Knock module for MS3

[piledriver]

Great, thanks for the info! I just didn't remember them being on all the time on the last one I did. Then again it was a 3.57 so the led's where inside...

I'm getting odd behavior though. On the bench I get a noise floor of 2.5-3.5%. When I put it in the car all 6 cylinders sit at 0%. running or not.

I do know that the engine must be running (see RPM) for it to "see" anything due to the knock window being timing dependent...
Figured that out doing tap tests with a crescenthammer to see if it was seeing anything.

Hope to get a second sensor installed for front pair (1/3) RSN, but the cars down for a few days,
Note: brake lines are totally incompatible with drill bits.

I just picked a new sensor up at O'Reillys for $16, late Neon sensors are common as salt, and the auld Bosch injector connector fits perfect.

[Mario]

This is on a Nissan Skyline. It's an inline 6 using 2 factory sensors. Car was running and there should be some noise... I would think. But it just sits at 0.

[piledriver]

This is on a Nissan Skyline. It's an inline 6 using 2 factory sensors. Car was running and there should be some noise... I would think. But it just sits at 0.

Are the factory sensors widebands or NB? The NB usually put out more signal.

You should be able to see a well timed tap with a hammer or crescent wrench with the default settings,otherwise start checking connections.
Have a 'scope?

[dvanderk]

Is there anyway you can test the knock sensor while the car is off? I was told that simple tapping of the sensor wont work, is it required to be on in order for hardware to see rpm before any readings can show?

[piledriver]

It will work if you hook it all up to a stim, but as the setup is only "listening" during the defined crank angle windows, it needs a working RPM signal.

You should be able to see something with the sensor hooked up to a DVM if you tap near the sensor with a wrench etc.
It is a microphone of sorts, so the output voltage may be quite low.

[piledriver]

Got my second sensor on, $16 to the Man at OReillys got me a second NTK sensor in a BWD box, rev C of the same PN.

Did a quick test to determine which wire was which sensor only to discover that most of the baseline noise is noise of an electrical nature.
Same noise floor with or w/o sensor connected, rev engine etc, or with sensor connected (but in hand, literally, as in not bolted to engine)

Will be hunting ~12 feet of star quad, but I'm wondering if a good stereo analog preamp (for a differential input) might be worth doing.

Knock still seems easy to very pick out in the logs, and it works great, but knowing most of the "signal" I'm setting thresholds around is simply electronic trash is annoying to an old ECM troop.(It's OK if it's intentional electronic trash )

[Mario]

but knowing most of the "signal" I'm setting thresholds around is simply electronic trash is annoying to an old ECM troop.(It's OK if it's intentional electronic trash )

[nismoautoxr]

Hi guys . MS3 and knocksense newb for sure. I am gathering that the resonant sensors like I have on my LS1 are pretty much unuaseable with knocksense and in my case even more so since the cam and spring setup create considerably more noise than the stock sensors were tuned for . Is it safe to say that pretty much any bosch knock sensor that has a 2 or 3 wire connector on it is probably a wideband knock sensor ?

[piledriver]

Hi guys . MS3 and knocksense newb for sure. I am gathering that the resonant sensors like I have on my LS1 are pretty much unuaseable with knocksense and in my case even more so since the cam and spring setup create considerably more noise than the stock sensors were tuned for . Is it safe to say that pretty much any bosch knock sensor that has a 2 or 3 wire connector on it is probably a wideband knock sensor ?

Usually, but the 2005 Neon ones I'm using are NTK, same plug, just no pigtail, connector built into the sensor.

[piledriver]

Figured out a relatively fast method to pull the thresholds for knock.

Plot knock_in vs. rpm in MLV and pull off the top of the noise line at the RPMS in your threshold graph.

Individual cylinder knock can show interesting things too, I pulled a few degrees from #1 at 2200-3K.

[nismoautoxr]

Im looking at using 2 of these http://www.rockauto.com/catalog/moreinfo.php?pk=1112263

They fit a number of different ford applications ...they are cheap as hell and very easy to find in the boneyards and I figure since ford used them on lots of different engine displacements that they were very likely flat response , non resonant sensors . Brand new they go from anywhere in the 20-30 dollars each new. I however was not able to find any actual documentation to confirm that it is indeed a flat response sensor .

I assume these can be used directly with the knocksense module without any sort of amplifier right?

This PDF http://delphi.com/shared/pdf/ppd/sensor ... sensor.pdf suggests that it probably is with a ford connector on it .

[piledriver]

The late Neon NTK sensors I'm using are $16 ea out the door at OReillys, and seem to work peachy for half the price of many I have seen.
They do lack a pigtail, but use std injectror sensors (old skool Bosch, EV1??)

I plan to run some shielded twisted pair or starquad mic cable to each sensor direct from the knock board, perhaps with an XLR connector back near the MS for ease of install.

The module has it's own programmable gain amp setup for the sensors, from the chip docs it could be setup for differential inputs, but I haven't looked closely at Jeans board to see if he did that. yet.

You can set the gain for each cylinder.

