Power FC PFC Knock Sensor Level Question
#1
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PFC Knock Sensor Level Question
Friends,
I just installed the PFC today on my FD with these performance mods : dp, mp, cat-back, fuel pump, and pulleys. The PFC has the base map and I don't have any tuner live close to me in 500 miles radius.
The base setting seems to run just fine today; the only concern I have is on the knock level. I ran a little bit of hard acceleration and I got a peak knock at 73 until boost level of 0.67 kg/cm2, then I backed off. Is this normal with the other PFC users?
Or is it that I need to adjust my fuel and ignition timing map on some rpms to lower the knock level?
If anyone is running the same mods and have their maps corrected, would you mind sharing them with me?
Thanks a lot in advance.
AndrewD
I just installed the PFC today on my FD with these performance mods : dp, mp, cat-back, fuel pump, and pulleys. The PFC has the base map and I don't have any tuner live close to me in 500 miles radius.
The base setting seems to run just fine today; the only concern I have is on the knock level. I ran a little bit of hard acceleration and I got a peak knock at 73 until boost level of 0.67 kg/cm2, then I backed off. Is this normal with the other PFC users?
Or is it that I need to adjust my fuel and ignition timing map on some rpms to lower the knock level?
If anyone is running the same mods and have their maps corrected, would you mind sharing them with me?
Thanks a lot in advance.
AndrewD
#2
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Of the three cars that I have intensively helped tune,
normal knock reading under boost are in the high teens to low 30s.
You will also notice knock levels of the first couple of runs to be higher than later. I contribute this to thermal expansion of the turbo and exhaust system, and maybe loose carbon burning off.
normal knock reading under boost are in the high teens to low 30s.
You will also notice knock levels of the first couple of runs to be higher than later. I contribute this to thermal expansion of the turbo and exhaust system, and maybe loose carbon burning off.
#4
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I run more mods than you with almost stock timing for 10-12PSI boost, and less timing for above 12PSI.
You want a safe starting point:
take out 2 degrees for IGL and IGT for (P16 - P20, N9 - N20). Add 3% more fuel for PIM 4.0 and 4.5 volts.
Wide band tune next for about 11AFR. If you had an upgraded IC, ignition, cooling system, and fuel system, you could go leaner on the AFRS.
If you had a datalogit, I could send you my maps or you can get it from the datalogic group.
You want a safe starting point:
take out 2 degrees for IGL and IGT for (P16 - P20, N9 - N20). Add 3% more fuel for PIM 4.0 and 4.5 volts.
Wide band tune next for about 11AFR. If you had an upgraded IC, ignition, cooling system, and fuel system, you could go leaner on the AFRS.
If you had a datalogit, I could send you my maps or you can get it from the datalogic group.
#5
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POWER MODS:
M2 hard pipes with K&N filters.
Non-seq turbos with clipped turbine wheels.
Compressor outlets enlarged. Turbo housing
modified for smoother exhaust flow.
Enlarged WG.
Efini "Y" pipe set.
Blitz FMIC.
Greddy throttle body inlet elbow.
Secondary vacuum throttle plates and their
center support removed.
The exhaust is ported. Intake ports are stock.
Engine rotating parts were dynamically balanced.
N-Tech SS down pipe.
Shane Racing SS resonated MP, Bonez hi-flow cat for inspections.
HKS turbo cat back exhaust.
SR power pulley.
Racing Beat aluminum flywheel.
ACT street/strip clutch.
Apexi PFC with commander.
Air temp sensor moved to IC outlet pipe.
NipponDenso high performance fuel pump.
1200cc secondary injectors.
Craine HI-6R.
Taylor spark plug wires.
NGK B9EGV plugs.
M2 hard pipes with K&N filters.
Non-seq turbos with clipped turbine wheels.
Compressor outlets enlarged. Turbo housing
modified for smoother exhaust flow.
Enlarged WG.
Efini "Y" pipe set.
Blitz FMIC.
Greddy throttle body inlet elbow.
Secondary vacuum throttle plates and their
center support removed.
The exhaust is ported. Intake ports are stock.
Engine rotating parts were dynamically balanced.
N-Tech SS down pipe.
Shane Racing SS resonated MP, Bonez hi-flow cat for inspections.
HKS turbo cat back exhaust.
SR power pulley.
Racing Beat aluminum flywheel.
ACT street/strip clutch.
