What is engine knock? Fine Knock Learning, Knock Feedback and DAM

Harvey ,aka the Boost Creep, comes by the shop to discuss Subaru engine knock, ignition timing and what to watch for on your Accessport. He brings some serious knowledge on how fine knock learning, feedback knock and DAM work together to control ignition timing in Subaru engines.
You can find Harvey here
www.theboostcreepltd.com/
/ theboostcreep
[e-mail]
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00:00 - Intro
00:47 - What is engine knock?
01:47 - Subaru EJ vs FA knock difference
02:34 - Different kinds of knock
04:46 - How does engine timing work?
05:17 - Ignition before or after TDC (Top Dead Center)
08:34 - Different levels of engine knock
09:53 - Knock pressure waves inside an engine
10:42 - Knock sound frequencies
11:00 - Knock sensors are microphones
11:40 - Sounds that cause false knock
14:10 - Knock sensor shows symptom but not actual event
15:50 - What parameters to watch on an Accessport
18:36 - Feedback Knock and Fine Knock Learning
22:09 - DAM (Dynamic Advanced Multiplier)
28:00 - When values should be dynamic or consistent
28:30 - Best way to watch for knock
31:00 - Look at the log data not the Accessport screen
31:22 - DAM on EJ vs FA
32:07 - Knock is not on or off, it’s progressive
33:16 - Raw knock data doesn’t include ECU filtering used to exclude false knock
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[@DevanVillalovos-eo8bm]

This video is pure gold! Every person installing an accessport and/or modifying/tuning an EJ engine at all should watch this!!!

[@FlatironsTuning]

Thanks very much Devan! Really appreciate it. Thanks for watching and Stay Tuned!

[@jackemarleeyoung]

I understand these are niche topics but please keep bringing them! They are extremely useful ❤

[@FlatironsTuning]

Thanks very much, and please share if you can. The more views that we can get on this kind of content, the better. It will help us to keep coming up with more. Thanks for watching and Stay Tuned!

[@warusweims]

What a great explanation of knock. This video has not existed in all of KZbin until now. Thank you for this!

[@FlatironsTuning]

Absolutely! Very glad you found it helpful and thanks for watching. Share if you can. Stay Tuned!

[@beaches2mountains230]

LOVE THESE..WOULD REALLY, REALLY LOVE TO HEAR MORE OF THESE TUNER TALKS AND THE DETAILS INVOLVED. THE MORE IN DEPTH THE BETTER !!!!

[@brianherrman6291]

This is gold! Thanks Harvey!

[@FlatironsTuning]

Thanks for watching and Stay Tuned!

[@jonnyturbo6142]

another great video with tons if knowledge, thanks!

[@FlatironsTuning]

Absolutely! Thanks for watching and pass it along if you can. Stay Tuned!

[@mrtitanium427]

the point about being aggressive with the throttle or shifting is an excellent reminder because of its corelation to harmonics and spontaneous disassembly 😃

[@FlatironsTuning]

Thanks for the comment and thanks for watching. Stay Tuned!

[@0236king]

Love the show guys. I learn a lot everytime.

[@FlatironsTuning]

Very glad to hear it. Thanks for watching and Stay Tuned!

[@matd8958]

Great video guys. Cleared alot info up for me. Every second was on point

[@FlatironsTuning]

Very glad to hear it. Glad the video helped! Stay Tuned!

[@Kush2020]

Awesome video and very informational!

[@FlatironsTuning]

Thanks very much and thanks for watching. Stay Tuned!

[@Dan-nl2ug]

Thank you flatirons you guys are awesome on STI content,Harvey is awesome,want to thank him for his time,the knowledge he brings is awesome

[@FlatironsTuning]

Very glad that we could help Dan! Thanks for watching and thanks for the comment. Stay Tuned!

[@philippday9195]

Harvey is amazing at his craft... he's sensible and backs it with knowledge and experience... what more could you want! He's the only guy that touches my '06 Hawkeye! Thanks for a great, in-depth video 👍🏾

[@FlatironsTuning]

Thanks for the comment and thanks for watching. Very glad that the video was helpful! Stay Tuned!

[@scoupemaster]

very good info on a complicate subject thanks

[@FlatironsTuning]

Thanks for watching and thanks for the comment. Stay Tuned!

[@its_ancient]

Really good information, i just recently picked up my first wrx and it has been a dream.

[@FlatironsTuning]

Thanks for watching and thanks for the comment! Glad that this was a helpful conversation. Enjoy the WRX and Mod responsibly. Stay Tuned!

[@thewayfaringanarchists8157]

What a great break down of a super confusing topic. I learned to tune my 04 Sti about 3 years ago, this would have saved me countless hours of research and worry. Thanks again. You guys are amazing

[@FlatironsTuning]

Thanks very much for the comment and very glad that the video was helpful. Pass it along if you can and Stay Tuned!

[@pv4083]

As a new owner of a 2021 sti. It would be nice to see a video that shows all the great things these Subarus do but to offset all the education material that can seem a bit worrying. As always..thanks for the great video.

