2021 Accord Sport 2.0 Stage 2 Knock Count

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pconcha419
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Joined: Wed Apr 14, 2021 6:30 pm

2021 Accord Sport 2.0 Stage 2 Knock Count

Post by pconcha419 »

hi just wondering, Im currently running stage 2 high octane +6psi map and a kn n drop in filter on my 21 accord sport 10 speed AT. I've been monitoring it on my Hondata app and my knock counts fluctuate between 20-60 and usually stays around 30 and my knock control varies from 55-75% and usually sits around 55%-59%. is this normal? Thanks.
EFICU
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Joined: Mon Feb 25, 2019 10:14 pm

Re: 2021 Accord Sport 2.0 Stage 2 Knock Count

Post by EFICU »

Do you have any datalogs you can post showing your concens? They generally give the Hondata guys a little more info to help answer your questions like these.
pconcha419
Posts: 7
Joined: Wed Apr 14, 2021 6:30 pm

Re: 2021 Accord Sport 2.0 Stage 2 Knock Count

Post by pconcha419 »

haven't data logged yet just my observation on the Hondata app. I'm new to this whole thing barely figured out how to use the app. Thanks for replying
EFICU
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Joined: Mon Feb 25, 2019 10:14 pm

Re: 2021 Accord Sport 2.0 Stage 2 Knock Count

Post by EFICU »

pconcha419 wrote: Wed Apr 14, 2021 11:13 pm haven't data logged yet just my observation on the Hondata app. I'm new to this whole thing barely figured out how to use the app. Thanks for replying
Gotcha, hopefully someone will chime in for you. I do k series stuff so it’s difficult for me to say how “normal” your concerns are. If you are getting 60 actual knocks, then the tune is a little aggressive for the octane fuel you run and your setup. I’m assuming you’re running 91 or 93, whatever the highest you have where you live? The knock control values sound fairly normal if they are similar to 10th gen Civics I believe.

If you have any questions on datalogging or anything PM me. It’s an easy process and posting the datalog here gives some visual data we can look at for you. From what you say though, I wouldn’t say you have any serious red flags, but you’re smart to try tp find confirmation, sorry I can’t be more help.
pconcha419
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Joined: Wed Apr 14, 2021 6:30 pm

Re: 2021 Accord Sport 2.0 Stage 2 Knock Count

Post by pconcha419 »

So I tried putting Lucas octane booster with my 91 pump gas and it was the worst decision ever. It worked from full tank to about half a tank but after that my knock control shot up to 99% and my car was pinging and knocking while underload. It took a whole day to bring it down to 70% and had it on eco mode the whole time. It took me about 2 full tank worth of gas for the problem to slowly go away. I flashed it back to stock and drove it for a while until I didn't have pinning anymore. My kcontrol on stock tune would go up no higher than 70% and knocks were around 30 knock count per one hour of driving. I flashed back to stage 2 6 psi high octane and was still getting knocks here and there but no audible pinging or felt loss of power. on 1 hour drive I had 30 knocks and 70% k control. So with the advice of a fellow accord owner I filled up with 1.5 gallon e85 and the rest was 91. Right away I saw the results and it was like magic. no more than 10 knock count on a 20 min drive and my k control was at 54% the whole time. It shot up to about 63% when I had the few knocks but it shot back down to 54% after I stop pushing it. Hopefully I found the fix finally.
EFICU
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Joined: Mon Feb 25, 2019 10:14 pm

Re: 2021 Accord Sport 2.0 Stage 2 Knock Count

Post by EFICU »

pconcha419 wrote: Tue Apr 27, 2021 10:54 pm So I tried putting Lucas octane booster with my 91 pump gas and it was the worst decision ever. It worked from full tank to about half a tank but after that my knock control shot up to 99% and my car was pinging and knocking while underload. It took a whole day to bring it down to 70% and had it on eco mode the whole time. It took me about 2 full tank worth of gas for the problem to slowly go away. I flashed it back to stock and drove it for a while until I didn't have pinning anymore. My kcontrol on stock tune would go up no higher than 70% and knocks were around 30 knock count per one hour of driving. I flashed back to stage 2 6 psi high octane and was still getting knocks here and there but no audible pinging or felt loss of power. on 1 hour drive I had 30 knocks and 70% k control. So with the advice of a fellow accord owner I filled up with 1.5 gallon e85 and the rest was 91. Right away I saw the results and it was like magic. no more than 10 knock count on a 20 min drive and my k control was at 54% the whole time. It shot up to about 63% when I had the few knocks but it shot back down to 54% after I stop pushing it. Hopefully I found the fix finally.
Are you still just monitoring this stuff on the app, or are you making actual datalogs and saving them now? It would be good to see a datalog and your calibration to analyze the issues.