Apexi PFC with commander.
Air temp sensor moved to IC outlet pipe.
NipponDenso high performance fuel pump.
1200cc secondary injectors.
Craine HI-6R.
Taylor spark plug wires.
NGK B9EGV plugs.
#6
my brother's FD reads over 90 for knock, oh yeah that's at idle. From what I hear the FD's knock sensor is not accurate unless you leave the engine completly stock. My brother's FD has been modded and tuned by the best. Tuner says all the knock readings are coming from a loud exhaust
#7
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The knock sensor can be a valuable tuning tool even on modded 7's. My knock is very consistent under wide open throttle and I run a full open exhaust with a bunch of mods and a single turbo.
The only time I get inconsistent high numbers is during shifting, decel, or detonation (seen the broken apex seals after fuel pump died, accompanied with high knock of 100+ at the top of 2nd gear).
The only time I get inconsistent high numbers is during shifting, decel, or detonation (seen the broken apex seals after fuel pump died, accompanied with high knock of 100+ at the top of 2nd gear).
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#10
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My knock sensor shows consistently below 15 around town, and usually below 40 under WOT. These are when viewed through the Datatlogit logs. The commander peak hold often shows knock readings in excess of 150 which is really scary stuff until I tracked the readings with the datalogit logs. The logs revealed a huge momentary spike about 1-3 seconds AFTER throttle release, while showing AFRs in the 10-11 region and in a no-boost zone. Source of the knock has never been determined but is likely due to backfire or mechanical noise.
Unless you have logs, either through dataloit or dataq or even the v2.0 TE wideband you cannot reliably diagnose PFC knock readings based on information from the commander.
Unless you have logs, either through dataloit or dataq or even the v2.0 TE wideband you cannot reliably diagnose PFC knock readings based on information from the commander.
#16
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On my PFC-Commander I have no numbers only a stripe indicating knock. Maybe I have an older Software Version ? Is it possible to update ?
When viewing the screen with the Stripe on it press the up arrow key on the commander this will display the peaks of all your selected displays. When driving I use the 4 display setting so I can see real time and a peak.
To remove the peak display press the down arrow.
#20
I am getting the same kinds of numbers, if I drive conservatively, I usually get around 10-15, but with the occassional spike to 130 and even once to 180. scared the hell out of me. I have noticed that it may be more related to load than boost. Sometimes under high boost the numbers just stay low.
The other day I was cruising in 5th, and let it slide down to 70mph, then stepped on it. the damn thing jumped to 135! I did it to see if load had anything to do with it, and it looks like it did. my boost was only around 40 or so. I have been experimenting with it, keeping the revs up and so on, and even though I still get the occassional spike, it seems to be more related to load than anything else.
anyone else try this? But sometimes downshifting and letting the revs go up and the boost spool I still get spikes sometimes.
The other day I was cruising in 5th, and let it slide down to 70mph, then stepped on it. the damn thing jumped to 135! I did it to see if load had anything to do with it, and it looks like it did. my boost was only around 40 or so. I have been experimenting with it, keeping the revs up and so on, and even though I still get the occassional spike, it seems to be more related to load than anything else.
anyone else try this? But sometimes downshifting and letting the revs go up and the boost spool I still get spikes sometimes.
#21
One last thing: the manual mentions something about knock not being significant unless it is over 100 or something to that effect. Could we then assume that anything under 100 could be considered acceptable?
Are these spikes detonation or not always?
is a milisecond of 150 spike enough to kill the engine?
Any ideas?
Are these spikes detonation or not always?
is a milisecond of 150 spike enough to kill the engine?
Any ideas?
#22
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If 150 represents real knock (detonation) the YES it can be enough to kill an engine!
What we are saying here is that you have to datalog your knock in relation to all other variables. See where your trransients occur and determine the cause, if possible. I gaurantee you will not be able to do so reliably watching a gauge or setting a peak hold.
What we are saying here is that you have to datalog your knock in relation to all other variables. See where your trransients occur and determine the cause, if possible. I gaurantee you will not be able to do so reliably watching a gauge or setting a peak hold.
#24
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Its not the knock reading that matters as much as when and where and the cause. The knock sensor is nothing more than a microphone and hears everything. As a rule of thumb, if you see knock readings of 100 for more than just a fraction of a second every now and then, you have a definite problem but no-one can diagnose the source just from the reading.