i just got my car running again and im getting knock reading up to 22. Is that normal or too high?Im still break-in my motor, so im not driving it hard yet. I had XS tune a base map with my mods. I just want to blow my motor again. so im alitte worry.

 

They say less than 60 is good, but I try to keep it below 40 if I can... 22 is absolutly no problem

 

oh thank! I

 

****, mine knocked at 89 once, but it was at like 2000rpms under light throttle. Is that bad? It dosen't knock higher than 38 under WOT.

 

Mine knocks at close to 100 regularly, hit 189 a few times. Engine still going strong, so go figure.

 

last night i had a 89 knock reading under wot at about 6000 rpm.

 

159 here, purrs like a kitten..

 

Mine is kinda round 100s. I dont know if that is too good but no problems so far.

 

Page 13 of the instruction manual says:

"There is no value to the Knock level. Please use it as a reference for tuning"

Basically, if you're always in the 20s but then one day you hit 150, that's probably bad. If you're always around 100 and your motor hasn't blown up yet, it's probably normal. I think each car will have different "normal" knock readings.

 

I've been railing and railing on my engine and have been getting an average knock of about 20 or so. I just recently took it out all the way through the middle of 4th Gear, it read a WHOPPING 14!!!...

...then again, when I get on really bad roads, my knock seems to go up...

...or when I don't fill up on Gas...

 

You all need to get a wrench and tork your knock sensors... I may go down... those are actually some slightly dangerous knocks regardless of what the manual says...

 

Be careful torquing your knock sensors, the sensor is very difficult to gain access to, and I broke mine trying to torque it.

Does anyone see any harm in running without a knock sensor? I haven't had one on my car for over a month and so far it's been completely innocuous.

 

Funny, I just read your other message about breaking the intake temp sensor.

You big muscle man....

-Matt

 

Heh, tell me about it.. It's strange, I'm not even sure what I did to my knock sensor. It just stopped working and would just display "1" on the monitor screen. Before that I was consistently getting knock readings in the 100's.

Anyhow, there's no way I'm going to go buy another $200 microphone from Mazda just to get a bunch of arbitrary readings.

 

Yeah, I'm bringing up some old posts
I'm just curious...if the knock reading as no true meaning, then what exactly DOES it mean?

Does ANYONE know what figure in the knock means that you are detonating? It's there so it MUST mean soemthing.

 

Max at ~ 100 so far (in the light throttle range). I have noticed that if the A/C is on, it runs abit higher on average.

 

OK, I'll bite and ask the obvious dumb question. It was my understanding that the stock ECU didn't include any retard based on knock, thus the "need" for people to put the aftermarket system on. So what the hell is the sensor even for???? I didn't think it ever triggered anything like a check engine light. Maybe it was thrown in there in the early design stages and then Mazda realized it wasn't reliable and just decided not to use it?

For the record, I generally see 30's on mine, but at WOT redline runs I see occasional peaks of 100. Unfortunately I haven't been able to catch it on a graph of knock vs RPM yet to figure out if maybe it's just noise from shifting or anything. Was racing a 928 this morning and then looked down and saw the peak of 100....

 

The Stock ECU did have a timing retard function for knock but it was only 4-6 degrees. which works with a stock setup but once you start making more power it's just not enough. The PFC has no knock retard. You can run a J&S but it only does the leading plugs so it has limits and issues too. I've seen that the values from THe PFC are as stated above, a value that changes car to car.

 

Cool, I had never read anywhere about the stock retard. By the way, for what it's worth I caught my knock peak yesterday on the graph, and it happened at 7500 right at the peak RPM when I shifted and stopped accelerating. Just one spike. Probably noise.

 

My knock reading shoots upwards when I blip the throttle. I've read somewhere that the stock knock sensor has a hard time distinguishing normal engine noises above 3000 RPM from detonation. This was from someone selling the J & S, I think. Anyway, It sounds like this is true if bumps in the road affect the reading. It must be at least partially effective, as when I test drove my car before I bought it, it would puff black smoke at startup and when blipping the throttle. I saw the guy put in 89 octane, and when I started putting in 94, I never saw the black smoke again. I believe it was retarding the ignition enough to run really rich.

 

OH OK, check this out, I though I put this out, but maybe not. This problem has came up a lot, many different people and APEXi, RE-Amemiya and a few other
companies say the same thing, the stock knock sensor is GARBAGE!!!. If you worried about get an aftermarket sensor, or something. This happens only with the POWER FC that I have heard, APEXi says its the car, and Im sure if I asked MAZDA they would say it APEXI, bottom line if you have the power FC just turn off the Knock warning and dont view the knock level.
If you have more question feel free
Jason
JT-Imports
Yokohama Japan
www.jt-imports.com

 

I think the stock knock sensor is garbage also, but I know that I have HEARD knock, and looked up at the PFC and there it was...78 reading. Normally, it will stay around 20 or so, and it will run great. But I must have gotten a bad batch of gas or something because at 6000 rpm's, it started to run like crap and then "bang"...knock...

 

Up until recently, my highest reading was arnd 100-120. I just installed my M2 CAI and Efini y-pipe a week ago and this past Saturday for the first time I noticed readings up to 159 which is the highest Ive ever seen. But Ive only owned my car since last fall.......so I dont know if my mods, outside temps or a combination of both has somethng to do with it. One thing I think I noticed is it seems to go haywire if Im goin uphill (even slightly) in a higher gear running low revs.
Anyone else notice when theirs is goin a lil crazy?

 

Well, if its anything like my prelude's knock sensor, basically there is a bit of variance between the sensors. If you change knock sensors then you end up having to re-tune your j&s to the new one. I'm not sure if its like that on the FD, but I would imagine so, which would explain why they say that it should be around the same reading and not jump alot higher, but that the base isn't super important.

 

Here is stupid question #2:
I don't have a knock sensor. With my Haltech setup, how much retard should I run with each pound of boost? I'm new in the turbo world and I don't know the basics.