Knock Reading

[karting]

Hi, just a quick question, i have a Power fc and commander, im just wondering what the knock reading should roughly be around on a rotary. Just for piece of mind tbh

Thanks

[turbotoaster]

depends on a few things mate, loose things in the engine bay will affect it because it will think its knock.

im running a stock downpipe and cat, driving around in vacuum i normally get between 30-38, had it up to 79 on a flat out run to redline.

i did put my foot down to the floor in 5th at 1500rpm to see at what rpm my first turbo hit full boost, knock went to 118 and heat light come on, never been that high before and dont know if it was the circumstances of loads of boost at low rpm or just something rattled setting it off.

what sort of readings are you getting?

[karting]

i booted it today and went to 111 (why i asked),  but usually it is around 30\'s - 40 might go up to 50/60s if im doing a bit of fast roading.

[turbotoaster]

well 111 is way to high in my opinion, if it happens again maybe pull a bit of timing out, do you know roughly what rpm it was when it happened?

[karting]

i didnt check, but it was whilst showing off, i however dont ever remember in the past it being that high before, and rest of journey home it never got near that

[Jono FD3]

to be honest... I reglarly see 100 + when I view the knock!! But like said above, it could be some mettal to mettal contact with something, a loose nut rettling or even something stupid like a turbo about to spit the dumby, or even a nakerd sensor! you just can\'t tell, which is why alot of people don\'t bother looking!

The other thing is, once the knock sensor has picked it up, the damage is done... similar to the stock water temp gauge!

Jono

[turbotoaster]

well keep an eye on it, when you see it go up look at what rpm it is, if its around 5000-6000 then you need to pull some timing, if its when your not pulling big revs etc then probably something loose in the engine bay

[Timmy]

You can get knock at low rpm i\'ve had it at about 2500 rpm turned out to be a gap in the map. Unless you know your knock sensor is broken it\'s worth investigating.

[adib]

been driving my rx every day for 5 years and see 100+ all the time and engine not blown yet.

[ashc]

old knock sensor in the car is notoriously poor, mine was reading way high, reworx just disabled it in the pfc settings - if the map is safe, ignore it.

[trotter]

My dump valve sets mine off, as does tyre roar, exhaust noise and a whole host of other things!!

Pip set up my map and told me to just ignore it because (and i\'m paraphrasing here) "if it was that high you\'d be picking bits of tips off the Moon"

[karting]

Thanks guys, feel alot better now!

[neil_jdmr]

If you have ANY aftermarket exhaust or downpipe or a slightly dodgy engine mount or even a loose engine bay bolt can cause this to go crazy. A waste of a sensor imo.

[leefitz]

how do you go about reading the knock sensor?

[turbotoaster]

if you have a power fc it will show it on the hand commander