Theory on my knock retard...
 

so I installed the dashhawk last week, did a few data logs despite the ridiculous weather going on here in MD (95+ degrees with tons of humidity). everything looked good, for the most part. on my third run I picked up ~2 degrees of KR for a few hundred RPM's around 5K RPM, but I'm blaming that on heat... it was about 100 degrees outside and I didn't give the car enough time to cool off between runs. I did a few more runs the next night when it was a little cooler and got zero KR and my other numbers looked right on. anyway...

I have noticed over the last few days that I get some sporadic KR right as I'm pulling out onto the road and driving away in the morning. this happens at very light throttle, as I'm just cruising down the road nonchalantly. this only happens shortly after I start the car, after the car has been sitting for a while. I get a blip of KR, sometimes as high as ~7 on the dashhawk, and it disappears. throughout all this the engine sounds perfectly normal to me. after I drive for a few minutes, it goes away. I find it hard to believe that there is actual predetonation going on.

my theory is that as the car is still warming and loosening up, vibrations in the engine bay are more pronounced than they are when all the rubber and synthetic parts get warm and loose. I'm wondering if some random, benign noise in there is tripping the knock sensor. I've read about how sensitive our KS can be.

I'm running a CP-E rear motor mount, 60 duro if I remember correctly. do you think it's possible that this is a side effect of using the stiffer mount? think it's possible that this is part of the reason why Mazda went with the pathetically flaccid OEM rear mount to begin with? I could see them running into this problem during testing, and choosing to soften up the rear mount rather than changing a critical piece of their engine mgmt system...

thanks for reading the long post

Mine is just the opposite. I don't see any in the morning (temps around 90). I get mine on the way home when it's around 105 outside. Always in the first three gears while pulling away from a redlight or stop sign, usually peaking around 1.4 but sometimes hitting 5. I hardly ever see it while cruising and changing gears. Last summer I had the stock motor mount and saw 0.0 knock at all times. Now I have the StreetUnit mount, so maybe it's a combination of stiffer mount and heatsoak while in traffic? My BAT's are usually in the 160s.

It could. I noticed that when i had my TRZ Poly, random KR happened way more often. When i put the stock mount back in, it was better. Then again, i did some other minor changes like tightening hoses/clamps/etc that could have improved this.

When the car was bone stock with a stock tune, i barely saw these instances of random KR.

I now have the 60 CP-e along with custom tune and i only see the .3/.7kr problem that a lot of us have.

read my post from this thread

http://www.mazdaspeedforums.org/foru...60/#post563330




.3 and .7KR is nothing to worry about. my car gets those blips every single time i drive the car around town.

Stiffer mounts was something I thought may contribute to KR months and months ago. However, I went from Corksport MM inserts to a CP-E 75 duro RMM and I get no more KR than I did before. I do believe isolated rattles in the engine bay, like a heat shield, can cause KR.

i too get teh "just started my car and am in the first 10 minutes of driving" kr readings...usually abou 5-7 and it goes pretty much constant at part throttle for about a minute or two...after about 5 mins of driving (or by the time i get to the highway) it is completely gone

read my post above

Same here. Everyday I get on the interstate, at the EXACT same place on this little hill I get random KR just as I peak the hill, sometimes as high as 7KR, usually around 2900 RPM. It's always in the first 10 minutes of driving, then I don't get it ever again.

This happened both with and without my CP-E RMM, so it's probably related to the warming cycle.

i changed all my mounts and added a kicker mount. i get the same crazy pt knock as i did before. no more, no less.

i'm sure they know that by now.

I see .3 and .7 consistently coming off idle, and passing 5K rpm--just about every time...

But, IMO anything higher than .7 isn't phantom knock, there is something causing it..

funny to think about how KR readings arent truelly indicating knock. It's sound sensors right? So something like a motor mount absorbing vibrations could potentially change it's readings.

although the theory with the company gettin flacid on us is not gonna work. With a sensor they could change the set input it would have to go over for it to read anything above zero.

I too get the warm-up knock in the morning that goes to 5.9 and then works its way down to 0 if you hold the pedal at the same place while the computer is doing its thing.

I'm also in MD with this horrendous humidity. My MS6 does this only after it has warmed up, and only on very light throttle, in vacuum. My only mods are AP Stage1 + SF 91 and the COBB SF intake. I've noticed that it does it when my temps go to 160+ more... REALLY hope it's just the engine adjusting timing............ I've seen as high as 7.3 on very light throttle, but I never hear any pinging, rattling, or feel any difference... and I don't see any knock with more throttle all the way up to WOT... so I think (hope) it's the phantom knock syndrome....

yes it is adjusting timing, keep your foot on the gas in the same position when it's doing it (as long as it's safe so you wont crash) and it'll go down shortly. no harm done

Yup, that's what I do and then it doesn't do this again until the next morning. If I interrupt the adjustment by lifting off the gas pedal then it does it again but then time with less degree adjustment. Say it was 5.9 the first time, the second time would be 3.9.

I don't even bother to look at it anymore unless I'm doing WOT pulls.

Ok guys, thanks! I get it, but it just seems weird to me... but at the same time, I don't hear any pinging or rattling when it happens. I guess that PTP thread about the engines hydrolocking on oil when cruising on the beltway has me scared. Like I said, I get 0.0 kr when warming up. Here's a pic of the log I took with it that I posted in that PTP thread... This is what I saw at light exit ramp throttle after a 25 mile cruise @ 70 mph.

http://i149.photobucket.com/albums/s...realm/pic1.jpg

I've attached the full excel log as well, just for future reference. I guess I'll have to wrap my head around partial throttle, light load knock being "ok" as you guys have suggested, but I still feel that the car is trying to squeeze out way too much timing for such a low throttle, or the system is getting heatsoaked or something...

yeah... heatsoak can do this and especially with the heat nowadays it could be a particular problem.

honestly, if you arent hearing the clicking it probably isnt a problem. Old info, but meth could clear up this problem... I honestly dont think you need it but meth would provide the quick cooling and it supposedly clears the system in other ways too

just a thought from another fellow hater of KR

looks like the typical "adjusting timing" thing to me. if you let it run it's course it shouldn't do it again until the engine has cooled down, is that the case?

also, it should go away almost instantly if you press the gas down more. you'll interrupt it as it's certainly not going to continue the test if you all of a sudden go WOT

Agree...