I know twr used to have something similar on his old car but other than that i cant think of anyone else who has run it? if you have please post up some info because im planning on including this in my project.
knock link
- Thread starter Sho Amo
- Start date
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Yes, Pat runs one and I have run one as well. It works well, however, I ditched it after learning how to tune 
The TwEECer allows you to see the computer pull spark and if you're not going for all out power, then you may not need it. I always tune for the street and 91 octane.
The TwEECer allows you to see the computer pull spark and if you're not going for all out power, then you may not need it. I always tune for the street and 91 octane.
1slickRED89
Guest
I actually built a DIY knock sensor based on these directions, it was a little too sensitive. I found it was going off all the time.
http://www.gnttype.org/techarea/projects/projectspage.html
later experience has taught me that as far as detonation goes, a little ping is not bad and overall insignificant. basically, if its bad enough to hurt the engine, you are going to hear it, assuming your not hearing impaired. at the point you hear it in the drivers seat, borderline its called or BLD, the engine can take between 4-10 degree more spark before it goes into detonation induced torque drop. its called torque drop because in a development environment where the engines torque is constantly monitored, the cylinder(s) that 'goes' stops contributing its torque and the engines output goes down correspondingly on the readout screen. this would be where the engine basically blows up, melts channels in the piston top, tulips valves, scuffs the bore and piston skirt, etc.
an alternate to the electronic thing, is to somehow snake a chunk of copper pipe and bolt it to the engine block (crush the one end and drill a hole on the flat, thru which the bolt goes) and let the other end hang free in the cabin of the car, it will transmit the high frequency ping sounds so you can hear it better. but again, when it gets to the point where engine damage is imminent, you won't need any assistance to hear it.
http://www.gnttype.org/techarea/projects/projectspage.html
later experience has taught me that as far as detonation goes, a little ping is not bad and overall insignificant. basically, if its bad enough to hurt the engine, you are going to hear it, assuming your not hearing impaired. at the point you hear it in the drivers seat, borderline its called or BLD, the engine can take between 4-10 degree more spark before it goes into detonation induced torque drop. its called torque drop because in a development environment where the engines torque is constantly monitored, the cylinder(s) that 'goes' stops contributing its torque and the engines output goes down correspondingly on the readout screen. this would be where the engine basically blows up, melts channels in the piston top, tulips valves, scuffs the bore and piston skirt, etc.
an alternate to the electronic thing, is to somehow snake a chunk of copper pipe and bolt it to the engine block (crush the one end and drill a hole on the flat, thru which the bolt goes) and let the other end hang free in the cabin of the car, it will transmit the high frequency ping sounds so you can hear it better. but again, when it gets to the point where engine damage is imminent, you won't need any assistance to hear it.
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sho_sc
New Member
This is what I use :
http://www.msdignition.com/Products/Towing_/_Marine/Towing/8964_-_Engine_Knock_Alert.aspx
Once I learned how to read it/calibrate it, it has become invaluable. With aftermarket cams and the shim/bucket arrangement, our engines are really noisey. So, it did give a lot of false positives until I figured out what was noise and what wasn't. When you are running the amount of boost I am, you don't have time to "wonder if that is knock that you hear" and with the open exhaust, you couldn't hear it anyway.
http://www.msdignition.com/Products/Towing_/_Marine/Towing/8964_-_Engine_Knock_Alert.aspx
Once I learned how to read it/calibrate it, it has become invaluable. With aftermarket cams and the shim/bucket arrangement, our engines are really noisey. So, it did give a lot of false positives until I figured out what was noise and what wasn't. When you are running the amount of boost I am, you don't have time to "wonder if that is knock that you hear" and with the open exhaust, you couldn't hear it anyway.
I'm using the KnockLink device:
http://www.linkecu.com/products/AncillaryDevices/KnockLink
The LED's were moved out of the box so that I could put them where I could see them better - up on the A-Piller boost guage next to the Exhaust Gas Temperature gauge as seen in this picture:
http://panamapat.no-ip.info/SHO/Pic/011220183910_016.jpg
The Knocklink needs a knock signal. Rather than attempt to tap into the existing knock sensor circuit, I added another knock sensor installed next to the existing knock sensor. I've got some pictures some place, and will dig up if you need it.
Here is a video of link monitor in action. I was running boatloads of timing to hit a good dyno number and you can see quite a bit of engine knock. You can't hear any engine knock, perhaps because of the exhaust and supercharger noise.
http://panamapat.no-ip.info/SHO/Vid/SHO_Dyno.mpg
Lastly, you'll need to do some Knocklink calibrations once installed. If its set to sensitive, the lights will light up with just normal engine noise.
gmorrell
Never been a noob...
I looked at the circuit and docs you linked, that circuit is really only useful when used on the knock output line from a Buick GN turbo ignition module that does the band limiting and knock threshold detection for the knock sensor. All that circuit does is stretch the knock pulse output from the Buick ignition module into something long enough to illuminate an LED so your eye can detect it. There's no knock threshold detection or band limiting going on there, it's just a classic 555 timer configured as a pulse stretcher.
Knock detection isn't easy, OEM systems often use piezoelectric knock sensors (accelerometers) that are sensitive to (mechanically tuned to...) the knock frequency of a particular engine. Knock typically occurs between 4KHz and 7KHz. Cylinder bore diameter and combustion chamber temperature are the main variables that affect knock signature frequency, knock frequency goes down as bore size increases and as combustion temperature decreases.
OEM systems also apply electronic band limiting (limiting the frequency response of the system) to the knock sensor signal to help reduce false triggering from engine mechanical noise and engine block structural resonances and vibration.
Additionally knock threshold sensitivity changes with engine load, engine RPM, coolant temperature, etc, and these parameters are usually mapped on an engine dyno under controlled conditions.
The last thing is that knock occurs only between 10º and 70º after top-dead-center of the cylinder event, so it only makes sense to look for knock between 10º and 70º ATDC, as any events outside of this period aren't knock, they're false triggers - noise.
I'm not trying to discourage anyone from using or trying an aftermarket knock detector, but unless said device gives you the ability to determine and set the knock frequency range to your specific engine, adjust the knock detection thresholds, and interface with the crank sensor so that events outside of the 10º and 70º ATDC window are ignored, you're probably just adding noise-sensitive pretty blinking lights.
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popsracing
EFI Calibrator
Knock sensors are too sensative in the Fords and blowers create alot of "noise", we have uncorked all the knock sensor control in B.E.
gmail
Well-Known Member
That's neat you can piggy back the Knock Sense with the coolant temp input. With the coolant temp signal being near linear any sudden rise caused by a knock event should immediately raise the coolant temp signal and pull timing. Or so I believe.
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