Welcome to the North American Subaru Impreza Owners Club Monday November 19, 2018
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Engine Management & Tuning > AccessPort

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.
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 09-28-2018, 11:48 AM   #1
Bananana
Scooby Newbie
 
Member#: 492040
Join Date: Sep 2018
Default Feedback Knock Correction -3.85 on WOT 2011 wrx GR

I have been trying to help out my good ol buddy with his wrx, if anyone could give some insight it would help alot, I also own a wrx GR but im also puzzled as to why he is experiencing knock. His car is protuned.

So first things we did was clean the maf sensor (still knocking). Theres a heatshield rattle from the exhaust manifold but never registers a knock when its audible on lower rpms so we dont think its that. He always uses 93 octane BP gas (top tier). I helped him log the following below:

First two logs are 3rd gear WOT, and last log is gradually getting into higher RPM range but staying out of boost. Have a good one all!


https://docs.google.com/spreadsheets...gid=2075658681


https://docs.google.com/spreadsheets...#gid=419546339


https://docs.google.com/spreadsheets...gid=1678070106
* Registered users of the site do not see these ads.

Last edited by Bananana; 09-28-2018 at 12:02 PM.
Bananana is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 09-28-2018, 02:07 PM   #2
86Dreams
Scooby Specialist
 
Member#: 385256
Join Date: Mar 2014
Chapter/Region: Tri-State
Location: Harriman NY
Vehicle:
V7 S204

Default

Taking it that this is a new phenomena? is there oil in the tmic, maybe? how are the fuel trims? have you tried replacing the engine fuel filter?
86Dreams is online now   Reply With Quote
Old 09-30-2018, 02:22 AM   #3
Bananana
Scooby Newbie
 
Member#: 492040
Join Date: Sep 2018
Default

Quote:
Originally Posted by 86Dreams View Post
Taking it that this is a new phenomena? is there oil in the tmic, maybe? how are the fuel trims? have you tried replacing the engine fuel filter?
We haven't had a chance to check it out the TMIC yet but will do some hopefully, havent changed the fuel filter, car didnt seem to hesitate at all. I dont think he is monitoring fuel trims

Last edited by Bananana; 09-30-2018 at 02:34 AM.
Bananana is offline   Reply With Quote
Old 09-30-2018, 04:42 PM   #4
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

Hard to read the logs on my phone, but, throw some octane booster in the car. Real stuff, not the crap stuff. You can use xylene and the online calculator or, find some torco or similar.
PDXREALTOR is offline   Reply With Quote
Old 09-30-2018, 06:51 PM   #5
Jersey Man10
Scooby Newbie
 
Member#: 427632
Join Date: Aug 2015
Default

Get with his tuner. Also those pulls arenít even to redline wtf.
Jersey Man10 is offline   Reply With Quote
Old 10-13-2018, 02:11 AM   #6
Bananana
Scooby Newbie
 
Member#: 492040
Join Date: Sep 2018
Default

new log, just driving in third and then knocks -4.20....Log attached, first instance of knock starts at line 55. Really need help because i don;t know anymore what else i can do to diagnose...All that is left is to check pre-turbo inlet leaks.

https://docs.google.com/spreadsheets...it?usp=sharing
Bananana is offline   Reply With Quote
Old 10-13-2018, 02:12 AM   #7
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

Quote:
Originally Posted by Bananana View Post
new log, just driving in third and then knocks -4.20....Log attached, first instance of knock starts at line 55. Really need help because i don;t know anymore what else i can do to diagnose...All that is left is to check pre-turbo inlet leaks.

https://docs.google.com/spreadsheets...it?usp=sharing
Did you put octane booster in? How much and what kind if so?
PDXREALTOR is offline   Reply With Quote
Old 10-13-2018, 02:22 AM   #8
Bananana
Scooby Newbie
 
Member#: 492040
Join Date: Sep 2018
Default

Quote:
Originally Posted by PDXREALTOR View Post
Did you put octane booster in? How much and what kind if so?
No octane booster was put in. Car is tuned for 93 octane and we are running 93 octane shell v powered..not sure how octane booster would help fix this issue.
Bananana is offline   Reply With Quote
Old 10-13-2018, 02:35 AM   #9
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

If you put a quality octane booster in and it doesn't knock you know you have a mechanical or tuning issue.

