Hey guys,

i am going crazy because i cant really lower my Knock - value.

3 Months ago, i had a RacingBeat FULL exhaust on my S5 Turbo. the Knock values were 45-55 during cruise, and around 20-25 WOT.
now my car is equipped with a 3" Corksport exhaust, and the Knock increased dramatically.. i dont know why.
during cruise i read 65-75 knock ( 22° BTDC, 12,3-13,1 AFR, -320mmHg),
WOT 40-55 knock (ca. 17° BTDC, 11,2 AFR, 0,80kg/cm²~~12psi)

My Knock Sensor ist at rotorhousing 1, if i plug it to rotorhousing 2, it reads only 1/2 of the knock: max 30 during cruise and 15-20 WOT.

I have tried many things, for example retarding my timing by up to 12° over the whole map (Test function) and enrich the mixture to 12,0 AFR during cruise and 10,2AFR WOT.. in BEST Case, it drops down knock by 2 - 4 lvls.. lol!

I also checked for loose bolts, covers etc. i also pulled out the power steering because it made some noise..


is there any chance to figure out TRUE knock??
its really horrible.. i CANT enjoy driving, because i am looking all the time to my knock lvls and AFRs..

if you want inj/ign maps, i can load them up.

 

ok here are the maps:

INJ-MAP



IGN Leading MAP


IGN SPLIT


The Ignition is almost BASE-Map, just 3-4° advanced in high RPM under boost, the cruise sector is untouched except for the split.

The Mods to the car are as follows:

Streetport,
portmatched intake,
2nd throttlebody plates taken out,
Apexi Air filter,
Apexi 3Bar MAP Sensor,
Walbro 255 Fuel Pump
SARD 800ccm secondarys set on 0.20ms lagtime

like i said before.. i changed nothing but the exhaust, AND from mineral oil (Penzoil or Castrol GTX 20w50) to synthetic: Royal Purple 20w50.

under 12psi of pressure and WOT i geat readings of 11,3-11,4 AFR, but my plugs are telling another story.. they are almost white! especially the Lead-Plugs.
Before changing the exhaust system and Oil, it was all fine chocolate brown.

 

what plugs are you running? you aren't running the stock leading plugs are you?

 

i am! i thought it is ok to run the stock plugs..
I have changed them 400miles ago:

NGK BUR9EQP (Trail)
NGK BUR7EQP (Lead)

there is almost no difference in color between trail and lead, they are both grey / almost white

oh.. and after the rebuild of my engine in 2007 (2000 miles ago) and with the racing-beat exhaust, i was running the stock plugs too.
the sparkplug wires are MSD.

 

Maybe someone could answer this better than me but your split in higher RPM seems to be aggressive.

 

thanks for the advise, i will check it out! i ran split of 10 in that area before, but it changed almost nothing to knock going a bit more aggressive.

Here are some pictures of my plugs:

the old ones, pulled ~400 miles ago, they had racingbeat and corksport exhaust with same map.



and this are pictures of the the plugs which i changed 400 miles ago, ran with the map i posted above.

 

How much boost are you running? What octane gas? First, you need to get a knock baseline by running a tune that you know will not knock. Richen the AFR to 10.5-11.0, pull a few degrees of timing, and lower your boost to 14 psi or less. Do a couple of wot passes and trend the knock. Those readings will then be your baseline. If you read the same amount of knock with your "super safe" tune as your current tune, you can be 99% sure the readings are noise due to the sensitivity of your knock sensor and/or mechanical noise.

 

My max. boost is 12-13psi on the stock turbo.

so its practically IMPOSSIBLE to get know with retarted ignition and rich AFRs?
Well i tried something like this, but never under WOT, only during cruise, and the knock wouldnt drop by more than 2-4.
i will try it out under WOT.

my boost curve is weird also, but its because of the Ports i think:

5600 @12 psi
6000 @10 psi
6400 @ 6 psi
6800 @ ~5psi
7200 @ ~3psi
7600 @ ~3psi

 

I think the level of detail that you would like to get into would merit either or both:

A SPA quality Dual EGT Gauge
Safeguard type of system

If knock is your primary concern then you timing must be your focus.

 

well it seems to do nothing if i retard timing, even 10° less!
The weird thing is, that the exhaust change only brought me ~ 15-20 knock extra, havent changed the timing at all.

and most weird to me: why is the sensor detecting 1/2 knock if plugged to rotor2.. is there LESS noise? or is Rotor2 making less knock?

well you see my IGN Map up there, do you mean its to advanced? its almost the BASE-Map of the Power FC, well in fact, the cruise are is! Dont know how much knock i would get with stock split, in the cruise area stock split is average 0-2!

 

Your high boost timing is less than my mild port GT35R FD, and I run 11.2 AFR at 14-15PSI boost.

Your higher rpm split is too aggressive for a single turbo.

Your fuel correction map is useless by it's self. You should recalc for ease of future tuning. Even a recalced base map would be useless to view as it does not show real AFRs that the engine would run.