The knock control on these newer Hondas use learn capabilities for the knock control. When you added octane booster the ECU thought you had higher octane fuel so it dropped the knock control value and added timing. As you got lower in the tank, the octane rating most likely dropped and it began to knock because the ECU thought you had higher octane and you no longer did. So the knock control goes up dramatically to try to reduce the knock.

Another issue I see is you're running a high octane map, yet you're running on 91 octane. It will for sure knock because the tune you have is setup for 93 octane. Seems like a small difference from 91 to 93, but it can be the difference between knock and no knock, especially if you're running 91. Looking at the stock tune, and the high octane tune, it looks like the ignition changes are only in the higher load areas. If you made a datalog while it was knocking I can look at it and see where the knock is occurring. Then maybe help you make a determination. Without a datalog, we are making assumptions honestly.

Have you put any thought into having it tuned properly? Adding some e85 and stopped driving it hard isn't what I would call a fix for the problem. Too much timing is most likely the issue. Removing ignition where it sees knock will allow you to drive it without worries. Especially when you don't have e85 near you to throw in a gallon and a half.

Anyways, let me know if you made a datalog during the knock events. If not, you really need to start datalogging your drive so we can try to help you. If you post the calibration you're driving on, I can look it over and compare the ignition tables with those designed for 91 octane.
pconcha419
Posts: 7
Joined: Wed Apr 14, 2021 6:30 pm

Re: 2021 Accord Sport 2.0 Stage 2 Knock Count

Post by pconcha419 »

Thank you for your quick detailed reply. I just figured out how to data log and will start saving and uploading them. When i did 1.5 of gallon of e85 the knocking issue is very minimal now but its a tenporary fix. I will get my car tuned properly soon. Even on stock tune these cars knock?
EFICU
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Re: 2021 Accord Sport 2.0 Stage 2 Knock Count

Post by EFICU »

Yeah, once you datalog the driving we can see where the knock is occurring. That is the only way someone like us can help you reduce or remove the knock events.

The knock got better because you put a 1.5 gallons of essentially race gas in it. So by my calculations, 13.3 gallons of 91 mixed with 1.5 gallons of e85 gives an octane rating of 92.72 (internet says you have a 14.8 gallon tank). Since this is close to 93 octane, which the tune is designed for, the knock was reduced. Once the octane rating went back down to 91, the ecu was trying to scramble to reduce timing based on the rising knock control. Once you start adding too much e85, the target AFR becomes difficult to hit without adding the flex fuel sensor package. If you added a flex fuel sensor package, you could run straight e85, or a 50/50 mix and the knock would disappear completely because of the increased octane. Not sure the threshold to stop adding e85 into the mix without a flex fuel sensor, but I don't think you'll see much of an issue at 1.5 gallons.

Yes the factory tune can have knock, especially with 91 octane. Honda, and any other OEM manufacturer usually have one calibration file for all cars your model. They don't know whether you have 91 or 93 where you live. That is why they introduce knock control strategies so that when you have 91 octane fuel, the the ecu can pull timing as needed and monitor that in real time. Meanwhile, a person who lives in an area that has 93 octane, the same tune your car has will work to find the optimal performance for what it sees through the knock sensor data. Also, it's there for the people who don't read they must use premium fuel of 91 or 93. The ecu will then work overtime to reduce as much timing as possible, which it can only pull so much before problems occur. For all these reasons is why there is no one tune that works for all cars and scenarios. Hence why we tune these cars for the mods done to it and on a case by case basis like which fuel they use. Hondata works hard to provide basemaps that work on a large number of vehicles. You have to understand the difference between high octane and low octane to make the best choice. Instead of “high octane” in your calibration title, think of it as reading “93 octane”. You simply have too much ignition in the calibration for the octane you run. That's why I was mentioning, if you can datalog a drive with shows the knock you state, and post that with the calibration you have in the car, we can look at it and see where the knock is occurring. Then adjust the ignition to remove the knock so you can enjoy the car without worries.