If it does still knock you know you have a false knock issue.

I run hybrid boost and haven't tuned any turbo dynamics, but, that's the only thing that stood out in your last log. I forgot to look at timing. But, doubt that's it.

Your at low load, low throttle pos, and the knock happens right as you enter boost. I've been there and it was super easy to go to home depot and get some xylene for the tank. Turned out, my car didn't like the lightweight crank pulley.

Putting in 100 octane proved it was false knock. I took the last item I put on, off and.... Problem solved.

Youre asking for help..... I suggested octane booster. Take it or leave it.... Maybe someone else will chime in.

Last edited by PDXREALTOR; 11-04-2018 at 08:00 PM.
PDXREALTOR is offline   Reply With Quote
Old 10-13-2018, 04:06 PM   #10
Bananana
Scooby Newbie
 
Member#: 492040
Join Date: Sep 2018
Default

Quote:
Originally Posted by PDXREALTOR View Post
If you put a quality octane booster in and it still knocks you know you have a mechanical or tuning issue.

If it doesn't knock you know you have a false knock issue.

I run hybrid boost and haven't tuned any turbo dynamics, but, that's the only thing that stood out in your last log. I forgot to look at timing. But, doubt that's it.

Your at low load, low throttle pos, and the knock happens right as you enter boost. I've been there and it was super easy to go to home depot and get some xylene for the tank. Turned out, my car didn't like the lightweight crank pulley.

Putting in 100 octane proved it was false knock. I took the last item I put on, off and.... Problem solved.

Youre asking for help..... I suggested octane booster. Take it or leave it.... Maybe someone else will chime in.
Im not familiar with octane boosters as i have never used them, is it ok to use on quarter or less tank, just so it doesnt linger in the fuel tank for too long. The last thing the car had replaced was a drop in filter from cobb, same filter as old one because it got dirty, chances of that being the culprit imo is really small, but who knows....
Bananana is offline   Reply With Quote
Old 10-13-2018, 04:40 PM   #11
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

Quote:
Originally Posted by Bananana View Post
Im not familiar with octane boosters as i have never used them, is it ok to use on quarter or less tank, just so it doesnt linger in the fuel tank for too long. The last thing the car had replaced was a drop in filter from cobb, same filter as old one because it got dirty, chances of that being the culprit imo is really small, but who knows....
Here's a mix chart. http://www.gnttype.org/techarea/misc/octanebooster.html
PDXREALTOR is offline   Reply With Quote
Old 10-13-2018, 06:53 PM   #12
Jersey Man10
Scooby Newbie
 
Member#: 427632
Join Date: Aug 2015
Default

What mods are on the car besides the tune?
Jersey Man10 is offline   Reply With Quote
Old 10-19-2018, 12:57 PM   #13
Bananana
Scooby Newbie
 
Member#: 492040
Join Date: Sep 2018
Default

Quote:
Originally Posted by Jersey Man10 View Post
What mods are on the car besides the tune?
downpipe, intake, ewg, ebcs
Bananana is offline   Reply With Quote
Old 10-26-2018, 01:16 PM   #14
Bananana
Scooby Newbie
 
Member#: 492040
Join Date: Sep 2018
Default

Quote:
Originally Posted by PDXREALTOR View Post
If you put a quality octane booster in and it still knocks you know you have a mechanical or tuning issue.

If it doesn't knock you know you have a false knock issue.

I run hybrid boost and haven't tuned any turbo dynamics, but, that's the only thing that stood out in your last log. I forgot to look at timing. But, doubt that's it.

Your at low load, low throttle pos, and the knock happens right as you enter boost. I've been there and it was super easy to go to home depot and get some xylene for the tank. Turned out, my car didn't like the lightweight crank pulley.

Putting in 100 octane proved it was false knock. I took the last item I put on, off and.... Problem solved.

