Help with knock above 10lbs of boost
03-07-2017, 08:52 AM
#21
yes but very reliable. as usual a combination of methods is a good bet.
off track a bit, i have chatting with an engineer buddy about 2.2 ecotec swaps. I learned they use some fancy computing to sense combustion results through the sparkplug itself...instead of knock sensors
off track a bit, i have chatting with an engineer buddy about 2.2 ecotec swaps. I learned they use some fancy computing to sense combustion results through the sparkplug itself...instead of knock sensors
03-07-2017, 08:55 AM
#22
All of my diesels engine I design, prototype and then test on the engine dynamometers here at work have Optrand In-Cylinder pressure transducers modified to fit the glow plugs.
All of the Spark ignition gaseous fuel engines I build and test, get Optrand pressure transducers installed into a spark plug I supply them that they modify. I typically use a 720 degree indexed incremental encoder ont he front of the crankshaft and resolve the pressure data to 0.5 CAD which is enough resolution for most of what we need to do.
All of the Spark ignition gaseous fuel engines I build and test, get Optrand pressure transducers installed into a spark plug I supply them that they modify. I typically use a 720 degree indexed incremental encoder ont he front of the crankshaft and resolve the pressure data to 0.5 CAD which is enough resolution for most of what we need to do.
03-07-2017, 08:59 AM
#23
One of my senior engineers here I work with doing our engine and fuel system designs, use to work for Ford and then Roush. He mentioned this as well....Apparently they could estimate cylinder pressures and other things like charge motion based on the measureable electrical parameters from the power electronics that fire the spark plug. Pretty cool. Not sure how it turned out in the end. I will ask him today and report back.
03-07-2017, 09:15 AM
#25
9 Second Club
03-07-2017, 09:33 AM
#27
the factory knock sensors on an otherwise stock engine works reasonably well...the knock sensors are tuned for the harmonics created by the factory engine rotating assembly and valvetrain vibrations...also the engine mounts (engine rigidity) makes a difference as the chassis is its own harmonic system as well. I mention all this, because when a lot of these things change, sometimes some adjustments to the knock sensor settings need to be made. I have seen false knock on a few of my customers cars.
I would get ahold of the tune and some data logs and see where your operating. If he has 25 degrees ignition timing in it at 10psi on 93 octane then ya it will probably actually knock and not just be false knock. If the sensor is reporting knock, and i pull timing out in that location and the knock does not resolve itself, you can usually assume its false knock. I desensitize it in various ways until it is gone, then introduce some timing until the knock sensors start to report knock in the same or different location...this gives me a kind of indication that the knock sensors are following the trend.
If i am on the ragged edge and not sure if the knock is real or not, i use a pair of knock ears...they have allowed me to squeeze every last bit out of a setup when i thought it was done...it wasnt, the knock was being reported but not actually there.
For the most part i rely on the factory knock sensors, but as i said, they may need some adjustment. And without your "tuners" tuning parameters we cant really guess if its real knock or not.
Btw the 2 inch collectors are not the issue. Your turbine housing is large for your power and the collectors are not restrictive at that power. Meaning backpressure is not causing high egt's, resulting in knock. Either his tune is too aggressive or the knock sensors need to be adjusted.
Hopefully that was a little more helpful and constructive than the previous responses
I would get ahold of the tune and some data logs and see where your operating. If he has 25 degrees ignition timing in it at 10psi on 93 octane then ya it will probably actually knock and not just be false knock. If the sensor is reporting knock, and i pull timing out in that location and the knock does not resolve itself, you can usually assume its false knock. I desensitize it in various ways until it is gone, then introduce some timing until the knock sensors start to report knock in the same or different location...this gives me a kind of indication that the knock sensors are following the trend.
If i am on the ragged edge and not sure if the knock is real or not, i use a pair of knock ears...they have allowed me to squeeze every last bit out of a setup when i thought it was done...it wasnt, the knock was being reported but not actually there.
For the most part i rely on the factory knock sensors, but as i said, they may need some adjustment. And without your "tuners" tuning parameters we cant really guess if its real knock or not.
Btw the 2 inch collectors are not the issue. Your turbine housing is large for your power and the collectors are not restrictive at that power. Meaning backpressure is not causing high egt's, resulting in knock. Either his tune is too aggressive or the knock sensors need to be adjusted.
Hopefully that was a little more helpful and constructive than the previous responses
Here's why
1) he told me he pulled a shitload of timing and it still knocks
2) the k member, complete drivetrain, and mounts (half of them are poly), have all been swapped. And i put on a short tunnel torque arm
question, what spark table do i need to post to display my timing?
Sorry for the dumb question, i'm not good with hp tuners yet
03-07-2017, 09:38 AM
#28
Like truckdoug said, read the plugs. It's The only way to be 100% sure. When I dial in timing I don't use knock sensors at all. I don't care how hard it is it needs to happen to truly verify and Stevie it right. Ideal tuning would take place at a track or strip of road where you can put some load on the engine. Pull up, swap new plugs and make a hit. Immediately shut off the engine and pull the plugs. You will have your answer then.
