. knock 40 is mild, knock 60 is warning, knock 100 is bad etc etc..

normal driving should be 0 or very very low

yes, but who sets normal driving = 0 knock? certainly each car has a different "normal"

Ugh, I tried resetting the knock sensor information and I'm still getting the same problem! :(

In the setup screen it's on about 63ish at 1,400rpm and 80-90ish at 3,400rpm yet when I take it to the monitor mode I still get 2,3,4 displaying in neutral with the throttle closed but as soon as I put my foot down a little it just jumps to 0..

I'm doing all this while the car is completely warmed up - oil temp wise.

this is normal.. it has to do with how the SAFC interpolates knock values.. you will often find that after a long driving session (where your knock might have been say 10-15, you will come to rest in neutral and the knock will jump up 8-10 while idling. dont worry about it.

but I'm not getting any knock reading while driving..that's my problem..?

I did a bit more of an investigation:

0 Knock readout in Drive at all times

1-4 when in Park or Neutral

WTF?!

Edited by so_tred

bump, I really want to figure this out..

The 34 has 2 knock sensors coming in/going out of the ECU, could it be that the other knock sensor might somehow respond differently? I really don't want to go pulling things apart again though unless its for sure that's what it is.

I just found this on another message board:

"I was wondering what other peoples knock readings were. WHile at idle, my knock reading goes anywhere from 2 to 16. When I give any throttle at all, the knock reading goes to 0 and stays there."

Reply: "I think at idle your picking up valvetrain noise and other noises.. Low idle you can hear rattles and other noises that you normally wouldn't associate with engine knock.

Even at low RPM its possible to pick up noise.. The truth is that knock sensitivity needs to be fairly numb at low RPM especially at idle, and progressively more sensitive at mid-upper RPM's where you'd typically produce the peaks of boost and up from there.."

Sound about right?

But why does everyone elses here not behave like mine & this guys..

Edited by so_tred

i have no idea how the safc figures out its knocking levels but the powerfc does exhibit any of this behaviour

you dont need to calibrate the pfc knock sensor and it just works out the box.

you get knock display which increases as detonation occurs, via the factory knock sensors

the higher the voltage from the sensor, the higher the value of knock

Michael gets high figures like (80-200) in his RB20 if he floors it onto the freeway. Not too good :(

I leave my car in the sun alot and it's always knocking when I start the car in summer :rofl: Runs like crap in the heat... of course I think my coilpacks might be fried which doesn't help :P

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I mean, I got two VASS engineers to refuse to cert my own coilovers stating those very laws. Appendix B makes it pretty clear what it considers 'Variable Suspension' to be. In my lived experience they can't certify something that isn't actually in the list as something that requires certification. In the VASS engineering checklist they have to complete (LS3/NCOP11) and sign on there is nothing there. All the references inside NCOP11 state that if it's variable by the driver that height needs to maintain 100mm while the car is in motion. It states the car is lowered lowering blocks and other types of things are acceptable. Dialling out a shock is about as 'user adjustable' as changing any other suspension component lol. I wanted to have it signed off to dissuade HWP and RWC testers to state the suspension is legal to avoid having this discussion with them. The real problem is that Police and RWC/Pink/Blue slip people will say it needs engineering, and the engineers will state it doesn't need engineering. It is hugely irritating when aforementioned people get all "i know the rules mate feck off" when they don't, and the actual engineers are pleasant as all hell and do know the rules. Cars failing RWC for things that aren't listed in the RWC requirements is another thing here entirely!
    • I don't. I mean, mine's not a GTR, but it is a 32 with a lot of GTR stuff on it. But regardless, I typically buy from local suppliers. Getting stuff from Japan is seldom worth the pain. Buying from RHDJapan usually ends up in the final total of your basket being about double what you thought it would be, after all the bullshit fees and such are added on.
    • The hydrocarbon component of E10 can be shittier, and is in fact, shittier, than that used in normal 91RON fuel. That's because the octane boost provided by the ethanol allows them to use stuff that doesn't make the grade without the help. The 1c/L saving typically available on E10 is going to be massively overridden by the increased consumption caused by the ethanol and the crappier HC (ie the HCs will be less dense, meaning that there will definitely be less energy per unit volume than for more dense HCs). That is one of the reasons why P98 will return better fuel consumption than 91 does, even with the ignition timing completely fixed. There is more energy per unit volume because the HCs used in 98 are higher density than in the lawnmower fuel.
    • No, I'd suggest that that is the checklist for pneumatic/hydraulic adjustable systems. I would say, based on my years of reading and complying with Australian Standards and similar regulations, that the narrow interpretation of Clause 3.2 b would be the preferred/expected/intended one, by the author, and those using the standard. Wishful thinking need not apply.
    • Yes they do. For some maybe. But for those used the most by abusers, ie Skylines, the numbers are known. The stock eyebrow height for R32/3 Skylines is about 365/375mm or thereabouts. The minimum such heights are recorded in adjacent columns in the database.
×
×
  • Create New...