Youre asking for help..... I suggested octane booster. Take it or leave it.... Maybe someone else will chime in.
I should be getting my torco tomorrow, quick question as it seems a common side effect of this product is it leaves an orange residue on sparkplugs, should I be worried about this?
Bananana is offline   Reply With Quote
Old 10-26-2018, 03:10 PM   #15
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

No. I run 3oz torco per gallon 100% of the time. All my internals are orange.
PDXREALTOR is offline   Reply With Quote
Old 10-26-2018, 03:37 PM   #16
GlarryHoodDIT
Scooby Specialist
 
Member#: 460907
Join Date: Jan 2017
Chapter/Region: RMIC
Location: Colorado
Vehicle:
2016 WRX

Default

If you run an octane booster and raise your octane level and stop knocking couldn't that just indicate the tune is too aggressive for the current gas being used? Why is it automatically false knock? If you raise your octane from 91 to 93 and stop knocking couldn't that be the reason? A higher octane not that it was false knock?
GlarryHoodDIT is offline   Reply With Quote
Old 10-26-2018, 03:49 PM   #17
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

That's the point. Raise the octane and if the knock goes away its likely a tune or mechanical issue.

If knock remains - its likely false.

*likely*
PDXREALTOR is offline   Reply With Quote
Old 10-26-2018, 04:02 PM   #18
GlarryHoodDIT
Scooby Specialist
 
Member#: 460907
Join Date: Jan 2017
Chapter/Region: RMIC
Location: Colorado
Vehicle:
2016 WRX

Default

Oh ok. That's just the exact opposite of what you first posted. Unless I misunderstood.
GlarryHoodDIT is offline   Reply With Quote
Old 10-26-2018, 04:10 PM   #19
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

Quote:
Originally Posted by GlarryHoodDIT View Post
Oh ok. That's just the exact opposite of what you first posted. Unless I misunderstood.
No, I miss-typed. My mistake, good catch!
PDXREALTOR is offline   Reply With Quote
Old 10-27-2018, 01:30 AM   #20
chukiichuu
Scooby Newbie
 
Member#: 303157
Join Date: Dec 2011
Chapter/Region: Tri-State
Location: New York City
Vehicle:
2011 WRX
SWP

Default

Quote:
Originally Posted by PDXREALTOR View Post
No, I miss-typed. My mistake, good catch!
So just to confirm after reading this thread im a little confused, put in octane boostet if A. Knock goes away its tune or possibly lose clamp/engine damage or if B. Knock remains its false knock anything from a heatshielf rattle to who knows? I have a loose heatshield and wanna make sure this wont happen to me lol....
chukiichuu is offline   Reply With Quote
Old 10-27-2018, 03:04 AM   #21
GlarryHoodDIT
Scooby Specialist
 
Member#: 460907
Join Date: Jan 2017
Chapter/Region: RMIC
Location: Colorado
Vehicle:
2016 WRX

Default

Correct.

If you're running 91 octane gas and you start getting knock, then you raise your octane (via torco or xylene) to 93 and you don't get knock anymore, then it's likely the tune was too aggressive or there is a mechanical issue with your motor. Octane = measurement of a fuel's resistance to knocking. So if you add more octane and the knock goes away then that was likely the problem.

If in the same situation, you're running 91 and you start getting knock, then you raise your octane and you still get knock, then it's likely not an octane or mechanical issue but likely false knock. If it was due to aggressive tuning or a mechanical problem then raising the octane would mitigate it. If it's a problem like a heat shield rattling, then no matter how high you raise your octane rating it won't matter because it's the noise of the rattle setting off the knock correction not actual knock.That would be false knock.

Obviously this isn't 100% fool-proof, just because you add torco and the car still knocks doesn't mean it's definitely false, the tune could still be too aggressive or something. But this is an easy way to check without ripping your engine apart.

Last edited by GlarryHoodDIT; 10-27-2018 at 03:10 AM.
GlarryHoodDIT is offline   Reply With Quote
Old 10-31-2018, 12:20 AM   #22
RolyatMusic
Scooby Newbie
 
Member#: 493126
Join Date: Oct 2018
Unhappy feedback knock at WOT

https://docs.google.com/document/d/1...it?usp=sharing

i didnt do a redline pull but its most likely enough to see whats wrong or get to somewhere. what do you think it could be? its not bad fuel becuase ive been going to all shell stations and its all 92 v power. and i just tightened all my hose clamps for boost leaks too...
RolyatMusic 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 12:15 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2018 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.