At least I'm assuming that it has to be noise. For example....a minute ago while sitting at idle with the clutch in, I slowly increased the revs to 2000rpm and I saw a knock reading of 127 in the PFC. Strange thing is, at idle (~1100rpm) my knock value is 1 and only raises to 3 by 1300rpm...then 40 at about 1500rpm, 80 at 1700rpm, etc etc. My peak knock value while driving around always seems to be in the 140's, but probably averages about 100-110.

I am ready to finish tuning this thing, but these high knock readings scare the hell out of me. When I am in boost (~7psi around 3500rpm in 4th gear) the knock drops down to the 60-70 range. I have searched for things that could be loose in my engine bay, but everything seems good. There isn't much left after removing all the emissions, a/c, power steering, cruise, etc. I also replaced the knock sensor and the readings didn't change.

Things that I believe could contribute to the noise:
-Delrin Bushings (all suspension and differential)
-Polyurethane motor mounts
-Stiff Suspension
-4" Exhaust (with a high flow cat that doesn't really do anything)

Any ideas?

 

I think your ignition timing may need to be increased in those areas. Do you have an EGT installed? it isn't necessary to have one of these but when tuning ignition with an EGT it has a higher heat when too advanced and STILL higher heat when retarded too much so it will give you a nice middle.

 

The first thing to do, is to shake you exhaust, engine, IC, etc, and listen for noise caused by poor fitment. PARTS hitting PARTS is always a first consideration and is common.

 

My car is just the same.
Cruise knock is around 100-150.
But at 20psi and 5000rpm the knock is less than 5.
Idle is 1-3.

My knock just got worse the more mods i added to the suspension.

I got delrin bushins, all around.
Gear braze and diff braze.

I driven the car like that 2 years now, and ignore the knock readings now.
Scary the first week.
Over 3000 rpm the knock drops a notch.
And under boost it drops all the way down.

 

Some engines are lucky enough to have a somewhat trustworthy sensor, but I don't even look at the knock values anymore on my car.

 

My knock is between 60 and 80 under boost (up to 14 psi) and has been since I began tuning.

I don't ignore it because there is a pattern there, but some people see knock in the 20s under boost. I have another knock sensor waiting to go in, which may help.