Tuning for water injection: fuel, ignition, and EGT

[Richard L]

Originally Posted by hotrod

... It is a suspected carcinogen, it is not compatible with copper and there are cautions against mixing with more than 2% water....

Larry

Sound just like the right stuff for the boys.
I was thinking mixing 95%-98% of water to PO just to offset the slower burn rate of WI or race fuel.

At longer polymer chains, would it solidify? another thing to find out.

Richard

[JohnA]

Originally Posted by HOODEY

With the Knock Link how do you set the sensitivity. ..

It's got an adjustment screw.
Normally you have it fully counter-clockwise (full sensitivity) and only turn it a bit if it gives too many false 'reds'

It's a balancing act, it also depends on where the sensor has been fitted, or how it is coupled to the engine.

[Gert_]

ChassisEar:



ChassisEar for fine tuning, KnockLink for safety use.

Gert

[espritGT3]

...KnockLink for safety use.

While I haven't tried the KnockLink per se, I have experimented with a similar device made by another manufacturer. If one's car is fitted with an OEM knock sensor fine, but if not, it gets more complicated. Knock sensors come in two basic types, resonant and non-resonant, also known as flat response type sensors. The resonant sensors tend to be more application specific. Each motor has its own resonant frequency at which knock occurs, being dependent upon cylinder bore among upon things.

Using a resonant type knock sensor in a motor other than the application it was designed for can result in false warnings. In my personal experience testing 2 different GM resonant knock sensors in a 4 cyl turbo motor, the sensor would regularly confuse valve train mechanical noise with knock.

While it is true that the display sensistivity may be turned adjusted, without actually being able to hear detonation one runs the risk of "desensitizing" the unit excessively. Inaudible knock could be occuring without one being aware of it.

Below is an interesting primer on knock sensors and the signals they produce:

http://deviantmethods.com/bigmoose/pages/knock.htm

Here is another site with more information on flat response type sensors:

http://www.delphi.com/pdf/ppd/sensors/et_flat_knock.pdf

For a universal application I'd be inclined to go with a flat response type sensor, which is also what Bosch Motorsport recommends with their stand alone racing ECU's. However, I have yet to find an aftermaket logger that will read their low voltage output without an amplifier.

espritGT3

[JohnA]

This Delphi 'flat repsonse' sensor looks like the Bosch one that comes with KnockLink

[espritGT3]

Originally Posted by JohnA

This Delphi 'flat repsonse' sensor looks like the Bosch one that comes with KnockLink

If Knock link comes with a flat response sensor, that's certainly a step in the right direction. Now if I could only hear the knock (mid engine car) to calibrate it.

espritGT3

[Gert_]

Originally Posted by JohnA

This Delphi 'flat repsonse' sensor looks like the Bosch one that comes with KnockLink

Mine came with part nr.# 0 261 231 006

Gert

[espritGT3]

Originally Posted by Gert_

Mine came with part nr.# 0 261 231 006

Gert

I decided to opt for a J&S Safeguard, configured coincidentally, for the exact same Bosch sensor. J&S allows one to choose the type of knock sensor they prefer, resonant or flat response.

http://www.jandssafeguard.com/images...0261231006.jpg

I considered a KnckBlock but wasn't able to obtain much technical information on the unit from KnockLink's US reseller. Do you have any experience with it? Does it retard ignition sequentially?

espritGT3

[JohnA]

KnockLink is just a display thing (and a pretty ugly one at that!)
It doesn't retard or anything, just passively light up LEDs

[espritGT3]

Originally Posted by JohnA

KnockLink is just a display thing (and a pretty ugly one at that!)
It doesn't retard or anything, just passively light up LEDs

John,

I'm aware that KnockLink is just a display, but apparently they make a kncok retard as well, called "KnockBlock". While the local dealer could give me a price on it, I've never seen one and additional information on its operation is scarce. Being familiar with the KnockLink I thought you might know somehting about their knock retard unit as well.

Thanks,

Mike