[@FlatironsTuning]

Thanks for the comment and thanks for watching. Stay Tuned!

[@mannyp36]

Wow great information ℹ️…my DAMN dropped 2 days ago 0.87 from 1.0

[@crazyDIYguy]

Im really glad I watched this, I just adjusted my FLKC ranges to wayyy wider than stock map. I imagine Subaru had consistent false knock in those low load or high rpm ranges, maybe ill switch it back. Thanks for the video 👌🙏

[@FlatironsTuning]

Thanks for watching and glad it was helpful! Stay Tuned!

[@Talljoystick]

Great video explaining some more very complex subjects. I tend to see -2.8FK or less with a minimally modified EJ wrx, but occasionally see some -4 - -5.6 FK events but they seem to always happen when I shift at lower speeds. Anytime I am WOT it never has a single FK event so I don't worry much about it. I also ran into a constant FKL of -1 - -2.8 and once I replaced plugs, the FKL went away completely.

[@FlatironsTuning]

Thanks for the comment and thanks for watching. Stay Tuned!

[@brutalmisfit99]

I’m currently having the same issue, low throttle in first gear I get 1.40 FK

[@not12listen]

This video goes a long way to really demonstrate that tuning is a craft, and that when someone is doing a proper job at tuning, the cost is absolutely warranted. I have friends that are not automotively inclined, and when they see a bill for $600 for maintenance, they audibly gasp. When you dig into the detail that the intake manifold had to come off to replace a ruptured gasket, etc - the automotively inclined understand what is involved, and realize the amount of time & effort involved, can rationalize that bill. Good work is rarely free and amazing work has a price.

[@FlatironsTuning]

Could not agree more. Thanks for watching and thanks for the comment. Stay Tuned!

[@Cobese]

i would argue that you might not be as “automotively inclined” as you think you are. it would be difficult for me, and most mechanically inclined people i know, to justify a cost of $600 to replace intake manifold gaskets when i could do it myself for $30 and 4ish hours of my time

[@lucian7182]

Yeah my local performance shop would charge me about 2 hours of labor for the manifold gaskets 120 an hour.

[@antonistrelatas]

Awesome video .that accesport can cause crazy anxiety, if you don’t know

[@FlatironsTuning]

Thanks for watching and thanks for the comment. All the data that you can get from the AP can definitely cause some confusion. Hopefully this helps to shed some light on what some of those data points mean. Stay Tuned!

[@beaches2mountains230]

REALLY WOULD LOVE TO HEAR TUNER INFO ON THE FA24 !! WE HAVE DECADES OF DATA ON THE EJ'S AND IVE GOT 3 OUT IN THE DRIVEWAY BUT ID REALLY LIKE TO SEE AND HEAR MORE DETAILED ANALYSIS OF WHAT TUNERS HAVE EXPERIENCED AND WITNESSED WHEN TUNING FA24DIT'S. ENGINE HAS BEEN OUT 6 YEARS+ AND THERES NOT MUCH DATA OUT THERE FOR THE PUBLIC.

[@notsponsored103]

Haha😂love that thumbnail

[@FlatironsTuning]

Thanks very much, and thanks for watching. Stay Tuned!

[@publiusscipio5697]

Wish I had found y’all’s channels BEFORE I needed to get a second engine. Oh well

[@FlatironsTuning]

Glad you found us now, and hope the videos have been helpful. Thanks for watching and Stay Tuned!

[@ivtec4fun55]

92 Octane on my EJ255 WOT I run it 4 degrees @ 22psi from 3200-5000 rpms or so, it starts minor knocks around 6-8 degrees @ 22psi. It just is what it is.

[@FlatironsTuning]

Thanks for the comment and thanks for watching. Stay Tuned!

[@4BanginST]

Can you please do a video of pros amd cons of a lightweight flywheel vs an normal mass?

[@FlatironsTuning]

That is a great question. I'll add it to our Question of the Week list. Thanks for watching and Stay Tuned!

[@paulmarsdensr1095]

A great video, guys. I will be keeping my 2020 STI stock as my daily driver. Why is the Cobb Access Port so expensive? and does it void your warranty if you install it?

[@FlatironsTuning]

Those are good questions. I'll add them to our list. Thanks for watching and Stay Tuned!

[@nickkalister6291]

huh, i would have thought that knock feedback and fine knock learning modes were active simultaneously and the feedback knock data would be used to make the changes in the fine knock learning table?

[@KrGsMrNKusinagi0]

how about when you push your motor pass stock specs expect it to fail nomatter what tune?

[@RawburtPurez]

I regularly get FBK and FKL -3.5ish to -7.00 during WOT in my 2021 stock STI. At this point I seem to beat everyone on the internet and it has me worried (DAM pretty much never ever leaves 1.00)

[@TommyTranSti]

is your car still running strong? i get FKL up too -11 but i rarely get FBK and my DAM never leaves 1 as well

[@xaviormckittrick9394]

I got a Wrx 2016 my Acessport reads that I have feedback knock at 80 with .375 DAM is that okay?

