Black R

I know J&S has one, and it automatically retards timing if it senses knock.

BUT a friend of mine had one and it basically would think the motor was knocking as soon as vtec clicked... so that sucked. He had to basically turn the sensitivity all the way down so it was next to useless.

I also remember reading somewhere about TOO using a GM knock sensor...

Anyone else using anything neat or sophisticated?

I'd like to be able to take the knock sensor and mount it externally during tuning for different cars so it could be part of a mobile tuning package (along with wideband).

Thoughts?

boostedcivicsir

caspers electronics makes one that uses the gm knock sensor but the downfall of it is, you need a 1/4 pipe thread to put it into. and the only thin i think it can go into is an ac bracket hole drilled and retapped.

Si Shane

http://pw1.netcom.com/~bsundah...ogram

No need as i ssee it.

Black R

thanks for the link!

2point2

I really want to try this out..



http://www.plxdevices.com/R-500_productinfo.htm

*Boostwerks*

Search for "knock link" its a visual modual that shows knock utilizing the stock knock sensor! If you don't have a knock sensor, you can always get the ever popular Bosch unit.

It has a sensitivity adjustment, and works great...

Si Shane

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slow poke &raquo;</TD></TR><TR><TD CLASS="quote">There are plenty of DIY kit’s with a simple knock sensor and headphones that would work for what you are looking for. Listening for yourself on the dyno provides as a GREAT TOOL </TD></TR></TABLE>

The link i provided i found just about a week ago on this board. It was extremely helpful to me. Listening to the motor does it for me, i really dont need a knock sensor to tell me when i'm detonating with the headphones on. You can hear some cool stuff.

Andre

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Black R &raquo;</TD></TR><TR><TD CLASS="quote">BUT a friend of mine had one and it basically would think the motor was knocking as soon as vtec clicked... so that sucked.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slow poke &raquo;</TD></TR><TR><TD CLASS="quote">You are 100% right about the J&S and the loud v-tec causing problems.</TD></TR></TABLE>

Either both of you have an old Safeguard or you haven't read the manual

Hyaboosta

The emenage has a Knock sensor that can be used too. I have it but need to research it before I install to find out how it works

Andre

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slow poke &raquo;</TD></TR><TR><TD CLASS="quote">
I have been meaning to get with the J&S guys to see if my classic V1 will work with a 2 channel wasted spark setup.</TD></TR></TABLE>

The J&S can be used with the Ultra MDI wasted spark ignition, that's what i have.

If you have 4 ignition outputs you could use the 4 channel J&S.

Andre

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slow poke &raquo;</TD></TR><TR><TD CLASS="quote">
Please hook it up with more info if you do have 2 drivers going through your J&S </TD></TR></TABLE>

No, only 1 wire goes through the J&S, the MDI then plugs into the distributor plug.

But why aren't you using the AEM EMS knock features?

Black R

Andre, thanks for the link.

I'm glad to see J&S has addressed these issues.... how effective is this newer unit?

That plx device sounds very interesting as well!

EE_Chris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slow poke &raquo;</TD></TR><TR><TD CLASS="quote">The Honda Knock sensor is the best sensor you can get for a Honda engine as it is specifically designed for the frequencies the Honda engine puts out. </TD></TR></TABLE>

But isn't this true for stock components? Once you start adding forged internals and such, doesn't the knock frequecy change or does the Honda KS have a wide enough bandwidth?

raene

From what I recall the frequency is dependent on the size of the chamber, not on the components used, but the forged components rattle around and cause false knock. If you bore the engine out then yes, the knock sensor loses efficiency.

Isn't the knock sensor itself unfiltered, with the filtering circuitry on the board?

Knock Sensor basics

Detonation Frequency

EE_Chris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by raene &raquo;</TD></TR><TR><TD CLASS="quote">Isn't the knock sensor itself unfiltered, with the filtering circuitry on the board?</TD></TR></TABLE>

Audio goes up to 20k. If someone spoke into a microphone @ 20kHz, it should pick it up and produce an output.

However, what if someone were able to belt out a frequency of 1MHz - you still think the microphone would pick it up and produce an output?

So in that sense, since the KS is a microphone, it has a limited bandwidth.

