Knock Sensors....On or Off??

[Marauderjack]

It seems like I remember my knock sensors were turned "OFF" in the ProCharger Diablo Tune......should they be "ON" in the SCT tune with a blower???:confused:

Will activated knock sensors react too much (constantly pull timing) with a blower (mechanical noise) and can they actually save a blower motor if turned on??:confused:

Input please.....

[Zack]

They don't do a damn thing and are a false sense of security IMHO.

[MOTOWN]

There is no way in hell i would turn off the knock sensors in a tune , i would rather roll the dice with them than with not.

[Bradley G]

I was told by my tuner they would not keep your motor from going boom if they were utilized.

[Zack]

There is no way in hell i would turn off the knock sensors in a tune , i would rather roll the dice with them than with not.

I used to use them way back when.
They never pulled timing enough to stop detonation.

By turning them off, it makes you utilize your ears every second of driving.

[lji372]

I used to use them way back when.
They never pulled timing enough to stop detonation.

By turning them off, it makes you utilize your ears every second of driving.

i have tinnitus is that a factor??

[rauder88]

i have tinnitus is that a factor??

WHAT?
I agree, it won't pull enough timing

[MOTOWN]

I used to use them way back when.
They never pulled timing enough to stop detonation.

By turning them off, it makes you utilize your ears every second of driving.

I couldn't hear detonation over the loud azz Blow off valve and the blower!

[lji372]

WHAT?
I agree, it won't pull enough timing

:rofl:

i'm not blind :lol:

[chief455]

They don't do a damn thing and are a false sense of security IMHO.
X100
all on, pulled a little timing during datalog during throttle bursts, engine was already toast. the react to headers, valvetrain noise, and sometimes detonation.

rely on top notch parts, a safe tune and constant monitoring good gauges.

[Jeronimojc]

X100
all on, pulled a little timing during datalog during throttle bursts, engine was already toast. the react to headers, valvetrain noise, and sometimes detonation.

rely on top notch parts, a safe tune and constant monitoring good gauges.


What gauges do you monitor to keep an eye on detonation?


Sent from my iPhone using Tapatalk

[Zack]

What gauges do you monitor to keep an eye on detonation?


Sent from my iPhone using Tapatalk

There are none. I just bought the AEM failsafe wideband gauge to cut power if the AF goes too lean.

Back to detonation, IIRC a company makes a device to monitor it and dial it back. J&S vampire its called. Pricey

[chief455]

What gauges do you monitor to keep an eye on detonation?


Sent from my iPhone using Tapatalk
air/ fuel and fuel pressure should be watched to detect possible leaning, which would cause detonation.
and blips in fuel pressure or seeing a/f higher than usual = look for mechanical problems before driving!

[Jeronimojc]

Does the stock knock sensor show a warning light? It shouldn't be too difficult to get something on the dash that lights up when knocking is detected.

Here is a Vampire (knock control system) that looks pretty good. It controls timing and you can adjust the sensitivity.

http://www.jandssafeguard.com/VampirePage/Vampire.html

[Jeronimojc]

I found some knock sensor gauges, but they are ugly!!

http://www.mercurymarauder.net/forums/attachment.php?attachmentid=40 756&stc=1&d=1421265603



Doesn't the Scangauge show knocking? This got me thinking, one could connect a Bluetooth OBDII transmitter (http://www.cravenspeed.com/obdii-connector/) and use an App like the "OBD II vehicle monitoring and diagnosis" for Iphones (https://itunes.apple.com/us/app/engine-link-obd-ii-vehicle/id591557194?mt=8 (https://itunes.apple.com/us/app/engine-link-obd-ii-vehicle/id591557194?mt=8)). In my case, I have an App radio so I could display whatever functions the app shows in my radio screen. The problem is none of this gives you an alarm, but at least you could monitor things whenever.

[lifespeed]

Modern knock sensors are not fooled by mechanical noise like they were in the "old days".

[martyo]

Modern knock sensors are not fooled by mechanical noise like they were in the "old days".

But that does not hold true for the factory knock sensors with which the Marauders are equipped.

[lifespeed]

But that does not hold true for the factory knock sensors with which the Marauders are equipped.

So, what have you seen?

[martyo]

So, what have you seen?

The factory sensors are susceptible to noise from the motor and its connected accessories, especially a centri style blower.

If I recall correctly when the factory software (which many folks are no longer running) hears noise it tries to neuter the motor by pulling something like 10* of timing or thereabouts.

