KR explained

[Jake5713]

Great write up
and @stealth
your first comment had me laughing so hard, It would have been even better If we could shop a picture of Lex in a wheel chair bald etc.
this does address my concerns with knock thanks lex

[rfinkle2]

Originally Posted by skiptowncat Any thoughts on KR in a particular gear, I'm getting anywhere between 2-4KR @~4.5k but only in 5th gear@ WOT?? @Lex @rfinkle2

Lex is the expert, but I'd have to think that you are seeing different load values for longer durations of time in 5th gear.

[TiGraySpeed6]

Here's a spiffy bit of KR for ya-

sadly the log does not include APP or coolant temp, and I've asked that he include them in the future. I have asked the owner if his speed6 was up to operating temp, or if he had a batch of bad/cheap gas, but haven't heard yet...

I'll be sending a link to this post, hopefully he'll chime in if ya'll have any questions-

[atvfreek]

Originally Posted by TiGraySpeed6 Here's a spiffy bit of KR for ya- sadly the log does not include APP or coolant temp, and I've asked that he include them in the future. I have asked the owner if his speed6 was up to operating temp, or if he had a batch of bad/cheap gas, but haven't heard yet... I'll be sending a link to this post, hopefully he'll chime in if ya'll have any questions-

When the kr started, he was only at part throttle (TP 15%) so when he went wot, the PCM still hadn't put the timing back in.

[skiptowncat]

Originally Posted by rfinkle2 Lex is the expert, but I'd have to think that you are seeing different load values for longer durations of time in 5th gear.

I think I had already figured it out. Recently changed the open loop overload timing to match my normal table (following what I saw in a ots map) For some reason in 5th I seem to be hitting over my target which I'm guessing is why this is happening. I had advanced the normal table quite a bit previously. Just running in a new revision now, I'll let you know how it goes.

[Lex]

Originally Posted by skiptowncat Any thoughts on KR in a particular gear, I'm getting anywhere between 2-4KR @~4.5k but only in 5th gear@ WOT?? @Lex @rfinkle2

In any car you will see engine load go up as you go up in gear. The resistance to acceleration is higher so the engine will work harder and for longer. This increases the components that generate knock and these are cylinder pressure, temperature, and boost. As a rule of thumb, I look at mostly 4th gear when tuning because it will expose KR more readily than 3rd and running 5th to redline gets dicey in most areas.

[Dano]

Originally Posted by Cataphract_40 Fast forward to 2:14 Mazdaspeed 3 vs 2009 WRX - YouTube

I miss Rodrigo's Xtranormal vids...he put alot of work into those...need to lookup the two really long ones about MSF gossip...too funny. IIRC I get hacked in one of them

oh and great writeup lex...as always you are very clear and concise...

[Stealth01]

Originally Posted by Lex ...and running 5th to redline gets dicey in most areas.

Oh come on, just because you'd be doing 130....sheesh.

[TriO]

i get a LOT of part throttle/low load KR nowadays but i never used to... infact i remember logging 20-30 mins for pretty mixed and spirited driving one night and only finding a few instances of knock in the whole the whole log.

i wonder what could have caused the change??

also every time i shift i get a fair amount too... i'm hoping it's just a mount wearing or something.

[rfinkle2]

Originally Posted by TriO i get a LOT of part throttle/low load KR nowadays but i never used to... infact i remember logging 20-30 mins for pretty mixed and spirited driving one night and only finding a few instances of knock in the whole the whole log. i wonder what could have caused the change?? also every time i shift i get a fair amount too... i'm hoping it's just a mount wearing or something.

Is it just for 1 tankful, or a trend in general?

It could be that your load values you are hitting in the cold months are different, and the timing @ those load values is also different.

There is also a multiplier in one of the tables that is based on coolant temp if your car is now running a bit cooler, it may be allowing for slightly more timing.

[TriO]

Originally Posted by rfinkle2 Is it just for 1 tankful, or a trend in general? It could be that your load values you are hitting in the cold months are different, and the timing @ those load values is also different. There is also a multiplier in one of the tables that is based on coolant temp if your car is now running a bit cooler, it may be allowing for slightly more timing.

a trend in general....

so are you saying that you think a possible change in timing is causing real knock then??

should i be worried?? i feel as if my car is always a few mins away from blowing lol

[rfinkle2]

Originally Posted by TriO a trend in general.... so are you saying that you think a possible change in timing is causing real knock then?? should i be worried?? i feel as if my car is always a few mins away from blowing lol

No. Didn't mean to alarm you. If the knock is a part throttle, I wouldn't even think 2x's about it.

Even @ wot, you are almost never going to see 0 KR.

[TriO]

Check out these logs then.

Just installed new internals and downpipe and now on a slightly tweaked OTS stage 2 map.

Went out to do a MAF cal and a few pulls... keep getting knock with the MAF cals but none whatsoever @ WOT...

