Interpreting knock

Gtfo

Low load knock is not much to worry about,my knock sum usually goes up pretty high in low loads,even the ecu stock setting will ignore this.

http://www.romraider.com/RomRaider/HowToUnderstandKnockControl

pleeeease log feedback knock and fine learning knock, knock sum shows knock totals but determining exactly where it's happening is difficult. also shorten the log, it's too long, do a 100% wot log 2k rpm to redline in 3rd gear, log:

 

engine speed

engine load

man relative press corrected

mass airflow g/s

feedback knock

fine learning knock

Not sure what you mean - knock sum shows the exact instant the ecu hears knock. The moment it increments in your log is the instant you knocked.

Not sure what you mean - knock sum shows the exact instant the ecu hears knock. The moment it increments in your log is the instant you knocked.

 

 

Knock will show up in a perfectly healty tune at certain times. Example; Shift knock is what I see alot. When I do a third gear pull I see no knock.

 

So, in short, if your not seeing any knock in a WOT data log your probably OK. Learning view is your friend. It can help you tune out light load knock. Seeing where you sit in a learnign view is my prefered method to see what is going on in closed loop, low load conditions. You want to reset the ecu and drive for a day or so then you get a good learing view.

Yeah...I get a ton of low load low RPM knock too. WOT runs are clean. I log Knock sum and use my LV to see what is going on with the learned knock.

 

My car has always knocked at cruise - even after lowering timing and going to E85 - I am pretty positiive it is just noise.

You are knocking..at 4337, 5502, 5903 and 6060 RPM.

 

I consider that a lot of knock Wherever you see the the knock sum number increments it means the knock sensor is detecting knock (or noise). For the most part, assuming nothnig is banging around loose in your engine bay - above 3,000 RPM is knock sensor is pretty accurate.

Not very likely - what is more likely is a bad batch of gas.

 

Perhaps you should ask your tuner to have a look at the log. I suspect he needs to pull a little bit of timing. i think you should limit your WOT runs until he/you get it figured out.

Ahhh...if this is your first rev it is still a work in progress. It will definitely get ironed out. I assumed this was a completed tune.

 

For future reference; a solid tune should not show any knock during WOT. You may get an occasional knock event at WOT, but if it is repeatable the tune should be adjusted. Knock during low RPM load load situations is very common and not much to worry about...

 

Good luck with your tune.

Holy crap, your first (based on the timestamp) LV is horrendous. But then two days later, your LV looks fine, wtf...

 

Anyway, let Infamous take care of it. He's responsible for tuning your stuff right now. By the final revision it should all be straightened out.

Yeah, your LVs are messed up. You're only on revision 1. It's to be expected. Just follow Infamous's instructions.

Why do people do this? A tune takes a while, you're going to be knocking less and less up until the final revision.

I think the issue that bmx has with what you did as you posted, seemingly as if asking for help, without mentioning that you are in the process of being tuned by Infamous. It's Infamous's responsibility to take care of the tune, which he will as long as you proceed with everything like he tells you too.

 

I understand you want to learn what's going on and stuff but asking us to tell you what should be done and how things are supposed to go raises a big problem: what we say may directly conflict with what Infamous says or does.

The link that NSFW posted is a comprehensive "essay" that will answer all your questions, you sound surprised and somewhat floored that you're knocking based on the first post.

 

I noticed in another thread that you were in the process of being tuned by infamous, this thread was created after that post. Nobody has patience when it comes to infamous tunes and are floored when they see pulled timing and knock when the tune isnt said and done. I get the learning "urge", but you failed to mention you were in the process of being tuned....THEREFORE that would lead everyone else to think you're either stock or modified post tune and that now you are knocking unexpectedly....and looking for help on how to correct it.

 

There are some customers that come on here and are noobs and just figured out how to use RR and learning view and are floored and appalled on what they find mid-tune. Give it time, and it still doesnt matter what octane you're using, you will still knock until the tune is done.

Interesting observation / question. Just went to E85 in my '05 leggy and (like you'd expect) have perfectly clear LVs. Never seen a single bit of knock during my WOT pulls. I am not concerned that I have a legitimate knock issue.

 

However, when I've flashed a new map with E85, it takes a loooong time for my IAM to move from 0.75 to 1.0 (much longer than it ever did for 93 octane...I've done a lot of flashing of my ECU during tuning and always follow a log early on to see how things look). And it knocks like crazy during this time.

 

For example, just flashed a new E85 rev, started car, drove about 1 mile and had 26 'knock' events detected by the ECU. IAM stayed at 0.75. With 93 octane, it would usually switch to 1.0 almost immediately and never had more than 10-15 knock events.

 

I know these are low load and my LV is totally clear. Just wondering why this is happening. Any ideas?

Whenever you reflash, it goes to 0.75 as a safety feature. IAM won't go up to 1 until the ECU sees that it's safe to advance to 1. If you are getting a buttload of knocks while it's 0.75, it thinks you're actually knocking (which you might be, or it might just be noise) so it'll stay in the 0.75 mode to be safe.

 

Is E85 more prone to low load knock?

 

That 0.75 is something you can change. I've been flashing almost every single day making minor changes to my table, so I know it's safe for me to just start at 1 right off the bat.

Is E85 more prone to low load knock?

 

Yeah, that's sort of what I was asking. Like I said, I'm not concerned that this is a 'real' issue. Car still goes to 1.0 IAM eventually and I don't see any WOT knock. Just curiuos why all the false knock now that I'm on E85.

I get a ton of low load knock on 93 AND E85.

 

Since I am working my maps I set initIal IAM to 1 - no need to wait for it to climb from 0.75 to 1.