[Zack]

Sergnt Mac and I converted to MAV2 processors and added an additional knock sensor back in 04.
It did nothing.
This is exactly how the scenario plays out:

You go WOT, it pings.
You can log the pcm pulling timing and it still pings!
I know that is hard to believe, but Ive done my own testing...
Knock sensors are a joke on these cars.

[martyo]

Sergnt Mac and I converted to MAV2 processors and added an additional knock sensor back in 04.
It did nothing.
This is exactly how the scenario plays out:

You go WOT, it pings.
You can log the pcm pulling timing and it still pings!
I know that is hard to believe, but Ive done my own testing...
Knock sensors are a joke on these cars.

I was not saying anything counter to that.

[lifespeed]

Sergnt Mac and I converted to MAV2 processors and added an additional knock sensor back in 04.
It did nothing.
This is exactly how the scenario plays out:

You go WOT, it pings.
You can log the pcm pulling timing and it still pings!
I know that is hard to believe, but Ive done my own testing...
Knock sensors are a joke on these cars.

I think that is the expected behavior, called hysteresis of knock. Once detonation begins, timing must be reduced significantly below the "correct" non-detonating timing setting to stop the pinging.

Let's say your engine runs good at 28 degrees advance, and pings at 30 degrees. One would think that pulling the timing back to 28 degrees would cause the detonation to stop, but it doesn't. It might require reducing timing to 24 or 22 degrees to quench the detonation. After the detonation is stopped timing can then be safely set back to the baseline.

This is well-understood, and incorporated in some PCM knock logic. What did they do in the Marauder PCM? I don't know. There are numerous other details, such as only listening right after ignition to help ignore extraneous noise, etc.

[martyo]

What did they do in the Marauder PCM? I don't know.

As I said, if I recall correctly the factory programming calls for a reduction of 10* of timing. The idea being to clamp down on the detonation as quickly as possible.

The problem is that this effectively neuters the engines ability to make power

Of course, the PCM in the Marauder is technology that is well older than ten years and processor speeds and functionality have taken some good strides forward since then. Nonetheless, most of us are stuck with the processor platforms that came with the car and changing them out is not a simple, or cheap, task.

[martyo]

Sergnt Mac and I converted to MAV2 processors and added an additional knock sensor back in 04.
It did nothing.


Zack when you guys did that, did you retune your cars?

[chief455]

Does the stock knock sensor show a warning light? It shouldn't be too difficult to get something on the dash that lights up when knocking is detected.

Here is a Vampire (knock control system) that looks pretty good. It controls timing and you can adjust the sensitivity.

http://www.jandssafeguard.com/VampirePage/Vampire.html
I like the idea of this, and hopefully they sensors they sell are better than 2004 stuff
this is a concern:
10) Once you have the engine running on the J&S unit, you are ready to test the knock sensor. The unit will not detect knock unless the following conditions are met:

a) RPM must be above 1750 RPM
b) Vacuum drops below five inches.

I know detonation happens at cruise RPM, and vacuum could be stronger than 5hg - still going to look into this system. $650 plus $50 per extra sensor could save an engine.:D

[Zack]

Zack when you guys did that, did you retune your cars?

Yes, Jerry W retuned them for us.

Knock sensors are great for adding timing, not removing it

[JohnnyP]

I like the idea of this, and hopefully they sensors they sell are better than 2004 stuff
this is a concern:
10) Once you have the engine running on the J&S unit, you are ready to test the knock sensor. The unit will not detect knock unless the following conditions are met:

a) RPM must be above 1750 RPM
b) Vacuum drops below five inches.

I know detonation happens at cruise RPM, and vacuum could be stronger than 5hg - still going to look into this system. $650 plus $50 per extra sensor could save an engine.:D

I manufacture the Vampire system. You are quoting from the instructions for a forced induction application.

For naturally aspirated applications, I change the enable point to 15 inches vacuum.

The sensor is just a microphone. It's what you do with the signal that matters.

[lifespeed]

The sensor is just a microphone. It's what you do with the signal that matters.

Right. It's all in the signal processing.

[chief455]

I manufacture the Vampire system. You are quoting from the instructions for a forced induction application.

For naturally aspirated applications, I change the enable point to 15 inches vacuum.

The sensor is just a microphone. It's what you do with the signal that matters.
Glad you found this to provide factual information!
So, why not enable a forced induction system microphone at 15 inches, just in case the detonation (bad gas, mechanical part failing) is happening before boost?
Would this cause 'false knock' system reactions?

[1Marauder]

I have to say this, I like big knockers!

[Jeronimojc]

I manufacture the Vampire system.


Awesome system!! I wish there was a more affordable kit though.



Sent from my iPhone using Tapatalk