Hey how does the Capser's knock guage work?

[themodfather]

the knock guage does iit use AV volts as a signal????? i know that is the output of a knock sensor (AC volts) so does a guage read the ac volts or whatever comes from the PCM??? and if so what signal does the PCM give the casper's guage!

 

[Taffy]

You hook this to the knock line that goes to the computer. THIS IS THE MOST IMPORTANT METER TO USE!!!!!!!

AFR is the next most useful gauge!!!!!

John is a great guy for help on the knock gauge, if not, let me know, I will help you out!

Thanks!

 

[themodfather]

Originally posted by Taffy
You hook this to the knock line that goes to the computer. THIS IS THE MOST IMPORTANT METER TO USE!!!!!!!

AFR is the next most useful gauge!!!!!

John is a great guy for help on the knock gauge, if not, let me know, I will help you out!

Thanks!

i know where to hook it up, i want to know what signal the guage uses?? ac volts or other?????
i am selling my TR and want to put the knock guage in my honda CRX rally car. i just want to know what signal the guage uses...

 

[Razor]

Knock sensor goes to an ESC module. The output of the ESC module module is how the knock sensor gives the signal. It goes low.

The knock sensor works like a microphone. The ESC module only passes a band of frequencies, the intensity of that signal is what cuases the "low" condition on the esc output wire.

To retrofit a knock sensor unto another vehicle, you need the ESC module as well. Theyre matched.

This is my understanding.. if i'm wrong, please correct me.

 

[themodfather]

my actual plan was to put my casper's knock guage into my honda crx the car already has a knock sensor, and i was wondering if i could display the output on the guage??? or does the caspers get a different signal from the ESC????

 

[TurboTR]

The knock gauge doesn't interface to the knock sensor itself; it just sees that the ESC module output has switched low, which is how it signals to the ecm that knock is ocurring. The gauge is only appropriate with an ESC module; it has no ability to interface with a knock sensor itself.

TurboTR

 

[Fuelie600]

Audible KNK detectors

If you are using one, please give me your honest feed back. Is it loud enough, and where did you purchase it? I'd prefer audible, as that is one less instrument I have to watch while trying to drive. Thanks Brian

 

[Squid4life]

TTT for my interest as well! Most people use the audible from Caspers, as well as the knock gauge. You may even have to use them together, but I am not sure. Hope someone else chimes in, I am curious of the answer as well.

Squid

 

[bruce]

Originally posted by themodfather
my actual plan was to put my casper's knock guage into my honda crx the car already has a knock sensor, and i was wondering if i could display the output on the guage??? or does the caspers get a different signal from the ESC????

You might investigate the MSD unit. In that it's tunable.

Casper's uses the ESC output as I recall, I doubt the ESC calibration would be really correct for the Honda.

Hope you read the thread on abnormal combustion.

 

[pacecarta]

i run with a caspers audible ,
it attaches to the harnes by the ecm . i used crimp tap lugs that accept spade connectors and put spades on the wires from the detector so it just plugs in then i velcroed it to the heater duct (attach the connectors high enough on the harness so you can swing out the ecm for chip swaps .

its it loud enough. yes , suprised me the first time it went off
i hear mine sometimes on start up (converter noise ) sounds like a keyminder or seatbelt buzzer but much louder
it went off when i broke my stock converter at the track and could hear it easily with the helmet on

running with alky i run with zero knock so its something i dont normally watch knock but if you are tuning it helps because no matter how distracting all your other gauges are that noise will alert you to lift off of the gas .
for testing it tried turning my alky off to get some knock , i needed about 4 degrees of knock retard on scanmaster before it went off .

i know some people using the caspers knock gauge let knock rise till it reaches a point where it gets into the red, in this case the detector may be going off and noise will probably annoy you ,
maybe some one running both with chime in on when the audible goes off in relation to the knock gauge lights

 

[Razor]

Anyone make a shock style dog collar hooked up to the ESC module.. those would sell like hot cakes

Buzzzzzzz.. lift

I too run an audible..its great when distractions are high.. like looking in the rear view mirror as that Viper gets dusted.

 

[TurboTR]

Hey that's a good idea; but maybe has a few liability issues to work through We could even use it to train ourselves to start slobbering like Pavlov's dog whenever the car starts to spool up (lol).

Sensing knock audibly is a pretty tough job since there can be so much background noise in the knock frequency range. The production approach generally includes an automatically adjusting threshold that tries to compensate for the overall background noise level (with no knock), and also as it changes with different speed and load conditions. Some people say that "dulling" the sensor pickup with teflon tape or different torque values or whatever can help relieve false knock on modified engines, but if you compensate for the background noise level and sensitivty in the signal processing in the first place, you can see how that might give questionable results too. If I was going to rely on one to tune an expensive engine with alot of power, I'd be interested in knowing just how sophisticated and useful some of the aftermarket adjustable units really are. Or are they simply a piezo mic preamp tuned for 6-7KHz with an adjustable threshold knob... If an engine generates enough background noise in the target frequency range, then a simple approach like that would be questionable at best IMO.

At one point in the early 90's I had the knock sensor playing directly through the stereo cassette input (I know- I'm a hopeless case lol) The hope was to hear the knock occur in glorious stereophonic sound. And to record the output, digitize it and find it in a pc sound file editor for example. It didn't quite work that way but was really interesting to at least get to hear what the sensor picks up.

TurboTR

 

[bruce]

Hopefully the ION detonation detection systems will be on the market, in the not too distant future, they'll be a huge leap forward in saving engine parts.

 

[themodfather]

thanks for the info, so now does anyone need a knock guage for a buick lol i have mine for sale i bought it used of f this board. selling my buick no need for the guage!