The EVO may be different on this, but from my 2G days, I never observed a situation where the ECU reported knock under heavy load and it wasn't detonation. Light load, low RPM where the threshold is low, sure, but never under heavy load.

I did have multiple times where I was getting detonation and the ECU never did anything about it.

540 on a RED could definitely be pushing it hard enough that it is near it's limits and system inefficiencies are causing issues. Have you tried turning up the boost to see if power picked up?

 

I'm running 100% WGDC Past 5k...so it's all the more boost it'll run.

Plugs are new... brand new I changed them before I got on the dyno. Gapped @ .022"

I'm not really concerned with getting the car to MBT, but I'd like to run it within 1% of MBT (power wise) to reduce my cylinder pressure. It seems weird to me that I can't run past MBT with 117octane.

I'm going to log my air temps in the intake manifold... I'm sure my intake temps are out of control leading to this issue.

I don't think the knock sensor is accurate because of my experience tuning cars on dyno's for several years. The wavy graph is yelling more ignition advance, yet the knock sensor is saying it's all done.

11.7-11.9:1 AFR's

I'm looking for a way to make the stock ecu not retard timing until maybe 4 counts of knock... or if I can filter the knock... filter it 1 "knock unit" less.

 

look up jcsbanks knock thread - its long and requires a lot of reading..

he shows you how to "decrease" the filter strength, so basically your knocksum will stay lower even thou the engine is more noisy.

you STILL NEED to check for real knock after doing this...

 

Thanks Tephra. I will use with caution.

 

You sure that waviness isn't the ECU pulling time from the knock counts?

Usually waviness from too little ignition advance aren't sharp dips like that.

if you are brave, turn the knock sensor off and see if the powercurve still dips.

- bryan

 

In that pull there were no knock events. A single knock count was had at 130 load @ super low RPM.

I'm transferring files from my failing laptop to my new one, so I won't have datalogs until probably tomorrow.

Bryan,
I see you point on the sharpness. Hrmm... Leads me to think the air-temp could be the culprit and the sensor is working just fine. Any insight into the "sharpness" of the waves? Possibly blowing the spark out?

 

It's amazing to me that people don't use their EARS and det cans enough.

Every stock ECU tuner should have them. You never know if a customer or friend that you are tuning is gonna run into a false knock issue.

I can hear 8 count knock sums quite clearly with headphones.

R/TErnie.. if you made yourself a pair of det cans wouldn't that answer your question?

 

Sorry not going to use det cans. My method works. Your method is based on mistakes. I don't tune on the knock sensor... Get it? Let me say it again... I don't tune by the knock sensor. I USE the dyno.

 

By the time you can audibly hear knock you're already doing damage. I've never had more than 4 counts of knock at that power level.

What we need is a cylinder pressure sensor NOT a goofy det can.

 

I can help you with the knock filtering, give me a call yo.

 

Bah, the hell with pressure sensors... ION SENSING... Or you could toss on some strain gauges as a cheaper alternative to an incylidner pressure transducer.

I am VERY reluctant to tune using a knock sensor. It can be effective on many setups, but I can't even attempt to tell you how many **** tunes I've seen that at "knock free." The knock sensor can lead you astray very easily. Particularly once you start moding the engine internals or as the engine become more worn out over time.

R/T Ernie, you've tuned a car without a knock sensor before, haven't you? Get it on the dyno, disable the sensor, put a full tune on the car, then enable the sensor and see what it's doing.

I honestly have yet to see a knock sensor pick up false knock at high load and high RPM unless it was from something that you could easily hear causing sever vibration in/on the block. Like I said, the sensor is good at missing knock though and that's why I don't trust them.

 

any luck on uploading the charts? like you said it seem's like it wants ignition advance but it wont take it.



ever log any of your intake temps also?