Welcome to the North American Subaru Impreza Owners Club Friday March 29, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > FA Series Factory 2.0L Turbo Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 03-26-2018, 03:36 PM   #1
kduni
Scooby Newbie
 
Member#: 434061
Join Date: Nov 2015
Location: West Texas
Vehicle:
2016 WRX
Metallic grey

Default False knock or toasted fa20dit?

I just added flex fuel to my build and my car is having fine knock learn in the 5500-6000 rpm range under knock ranging from 1.41-4 My tuner has tried everything he can but the knock is persistent. E-Tuned by Ron Watson of phatbotti tuning. If it was a tuning issue I'm confident he could have figured it out. He thinks it is false noise or a toasted cylinder.

I am wondering where I should start looking for something loose if it is false knock? Are there are common cultprates for causing false knock?

My Mods are:
Cobb flex fuel
Dcw300c fuel pump
Grimmspeed J pipe
Grimmspeed TMIC
Grimmspeed charge pipe
Grimmspeed EBCS
IAG AOS
TVG delete
ERG delete
Invidia Q300 catback
Perrin pitch stop
Perrin pitch stop mount
Perrin BOV
STI group N trani mount

Car is acting 100 percent normal, pulling hard to red line, no leaks no known issues what so ever.....except the knocking.

Any suggestions or help is much appreciated.
* Registered users of the site do not see these ads.
kduni is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 03-28-2018, 11:01 AM   #2
umscooby
Scooby Specialist
 
Member#: 50902
Join Date: Dec 2003
Chapter/Region: RMIC
Location: backroads
Vehicle:
98
$$$ Green

Default

What is your ethanol content? My tuner recently informed me that the FA20's are prone to knock, that can't be tuned out, on anything over E60 as well as 91oct.
umscooby is offline   Reply With Quote
Old 03-28-2018, 11:20 AM   #3
anarekist
Scooby Specialist
 
Member#: 468117
Join Date: May 2017
Chapter/Region: SCIC
Location: Southern Cali
Vehicle:
2017 WRX
DMG

Default

could be a bad knock sensor
anarekist is offline   Reply With Quote
Old 03-28-2018, 02:01 PM   #4
rtv900
Scooby Guru
 
Member#: 428511
Join Date: Aug 2015
Location: philadelphia
Vehicle:
2016 STI

Default

Quote:
Originally Posted by umscooby View Post
My tuner recently informed me that the FA20's are prone to knock, that can't be tuned out, on anything over E60 as well as 91oct.
^this statement makes less than no sense

can't be tuned out???????? Suggest to him dialing back peak boost and peak timing, that's a good start.
There's no such thing as detonation that can't be tuned out.
rtv900 is offline   Reply With Quote
Old 03-28-2018, 02:24 PM   #5
Twisty mountain road
Scooby Newbie
 
Member#: 402977
Join Date: Oct 2014
Chapter/Region: SCIC
Default

what is your whp/wtq? Even on an e-tune you should know approx. #s. Does it still knock with 91/93? What is your injector duty cycle and fuel pressure when at WOT between 5500 and 6000 rpm?

Feedback knock is different then fine knock learning. Because of the e-tune and days/weeks between tune changes, you could have had a knock event that your ecu is still learning to avoid. This can take days to weeks depending no how much you drive the car and how frequently you are in that rpm range.

As mentioned above, have Ron draw boost psi back down to 19 psi instead of 20 (or whatever it is tuned at) if it persists. There are a few good tuners in So Cali, Ron is one of them
Twisty mountain road is offline   Reply With Quote
Old 03-28-2018, 02:34 PM   #6
umscooby
Scooby Specialist
 
Member#: 50902
Join Date: Dec 2003
Chapter/Region: RMIC
Location: backroads
Vehicle:
98
$$$ Green

Default

Quote:
Originally Posted by rtv900 View Post
^this statement makes less than no sense

can't be tuned out???????? Suggest to him dialing back peak boost and peak timing, that's a good start.
There's no such thing as detonation that can't be tuned out.
"tuned out" may be a poor choice of words. Point is if OP is running Ethanol content higher than 60% he may have to do what you are just said, pull timing and boost. But then what's the point of running higher ethanol content if you have to dial it back?

I stand by my tuner's word which is the FA's, which btw I don't own, can't be pushed on fuel with ethanol content above 60%. At least in stockish or 'stage II' trim.

