Knock sensor on power fc

[«Cyph3r»]

Hi,

Just wondering what some peoples fc commanders read as peak knock when driving hard? What level should it stay under and what would be high enough to cause damage (shortened engine life etc..)? I have noticed mine has read up to 23 but more recently on fresh optimax only 13. What is acceptable as it has been tuned by a well known and reputable dyno tuner.

Thanks

Jamie

[Jimbo2000]

Originally posted by «Cyph3r»

Hi,

Just wondering what some peoples fc commanders read as peak knock when driving hard? What level should it stay under and what would be high enough to cause damage (shortened engine life etc..)? I have noticed mine has read up to 23 but more recently on fresh optimax only 13. What is acceptable as it has been tuned by a well known and reputable dyno tuner.

Thanks

Jamie

i think you're sweet as long as it stays under around 50-60

[GTS-t VSPEC]

The fact is you'll get lot's of different answers from lots of different people about this. If the tuner has done a good job there should be no pinging, check what the highest level you get under hard driving conditions, add a bit of a buffer, and you will have a reasonably safe knock level. If 23 is the highest you've achieved while driving hard, then it shouldn't go much past 30 unless something has changed, so might be worth backing off to check.

The knock sensor picks up all engine noises, not just pinging, so the level will be different between cars.

[Steve]

the check engine light flashes when it hits 60, as mentioned I dont think there is too much of a problem if it is under that, personnaly as GTSt has suggested, I keep an eye on it and if it increases much over any period of time it tells me perhaps I need to be careful - dirty plugs, changes in humidity or temperature etc.

I believe it is a guide only. I have had a tune where it regularly went up to 50-60, and no damage was done. The lowest I have seen is now, where it pretty much always sits below 20.

The highest I have seen is 98, no apparent damage, BUT I always back off when the check engine light flashes.

I hope that helps.

[jezzrrr]

Hi,

Just wondering what some peoples fc commanders read as peak knock when driving hard? What level should it stay under and what would be high enough to cause damage (shortened engine life etc..)? I have noticed mine has read up to 23 but more recently on fresh optimax only 13. What is acceptable as it has been tuned by a well known and reputable dyno tuner.

Thanks

Jamie

How do you know what the maximum reading is ? I have PFC and data logit but dont know how to retrieve things like max rpm, max knock etc ???

SK, you out there ?

[Steve]

Use the peak hold function. When in the monitor mode, push the right arrow

[Guest INASNT]

I see 65+ sometimes when fanging around at 20psi, time for a retune

[JasonO]

Hmmmm, It's been said before, but the knock reading on the PFC is an arbitrary value. It is an indication of knock only not a scientific measurement.

The differences between sensors and each particualr engine is enough to make so many differences in tolerance that you can only ever use it a s a rule of thumb.

I know that when my car was tuned previously the dyno op insisted that he could hear no knock from the engine even though the PFC readout was displaying upwards of 60. I have occasionaly seen in excess of 90 (but like Steve I would always lift off in this situation) and having recently stripped my engine found absolutely no det related damage.

My new build shows less than 30 even at more than 1 bar of boost

[Steve]

So when can we expect to see a full report of your results:)

[JasonO]

Jamie's or mine ?

[HeathGTST]

I got 84 knock last night 2nd gear came out of a corner sideways not reving hard with 4 people in the car... engine light flashed quickly then dispeared....

Would this have done much damamge if any??? it hasnt effected the knock levels since... I just shit myself when it happened.

My usualy knock level for casual driving with a few squirts is around 10-22 knock on PFC

[Busky2k]

Shouldnt cause any damage, but its a sign that maybe you should get your mapping or other things rechecked.

[Robo's]

Just experimenting with my new Power Fc, im getting low 10-15 on start up, should be this correct?

On hard throttle, im getting mid 30's!!

[HeathGTST]

nah no way dude. I occasionaly get get 2 on start up... When the engine is cold i get read outs of up to 15( i drive slow when im warming up... ie. shift <3000rpm)

on hard open throttle on a cold night i get about 15-25 knock which is good... You arent too far off the mark in regards to wide open throttle but if you are getting 10-15 when starting you might want to get things checked out. Bear in mind knock sensors pick up mechanical noise aswell so it may be even the starter motor.

Take it to Benny at Race pace. i think many people will agree that BENNY IS THE KING OFF SKYLINE

[Robo's]

If i give it a quick light rev in neutral i get a reading of 10-15, there is no load on it, it maybe just some mechanical noise so im not going to worry about it.

[Robo's]

What are your readings for ignition timing on map 15?

Im getting advance of 23,22, which seems around right

[performance-wise]

I normally have a readout of 2 or 4 on start up.

I took note of my max readouts the other day in a controlled environment.

duty- 32.0%

timing - 44 deg.

A/F - 3810mv

revs - 4520

speed - 167kmh

water temp - 81

knock - 69

These were taken at night time at a cooler temp and I always use ultimate.

Are these the max readouts? Is this the info to use to see how its runnin?

On hot days I have had knock readouts of up to 90 and once I got a 120! Of course I always keep an eye on it and I back off when it does start knockin.