Boost / Timing / HP
10-07-2004, 11:28 PM
#1
Three Wheelin'
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Boost / Timing / HP
Hi all,
I have been considering adding water injection to my 951. What my question is, does the stock DME retard ignition based upon a pre-programed look-up table, knock sensor, boost levele, etc?
The reason I ask, is that if the computer is retarding the ignition via a knock sensor, I may be able to get more power via water injection (the computer may be retarding my timing and I don't know about). If the knock sensor retards timing, then eliminating knock would give that timing back and allow me to make moe power.
BTW, I do not hear any pinging but I am running 19psi on 91 octane fuel.
If it retards timing some other method, is it possible to get the retard out without going stand alone?
-Dana
I have been considering adding water injection to my 951. What my question is, does the stock DME retard ignition based upon a pre-programed look-up table, knock sensor, boost levele, etc?
The reason I ask, is that if the computer is retarding the ignition via a knock sensor, I may be able to get more power via water injection (the computer may be retarding my timing and I don't know about). If the knock sensor retards timing, then eliminating knock would give that timing back and allow me to make moe power.
BTW, I do not hear any pinging but I am running 19psi on 91 octane fuel.
If it retards timing some other method, is it possible to get the retard out without going stand alone?
-Dana
10-08-2004, 10:38 AM
#5
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Yes, it retards timing via knock sensor only. But generally you would be able to tell as it feels like it's misfiring or hesitating. It can be subtle, but it's there. So if you don't feel anything, chances are your knock sensor is not activated.
What elevation are you? If you're running 19 psi gage, which would be "over" your ambient atmospheric pressure. At high elevation, your total absolute presure might not be as high as you think.
But generally, you'd think 19 psi would activate the knock sensor with 91 octane.
What elevation are you? If you're running 19 psi gage, which would be "over" your ambient atmospheric pressure. At high elevation, your total absolute presure might not be as high as you think.
But generally, you'd think 19 psi would activate the knock sensor with 91 octane.
10-08-2004, 11:01 AM
#6
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The KLR filters the signal from the knock sensor. If it evaluates the signal as actual knock it retards the timing x degrees. I'm not sure you can feel this... With the new knock display we are developing you will be able to visually tell when the KLR detects knock and the intensity.
While at it, we are looking into modifying the "x" degrees to be more suitable for timing values that are more aggressive than stock timing values.
While at it, we are looking into modifying the "x" degrees to be more suitable for timing values that are more aggressive than stock timing values.
10-08-2004, 11:13 AM
#7
Three Wheelin'
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Tommy,
I am running 19psig. At 6000ft, that is about 16psia. Even 16psia may be a little high running 91 octane fuel. However, 91 is what is commonly available.
The knock sensor readout would be great..
-Dana
I am running 19psig. At 6000ft, that is about 16psia. Even 16psia may be a little high running 91 octane fuel. However, 91 is what is commonly available.
The knock sensor readout would be great..
-Dana