Idea for Phantom knock elimination.

[GORBS88]

there's a million and one reasons the OEM KS isn't suited for a built engine and why it really isn't well suited for any engine in some peoples opinions. I ran without one for 9 YEARS, tuning the old fashion way and never lost an engine to detonation and only popped on HG in those 9 years from a faulty wideband reading at the track.

Now that i have a stand alone KS i still see PK rearing it's head as they are nothin more than piezo microphones based around a certain frequency range... google "big mooses knock sensor ramblings" there's other sensors out there that will wire into our cars, and are more tuned for the "knock sound" than hearing suspension, AC compressors and more... I run a saturn KS right now... although i do know bore size and stroke play a part in the frequency range it should be tuned to pick up i'm no knock guru, in fat i hate knock sensors but i HAD to have the J&S stand a lone knock system just for piece of mind but i ignore it half the time as its doing it's job and keeping my engine in one peice by pulling timing su[ppposedly before knock starts (Jon is a KS genius talking algorythims and more till your brain smokes )

Myt point... too many people look at the KS like it's the last leg before death of an engine and it's not... it's an OEM safeguard to keep warranty claims down for one, and on the other hand it's not meant for performance, it's meant to handle the soundds of daily driving... I liked notr having one, but i can deal with the J&S since i can program or eliminate it if needed

VERY well said!

I don't see how anyone can rely on a sensor designed around STOCK motor sounds when they are running forged internals, no balance shafts, big cams , stiff valve springs, solid motor mounts etc. The amount of extra noise that engine is going to make it's amazing that we all don't suffer from this problem.

 

[turboglenn]

^thanks... i'll tell ya something i saw not tooo long ago that will make you think too..

we had a mitsu on a dyno (GS-T) and while we were just running it up to third gear (but not WOT) i could tap on the block, bell housing and intake manifold with a cresent wrench and set off knock depending on how hard i hit it and how close iw as to the sensor....bas suspension bushings, bad pulley bearings,...there's way too much that can set it off.. I have a top of the line afterm,arket that's been programmed specifically for my car with forged internals na di can still trick it into pulling timing by slapping the gas pedal and mnay other things

EIT: some people might be thinking "why buy a 500 dollar knock sensor if you don't believe in them for tuning"......well that's simple... lets say i'm tuned on methanol injection and the bottle goes dry during WOT and all the sudden i'm at 15:1 AFR on pump gas, the J&S can pull 20* of timing and save the engine. I tune on the ragged edge to be honest most of the time (little conservative right now) but in doing that and in knowing the J&S is designed to pickup knock before it actually gets dangerouse and adjust thet timing in each cylinder accordingly I can and often do see 1 or 2 cylinders get between 2 and 8* of tiing pulled depending on conditions and if i'm on the n20, and i continue the pull, and even go up another gear if i'm "competing" and since it only pulls what's needed from each jug and gies it back as fast as it can, I can have timing being pulled and still run so hard you've never even guess there was timing being pulled..

for me it's a "safeguard" and that's it's name, the only time i use it for tuning is if i see it consistantly pulling the same timing at the same place day after day in every gear under light to medium cruising/accel

 

[tsitalon03]

A plastic washer sounds good. I have a metal washer that I coated in high temp rtv.

 

[donniekak]

Solution
Delphi Ionization Current Sensing Ignition Subsystems

 

[forcefed86]

Hmmm, so all you have to do is ground the knock sensor case to disable it like forcefed86 is doing? Isn't it already grounded by being screwed into the block

Forcefed86, go find out which wire damnit!!!!!

Man this thread blew up!

There is a dedicated ground wire going to the sensor and a voltage wire. You are grounding the dedicated ground so the ECM sees no voltage.

As knock occurs depending on the magnitude the piezo sensor produces a tiny amount of current, this tells the ECM to retard timing. More knock = more current = more retard. So by grounding this on a switch the theory is the ECM never sees the voltage.

I don't know why mitsu knock sensors have voltage going to the sensor. Most do not. I'm guessing these sensors are constantly sending some sort of varying voltage signal to the ecm that is deemed normal. Then a raise in voltage indicated a problem. I'm still breaking in my engine and haven't got much seat time at all in the car. So me grounding the ground wire may cause other issues. Time will tell I'll keep you all informed.

Just to be 100 percent this is the correct location for the sensor?

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[dsm-onster]

Man this thread blew up!

There is a dedicated ground wire going to the sensor and a voltage wire. You are grounding the dedicated ground so the ECM sees no voltage.

As knock occurs depending on the magnitude the piezo sensor produces a tiny amount of current, this tells the ECM to retard timing. More knock = more current = more retard. So by grounding this on a switch the theory is the ECM never sees the voltage.

I thank you. I will do this asap. I have a 13g n/t to turbo conversion fwd car that desperately needs this (hit's fvcking hard and throws everything around). . . It has all the potential in the world. If I can get it on stock maps with no knock sensor CEL or yanking timing from the phantom knock from being a bit different in it's layout and obviously shakey/dry chassis.

Ground it to the firewall? or to the sensors' ground on the ecu big plug?

 

[forcefed86]

I thank you. I will do this asap. I have a 13g n/t to turbo conversion fwd car that desperately needs this (hit's fvcking hard and throws everything around). . . It has all the potential in the world. If I can get it on stock maps with no knock sensor CEL or yanking timing from the phantom knock from being a bit different in it's layout and obviously shakey/dry chassis.

Ground it to the firewall? or to the sensors' ground on the ecu big plug?

Shouldn't really matter. I tapped the wire by the plug at the sensor and went to a firewall bolt because it was close and easy. As long as there is an easy path to a good ground the ecu shouldn't pick up on any information the sensor sends. Voltage will always take the easiest path to ground.

Problem I see with this is if the mitsu sensor sends a "normal" operation signal to the ecu it won't receive that voltage signal either. I dunno, my CEL light is off for the moment. I decided to stop playing with the tune until my kepspan unit gets here and I can properly datalog everything.

 

[GORBS88]

I thank you. I will do this asap. I have a 13g n/t to turbo conversion fwd car that desperately needs this (hit's fvcking hard and throws everything around). . . It has all the potential in the world. If I can get it on stock maps with no knock sensor CEL or yanking timing from the phantom knock from being a bit different in it's layout and obviously shakey/dry chassis.

Ground it to the firewall? or to the sensors' ground on the ecu big plug?

For the time it takes why not take the sensor out like it did?.. No splicing wires or anything. I'm under the impression you want to eliminate it entirely and not put it on a switch?
This way the circuit functions as it should and the ECU see's the circuit as it should.
I wouldn't feel safe grounding the circuit completely as it make cause some back feed issues from the ecu as it's not meant to see a completely shorted to ground connection.

just my 2cents. mabe i'm wrong (just saying it as i see it)