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Protuned? How often do you see knock? What magnitude?

Thoughts/Review/Comparison 
5K views 16 replies 16 participants last post by  Jay11STI 
#1 · (Edited)
For comparisons sake, to the gentleman who are protuned. What's your Stage? Power numbers? And most importantly how often do you see knock and what magnitudes do they reach? I'm interested to see if they increase with miles on vehicle, are more frequent with increased power levels etc... I'm also aware of guidelines stated by Cobb and what we consider "ghost" knock or real knock (values and circumstances).

Me: Currently Stage 2 for ~800 miles.
See ghost knock on a daily basis -1.4 and had one occasion of -2.8 during a non-WOT pull that I can not say for certain was actual knock.
 
#3 ·
Here is Cobbs recommendations on what constitutes bad knock.

General Guidelines for Monitoring Knock on a Subaru – COBB Support

For me as long as i dont see any knock above 2.0g/rev and it doenst pull more than about 2 Deg of timing then its fine. You mostly just have to be worried about WOT. The knock sensors on the EJ or set so sensitive no matter how perfect the tune is you are going to see something occasionally. Ill usually see a couple of hits on my 30ish min commute to work.

My mods since you asked are pretty much full bolt on+ Dom 1.5 & E85.
 
#4 ·
15 STI, stage 2 installed by Renner in Carson, tuned by Paul at Yimy. 292 whp and 310 wtq.

It gets -1.4 FBK usually until FLK learns it. It got a -2.8 FBK the other day cause I was too lazy to downshift before I stepped hard on the gas (WOT underload) while exiting the freeway.

These turbo cars will knock if you hit the gas hard at below 3000 rpm (or before the turbo spools up) with 3th or higher gear.

It is ok to get -1.4, and occasionally -2.8 knocks. I was getting -4. plus knocks with stage 1 protuned by cobb socal. Expect more knocks during temp above 90 degree. Nothing we can do about it with 91 octane here in Socal.
 
#5 ·
You will always see small amounts of knock correction in the 2015+ platform (both WRX and STi). Subaru revised their knock control strategy for 2015 and made it much more sensitive (which is good). Anything below -3 is fine from our experience. If you are constantly seeing -2.8 under WOT, add some octane to the car and see if it goes away. That will tell you 3 things, poor fuel quality, aggressive tuning or if it is just engine noise.

Chris
 
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#6 ·
I get small knock everyday. -1.4 & sometimes -2.80 but never under a load. I only have 91ACN gas available to me so knock will always be around. I do add an octane booster sometimes or 100 octane race gas sometimes as well. it makes the car feel smoother and a bit more responsive. I've learned to live with knock now I guess haha.
 
#7 ·
2011 STi sedan currently at stage 2+ or Stage 3 depending on what you go by nowadays. I was pro tuned back in 2013 when the car had 22K on it. Now it sits at 49,700 and still strong. Its been tuned for over 27,000 miles and still running the same as it did when it left the dyno. To be honest, I don't data log often at all. I don't want to buy into the paranoia and let the "ghost knock" get stuck in my head. The only time I would really consider data logging would be if I suspect a serious problem. I'd rather enjoy driving the car worry free. I will say the only time I do monitor knock is when I take long aggressive drives on mountain roads a couple times a summer. On this trips I push the car as if it were at the track. I haven't seen any reported knock from the AP on those trips.

2011 Sti
49,700 miles currently
Stage 2+ 295whp/340ftlbs @ 20psi
Protuned at 22,000 miles.
 
#13 ·
I just got tuned 2 days ago 2020 STI.
COBB TBE
COBB INTAKE
COBB 1050x INJECTORS.
AEM 340 FP
IAG RAILS, TGVS, AOS
GRIMMSPEED EBCS
FUEL HOSE KIT
93 OCT TUNE

319WHP/390 WTQ @22 PSI on Mustang Dyno.
How long Will this setup intially last me. Do you feel like the numbers are too aggressive even with the 2019+ STIs having the TYPE RA shotblock in the them? I’m hearing these turbos are good for around 330-350WHP.
 
#11 ·
Ill ask this in here instead of making another thread

Feedback knock always at 0
Dynamic advance multiplier always at 1
Fine knock learn goes as low as -11 or -8, after i let go the gas during WOT.

08 sti only mods are Cobb SF intake with Stage 1 SF map.

Should i worry about the fine knock learn???
 
#14 ·
Those numbers do not have much meaning to me having seen how drastic one Mustang Dyno can be to the next, especially considering most show "low numbers" and your numbers for your fuel are up there.

That said, how long it lasts (questioning the tune), will depend on boost, timing, fuel, etc.
 
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