Any ideas/comments?

[rfinkle2]

Originally Posted by TriO Check out these logs then. Just installed new internals and downpipe and now on a slightly tweaked OTS stage 2 map. Went out to do a MAF cal and a few pulls... keep getting knock with the MAF cals but none whatsoever @ WOT... Any ideas/comments?

I think that Lex would say that seeing KR starting to "count down" @ load values of .5 is nothing to be concerned with.

I'm not answering for him, nor saying I am as experienced as he is, but your maf cal log fits with many of the posts I've seen him make concerning PT KR.

[Dano]

wow that looks like something loose in/around the motor but strange that you don't see it at WOT...the harmonics must be different enough at WOT to prevent it.

look around in there to see if any piping is touching the frame or even very close. Also see if anything else is lose.

[Crazyspeed3]

lol im getting alot of kr but its below 2..

[bertrand_CX_7]

hey guys sorry for the nob question,

but I'm seeing late on my AP the KR reading 8.0

So I'm really not sure if this really means 8.0 of KR, that's why I'm asking just to make sure. The weird thing is that it's happening when cruising at the time I wasn't punching the car when I'm suddenly reading this on the AP. So no load on the engine when this is happening.

My tuning is not completed yet. There is still the regular gas pump to be tune out.

Anyone else seeing this?

[woodsmsp]

im going anywhere from 3.5 to 5.6 kr on my logs with the tune i have, im putting my tune back to stock till i get hpfp internals!!!

datalog.xlsx

[dereeek]

how about something like this:
anything out of the ordinary besides fuel pressure?
Does not having enough fuel cause knock this high?
Not mine.

[Dano]

I sincerely hope my eyes are deceiving me and you are not running 16AFR at WOT 22PSI and 5+KR.

if so please pull your plugs asap and see if there is any insulator left on them.

[dereeek]

was that directed at me? if so it's not my log, again. A person online was experiencing some knock and come to find out, it was a lot more.

[Dano]

Yes toward you but glad that wasn't your log . It was UGLY


Tappin

[dereeek]

Yes it is. Now back to my question, would dropping fuel pressure cause knock that high? Or is there something else going on that I'm not seeing?

[woodsmsp]

Originally Posted by Dano I sincerely hope my eyes are deceiving me and you are not running 16AFR at WOT 22PSI and 5+KR. if so please pull your plugs asap and see if there is any insulator left on them.

this is my log lol. this is a log i made after installing a stage1 sure aeros+93octane tune on my AP, its at 16psi. not 22. i took the tune off my ap and loaded the factory settings back onto my ecu

[Lex]

Originally Posted by woodsmsp this is my log lol. this is a log i made after installing a stage1 sure aeros+93octane tune on my AP, its at 16psi. not 22. i took the tune off my ap and loaded the factory settings back onto my ecu

Sounds like a tune is in order

[woodsmsp]

Originally Posted by Lex Sounds like a tune is in order

by what your saying is, the tune is whats causing these numbers on my log?

[Dano]

Originally Posted by dereeek Yes it is. Now back to my question, would dropping fuel pressure cause knock that high? Or is there something else going on that I'm not seeing?

absolutely! CDFP pressure needs to operate around 1600 or above and anything below say 1200 is dangerous and is an indication an upgraded CDFP is needed. Less fuel is being injected, AFR is leaner and more heat generated in the cylinder leading to knock.

Originally Posted by woodsmsp this is my log lol. this is a log i made after installing a stage1 sure aeros+93octane tune on my AP, its at 16psi. not 22. i took the tune off my ap and loaded the factory settings back onto my ecu

yup you need a fuel pump...good thing you took that map off. Some cars can't even run a S1 map without a pump.

Originally Posted by woodsmsp by what your saying is, the tune is whats causing these numbers on my log?

yes the tune is no bueno. you can run a Stage 0 map and still keep the AP installed and get more logs.

[woodsmsp]

Originally Posted by Dano absolutely! CDFP pressure needs to operate around 1600 or above and anything below say 1200 is dangerous and is an indication an upgraded CDFP is needed. Less fuel is being injected, AFR is leaner and more heat generated in the cylinder leading to knock. yup you need a fuel pump...good thing you took that map off. Some cars can't even run a S1 map without a pump.

fuel pump? or do you mean internals? if so i plan on getting the internals next week. im running the stock ecu mapping again made a log today at 13psi still getting a knock around 2.1 though. is the aeros causing this?