I watched him tune one in front of my car just 2 days ago...

mine

Last edited by umscooby; 03-28-2018 at 02:40 PM.
umscooby is offline   Reply With Quote
Old 03-28-2018, 02:42 PM   #7
GlarryHoodDIT
Scooby Specialist
 
Member#: 460907
Join Date: Jan 2017
Chapter/Region: RMIC
Location: Colorado
Vehicle:
2020 Golf GTI

Default

So much fantastic misinformation here.

FA20s are as knock prone as any Subaru motor, the difference is the knock control strategy is much more active on the FAs over EJs so knock gets heard more often. EJs are about 1/8 as sensitive as FA knock monitors.

Large amounts of ethanol can't be run due to limitations with the fuel pump, not because of detonation. Increased detonation from more ethanol makes so little sense it's stupid, why would more ethanol, thus a higher octane level, cause more detonation?

Op: Compression test? Spark plugs?
GlarryHoodDIT is offline   Reply With Quote
Old 03-28-2018, 06:17 PM   #8
kduni
Scooby Newbie
 
Member#: 434061
Join Date: Nov 2015
Location: West Texas
Vehicle:
2016 WRX
Metallic grey

Default

Quote:
Originally Posted by umscooby View Post
"tuned out" may be a poor choice of words. Point is if OP is running Ethanol content higher than 60% he may have to do what you are just said, pull timing and boost. But then what's the point of running higher ethanol content if you have to dial it back?

I stand by my tuner's word which is the FA's, which btw I don't own, can't be pushed on fuel with ethanol content above 60%. At least in stockish or 'stage II' trim.

I watched him tune one in front of my car just 2 days ago...

mine This Gen 2 GTX3076R is UNCHAINED! - YouTube
Been busy with work the last few days.

So I am running and tuned for an E50 blend. Ron caps the power at E50.

Changed the plugs at 20k, mileage at 29k currently.

Before doing a compression test I decided to go through and look at everything that I had ever touched under the hood to see if I could find something to attribute the false knock to. I noticed that the clearance between my Grimmspeed charge pipe and engine had gone from very tight to actually touching the engine. At high RPM/loads I think it was vibrating and making the false knock noise.

My front end got in a small fender bender a few months ago and I bet that's what did it. After I readjusted it I took the car out for some pulls....knock is completely gone. Now I need to ask Ron if we have any more room for increasing boost/timing since I found the source of the knock.

It was a stressful few days as I thought about a toasted engine.....but at the same time that would mean a new IAG block for more power down the line.
kduni is offline   Reply With Quote
Old 03-28-2018, 07:30 PM   #9
WRXTACY
Scooby Newbie
 
Member#: 15339
Join Date: Feb 2002
Chapter/Region: MAIC
Location: Fairfax, VA
Vehicle:
2015 CWP WRX
Flex Fuel tune by Phatron

Default

Quote:
Originally Posted by kduni View Post
Been busy with work the last few days.

So I am running and tuned for an E50 blend. Ron caps the power at E50.

Changed the plugs at 20k, mileage at 29k currently.

Before doing a compression test I decided to go through and look at everything that I had ever touched under the hood to see if I could find something to attribute the false knock to. I noticed that the clearance between my Grimmspeed charge pipe and engine had gone from very tight to actually touching the engine. At high RPM/loads I think it was vibrating and making the false knock noise.

My front end got in a small fender bender a few months ago and I bet that's what did it. After I readjusted it I took the car out for some pulls....knock is completely gone. Now I need to ask Ron if we have any more room for increasing boost/timing since I found the source of the knock.

It was a stressful few days as I thought about a toasted engine.....but at the same time that would mean a new IAG block for more power down the line.
nice!
WRXTACY is offline   Reply With Quote
Old 03-28-2018, 09:39 PM   #10
Harey
Scooby Specialist
 
Member#: 270569
Join Date: Jan 2011
Chapter/Region: International
Vehicle:
'15 Foz XT & GT86

Default

Great to hear! Put the clamp on the charge pipe close to the pipe flares (only the thickness of the hose material away). Otherwise the pipe can move until the pipe flare reaches the clamp.
Harey is offline   Reply With Quote
Old 03-29-2018, 06:18 AM   #11
rtv900
Scooby Guru
 
Member#: 428511
Join Date: Aug 2015
Location: philadelphia
Vehicle:
2016 STI

Default

Quote:
Originally Posted by umscooby View Post
"tuned out" may be a poor choice of words. Point is if OP is running Ethanol content higher than 60% he may have to do what you are just said, pull timing and boost. But then what's the point of running higher ethanol content if you have to dial it back?
I guess more context and specifics than word choice.
Again, it absolutely can be tuned out, it's just you have other issues.
Like Glarry said, fuel pump.
There's no such thing as not being able to run more than "x" percent ethanol, or methanol, or 91 or 85 octane without detonation, it makes no sense at all and telling a customer that is kind of a cop out answer.

