redbase

I just purchased a PFC from RX7 store, and was reading the manual: "Detonation levels over 60 does NOT necessarily mean that the vehicle is detonating. Use only as a reference." I noticed I have knock levels of 60-62 under normal driving conditions. So at what level or value of knocking should I get worried????

I have the following mods: M2 intake, Petit downpipe, gutted cat, and RB catback.

ttb

from my searches the pfc knock values don't mean anything. ignore it like i did.

artguy

you need to get your car on a wideband and see what your afr's are. simple as that. they need to be
11.2:1 approximately....leaner at vacuum and mayble just a hair richer up top at high boost for safety (spikes etc..)

j

artguy

btw...my knock is around 22 average....when i have run it lean it pinged at 60. if you see 60 every day and your car is not pinging then watch for anything over that.

imho

OC94Rx7

Glen from NZ / Datologit said anything over 60 is not good. I have almost the same mods as you except, I still use the stock Main cat. I will check my numbers if you like so, you will have some more averages.

Dr Wankel

From what I can tell, the #'s fluctuate greatly from one car to the next. I commonly see #'s in the 70-80 range but hear no pinging whatsoever and my O2 voltages still read very safe, I have occasionally seen it jump to 120 still with no audible pinging, (this has not happend in over 6 months though) What I find interesting i that my peaks only jump into the 70-80 range when i shift, and while under full boost they are generally 30-40. I have also heard of a few people who were experiencing erratic #'s, that just loosened the knock sensor and then retorgued it to the factor spec. They say this gave them a more consistant reading that was lower as well.

redbase

I don't hear any pinging, even under WOT. What numbers should I read regarding O2 voltages? If I run lean...whould those numbers change?

BTW: At idle, it runs REALLY rich! You get teary eyed from the fumes. I have an EGT, and under WOT my temps don't rise above 1400. Any comments?

ttpowerd

Yep, I heard that anything over 60 was not good but under that is fine. Most people I have talked to are between 20 & 30.

jspecracer7

If your crusing around and your knock is at 60, and you go WOT and it is still at 60, then don't worry about it. That's your "vehicle specific" knock. If your knock is ~20 and under WOT, it jumps to 60, then yes, that is knock.

Mine normally ranges under 17 knock. Under 4th gear pulls(at night), I've seen it jump ~70 knock...which is definitely detonation.

You can play with the PIM voltages to see where your knock range is coming from and then start tuning from there...if that's any help

redbase

If I mess with PIM voltages, won't that throw the check engine light on? What are the ranges for the PIM voltages I can play with? Is it a case of if I lower the voltage..I run leaner/increase voltage I run richer?

jspecracer7

Check engine light? Explain why How you described it is exactly how it works. You can use it this way to find where you need to tune.

pp13bnos

iTrader: (1)

My knock sensor is tight allright....but under light accel, (less than 3-4psi) i see upto 120 knock. Under full throttle, I see 60ish. Even runs upto 140+mph. I'm gonna go to the dyno next saterday. I'll try to figure it out then. CJ

jspecracer7

Whoa! ...that's knock. Are your spark plug wires in the right positions? That will cause knock like you wouldn't believe.