ironmang

Hi,

I don't normally post on these forums, but I drove my brother's fd to work today because I have a blown turbo on my dsm... but after the drive in I checked his PFC which read a knock count of 130. I know he mentioned that anything above 100 is bad. I didnt push the car too hard or anything. but i did notice a bit of backfire when I was localing it after i got off the highway. I suppose it could be random engine noise, but is there something I can check for or should I see if it still knocks so high again on my way home?

I don't remember what boost is set at but the pfc peaked at .79, air and water temps looked fine.

His mods include v mount, dp+catback, pfc .

thanks for the help... I don't want him returning from his trip to see that I blew his engine.

jeremyb

I posted a thread a few months ago saying that I had knock readings as high as 149. Basically in 3rd gear at partial throttle holding at a certain RPM with load had me a full bar on the commander for knock reading. Some said not to worry about it due to road noise, tire noise, etc. but it still worried me.

https://www.rx7club.com/showthread.p...=pfc+commander

Jeremy

ironmang

thanks for the info. I didnt think to check at what rpm it happened. I guess I'll see what happens when I go home.

Rx-7Addict

iTrader: (2)

Can the PFC knock sensor be trusted at all?

To me, it seems useless.. Mine will fly up over 100 if I hit a pot hole or an expansion joint in the road.

A knock sensor is nothing but a mic trying to pick up noise, right? Theres a lot of factors that can cause loud noises in your car.