RT

I have asked, "how many LED's on our knocklinks do each of us get" before.

There's a slight variation this time:
I assume that before we've all been talking about the # of LED's at high RPMs high boost with WOT. How about when the boost is just hit max?

If I put my car into first or second gear and let the clutch out with the car coasting fowards at say 2000rpm. At this point I give it WOT - of course not much happens for a second or two due to the lag of the STI. But the moment the boost starts to build and hit max (approx 4200rpm), I get a sudden 2 greens and sometimes 1 momentary amber.

Car's a MY01 STI RA with knocklink sensor on intake manifold and sensitivity set to max.

Can someone help with feedback? Is this what we're seeing as well? Or is there some sort of "mild det" thats happening before the factory knock sensor realises that something is amiss and retards the timing.

mutant_matt

RT,

From what Dave Power was saying whilst showing me an Ignition Timing and Knock Detection trace off an EcuTek trace, the new models (MY01&gt run on the limit of knock and the ECU pulls back the timing in real time as it sees knock occuring. So theoretically, you are getting the most out of the fuel you've got in there at any given moment.

I would guess that this is why you're seeing more noise on the Knocklink that perhaps you would not expect to see, particularly if you're used to watching it on an old shape Scoob.

Matt

RT

Matt, that's exactly what I feel also.

Isn't too encouraging when you're used to see a very quiet knocklink.

Anyone else have similar experiences?

R19KET

Unless you set the KL sensitivity up, or confirm it's working right, with a set of "det' cans", the lights are pretty meaningless.

It's common for the KL to be most active at between 3500~4500rpm (depending on car/turbo) because that's where you hit max boost (normally with some overboost).

You'd also expect some activity at high rpm, purely because of background engine noise.

But again, this needs to be confirmed with det cans.

People are always advised to set the "sen's" to max, because it's "safer", and gives an early warning, but at the same time, it can also be too conservative.

Correctly set up, and if the car is tuned for "max power" you should expect to see 2, and occasionally 3 lights up under WOT. This is "normal" on the KL scaling.

Mark.

RT

Tks much for the info. I've heard before that the knocklink is not a substitute for proper det cans. I know this! But when the darn thing keeps lighting up in front of you, questions questions questions keep popping into your head. (am sure lots of us suffer from this "disease")


I guess 2 greens is safe then. On the other hand if the big red LED is flashing, then better not ignore it!

Thinking about its operational logic:

1. Is the knock sensor ONLY a microphone that converts real time vibrations of a specific frequency into a linear signal out to the LEDs?

2. Or does it have a "memory" or "history" function that can remember what the vibration signature was over the last few seconds and detect any sudden/rapid rise of the "knock frequency", and then translate that info into the LED's signal. ie if the specific "knock frequency" does not occur suddenly, it will take that to be regular engine vibrations?

Clearly (1.) is simpler, but (2.) may potentially give a more accurate picture since the onset of knock is sudden. Does anyone know its operational logic for sure?

Deep Singh

Hi RT.In my MY98 STi I often get two green lights and can often have one green on all the time at motorway speeds.I have had it checked with det cans by one of the UK's best respected tuners who heard no det.As Ricket says if you are worried have it checked with det cans and set your mind at rest(and enjoy your car!)

JohnD

iTrader: (5)

What ECU`s other than Link store the det. count? Think I might ask BR to check it out at my Link "fine tune" I`ve only ever seen the greens flicker a little once or twice so I don`t expect to see much, if anything, stored.
JohnD

Deep Singh

John,remember that the det memory will be wiped once you switch off the engine,so keep it running when you arrive at Bob's.