I get knock from time to time and also over boost quite a bit (which im sure are spikes, i think) my knock count usually hovers around 3-6 when i do a few pulls. it generally happens on the first pull and to my understanding having done some research, you almost all the time disregard the first pull. However, as shown above this was like my 5th pull and it happened once before this (same day). I hit 16 knocks the first time and 19 on this one. side note: my cobb ap showed 31psi when i hit 19 knocks. i have no idea why it shows only 27psi. at the time of this occurrence i was WOT and i felt like the clutch my have slipped. i didnt take the time to note the rpms shoot up or not because i heard some pressure being released underneath the hood that wasnt the BOV (ive never heard before). is this normal?

I never really race around in my car to often and never track it. i have been noticing every time i want to do a hard pull im getting huge spikes in boost 27 - 32 psi with excessive knocks. nothing like this though.

my car has been professionally tuned and the temp today was a bit colder then when the car was tuned this doesnt explain why its been happening often though.

any ideas? more info?

 

I can't really tell you why it is happening, what mods are on the car? But I can say that is not normal knock and you should have your tuner address that ASAP. Those are very high counts of knock. i typically get a retune if i get anything above 3 on a regular basis.

 

All i have is intake exhaust with a tune. I got the tune about a year ago. im sure ill need a tune im just not sure if there is anything else wrong with the car.

 

It appears there is a difference of 4 psi between what the gauge on the AP registers and what you are logging ( 31 psi vs 27 psi).

 

yes....

 

Any consistent knock above count 3 at WOT should be looked into. Getting a random 3 count is ok if it is truly random. When you start getting huge numbers for knock like your logging, if that is actually knock then you are risking blowing your engine. I don't see wide-band data on your log, and that means your in the dark. If your fuel pump is dying, or the relay is stuck on low-voltage you could be getting lean conditions = BOOM. Want to keep your engine alive ? Set the check-engine light to flash at a knock count 5 (or 4), and get a wideband in there ASAP. You can see the light flash easy without looking off the road, and have a buddy staring at the wideband. Have him scream like a girl if at WOT you see 12 or higher and get off the gas if you see a light flash (the knock light). I know a guy who was "pro-tuned" to the edge of his injectors and lost his engine when the weather went cold. The denser air made the engine run lean = BOOM, buy buy. If I had to guess with those crazy boost numbers you are heading that way.

~Jaraxle

 

I'd reduce the timing a little OR throw a few gallons of E85 in the tank to see if those numbers go away. That's the only real way to know if those KR numbers are real or not.