Stand Alone Knock Sensor Gauge

[turbo87]

I was just wondering if you could buy a gauge to connect to the factor knock sensors? This would probably be a lot more reliable than the widely available AFR gauges.

If not would it be possible to make something Jaycar style with a warning light?

I know the PFC reads knock however I already have an EMS.

[turbo87]

Bump - anyone have any idea?

[GeeTR]

Hey Turbo87

Unfortunately I think you’ll find the smarts of a OEM knock system are in the micro controller, not the sensor.

The sensor is similar to a microphone, though with a heavy weighted center pole section instead of a delicate mylar cone. Vibrations go through the sensor and shake the center piece causing current fluctuations through the coil blah blah.

The sensor output is then read by a micro controller which is able to remove normal engine vibrations and concentrate on the larger knock events.

Its that algorithm that’s the key, and the reason why EMS don’t supply the ability with their ECU’s.

Your not f*cked yet, there’s a few options.

I rem a Zoom mag back in high school with a red turbo 240Z, back when it was still published on matt, mostly black and white paper had an article about using the decoder from a Delco?

>> http://www.linkecu.com/products/AncillaryDevices/KnockBlock

This mob known for ECUs’ that catch on fire ( recent HiOctane vid) have been making systems for years

>> http://www.techedge.com.au/

If your already making the hardware to heat / control and decipher wide band sensors for the tuning industry, one could guess where the next avenue for development would be – stay tuned

Lately I have a habit of spewing coffee fueled Hi-Po auto utopia at the end of my forum posts, this time I gota grip

Hope this helps buddy

Michael

[Sydneykid]

HKS make a combination Knock Amp and A/F ratio meter, they are around $900 or so. Very usefull tuning device, bit exy though.

The cheaper alternative ($150 or so) is to buy some chassis ears and use the best knock detector known, the human ear.

Of course Power FC's come with highly accurate knock amp included and display easily interpreted knock readings on the Commander (or Datalogit if you have one).

cheers

[RB30-POWER]

Link make two products that may be of interest to you.

http://www.linkecu.com/products/AncillaryDevices/KnockLink

http://www.linkecu.com/products/AncillaryDevices/KnockBlock

[RedDrifter]

The stock ecu will spit out a knock code (code 13 I think) if the knock becomes higher than the factory preset (which is conservative). Of couse you need a consult cable and software to do it though.

But you haveing an ems means its not much help here. :-(

[NewKleer]

i think the only fault code the ecu logs is if the knock sensor circuit isnt correct, not that its detecting knock over a certain level (code 34). some consult software like nissan datascan incorrectly reports it as simply "knock sensor" and most people interpret this as being that the ecu recorded a knock

[RedDrifter]

i think the only fault code the ecu logs is if the knock sensor circuit isnt correct, not that its detecting knock over a certain level (code 34). some consult software like nissan datascan incorrectly reports it as simply "knock sensor" and most people interpret this as being that the ecu recorded a knock

Well Yeah I thought that once too but if you have a good read throught he nissan manual for the R32 you'll find that it does document this. If the stock ecu detects knock it will switch to the secondary map for fuel and ignition.

I tested this theory quite some time ago and everything lines up.

It will spit out a knock code if the ecu detects knock beyond the ecu preset.

The stock ecu is a wonderfull thing.

[NewKleer]

R32 FSM, EN-396 says knock sensor fault code is only indicating disconnectiong/short circuit (or relating circuit issue).

it makes no mention of the engine registering a knock resulting in a fault code. maybe your sensor and/or wiring whenever you tested it was a bit iffy?

EN-297 says the same thing for the R33 FSM (that the fault code indicates "disconnection or short circuit in the knock sensor")

likewise for EC-51 in S14 FSM, and S15 FSM says similar things as S14 one

Edited November 11, 2006 by NewKleer

[RedDrifter]

I tested this on more than one vehicle so no iffy circuits there.