How much knock is OK at low RPM

[Lil-Steve]

I assume this is just because of the cold weather but I\'m getting big knock numbers on my PFC at lift off at low RPM.
 
I\'m routinely getting a max of ~145 when I\'m out for a drive I was just wondering what the knock value actually is db/knock events per second/knocks per quantity rpm? :confused:
 
I know knock isn\'t as damaging at low rpm and light throttle I\'m just wondering if high knock at low rpm over a long time will cause lasting damage?

[batman]

ive always wondered this my apexi some times shows large knock levels on the display but never had any problems ?

[MaLicE]

from what i have read the knock sens isnt that great and will register every noise it can, as its basically a microphone and grit hitting the bottom of your car could be setting it off...

[Archbish]

It isn\'t brilliant, and just picks up certain frequencies.  It\'s probably best to phone up one of the tuners to ask.  I don\'t think when slowing that it should be a problem, but I guess it\'s still feasible that it\'d occur (less fuel, so could detonate, but unlikely...).

[gandyRX]

i was told is basically just a microphone that listens to your engine, before my remap i was getting around 30 on idle and 60 when driving, after the remap i normally get around 1-3 on idle and no more that 25-30 when driving, it all depends on where it is, ow its been mounted and what with etc, i was also told that some fd\'s can run anything upto 150 safely, but any nre vibration can make it readmore

[Dr-Rotor]

Your all right. The knock sensor pretty much dosent mean a thing. As you have all said, its like a microphone...boost it over some bumpy roads and man hole covers and watch the numbers sore.

Nothing to worry about, you will know when you have knock cos you will hear it, Think of it this way, do you realy think that watching some numbers while you drive to see if you can prevent your car from detonating will save it?...dettonation happens so quickly you will not be able to prevent it and especialy not with the knock sensor the FD has.

For those worried about knock and dettonation install some water injection and forget about it. Enjoy the car, warm it properly and thrash the crap out of it.

[ttpower]

For those worried about knock and dettonation install some water injection and forget about it. Enjoy the car, warm it properly and thrash the crap out of it.

very nicely said lol  :wiggle

[DR SCHNITZEL]

*2 As above. Ill have a slice of that!

[Dr-Rotor]

Its funny cos its true.

[gsb876]

Also a thing to remember is if you get the exhaust popping it will bump up the knock reading too :Laugh

[gandyRX]

yeah mine jumps up abit when it bangs, or going down bumpy roads lol

[NurburgRob]

Originally Posted by Dr-Rotor  View Post

For those worried about knock and dettonation install some water injection and forget about it. Enjoy the car, warm it properly and thrash the crap out of it.

very nicely said lol  :wiggle

What sort of price is a good water injection system fitted to a moderately tuned twin tubby?

Any specific requirements for fitting water injection?

Thanks :cheers

[Ricco_04]

i was also told that some fd\'s can run anything upto 150 safely, but any nre vibration can make it readmore

150 will be a false reading.  I used to get that reading so phoned up Pip to check.  After telling me to calm down he informed me that anything that high would have pretty much shat apex seals out the noisy thing at the back of the car!

Fixed the sensor issues now and never get more than 40 in this very cold weather.