[@jacobadkins317]

So i’m running a cobb OTS tune but i’ve spiked to -6 at times of almost WOT or WOT itself but according to what i’ve read a negative number is good or okay but on positive knock is bad so i’m confused

[@palaciosfreddy9189]

Great insight & awesome video right here. Confirmed what i already knew and put me at ease (regarding my car worries) right b4 bed. Pay attention guys, and dont freak out when you see a -7.00 feedback knock sum while crusing on highway. What matters would be seeing that number while WOT . And whats notable here is what the tuner stated; the more built and engine is the more noise a knock sensor, especially a new one will pick up and register as knock. Dont freak out

[@FlatironsTuning]

Thanks for watching and thanks for the comment. Really glad that the video was helpful. Stay Tuned!

[@BuckingFeast]

What your guys' opinion on running a Cobb intake and just a Cobb accessport with stage 1+ OTS map?

[@FlatironsTuning]

Thanks for your question. That is a very good option. Cobb does a lot of testing for their packages and we do like their intake packages. Hope that helps and Stay Tuned!

[@user-td7ss4vb9d]

What if we dont have access port and the car is modified to stage one with only short intake. In Europe specifically dont use cobb access port

[@johnnada3377]

Hello. I have a bit of an off-topic question for you. I have an 08 STI and I was wondering if you guys know roughly what the stock engine vacuum pressure should be in Denver? I’m having a really hard time finding this out.

[@FlatironsTuning]

Thanks for your question and we'll see if we can help. Can you give me a bit more information about what you are trying to find? What do you mean by engine vacuum pressure? Thanks for watching and Stay Tuned!

[@johnnada3377]

@FlatironsTuning I don’t have a smoke machine so I’m trying to find out if I have a vacuum leak, but I don’t know what the pressure is supposed to be. On my access port, when I look at boost it says - 7.70 psi at idle. That seems a bit low to me, but I don’t know. Hope that clarifies it. I’m kind of a noob lol.

[@shaijugm]

My car knock correct learn values 15.762 degree, is it normal? Let me know it

[@jozeccav123]

My sti gets alot when cruising at around 2200 to 2400rpm on knock sum cylinder 4. And zero at any other time. Drives me nuts 😅

[@FlatironsTuning]

We actually discuss this specifically towards the end of he video. Here is the link with a time stamp: kzbin.info/www/bejne/op-biIF7e9iMl68&feature=shares&t=1996 Hope that helps and thanks for watching. Stay Tune!

[@jozeccav123]

@@FlatironsTuning thank you for that I was on break and didn't get to finish the video 😅. I also noticed that it only happens after the engine has warmed up ! Feed back 0,fine knock 0, DAM 0. This is a relief !

[@FlatironsTuning]

@@jozeccav123 Excellent!

[@jozeccav123]

Does going with equal length headers help with knock on a ej?

[@FlatironsTuning]

Thanks for your question. No, that would come down much more to the tune and over all condition of the engine. Thanks for watching and Stay Tuned!

[@Mike_44]

Knock knock! Who’s there? EJ.. EJ who?! EJ get ready to spend your money.. lol

[@paulmarsdensr1095]

If I install a Cobb Access Port on my stock 2020 STI, will I need a tune?.

[@FlatironsTuning]

Thanks for your question. Am I correct that you are comparing the Cobb off-the-shelf tune compared to a custom tune?

[@paulmarsdensr1095]

@FlatironsTuning No I will not be turning my STI. I just wondered if I ever got a Cobb Access Port and installed it, will I need a tune and would it void my warranty from Subaru and Carmax.

[@lucian7182]

@@paulmarsdensr1095 in order to install the accessport it flashes a stage 0 tune, which is basically a copy of your stock tune. Would the dealer be able to tell you installed an accessport yes, would they deny an engine claim? They would try to.

[@Zaid_Mohamed]

But det-cans need be used to tune and listen to actual knock. You can't just rely on the knock sesnor and parameters. with det-cans, you know if its real or false knock.

[@GR_Papi]

WTF ¯\_(ツ)_/ 😂 hilarious

[@FlatironsTuning]

Thanks very much! Sweethouse knocked the editing and thumbnail for this video out of the park :-) Thanks for watching and Stay Tuned!

[@sawyerptak9390]

Anxiety ports 😂😂

[@FlatironsTuning]

They certainly can be sometimes :-) Thanks for watching and Stay Tuned!

[@steelrain5626]

Subscribed

[@FlatironsTuning]

Thanks very much! Stay Tuned!

[@steelrain5626]

@@FlatironsTuningWill do. I own a 2020 wrx premium, this is right where I need to be.

[@marcoscordero7549]

If old boi didn't sound so nerdy I would never listen to him. Like if he sounded like a bro I wouldn't trust a word he said but he just sounds so smart that if he told me to pour coke a cola into my motor and I'd gain +20 hp I would be omw to pick up a 2L 10 sec later