Knock Reading

On startup these cold mornings mine is up at about 100.
After a few mins, goes down to a reading of less than 10.
After a spirited drive about 12 or 13.

kev gtr said:

On startup these cold mornings mine is up at about 100.
After a few mins, goes down to a reading of less than 10.
After a spirited drive about 12 or 13.

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So why would mine be giving me such high knock values, any ideas?

Maybe my SAFC2 is rubbish.

60 is regarded as the top end of what you want to be seeing under load.

Sounds like you need to get her checked out.

Almost double, that sounds bad man.
Guess its rising sun tomorow.

Thanks for the help guys.

cas sensor

I would not like to see my PFC record 40+ under load, when open throttle I see around 11-20

also what fuel you using - the higer the octane the better det proof why I only use v-power

I regulary see 120+ LOL, take every reading with a pinch of salt, knock sensors will pick up on other noises and read as det.

im using 99octane. Mapped by rising sun to 400bhp.

Max i have seen is 30, anything over 60 is bad, but sometimes its nothing to worry about.

I get 7 knock on cold start.

i agree with the CAS, i reckon that will be your problem. get it checked anyway.

as bruce mentioned it could be rattle through the engine with worn engine mounts or anything, but i defo reckon its your CAS

if its mapped by RSP then it cant be wrong can it?????

better watch because if the knock goes high it will turn the engine like cheese there was a member up here that got 86 on the knock and didnt last long

From what iv looked into anything over 45knock is damage, witch was listened too with Det cans on my RB26.

If it was mapped by RSP then it should be ok, could be that your knock sensor / sensors have came loose causing them to give high readings.

Also you have to take into account the condition of the road your on, bumps or bangs form suspension can be felt from the road-engine mounts-block-sensor

Picked my car up from tuning yesterday, as I went on M6 noticed 150!
Drove back to garage and we went out for an enthusiastic sprint.

In one cell on laptop it hits 150, either side of the cell its 30 on the laptop.

So I was told to ignore it as PFC false reading Also many many many runs on dyno and sometimes recording 150, there was absolutely no excessive knock through det cans.

Get it checked out but they can give falseys.

how are tha main bearings?oil pressure and age of the fuel pump?

Where are you taking your readings from? PFC or SAFC II?

If it´s SAFC II you need to go through knock sensor calibration to get a reading that is anywhere close to what it really is. Do a calibration and see what the readings are after that.

Also yes it´s correct you shouldn´t worry too much as other metallic noise that has same or similar frequency as knock can and will be picked up by the knock sensors too, so this can cause higher readings.

But keep an eye on the numbers and if they´re too high or at least higher than they´ve been before you should get it checked. Better safe than sorry.

SAFC 2, so im guessing I need it calibrated.

Thanks guys, appreciate all your help

No probs mate, let me know if you need any further help.

Got high 40's on one long pull to over 160mph and engine holed a piston....

Cheers,

markm3 said:

Got high 40's on one long pull to over 160mph and engine holed a piston....

Cheers,

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Odd, 40 shouldnt have done that surely