All of those fuels have limitations in some regard operating in spark ignition engines, period. You work around those and they work fine. If you want it all and won't give up anything they don't work fine.
They aren't magic.
It's not a coincidence diesel guys never talk about detonation. Different ignition fundamental, totally different ballgame.
We have spark ignition engines.
rtv900 is offline   Reply With Quote
Old 03-29-2018, 09:00 AM   #12
Perscitus
Scooby Specialist
 
Member#: 378214
Join Date: Jan 2014
Chapter/Region: Tri-State
Location: Blue Hole
Default

Quote:
Originally Posted by GlarryHoodDIT View Post
So much fantastic misinformation here. FA20s are as knock prone as any Subaru motor, the difference is the knock control strategy is much more active on the FAs over EJs so knock gets heard more often. EJs are about 1/8 as sensitive as FA knock monitors.

Large amounts of ethanol can't be run due to limitations with the fuel pump, not because of detonation. Increased detonation from more ethanol makes so little sense it's stupid, why would more ethanol, thus a higher octane level, cause more detonation?

Op: Compression test? Spark plugs?
GlarryHoodDIT is right on. OP - what you're seeing is no sign of anything being toast.

There is nothing wrong with seeing FKC or FLKC, lower IAM/DAM on these cars - E10 or E50 or anything in between.
This is how the knock strategy is supposed to function on these econoboxes.

The fine learned knock you might be seeing up north could have been learned at some point, and either a. is not indicative of any knock occuring, just showing you what KCA is being pulled up top
b. needs to be learned away and might decrease c. is just a function of a larger cell to cell timing jump or is AVCS related.
To tell you'd want to either trace the log against your Total Timing and/or KCA tables OR pull a Learning View (I don't think its possible to do that yet on these Hitachi-based FAxxDITs).

Its sensitive (some may argue oversensitive), dynamic, fairly primitive with limited fidelity sensors, meh inputs. False knock, FKC noise, PKC doing its thing, etc.
And so long as you're not seeing excessive (say >1-2 deg) FKC/FLKC under load and in boost, during WOT, etc. there is nothing to worry about,
and nothing you should or can do to eliminate FKC, FLKC and PKC noise.

Out of boost, low load and non-WOT FKC/FLKC can typically be ignored to, within reason and particularly if it decays away
or fluctuates instead of increasing with steady throttle, RPM, Load, etc.

For some reason very few people on here (and particularly those with FAxxDITs) realize that
if you see no FKC, FLKC and your DAM/IAM is pegged at 1, that's not a great tune, thats a botched tuned.

Disabling RC is a piece of cake, messing with FKC/FLKC activation ranges, KCA values, knock sensor sensitivity and timing enough to do so is a bad idea.

On a healthy tune, especially any E10 and it doesnt matter if AKI89 or AKI93... but even E30-50 tunes, you should always see some FKC and hope to get some minor FLKC
to populate the Learned Timing RAM table. If FKC and FLKC are always zero, no matter what you do... not a good sign.

Last edited by Perscitus; 03-30-2018 at 04:22 PM.
Perscitus is offline   Reply With Quote
Old 04-05-2018, 02:30 AM   #13
h4root
Scooby Newbie
 
Member#: 415859
Join Date: Mar 2015
Default

Stop Blaming Ron he is a Rocket Scientist, and I'm tuned by him (Astrophysicist/Comp Mathemtician) No issues here, so its clearly a problem with your car or the mods you put on it. I only get -1.41 fine knock learn at worst...
h4root is offline   Reply With Quote
Old 04-05-2018, 02:35 AM   #14
h4root
Scooby Newbie
 
Member#: 415859
Join Date: Mar 2015
Default

I think the problem is your "ERG delete" next time get an EGR Delete instead.

LOL Jk its probably all the grimmspeed trash you have on it.

