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Knock acceptable while "cruising", how much?
- Thread starter ManBearPig
- Start date
- Watchers 8
markmurfie
Well-Known Member
Your knock is more localized and consistent in a little bit different area and higher values, but rich on tipin is the same. My guess on yours is exhaust cam angles are to advanced. I would have expected to see 40*+ not a max of 20-22*. You are probably unintentionally lugging the engine from the shortened power stroke at those loads. That or you are getting low octane gas. Do you have knock at WOT?
stevnoof1
Well-Known Member
I use shells 93 vpower 90% of the time Valero 93 every now and then. Never had knock doing a wot pull. But I do have a problem with hard shifts setting the sensors off more often than I feel comfortably with. Normally it doesn't get up to 3* at part throttle but I was trying to make a point of letting it go longer I usually shift earlier. But it really only happens in 1st and second gear and as you can see it happens often. That is like 5mb of a 30mb log I couldn't upload, there was several more events just not as high. The car was also not fully warmed up at this point in the log. It's Definitely a pita.
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ManBearPig
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- #34
I'm curious to see another stock car's datalog under normal driving. Is a rich throttle tipin like both of us are seeing definitely abnormal? And if it's not, what can be done to correct it?
DarkestHour
Hi
I really need to get my hands on a 2015-2017 calibration file I can look at in HPtuners, but from my experience calibrating a Focus ST there is a tip in fueling table that richens it up. You could lean that out or simply get rid of it altogether.
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ManBearPig
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- #37
I unplugged the CMCV connectors and the only difference I saw is the car ran funny. reduced power down low and weird surging. It also idled with total spark much higher. 25ish degrees compared to the usual 10. Still saw the same kind of sporadic small knock activity, though.
I plugged them back in and took a short log making a few WOT passes with some hard gear changes. I saw the same kind of knock activity there as I do everyday driving. Sometimes I see a brief blip as soon as I roll into the throttle after a shift, other rimes nothing. I did notice that if I get going around 2500 rpm in second and stab the throttle, sometimes i'll see a brief blip of knock there as well, too.
All the knock seems to be related to the engine torqueing, but it quickly goes away. If I was seeing false knock from the exhaust touching the body somewhere, wouldn't you expect to see the knock stay for longer?
Short log attached here (although this shows no knock at all...like i said, its very intermittent) and I'd love input on how this looks overall in regards to fueling and everything else.
https://datazap.me/u/manbearpig/log-1510516664?log=0&data=1-16-18-28&zoom=966-1413
I plugged them back in and took a short log making a few WOT passes with some hard gear changes. I saw the same kind of knock activity there as I do everyday driving. Sometimes I see a brief blip as soon as I roll into the throttle after a shift, other rimes nothing. I did notice that if I get going around 2500 rpm in second and stab the throttle, sometimes i'll see a brief blip of knock there as well, too.
All the knock seems to be related to the engine torqueing, but it quickly goes away. If I was seeing false knock from the exhaust touching the body somewhere, wouldn't you expect to see the knock stay for longer?
Short log attached here (although this shows no knock at all...like i said, its very intermittent) and I'd love input on how this looks overall in regards to fueling and everything else.
https://datazap.me/u/manbearpig/log-1510516664?log=0&data=1-16-18-28&zoom=966-1413
markmurfie
Well-Known Member
LTFT and STFT are fine. There was a very very small positive knock event (start of second pull). To look at transient fuel, You would need to log MAP and lambse. Lambse would tell you if those rich tip ins are commanded or not.
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ManBearPig
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- Thread starter
- #39
I sent an email to Lund asking if the rich tip-in is being commanded. I see this on the stock tune and their tune so I suspect it is being commanded. Hopefully they'll be willing to tell me but I'd love to see logs from some other cars to compare.
I had cat deletes on the car that I've removed just to make sure that was not the problem. I've also tried another batch of octane boosted fuel using vp Octanium. Zero difference with octane booster. I'm leaning more and more toward some kind of false knock, even though I can't find the source.
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ManBearPig
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- #41
I happened to glance over and see the ngauge register a 2.6* knock on the drive to work this morning. I had just shifted into third gear, driving casually. I accelerated harder and it stayed at 2.6* until I had to let off due to traffic. I stayed in the throttle a good 3-4 seconds to see if it would go away but never did. Mostly I see small stuff go away knots immediately but every now and then I'll see much larger values that stick around. I never have captured something like this on a datalog though. I'm tempted to just take my ngauge out because it seems the car is just going to do this whenever it wants and I can't figure out why.
ahl395
Well-Known Member
I pretty much dont worry about it unless I see knock while accelerating. I've tried to chase down the cause of my false knock myself, have had two shops check, and have done a compression test, new plugs, etc.
If it's not knocking while you're in load it should be false. I'd rather it not do it, but I can't seem to stop it so :shrug:
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ManBearPig
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- Thread starter
- #43
I've changed plugs too but haven't checked compression. I suspect it's fine as the car had less than 10k miles and no behavior I'd attribute to serious damage.
Do you see knock under the same conditions as I am? Accelerating through the gears?
Edit I see you have an auto. When are you seeing knock?
Oakley_5OH
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So I have a similar issue. It all started when I put on Texas Speed catless headers. It’s intermittent but never at WOT and almost as I’m am going into a new gear. I’ve see up to +4.89 on my HPTuner going from 3rd to 4th at like 35 mph at 2200ish RPM.
I’ve replaced the header that I think the pipes were vibrating together. Bought an entirely new exhaust. Took the engine cover off. Removed the catch can. Had a 3rd party completely retighten the header bolts and exhaust. Removed the Mishimoto Coolant tank and put the stock one back on thinking it was vibrating against the UPR check valve. Etc etc. the list goes on. Still have it.
I had a similar situation where I found a slightly loose engine mount bolt and thought for sure it was the issue and still have it. Unsure where to go from here. It is only when dead stopped and revving to start moving or shifting from 2-3, 3-4, or 4-5 when I get back on the gas. It is so inconsistent that it has to be false. Just don’t know what is causing it. MT82 transmission 2016 PP.
I’ve replaced the header that I think the pipes were vibrating together. Bought an entirely new exhaust. Took the engine cover off. Removed the catch can. Had a 3rd party completely retighten the header bolts and exhaust. Removed the Mishimoto Coolant tank and put the stock one back on thinking it was vibrating against the UPR check valve. Etc etc. the list goes on. Still have it.
I had a similar situation where I found a slightly loose engine mount bolt and thought for sure it was the issue and still have it. Unsure where to go from here. It is only when dead stopped and revving to start moving or shifting from 2-3, 3-4, or 4-5 when I get back on the gas. It is so inconsistent that it has to be false. Just don’t know what is causing it. MT82 transmission 2016 PP.
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ManBearPig
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- Thread starter
- #45
Sounds pretty much identical to mine, but yours may be even more significant. 75% of the time I see less than 1*. Sometimes I see more but it's almost always less than 2*. About 1* of the time I'll see 3-4*
Something I haven't mentioned is that Occasionally I'll see knock when revving the car too. Like rev matching for a downshift or just blipping the throttle.
Do you monitor lambs also? Do you see the car go rich on tip-in throttle?
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