But yes, the signal is filtered on-board.

MidShipCivic

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slow poke &raquo;</TD></TR><TR><TD CLASS="quote">
The AEM knock features don’t even compare to the ability of the J&S. Not even close!
I am surprised you would even ask seeing how you have a J&S and all?? </TD></TR></TABLE>

Your wrong.

AEM does everything J&S can do.


Knock Control Configuration
The AEM EMS has 2 inputs for knock sensors. These can be passive, where data is displayed and/or
recorded or the feedback knock control can be enabled, letting the EMS take action to counter the knock.
To do this, the EMS can either retard the timing or richen the fuel mixture, or both. To setup the knock
control, you have to:

• Identify which cylinders correspond to each knock input.
• Identify the knock signal threshold above, which is “real” knock.
• Define the rate of additional fuel to be added for knock.
• Set a maximum amount of fuel to be added for knock.
• Define the rate that it will be removed after the knock is gone.
• Define the rate of spark retard to be added for knock.
• Set a maximum amount of ignition retard for knock.
• Define the rate of spark advance back to normal values after the knock is gone.
• Activate the knock system.
This type of description is best described in an example. For the purpose of this, an inline 4-cylinder
engine will be used with 1 knock sensor, connected to Knock1. It will also be assumed that this engine
running “wasted spark” and is using Coil 1 for Cylinders 1 & 4 and Coil 2 for Cylinders 2 & 3.
Open the Options | Coil dialog box. This allows you to activate the coils and assign which knock sensor
applies to that coil. For our purpose, we will activate the Knock1 checkbox for both Coil 1 and 2. This says
that all knock control actions triggered by the signal coming in on Knock Sensor #1 should apply to these
coils.
Open the Options | Injector dialog box. This allows you to activate the Injectors and assign which knock
sensor applies to that Injector. For our purpose, we will activate the Knock1 checkbox for injectors 1,2,3 &
4. This says that all knock control actions triggered by the signal coming in on Knock Sensor #1 should
apply to these injectors.
Alternately, you can go to the Options | Full List and just type in the values.
Code
Coil1Knock1 = “On”
Coil2Knock1 = “On”
Fuel1Knock1 = “On”
Fuel2Knock1 = “On”
Fuel3Knock1 = “On”
Fuel4Knock1 = “On”

Additionally, make sure that the Knock2 channels are off.
So now the EMS knows that if the Knock 1 input detects “knock” then whatever action it takes should
apply to Coil 1 and 2 as well as Injectors 1-4. Now we need to define what the EMS considers “knock”
These is a “Knock Noise Table” under the Ignition menu, which sets an RPM dependant threshold to filter
out background noise. Setting up this table is key to the success of this function. Whenever the knock
sensor voltage output exceeds this table’s value, it is considered to be “real knock” and the difference
between the actual knock signal and this threshold value determines the severity of the knock.
The best way to set this table is with the aid of the data logger. By logging the Knock Raw#1 channel
when the engine is under load and not knocking gives you a picture of the background noise on the knock
sensor channel. This is mechanical noise in the engine that is near the same frequency as knock but is
not real knock.
By using this data, you can now draw the knock noise table versus RPM. The table should be about 10-
25% above the typical knock sensor value that you recorded and will start off very low and increase with
RPM.
After setting up the knock sensors and the “Knock Noise Table” the EMS knows what knock sensor
applies to what cylinder and what Knock signal constitutes real knock

Black R

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slow poke &raquo;</TD></TR><TR><TD CLASS="quote">What link? The photo or did I miss something? Here is the link for the J&S's Honda instructions.</TD></TR></TABLE>


Yeah, I meant pic - but thank YOU for the link!

MidShipCivic

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slow poke &raquo;</TD></TR><TR><TD CLASS="quote">
NO bro YOU ARE WRONG!
The J&S retards INDIVIDUAL CYLINDER TIMEING not all the cylinders at the same time.
Now go ahead and tell me the AEM does that, go ahead

You think if the AEM did that I would go to all this trouble to get my J&S setup perfect.

</TD></TR></TABLE>

AEM DOES INDIVIDUAL CYLINDER RETARD

cueballsi

bump to track !