Max

I have switched from E.F.I. to carb and I ditched my computer but my knock sensor remains installed in the engine block.

If I wired a simple circuit from the knock sensor to an LED or some other small indicator light, would it flash if detonation occured?

Perhaps I could wire it directly to the Service Engine Soon light since it's no longer connected to anything else.

I like to run as much ignition advance as I can get away with. This might be a nice way to detect detonation if I got some bad gasoline or something. If it worked, it might keep someone from blowing a motor.

I could see this being especially useful for people running superchargers, turbos, or nitrous.

Has anyone done this? Would it work? Let me know what you think.

Thanks.

dankhound

Unfortunalty its not quite that simple. The knock sensor is piezo-electric. Simply put it creates voltage based on how much vibration it senses. Even when the engine isnt knocking its still creating some voltage. So its not an on and off type input youd need to wire to a light.

Max

Thanks for the feedback.

What if you wired it to a secondary volt meter? Do you think detonation would "pin" the needle or maybee make the needle whip back and forth?

Dialed_In

iTrader: (3)

Caspers electronics makes gauges for GM knock sensors. Most of the turbo buick guys use them.

Max

Thanks for the info.

I looked at the Casper website. They have knock gauges as well as audible knock alerts which chirp or beep depending on the severity of the detonation. On Monday I might call their techline to see if the gauge and / or beeper can be wired directly to my knock sensor since the car is no longer ECM equiped.

https://www.casperselectronics.com/M...vc?Screen=PLST

firebirdjosh

iTrader: (1)

I'd bet it works without the ECM. It's a fairly simple circuit.

Dialed_In

iTrader: (3)

I don't think the sensor puts out a signal that the gauge can decipher. I'm pretty sure it needs the ECM to interpret what the sensor is picking up and convert it into usable information.

firebirdjosh

iTrader: (1)

Well sounds like I can make a ton of money if that's the case. It's not very hard to build something like that.

Max

I like the idea of an audible alarm that beeps sorta like a radar detector. That way I wouldn't have to keep an eye on yet another gauge.

firebirdjosh

iTrader: (1)

Any updates on this? I'm building a circuit for my own car (new engine is almost ready, could come in handy for tuning) and may make a few extra if anyone else needs one.

Vader

Should be fairly simple. I'd think a 555 and a timer cap (for output pulse duration) would drive an LED. You may have to clamp down the input level for the CMOS high impedance input.

CamarosRUS

TTT

84z28350

whoooooooooooooossssshhhhhhhhhhh

CamarosRUS

Ditto...I just didn't want to be the first to say it!