ISV and KNOCK explained

[Trakx 0]

From the info i've got this is +/- how it works

 

The ISV has two functions:

 

1- It will open when +/- 5600 rpm is reached.

 

2- When the ecu senses knock.

 

The knocking is detected cylinder selective. Each cylinder has its own window. The signal is filtered through a bandpass filter to eliminate false ticks. The signal strength is then weighed on two maps for upper allowed amplitude and minimum allowed amplitude. rpm dependant. A register sums up filtered knocking events per cylinder and starts to pull back timing individually with 3.2

[jonny-5 0]

Very good, how do you find out things like this?

[andy 0]

I take it we're not talkiing about ISVs as in Idle Stabilisation Valves here then......? Must be a G60 thing? :scratch:

[flusted 0]

yep he means idle stabilizer. Good job i dont have 1 :lol:

[Trakx 0]

Many years serching for info.

 

I don't have an ISV also :D

 

One more thing. There no "safeguard" as you go above 2 bar MAP. The ECU will not retard timing.

The only limitation in using more than 1 bar boost is that the fuel and ignition map end at 1 bar so you have to use the last line in the map for ignition and fuel to, say, 1.2 bar. What will happen than is that from +/- 0.88 bar until 1.2 bar you will be overfueling and to much retarded. (note that 0.88 bar is the line before 1 bar, so from this point up the ecu will calculate values in between 0.88 and 1 bar)

[sparks 0]

thats helps alot cheers ive do have a g60 and have seen the so called get max boost fit a one way isv valve but was pretty sure it done something important but was not sure

 

maybe this will get those people with one valves to change back and SAVE there engines melted pistons dont look good !!!

 

heavens full of PG engines it dont need anymore

stu...

[flusted 0]

Do you know of anyone with a 1 way valve thats melted a piston? i ran 1 for about a year with no probs

[Trakx 0]

i'm not saying that you should or shouldn