Originally Posted by Dano absolutely! CDFP pressure needs to operate around 1600 or above and anything below say 1200 is dangerous and is an indication an upgraded CDFP is needed. Less fuel is being injected, AFR is leaner and more heat generated in the cylinder leading to knock. yup you need a fuel pump...good thing you took that map off. Some cars can't even run a S1 map without a pump. yes the tune is no bueno. you can run a Stage 0 map and still keep the AP installed and get more logs.

i reflashed to the stock0 map last night. which is everything stock but still get a KR around 2.3 at 13 psi... guess the aeros isnt helping? my kr is fine when not under alot of boost

[Lex]

Originally Posted by woodsmsp fuel pump? or do you mean internals? if so i plan on getting the internals next week. im running the stock ecu mapping again made a log today at 13psi still getting a knock around 2.1 though. is the aeros causing this?

Post the log. In some areas the stock tune has too much timing like where I live. My car saw 4.0 KR stock.

It can also be caused by other noise as described in this thread. If you want to know if it's real knock, put 2-3 gallons of E85 in your tank when you next fill up and see if its gone. If the KR i still there at WOT it's noise from something else.

[woodsmsp]

Originally Posted by Lex Post the log. In some areas the stock tune has too much timing like where I live. My car saw 4.0 KR stock. It can also be caused by other noise as described in this thread. If you want to know if it's real knock, put 2-3 gallons of E85 in your tank when you next fill up and see if its gone. If the KR i still there at WOT it's noise from something else.

sweet! so adding some e85 should get rid of the KR if its not another noise then. when i get back home ill upload the new log or make another on my way home and load that one and post it up, thanks for the help!!!

[Dano]

Originally Posted by woodsmsp fuel pump? or do you mean internals? if so i plan on getting the internals next week. im running the stock ecu mapping again made a log today at 13psi still getting a knock around 2.1 though. is the aeros causing this? i reflashed to the stock0 map last night. which is everything stock but still get a KR around 2.3 at 13 psi... guess the aeros isnt helping? my kr is fine when not under alot of boost

yeas the SURE will make you run lean without a map for it.

fuel pump or internals will get your pressure right.

[skiptowncat]

I'm seeing KR of 1.5-2.5@ ~4.5k all of a sudden, I have tried making afr richer, reducing timing and load but it's still there. I'm gonna put the side mounts in and see if that shifts it.

[woodsmsp]

Originally Posted by Dano yeas the SURE will make you run lean without a map for it. fuel pump or internals will get your pressure right.

What map shpuld I run with the sri?

[painfulpillow]

I installed my CP-E fuel pump tonight and did some logging. I noticed some high KR near the redline (sorry for my mediocre log, it is row 367. Should I be worried about this?

[painfulpillow]

Oh shit, I didn't even notice the 6's. 354-381 is full of knocking.

[djuosnteisn]

Your afr's are way too rich... and timing is almost OTS.... which both make for very high EGTs. I wonder if that's contributing. Regardless, your car is not happy, and likely detonating.

You could use a tune man.... or at least try a different OTS map, or pull fuel yourself. Should help.

[Lex]

Originally Posted by painfulpillow I installed my CP-E fuel pump tonight and did some logging. I noticed some high KR near the redline (sorry for my mediocre log, it is row 367. Should I be worried about this?

Those 5s and 6s that just happen all of a sudden smell suspiciously like mechanical noise ... cars that I see do this generally have an issue with something internal to the engine. A compression test won't hurt.

[painfulpillow]

Originally Posted by djuosnteisn Your afr's are way too rich... and timing is almost OTS.... which both make for very high EGTs. I wonder if that's contributing. Regardless, your car is not happy, and likely detonating. You could use a tune man.... or at least try a different OTS map, or pull fuel yourself. Should help.

What do you mean pull fuel myself? Changing the AFR's? I was hoping the OTS map would work well with my setup. I had read on the forums about 3rd gear knocking, random mechanical noise knocking, etc but it's weird that it just happens all of a sudden. Should I just try another stage 1 map with another intake or maybe try stage 2 (no upgraded DP though).

What should I look for regarding mechanical noise? I read another thread about the chain being loose, VVT,whatnot but I'm lost as to where to look.

If all fails, I might just go for a nice tune. Only downside is I plan to upgrade to stage 2 in the future, so I'd hate to pay twice for the service.

[djuosnteisn]

You should try to determine if the KR is noise induced, or actual. You can do this by increasing the octane of the fuel.. (throwing in 2 gallons of e85 to a full tank of premium)...

If the KR disappears.. then it was real. If it remains, then it's likely mechanical.

Most common causes for mechanical noise are things rattling in the engine bay, and banging against the motor (or intake mani / exh mani), or injector seals, or VVT as you stated.


If the KR is deemed real... then you should try a few other OTS maps... but read the help file, and don't go wot on them right away. Let the ECU learn fuel trims, and if the trims look decent, then try a single wot pull, and see if there is any KR, and how your AFR and boost look.

[rgvms6]

I hate knock. Last night i reflashed my 6 and it would go up to 2.8 and even at 5 sometimes under heavy driving. Scared the crap out of me so i went to stage one instead