Knock Sensor Bushings?

Just wondering if this idea had any merit?
http://www.techtonicstuning.com/viewpart.asp?partnum=133.375
"This aluminum bushing bolts between block and the knock sensor. Dampens engine noise to the knock sensor for smoother running engine and most cases more power."

I figure with all the rocks and crap banging off the skid plates and what have you, maybe this bushing would be useful? Perhaps cut back on some of the retardation, short of kicking me out of the car.

My golf has a 2 liter 16v on the cis-e motronic with 2 knock sensors. When I put it together I measured the compression ratio to be 10.4:1. Cams are stockers.

Yay? Nay?

Alot of Turbo Ford 2.3T guys just remove their knock sensor. I don't endorse that, but that's what they do. Apparently the stock Ford ECU is really bad about severely retarding timing unneededly. So I've read. $25 seems a bit much for a piece of aluminum with a hole in it though.

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Grant Hughes

Grant, it's that the KS in general for a performance engine is useless. If you're getting that much knock, you have a tuning/fuel/timing issue. Really you loose power either way, KS pulls timing or from detonation. It seems most stock turbocharged cars are pretty fragile if pushed too hard. The Ford 2.3T being one fine exeption. I haven't run a KS on any of my cars in years. I haven't blown up an engine yet. As to the stock computer being a POS, that's true. The problem is it ignores detonation after 4k rpm, cause it lifts the boost limit to 15 and dumps fuel at the same time. Try getting a KS to work well with a programable ECU. My friend Jason has tried with the programmable Dodge ECU's and found it was a waste of time, and he's a programmer by trade.

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Scott Manley
Spokane, WA
86' XR4Ti
37

I've never heard of such a thing. I'm pretty sure knock sensors are like microphones, in that they are "listening" for a specific harmonic frequency range within the block. If they were susceptible to vibration, I would think regular street driving would result in false knock detection. Engines vibrate, cold forged pistons slap, shit happens.

I think, if you really wanted to try something like this, your best bet would be to find something that is more apt to absorb vibration than aluminum. Perhaps you could slip a section of hose or left over silicone coupler over the sensor to better isolate it from debris. Put a delrin/plastic washer between the sensor and the block and zip tie the sleeve around the sensor. I think that would do more to isolate rougue vibrations than a metal sleeve.

Just my two cents.

EDIT: twice for flagrant typos that annoyed me and required assassination

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Brian Driggs | KG7KCA | PHX, AZ | 89 Pajero
alterius non sit qui suus esse potest



Edited 2 time(s). Last edit at 07/06/2006 12:41PM by DR1665.

Yeah but it's one of the first things the turboford guys will tell you to do. Most people don't really have performance engines (stock with more boost and bolted on items) and generally have a problem with fuel and/or timing. That's what makes things like APEX AFC or whatever those things are called so popular (fuel management computers).

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Grant Hughes

Not really,

M-Sport, using Pectel management, removes the Knock Sensor, after the mapping is loaded and data logged. They do the same for the O2 Sensor. In case of GrN cars they do not physically remove either, they leave them connected (After the mapping is loaded and data logged, again) but without measuring anything meaningful. The KS is as mentionned above is mounted with a thick washer and the O2S is mounted on a bracket on the exhaustbut not measuring anythong from the exhaust pipe, it is outside kinda parallel to the exhaust, it still gets heated by the exhaust gasses and thinks it's working but only gets O2 reading from under the hood instead of inside the exhaust, thinking that all is fine and dandy.

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Cheers
M.Samli
Phoenix AZ
Gaylant VR4
EVO III GSR (Stolen)


Rallies are no place for traitors

DR1665 Wrote:
-------------------------------------------------------
> I've never heard of such a thing. I'm pretty sure
> knock sensors are like microphones, in that they
> are "listening" for a specific harmonic frequency
> range within the block.e.
>
> Just my two cents.
>
>You're right saying they're tuned for frequencies, but a standard test is to watch for when running the engine with timing light going when you simply whack the block with a small peen hammer or big herking prybar.

In other words, they DO retard all the time for spurious reasons.

A WRC mapper/dyno guy told me "Mfgs are concerned with maximum lifespan of the motor and a big range of posssible fuels etc, WE control everything better, we know what its getting for fuel, we know the temp, so we know we can run it TO THE EDGE; we don't need no stinkin knock sensor and you ain't getting one."
> DR1665.

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
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is 3 hours behind Eastern Standard Time.

NoCoast Wrote:
-------------------------------------------------------
$25 seems a bit much
> for a piece of aluminum with a hole in it though.

Yeah, I'd definately make my own. Especially since I have 2 knock sensors. I was mostly using the link as a description of what I meant.
I'll give this a try and see if I notice any difference.

sagsert Wrote:
-------------------------------------------------------
> Not really,
>
> M-Sport, using Pectel management, removes the
> Knock Sensor, after the mapping is loaded and data
> logged. They do the same for the O2 Sensor. In
> case of GrN cars they do not physically remove
> either, they leave them connected (After the
> mapping is loaded and data logged, again) but
> without measuring anything meaningful. The KS is
> as mentionned above is mounted with a thick washer
> and the O2S is mounted on a bracket on the
> exhaustbut not measuring anythong from the exhaust
> pipe, it is outside kinda parallel to the exhaust,
> it still gets heated by the exhaust gasses and
> thinks it's working but only gets O2 reading from
> under the hood instead of inside the exhaust,
> thinking that all is fine and dandy.
>
> Cheers
> M.Samli
> Phoenix AZ
> Gaylant VR4
> EVO II GSR
> STC Mouthpiece
> Instigator Extraordinaire
>
> Avatars are like underwear, change them daily.

Same thing for Mopar Performance computers, like the Super 60 (for track only). My friend Jason wasn't getting closed loop when he tried one. He looked in the code and found it disabled (actually they just set closed loop for 265degrees engine temp!); These computers have a fairly slick individual knock detection system, but for the performance computers it's disabled.

Also I believe Porsche Cup cars are set up the same.

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Scott Manley
Spokane, WA
86' XR4Ti
37