High knock values at cruise proves that it is noise not knock unless something is seriously bad as seal blow-by. Maybe bad sensor or rotor slap against the housing caused by worn bearings.

 

hey chuck,

what split do your recomend in boost and high-rpm area for the stock s5 turbo? (single turbo) can you tell me why my timing is "aggressive" for a singleturbo?

so.. if my knock dont get higher than 60 under WOT and boost, i am fine?

 

Q1: what split do your recomend in boost and high-rpm area for the stock s5 turbo? can you tell me why my timing is "aggressive" for a singleturbo?
A1: Your IGL is good to even maye too conservative at high rpms. It is your IGT (split) that is HOT at high rpms. I ran 10-8 split on stock ports with non-seq.

For single turbo, I don not run less than 10 split. Look at your. I had recently posted a good split curve on this forum.

Q2: if my knock dont get higher than 60 under WOT and boost, i am fine?
A2: 60 is too high even for me. I do not like over 30. But that depends if it is knock and not a noisey engine.

 

he is running an s5 turbo. S5 turbo is capable of only 220-250rwhp... way less than even non sequential stock twins. Not even in the same league as a single turbo FD.

 

well i havent been to a dyno yet, in germany they are VERY expensive. 1 Run costs you around 80$ and you aren't allowed to run it yourself. So pay 80$ for one run, and you just know what your power output is.. nothing more.

thats why i am tuning my car on the "street" of course on freeway etc.

the power output of the car is much more than stock or just a full 3" without cats and a F.C.D.
the portjob gave an amazing higher power output to the car.

My engine-builder was very confident, that the car should produce over 280whp at ~13psi of boost on stock turbo, i terrorized him asking over and over the same question, because i could not believe in it lol.
well.. i have driven countless cars, and it really feels like more than 250whp (~300@ flywheel).

adjusting timing is new to me, so i want to learn as much as possible about it. many people running over 300whp arent even touching those ignition maps.


As i bought the Power FC from new-zealand, it came out of a car with streetport (dont know how big the ports were) with ~ 0,6kg/cm² of boost, so almost stock boost. But the map was VERY retarded, avg 3-5° less then mine in the high RPM and boost area. The split was very bad also.. more negative split (even in boost and high-rpm) then the Base-Map!

 

On my non-seq FD with very mild ports and 347whp at 15psi boost, my split was 10 up untill 6400rpm then went to 8. You have 7s and 6s.
But I ran more timing than you.

Once again an old engine with blow by the apex seals will detonate.

 

hey guys,

well i changed my leading plugs to NGK-BR9EIX, 10s werent available right now. My trailings are BUR9EQP.
I have richen up my Map for cruise area, and especially boost+high-rpm, and even rised the secondaries injector lag-time.
Checked the plugs after 100miles again.. the new leadings are white/grey, and the trailings are carbon-black!

I have noticed, that very cold air, messes my AFR up. Well i know that colder air is more dense (= more O2 in the air -> lean mixture) but thats not the case.. i thought that the Power FC has a function to correct such parameters like whether i am in the mountains or in the valley, if i am driving threw summer or winter.

with ~ 20-25°C AirTemp i am getting 11,0-11,2 AFR at 0,8kg/cm² boost.
with ~ 2-7°C AirTemp i am getting 11,4-11,7 AFR at same boost lvl.

so isnt my PFC working well, or have i to retune my PFC for each drop in AirTemp?

I have also noticed, that the knock rises with temp-drop, but i think thats self-explanatory, because my mixture becomes more lean.

 

With a DL, you can adjust the Settings 2 Air Temp vs Injector table.
The stock values are crap. Mazda made the engine run very rich at higher temperatures due to undersized radiator and IC. Thus when the temps drop, they leaned out the engine.

As I have stated a few times and is in my notes, tune your AFRs then check across the season to adjust the table. Best to adjust timing in cold weather when the engine will make the most power and have higher knock levels.

If leadings are clean and trailings are black, maybe your raes are bad or not firing. Play with idle timing to verify or pull all plugs and verify sparks.

 

well i see..
hmm my ignition timing is almost like stock.. so mayb i have to retard it more?

I run MSD-Spark plug wires, in the FSM i read something about the stock NGK wires, that they have to have 16k Ohm on 1m. Well i measured my MSDs and the voltmeter tells me 0.15~Kohm on the leading, and 0.9~kohm on the trailing. Could the Wires somehow influence my ignition timing by less resistance?

I also notice NO missfiring during cruise or full throttle, only by idling or deceleration it pops smoothly in the exhaust system, some kind of bubbling sound on deceleration.

 

did you already try to change the knock sensor or checking wiring ?

 

Less impedance wires do not affect timing, only increases amperage/watts to the spark.

 

ok so it makes sense running low-imp wires on a tuned car.

@Bluebull

yes, i have another knock sensor. doesnt matter which i use, the knock-value is always the same.

i wonder why Rotorhousing 2. is showing much less knock, if the sensor is plugged to it. like stated above, on Rotor2 i have 1/2 knock compared to Rotor1.