Once the ignition is tuned for your car and octane, the concern of knock will go away. If you put e85 and octane booster in the car it will only mask it as you mention. Once you get the ignition reduced, you will actually notice an improvement in performance. When the knock control goes high, the ecu pulls a lot of timing to protect the engine. Say you have 20* of timing in your calibration where it is seeing knock, the ecu may pull 8* of timing down to 12* to protect the engine in that area. If you simply reduce the timing in that area to 16* in the calibration (say for the sake of this conversation this is the point where the engine won't knock), the ecu will deliver that 16* of timing to the engine instead of 12* it thinks it has to in order to protect the engine with too much timing in calibration. So there is 4* of added timing over what you are feeling now, which can be a big difference. A lot of guys get hung up on getting the most ignition possible in the table, when really the goal is finding the right ignition the car likes so the ecu does not need to interfere. When the ecu interferes, it will do what it needs to in order to protect the engine. When I tune 8th and 9th gens, my goal is to tune the ignition to where no knock occurs so the knock control doesn't need to kick in, because there is no knock. Then if my customer gets some bad gas or can only get say 87 octane on a road trip, there should still be very little knock, but also the ecu can step in to reduce knock for the reduced octane or bad gas they got. For your car though, the knock control will always interfere, apparently it's how Hondata designed it. By properly tuning the ignition as needed though, you reduce the need for it and lower the knock control value you mention in your post.
pconcha419
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Joined: Wed Apr 14, 2021 6:30 pm

Re: 2021 Accord Sport 2.0 Stage 2 Knock Count

Post by pconcha419 »

R u local to socal? I want u to tune my car. You have calmed down my worries so much. Its starting to make sense now. I cannot thank you enough for going above and beyond to answer my questions and putting me at ease. The time and effort u spent is more than enough. Truly appreciate it.
EFICU
Posts: 635
Joined: Mon Feb 25, 2019 10:14 pm

Re: 2021 Accord Sport 2.0 Stage 2 Knock Count

Post by EFICU »

No, I'm in NorCal. I'll be honest, as I mentioned before, I can probably help you to reduce the knock but I don't tune newer generation Hondas in the general sense. I have done a few 10th gen Civics, but I don't have a whole lot of experience with them. The tuning on the newer Hondas is very different from 8th and 9th gen Civics. Since you are running a Hondata basemap, I can probably help look at the fueling and help remove the knock through ignition timing, but I don't manipulate torque management and stuff like that. We would clean up the tune you're running on now, which I'm sure would make you happy, power wise. I would need to see twenty minute datalogs of you doing stop light to stop light type driving.Then we can creep up on other stuff once I see what we're working with.

Let me know. Either way, I'm glad your concerns have calmed down some. I know the helpless feeling you have. It really comes down to octane, or lack of it here in California.
pconcha419
Posts: 7
Joined: Wed Apr 14, 2021 6:30 pm

Re: 2021 Accord Sport 2.0 Stage 2 Knock Count

Post by pconcha419 »

Honestly Im pretty happy with the basemap minus the knock. Im not planning to do major stuff until later down the road. my next mod is just the flex fuel kit. If we can figure out like you said how to clean up the basemap would be perfect for me. Is there any way to contact u privately? also I don't have a windows laptop so literally I have to go to my local auto shop to borrow their laptop for me to mess with hondata. I just figured out how to datalog from my flashpro and how to download them. so il be working on those logs. do I need to stop using e85 for the logs? my next day off which is next wed, I can work on the logs the whole day. I was tripping the whole time before you gave me some sense to what really is going on. A lot of sleepless nights, a well known tuning shop actually told me there's internal damage to the engine but I think they just wanted me to spend 700$ on tuning the car. But I really appreciate the time and knowledge u have shared with me. it makes me feel at ease. Thanks again.
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