My mods Dyno Tuned by Ron:
Cobb AP
Cobb Flex Fuel
AEM Cai
Depo Racing Catted J-Pipe + Int Pipe
TGV Deletes
Stock TMIC
Stock BPV
Stock Boost Controller
275/308 91
350/350 e52

Quote:
Originally Posted by kduni View Post
I just added flex fuel to my build and my car is having fine knock learn in the 5500-6000 rpm range under knock ranging from 1.41-4 My tuner has tried everything he can but the knock is persistent. E-Tuned by Ron Watson of phatbotti tuning. If it was a tuning issue I'm confident he could have figured it out. He thinks it is false noise or a toasted cylinder.

I am wondering where I should start looking for something loose if it is false knock? Are there are common cultprates for causing false knock?

My Mods are:
Cobb flex fuel
Dcw300c fuel pump
Grimmspeed J pipe
Grimmspeed TMIC
Grimmspeed charge pipe
Grimmspeed EBCS
IAG AOS
TVG delete
ERG delete
Invidia Q300 catback
Perrin pitch stop
Perrin pitch stop mount
Perrin BOV
STI group N trani mount

Car is acting 100 percent normal, pulling hard to red line, no leaks no known issues what so ever.....except the knocking.

Any suggestions or help is much appreciated.
h4root is offline   Reply With Quote
Old 04-05-2018, 09:29 AM   #15
mishapopa
Scooby Specialist
 
Member#: 393629
Join Date: Jun 2014
Chapter/Region: W. Canada
Location: Calgary
Default

Quote:
Originally Posted by h4root View Post
Stop Blaming Ron he is a Rocket Scientist, and I'm tuned by him (Astrophysicist/Comp Mathemtician) No issues here, so its clearly a problem with your car or the mods you put on it. I only get -1.41 fine knock learn at worst...
Quote:
Originally Posted by h4root View Post
I think the problem is your "ERG delete" next time get an EGR Delete instead.

LOL Jk its probably all the grimmspeed trash you have on it.

My mods Dyno Tuned by Ron:
Cobb AP
Cobb Flex Fuel
AEM Cai
Depo Racing Catted J-Pipe + Int Pipe
TGV Deletes
Stock TMIC
Stock BPV
Stock Boost Controller
275/308 91
350/350 e52
mishapopa is offline   Reply With Quote
Old 04-05-2018, 09:51 AM   #16
simpleJ
Scooby Specialist
 
Member#: 391748
Join Date: May 2014
Chapter/Region: NESIC
Location: The Shire
Vehicle:
2015 WRX CWP (sold)
2019 STi CWP

Default

Quote:
Originally Posted by h4root View Post
Stop Blaming Ron he is a Rocket Scientist, and I'm tuned by him (Astrophysicist/Comp Mathemtician) No issues here, so its clearly a problem with your car or the mods you put on it. I only get -1.41 fine knock learn at worst...
That doesn't mean anything. A computer programmer, engineer, or self taught HS drop out could tune just as well if not better than someone with a ph.d.


Quote:
Originally Posted by umscooby View Post
"tuned out" may be a poor choice of words. Point is if OP is running Ethanol content higher than 60% he may have to do what you are just said, pull timing and boost. But then what's the point of running higher ethanol content if you have to dial it back?

I stand by my tuner's word which is the FA's, which btw I don't own, can't be pushed on fuel with ethanol content above 60%. At least in stockish or 'stage II' trim.

I watched him tune one in front of my car just 2 days ago...
Get out of here. You're spreading nonsense. EJ's can be tuned within like 4 dyno pulls even on some crazy set ups. Just does not translate, sorry.

Quote:
Originally Posted by h4root View Post
I think the problem is your "ERG delete" next time get an EGR Delete instead.

LOL Jk its probably all the grimmspeed trash you have on it.

My mods Dyno Tuned by Ron:
Cobb AP
Cobb Flex Fuel
AEM Cai
Depo Racing Catted J-Pipe + Int Pipe
TGV Deletes
Stock TMIC
Stock BPV
Stock Boost Controller
275/308 91
350/350 e52
Calls GS trash, has AEM CAI and DEPO down pipe....

Got damn this forum is great some times.
simpleJ is offline   Reply With Quote
Old 04-05-2018, 09:57 AM   #17
Veritas1286
Scooby Newbie
 
Member#: 410759
Join Date: Jan 2015
Location: Charleston, SC
Vehicle:
2015 WRX
Dark Gray

Default

Nice trolling. For someone so trusting in Ron's word - you neglect that he specifically lists Grimmspeed in his recommendations list.


