Help knock

[ahsueh]

I have had set "Knock Sensor Cal table" but still had knock(over 2V) from log. Is it true knock or just engine noise? Could I ignore it ?

Wiseco pistions / Eagle rods
No Banalce Shaft
2G Knock sensor
FIC 950cc inj
GT30R
HKS 272/272
BPR8ES

[talontsi37]

Run a log and drive the car from like 2000 RPMs to redline without giving it any boost in like 3rd gear(slowly accelerate). Check the log and this should help you determine how loud your engine is. Then set up your knock cal based off of how much knock you saw with no boost.

[ahsueh]

I run a log with low timing(10) before and then set up the "Knock Sensor Cal table". It read no Knock #1 from log but still retard timing and add fule when over 5k rpm. Please help.

[JrCRXHF]

my EMS does not read knock on senor #1 it reads it on senor #2.

[TheBoz2]

My Knock Control settings

Knock Sensor Cal Table
.92___1.25___1.70___2.17___2.64___3.09___3.50-to end
0_____800___1600___2400___3200___4000___4800-to the end

Options - Fuel Control
Knock Fuel Add Max 1.56%
Knock %Rich/Volt 5.00 %/V
Knock Restore Rate 50 rev
Knock Decrease Fuel 1.95%

Options - Ign Control
Knock Ign Rtd Max 2.11 degree
Knock Retard/Volt 3.28 */V
Knock Restore Rate 50 rev
Knock Spark Advance 4.92 degree


So unless I see over 3 volts I dont even care.  I am running Ross Pistons and Eagle Rods on a 37r.

[TheBoz2]

Also the car make 433awhp@25psi on California Pump Gas.  And that was with intake temps at 120+ at idle.  The Temps in the booth were 112 degrees.  The car would see High knock when the Heat was really bad, however my car is at 5 degrees of timing from about 5k to 8.5k.

I hope this helps

[ahsueh]

Thanks for advices.

To TheBoz2
What are A/F and EGT of your car at degrees of timing from about 5k to 8.5k ?

I have a question, "Knock %Rich/Volt" is the amount of fuel added per volt over the "Knock Sensor Cal Table", "Knock Retard/Volt" is the amount of ignition timing to take out per volt over the Knock Sensor Cal Table. It's shown " add-fuel and retard" on the log  but the the knock sensor cal table is within limit, why?

[TheBoz2]

My car runs about 10.5-11.0 AFR's.

For your second question, I think you are asking why your car pulled timing if the Knock was under the max set in the cal table.  So I looked at your log, and at [161108_001.stf] 2:30.200, you hit 3.203 volts of knock, which should be why it pulls timing.  Just add 1 degree of timing at Load:209.4  RPM: 4746  and leave everything else as is.

Also your logs are showing engine load at 215, are you logging PSI?

[ahsueh]

I set up my Knock Sensor Cal Table according to yours and here is the lastest log. I also add fuel at 215kPa ~ 250kPa but still add fuel and retard timing with knock. The A/F is about 12~12.3, it maybe a little lean.

[TheBoz2]

What kind of gas are you running and what Octane?  If you are on pump gas I would richen everything up. 12.0-12.5 is a little lean for me.  Try to get that to 11.5 at most.  It still looks like there is legit knock.  on the new log file at 15:53.580 knock raw is 2.971(12.18AFR/10.42timing) after that it starts to pull timing and add fuel and right at the en of the run 15:54.620 you are at 4.144 on the knock.

Use "Knock #1 Raw" to evaluate your knock

high Knock Events
15:50.960  2.795knock  (11.78afr / 10.77timing / 4441rpm / 212.3load)
15:51.640  3.582knock  (11.84afr / 10.07timing / 4828rpm / 218.6load)
15:52.500  3.147knock  (12.01afr / 11.13timing / 5336rpm / 219.5load)
15:53.320  2.399knock  (12.07afr / 10.42timing / 5820rpm / 227.1load)
15:53.580  2.971knock  (12.18afr / 10.42timing / 5961rpm / 224.9load) // Timing and Fuel retard starts here
15:53.860  2.336knock  (12.18afr / 10.42timing / 6152rpm / 230.4load) // High Knock with timing and fuel pulled
15:54.380  2.301knock  (12.24afr / 10.42timing / 6441rpm / 227.5load) // High Knock with timing and fuel pulled

// Last leg of the run and started to get very noisy
15:54.540  2.028knock  (12.24afr / 10.77timing / 6520rpm / 227.1load) // A lot of Timing and Fuel pulled
15:54.380  3.235knock  (12.24afr / 10.42timing / 6535rpm / 224.9load) // High Knock with timing and fuel pulled
15:54.380  4.144knock  (12.30afr / 10.42timing / 6535rpm / 225.8load) // High Knock with timing and fuel pulled

So from what I see it looks like you are running pump gas, because if this was c16 or any other race gas you should not have any problems.  I would try to get your afr's into the mid 11's before messing with any of the timing numbers.  It really looks like you are just too lean for the fuel you are running.

Good luck, I hope this helps.

[ahsueh]

Thanks a lot for your help.
I live in Taiwan and my car uses 98 unleaded gasoline. My friends in US said that the 98 gasolines in Taiwan were equal to the 93 gasolines in US.

Here is the lastest log, I tried to add more fuel and A/F was below 11.5, but it looks like a lot of knock. I have no more idea for knock. Sad~

[Mello]

I use Knock #1 (2) Volts as it is scyned with the engine's ignition event where knock is most likely to happen.  My pump gas timing at 205kpa, 4000 to 6500 RPMs starts around 4* going up to 6.5*.  Lower your timing and see if it helps.

[TheBoz2]

Well is looks like your AFR's are more inline.  They are in the 11.2-11.3 range which is good.  It look like you added about 2 degrees of timing.  I would pull the timing back to the 10 range when the knock starts getting bad.  You are now seeing 4+ on the knock.  I would taper the Timing down from 5500 to redline.  But by redline you should be at about 10 degrees.  Try that and see if it helps out.

Also are you running the 2g knock sensor?

How is the car running, does it feel like it is running better after all these changes.