LED for knock sensor?

[jred321]

I don't know much about lighting stuff or anything, but wouldn't it be possible to wire an LED so that we could see when we were getting knock? Pins 57 and 59 and the knock sensor's + and -, so wouldn't we just need to hook up the + and - sides of the LED to each of these wires and be able to light up a light when it was knocking? Granted, we would need to know the correct voltage that the sensor has when it is knocking so we could select the right size LED so it would light up only when knocking, but I'm sure someone could figure this out. So would this work?

btw... http://users.wpi.edu/~jck15243/msppinout2.htm for the pinout diagram, it says both + and - will be less than 1 volt at idle, but what would they be if detecting knock?

 

[WeldingHank]

usually, when knock is detected. the voltage goes down. also, knock happens so quick, that the LED probably wouldn't be able to light up quick enough to tell you.

 

[ARunto]

you could just buy a J&S safegaurd unit...i think turboge has one forsale

 

[jred321]

but if you're getting high counts of knock, it will flash a lot, so you could say "uh oh" and lay off. i know you wouldn't be able to see one or two counts of knock, but really there is no need to worry about small counts anyways, i was more concerned with large knock counts.
i didn't know that the voltage went down though when knock was detected, that makes things more difficult


edit: come over here cause probetalk is down hank?

 

[jred321]

you could just buy a J&S safegaurd unit...i think turboge has one forsale

i was looking for $5 project including wires and LED and more of a way to just monitor if knock was happening or not, the J&S is a nice unit but a bit out of my price range

 

[WeldingHank]

yeah, ****** PT. right before myrtle madness it HAS to go down.

 

[John at J&S]

Here's a link to a German knock detector:
http://www.thielert.com/en/automotive_industry/engine_management_systems/knock_monitor.html

Here's one from a marine site:
http://www.eddiemarine.com/cart/details.asp?SubCategoryID=434&CategoryID=109

It takes more than an LED and a knock sensor. The least expensive detector on the market is the MSD, about $140.

Remember, you are trying to detect knock that you CAN'T hear, while ignoring noise that you CAN hear.

 

[KyRaceFan]

heres a related question.
Does the MSP have a knock sensor? And does it cut timing if knock is detected?

 

[jred321]

the pinout says it does, but i haven't looked for myself. and cutting timing would be the point of having one on there

 

[evilmonkeyMSP]

i was told by my service manager when he found out that the sales person but cheap gas in my tank that the ECU would detect this and would change the timing and reduce max boost or something along those lines

 

[jersey_emt]

i was told by my service manager when he found out that the sales person but cheap gas in my tank that the ECU would detect this and would change the timing and reduce max boost or something along those lines

Well, the ECU has no control over the max boost. The wastegate actuator controls it.

The pinout for the ECU has two knock sensors, I'm assuming that the ECU will retard timing a couple of degrees if knock is detected.

 

[PaulMP3]

I had a thread about this in the FI section a while back. Bevis said he could probally figure out how to make it.. I have been thinking of a J&S or a MSD knock sensor LED and audible alarm.