The integration time also effectively sets gain, lower the number, higher the signal level.
The sample window size also has an effect.
The docs from AEM (uses same chip, but pre-programmed knock window) show setting the gain to 2 or thereablouts for WB sensors, and the integrator to 180ish, YMMV.

Set the integrator time so your max signal has some headroom, and tweak the gains to make the channels follow the same curve.
I'm using the 3rd harmonic, or as close as possible. YMMV.

I have found that my #1 (only) tends to appear to knock from ~1800-2500, regardless of how much timing I pull // AFR or octane I throw at it, so I have to dig in a bit. (This is a very recent change, previously all 4 could care less even with an extra 30 degrees of timing)

The other 3 holes apparently could still care less. I suspect a mechanical rather than electronic issue, carbon turd in the chamber or loose piston pin?

I'm running 2.0 gain (or a tick or two less for balance) and an integrator time of 150uS.
Start window at 10ATDC and 50 degrees.
(I can "hide" my #1 noise by moving the knock window some at the RPMs in question, so there's actually something there, altough no audible knock)
Max level at redline is ~75%, but some of that is electronic noise, will see how it works with some better cables RSN.

[masterx81]

I've noticed that same 'strange' false knock reading in my setup. The 4 cylinder is the more 'noisy', despite that the cylinder are at the same distance from the knock sensor (subaru boxer engine). Obviously i have something wrong in the engine... Alto with 5deg of advance i read high knock, so...
I log a lot of (false) knock also with 0° of advance during the flatshift/launch.... Maybe the explosions in the xhaust cause false readings (that retard the timings....)

[piledriver]

Spent a little more time with it, did some mental processing...

Like real estate, knock sensors are highly sensitive to location, location, and location.

Switched sensors (in software), and the issue moved to #3 & 4
Set to only use #2 sensor (Flywheel end) and it's just about invisible.

If what I was seeing was real knock, I'd expect to see it on both ends to at least some extent (the alloy block is only ~18" long, maybe)

EDIT--Looks like I'm picking up some noise on the FW-end sensor---went in to verify which was which.
(EDIT---or possibly EMI, still need properly shielded cables, currently lacking entirely)

Played with the knock window a bit >3K is now 40 degree window, still starts at 10 ATDC, quiet as a mouse.

(if any of thre above is a logic fail, please speak up, ya'll)

I still have yet to actually hear it knock when trying to make it do so.

[piledriver]

Has anyone stumbled on the part# for the Nissan spark plug washer pressure sensors used on the Skylines?

Seems like the only practicla setup for retrofit, and might even work well with the knock detect setup.

[masterx81]

Interesting, those pressure sensor are fast-reacting? Can be used for PPP detecting?
I was unaware that on skyline have used a washer style pressure sensor...

[jsmcortina]

I still have yet to actually hear it knock when trying to make it do so.

I managed to simulate knock on my install with the car on stands, standing on throttle and brakes at low rpms in 3rd. Somewhere around 1200rpm/80+kPa I had too much timing if I remember correctly.

James

[piledriver]

Interesting, those pressure sensor are fast-reacting? Can be used for PPP detecting?
I was unaware that on skyline have used a washer style pressure sensor...

AFAIK they were used for knock,(thus need ~20 KHz BW) but I want to try them for pressure & knock...

RB26DETT IIRC, spent an hour googling for a part# to no avail, lotsa hits but no part#, may be JDM only.

Some Toyotas had a screw in pressure sensor that measured basically head stresses, but they seem to go for $500.
I think if I have to drill a hole in my head for it the Beru glow plug setup would get the nod for $100, 0-5v out.

James, thanks for the tips, I tried that and everything else and basically the only thing I got was a really funky (clutch) smell.

If I let it idle and get really nice and toasty in 100F temps i do get a little audible knock occasionally at tip in just for 1/2 second (with no knock retard on)
Almost suspect oil. (Hmmm oil mist spray in TB... maybe some diesel... Cetane is the opposite of octane for this purpose....)

[piledriver]

My bad, looks like I misread my original reference for the pressure//knock sensor spark plug xducers, they were allegedly used on the older VG30DETT (300ZX TT)

Still don't have a damned part#, so I'm starting to wonder if it was junk info to begin with.

OTOH I wasted a half hour on an alleged ion sense function of a common coil that didn't have it based on bogus info, so we well see...

[nuvolarossa]

piledriver, I think you mean these:
http://www.aus300zx.com/forum/showpost. ... ostcount=8

I would think they are Cylinder Head Temperature sensors, something like these http://gallery.trailtech.net/Computers/ ... ure_Sensor
they are used a lot in air cooled engines, but don't ask me why vg30det had those!
If I'm not wrong vg30det has knock sensors (I mean the piezo ones style we all know.
But I could be wrong.

spark plugs with integrated pressure sensors still cost a lot for an individual and they don't work as long term solution. It would be much better (and cheaper in the long run) to drill and tap the head to stick a pressure sensor in the chamber, if coolant passages around the cylinders and space allow this.
But if all car makers are going ion sensing, there should be a reason. (or more than one)