knock question for 3rd gen....reading the pfc commander...how much is too much?
 

I have been paying very close attention to my guages since installing my new motor and turbos......on the pfc commander I watch the knock meter rise very slightly and then fall down to zero....my car is running very very rich at the moment and will by dyno tuned soon. however....I did see a couple times where the knock meter went up to a length of about 3/8s of an inch...


how far is too far up the knock level meter on the commander unit?

at what point is the danger danger danger level?

for the most part it stays about one tick...which is about 1/8 of an inch....occasionally under accelleration it will hit about four ticks up the meter.

any ideas?


j

you can get a peak number using the peak hold feature, press the up arrow when your watching the 4 or less values (it does it when wathcing 8 parameters but you can't watch the real time values then), it will then have a small box showing the peak numbers beside the real time values. Looking at the bar is worthless, atleast with the peak number you can tell what your engines average is, then when tuning, you can tell if 55 was the average and now its averaging 75, timing might need to be turned down. Make sure the knock sensor is torqued to specs since loose ones tend to make the number artificially high. According to the manual, 60 is nothing to be worried about, some see a high number but its when they let off after a WOT run.

Tim Benton

thanks...Ill check it out.

the peak did come on the bar when I let off....

j

what are good numbers for me to compare to/shoot for?

I keep reading that the numbers are worthless and don't mean squat.

Myself, on a 3rd gear run, I hit between 30-40. If I shift inbetween a run, then it will jump up to about 70 or so. I've read that any little engine noise will appear through the knock sensor. I've done the same test several times, and I only get the high readings when I shift. I was wondering if I was running lean when I simply just let my foot off the gas, and nope, it consistently stayed in the 30-40 area

i dont know how the knock thing works, mine was always really low, but a friend of mine sees 120+ and we have the same mods.

mike

That's why you just use it as a base. In Flybye's case, since he knows it averages about 30 to 40 at WOT, if he starts seeing 90s, he might have gotten a bad tank of gas with lower octane, etc. Find your cars average, and remember it for future use. I was hitting around 40 at WOT, using octane booster dropped it to mid 20's, I then advanced the timing in certain maps sections (at WOT) and it went up to around 35 or so, but the car felt more powerful. Curious I went back to the dyno and it did make more HP on the dyno, with no changes to the fuel maps. Previous best was 326 rwhp and 276 ft/lbs. Now I made 334 rwhp even with slightly heavier wheels and an aazing 296 ft/lbs. If I stop using the octane booster, my numbers will climb back into the high 50 at WOT, where it used to be 40ish with my old timing maps.
With timing, becareful and do adjustments in 1 degree increments and test those changes before making more.
Tim Benton

OK this is straight from APEXi They say they have heard this SOOOOOOO many times and have troubleshot it. They found that the RX7 Stock knock sensor is not reliable. I had the same question, along with many others.

and their solution is??? :confused:

is there a better knock sensor they recommend.

you know I never asked.
Personally I think its their software....
I can ask, but I dont talk to them
very often, but I will post it when I
find out.