03-07-2017, 09:51 AM
#29
9 Second Club
Problem is....it isnt the only way to be sure.
Simply because all aspects of tuning require experience. If you dont know what you're looking for with the plugs....then it's almost pointless.
No one method is foolproof, as it relies on the tuner not being a fool.
Reading plugs isnt something I've ever done, largely because it is very impractical. But it's a doddle tuning in real time listening to ensure you stay detonation free ( again either from dyno or passenger seat, it's dangerous from the drivers seat )
Either way, from the info we're being given here and assuming it is all correct...best find another "tuner"
Simply because all aspects of tuning require experience. If you dont know what you're looking for with the plugs....then it's almost pointless.
No one method is foolproof, as it relies on the tuner not being a fool.
Reading plugs isnt something I've ever done, largely because it is very impractical. But it's a doddle tuning in real time listening to ensure you stay detonation free ( again either from dyno or passenger seat, it's dangerous from the drivers seat )
Either way, from the info we're being given here and assuming it is all correct...best find another "tuner"
03-07-2017, 09:59 AM
#31
9 Second Club
Unfortunately a picture of a single table doesnt really mean a lot.
A datalog showing what is actually happening at the time would be much better. There will be other tables and factors to take into consideration before anything happens at the plugs. A datalog should already have any corrections applied, so what it shows you, should be the actual timing etc
A datalog showing what is actually happening at the time would be much better. There will be other tables and factors to take into consideration before anything happens at the plugs. A datalog should already have any corrections applied, so what it shows you, should be the actual timing etc
03-07-2017, 10:29 AM
#32
Originally Posted by stevieturbo
Problem is....it isnt the only way to be sure.
Simply because all aspects of tuning require experience. If you dont know what you're looking for with the plugs....then it's almost pointless.
No one method is foolproof, as it relies on the tuner not being a fool.
Reading plugs isnt something I've ever done, largely because it is very impractical. But it's a doddle tuning in real time listening to ensure you stay detonation free ( again either from dyno or passenger seat, it's dangerous from the drivers seat )
Either way, from the info we're being given here and assuming it is all correct...best find another "tuner"
Simply because all aspects of tuning require experience. If you dont know what you're looking for with the plugs....then it's almost pointless.
No one method is foolproof, as it relies on the tuner not being a fool.
Reading plugs isnt something I've ever done, largely because it is very impractical. But it's a doddle tuning in real time listening to ensure you stay detonation free ( again either from dyno or passenger seat, it's dangerous from the drivers seat )
Either way, from the info we're being given here and assuming it is all correct...best find another "tuner"
03-07-2017, 10:39 AM
#33
9 Second Club
Drag race only...perhaps, as it sort of lends itself to doing that given how short a run or pull will be.
To use some popular stuff as an example, I'd be amazed if the GTR, Lambo guys etc are pulling plugs all the time to inspect. They may be...but I doubt it.
03-07-2017, 10:50 AM
#34
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16/17 degrees of timing at peak HP and load on a turbo 5.3 is not exactly pulling a bunch of timing. I'd run everything down around 10 degrees from .80 grams up and work your way back in from there.
Do a couple pulls logging KR, commanded timing, actual, and see where it is truly pulling and how aggressive.
Do a couple pulls logging KR, commanded timing, actual, and see where it is truly pulling and how aggressive.
03-07-2017, 11:01 AM
#35
16/17 degrees of timing at peak HP and load on a turbo 5.3 is not exactly pulling a bunch of timing. I'd run everything down around 10 degrees from .80 grams up and work your way back in from there.
Do a couple pulls logging KR, commanded timing, actual, and see where it is truly pulling and how aggressive.
Do a couple pulls logging KR, commanded timing, actual, and see where it is truly pulling and how aggressive.
03-07-2017, 02:56 PM
#39
Even with poly mounts my knock sensors would pick up knock at random times. Harmonics change a ton when you change things like transmissions, drive shafts, mounts, intakes, flywheels, balancers, etc. If you can’t adjust the sensors to suit your modified engine, it’s best to unplug/disable it IMO.
Disable the knock sensors and drop timing down to 10*. Get your AFR in check and set your max boost level. Then bump it a degree at a time watching plugs on the dyno. When it stops making big gains… stop adding timing. Done!
Disable the knock sensors and drop timing down to 10*. Get your AFR in check and set your max boost level. Then bump it a degree at a time watching plugs on the dyno. When it stops making big gains… stop adding timing. Done!
03-07-2017, 04:26 PM
#40
Originally Posted by stevieturbo
Depends what motorsport really.
Drag race only...perhaps, as it sort of lends itself to doing that given how short a run or pull will be.
To use some popular stuff as an example, I'd be amazed if the GTR, Lambo guys etc are pulling plugs all the time to inspect. They may be...but I doubt it.
Drag race only...perhaps, as it sort of lends itself to doing that given how short a run or pull will be.
To use some popular stuff as an example, I'd be amazed if the GTR, Lambo guys etc are pulling plugs all the time to inspect. They may be...but I doubt it.