Quote:
Originally Posted by h4root View Post
I think the problem is your "ERG delete" next time get an EGR Delete instead.

LOL Jk its probably all the grimmspeed trash you have on it.

My mods Dyno Tuned by Ron:
Cobb AP
Cobb Flex Fuel
AEM Cai
Depo Racing Catted J-Pipe + Int Pipe
TGV Deletes
Stock TMIC
Stock BPV
Stock Boost Controller
275/308 91
350/350 e52
Veritas1286 is offline   Reply With Quote
Old 04-05-2018, 10:05 AM   #18
anarekist
Scooby Specialist
 
Member#: 468117
Join Date: May 2017
Chapter/Region: SCIC
Location: Southern Cali
Vehicle:
2017 WRX
DMG

Default

but it was the grimmspeed part that was causing problems.
anarekist is offline   Reply With Quote
Old 04-05-2018, 10:09 AM   #19
simpleJ
Scooby Specialist
 
Member#: 391748
Join Date: May 2014
Chapter/Region: NESIC
Location: The Shire
Vehicle:
2015 WRX CWP (sold)
2019 STi CWP

Default

Quote:
Originally Posted by anarekist View Post
but it was the fender bender that was causing problems.
FTFY
simpleJ is offline   Reply With Quote
Old 04-05-2018, 11:09 AM   #20
GrimmSpeed
NASIOC Vendor
 
Member#: 136396
Join Date: Jan 2007
Chapter/Region: MWSOC
Location: Minneapolis, MN
Vehicle:
2020 STI, 2022 WRX

Default



Chase
Engineering
GrimmSpeed is offline   Reply With Quote
Old 04-05-2018, 11:30 AM   #21
noobultimatum
Scooby Specialist
 
Member#: 431550
Join Date: Oct 2015
Location: South Florida
Vehicle:
2016 WRX
ALL THE STAGES

Default

Quote:
Originally Posted by GrimmSpeed View Post


Chase
Engineering
I'll just be brutally honest here after seeing you around the forums for a while..

I love you, dude
noobultimatum is offline   Reply With Quote
Old 04-05-2018, 11:37 AM   #22
anarekist
Scooby Specialist
 
Member#: 468117
Join Date: May 2017
Chapter/Region: SCIC
Location: Southern Cali
Vehicle:
2017 WRX
DMG

Default

anarekist is offline   Reply With Quote
Old 04-05-2018, 11:41 AM   #23
noobultimatum
Scooby Specialist
 
Member#: 431550
Join Date: Oct 2015
Location: South Florida
Vehicle:
2016 WRX
ALL THE STAGES

Default

Quote:
Originally Posted by anarekist View Post
fascinating gif, they are playing speed chess and that guy actually loses.

Magnus Carlsen beats Ian Nepomniachtchi FIDE World Rapid Championship 2017 Round 10 - YouTube
...Irrelevant given the context
noobultimatum is offline   Reply With Quote
Old 04-05-2018, 11:52 AM   #24
GrimmSpeed
NASIOC Vendor
 
Member#: 136396
Join Date: Jan 2007
Chapter/Region: MWSOC
Location: Minneapolis, MN
Vehicle:
2020 STI, 2022 WRX

Default

Quote:
Originally Posted by noobultimatum View Post
I'll just be brutally honest here after seeing you around the forums for a while..

I love you, dude
I appreciate that, and the feeling is mutual

Quote:
Originally Posted by anarekist View Post
fascinating gif, they are playing speed chess and that guy actually loses.

Magnus Carlsen beats Ian Nepomniachtchi FIDE World Rapid Championship 2017 Round 10 - YouTube
Yup, Magnus made a mistake, and this is it blowing Ian's mind in real time while he tries to determine what Ian's actual motive was (if any). Outcome be damned, this is still the greatest reaction gif I've ever seen.

Chase
Engineering
GrimmSpeed is offline   Reply With Quote
Old 04-05-2018, 12:02 PM   #25
anarekist
Scooby Specialist
 
Member#: 468117
Join Date: May 2017
Chapter/Region: SCIC
Location: Southern Cali
Vehicle:
2017 WRX
DMG

Default

Quote:
Originally Posted by GrimmSpeed View Post
this is still the greatest reaction gif I've ever seen.
agreed
anarekist is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 03:42 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.