IW STi Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
2018 Sti
Cobb Sf Cold air intake
stock downpipe
91 octane
Protuned

I've been getting some FKL at WOT, from what I've been told you don't want any kind of knock at WOT.
If someone would please take a look and see what they think
I know I should be asking my tuner, but help isn't going to be free forever.

I have highlighted the problem areas, I also could not freeze the top row, I apologize


 

·
Registered
Joined
·
203 Posts
2018 Sti
Cobb Sf Cold air intake
stock downpipe
91 octane
Protuned

I've been getting some FKL at WOT, from what I've been told you don't want any kind of knock at WOT.
If someone would please take a look and see what they think
I know I should be asking my tuner, but help isn't going to be free forever.

I have highlighted the problem areas, I also could not freeze the top row, I apologize


Seems as though during the time you came off the dyno and until now the ecu was seeing enough feedback knock to calculate it into its longterm knock learning.

Being that the car is already very knock limited on 91oct, there was probably a combination of fueling, timing, boost and intake temps that caused knock at certain load ranges and the computer had to pull timing to keep it from knocking in those cells.

I would express my concern with your protuner and see what he says. If he doesnt want to make an adjustment to a 91oct subaru with boost then i would find another tuner.

I would never let a car i tune go off the dyno knowing its physically knocking enough to activate Fine knock learning. Especially since it is under boost.

Take my words with a grain of salt as there could be other noise issues or other issues for the knock sensor to detect something. As a knock sensor is literally an acoustic peizioelectric microphone. The value being seen is just a frequency at a certain dB that the sensor is catching as determined by the ecu.

Good luck!

Sent from my SM-G965U using Tapatalk
 

·
Vendor
Joined
·
380 Posts
So that log has a touch of FKL in one spot where you transition at 1/4 throttle onto boost. It's running 40 degrees of timing and 14:1 A/F. This is really common. It's not ideal but it's at such low load I wouldn't worry about it too much. Most tuners just tune WOT. We tune almost everywhere for reasons like this.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
Okay, I gotcha! I’m still seeing the -3.85 as soon as I get into boost it seems like! I just don’t know when to be concerned, because I hear and read different things from people.



So that log has a touch of FKL in one spot where you transition at 1/4 throttle onto boost. It's running 40 degrees of timing and 14:1 A/F. This is really common. It's not ideal but it's at such low load I wouldn't worry about it too much. Most tuners just tune WOT. We tune almost everywhere for reasons like this.
 

·
Vendor
Joined
·
380 Posts
With a solid tune and the fuel the tune was based on in the tank we don't seem much if any FKL on STIs (the VA WRX is different). Occasional non WOT FBK is going to happen on our cars, it's just the way it is. My opinion is as long as it's not happening on high boost or in a consistent place in the tune it's OK. YMMV.

Okay, I gotcha! I’m still seeing the -3.85 as soon as I get into boost it seems like! I just don’t know when to be concerned, because I hear and read different things from people.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #8
I’ll be sure to keep that in mind! I really appreciate the help!! Thanks!!


With a solid tune and the fuel the tune was based on in the tank we don't seem much if any FKL on STIs (the VA WRX is different). Occasional non WOT FBK is going to happen on our cars, it's just the way it is. My opinion is as long as it's not happening on high boost or in a consistent place in the tune it's OK. YMMV.
 
1 - 8 of 8 Posts
Top