Aeroforce gauge knock reading

[efroeh]

Hey guys I just got my triple sos pod installed with Boost and oil pressure gauge. The third is a duel Aeroforce gauge. I'm playing with the different setting and was looking at knock sensor. What does it mean when it reads a negative number or a positive number? Been getting negative when on highway but been raining too hard to really see what it reads at wot.

 

[JPs2013GT500]

A negative value means it's adding timing whereas a positive value means it's pulling timing.

 

[efroeh]

A negative value means it's adding timing whereas a positive value means it's pulling timing.

Perfect thanks.

 

[Cman01]

Yep you want to see -#'s for knock while your revving out the rpm range of your engine. It's ok to have a little minor + # (like 0.25-0.5) the instant you punch it but it should go - a second or two into your pull in any gear (ALA you are in the right gear for your speed and not bogging the engine).

Tony

 

[efroeh]

Yep you want to see -#'s for knock while your revving out the rpm range of your engine. It's ok to have a little minor + # (like 0.25-0.5) the instant you punch it but it should go - a second or two into your pull in any gear (ALA you are in the right gear for your speed and not bogging the engine).

Tony

So if there is some knock how do I fix this? And what does it mean?

 

[efroeh]

So after a few hard pulls threw 3rd and 4th I noticed it's reading 2.00 of knock I changed my tune to my 91 octane tune thinking maybe fuel wasn't the best it's 94 fuel but who knows. Same thing but with the 91 it feels like it's got more power. I'll have to do some data logs and send it to lund but what can I do for the weekend as I think there gone?

 

[Cman01]

So if there is some knock how do I fix this? And what does it mean?

You will always have that little minor + knock the instant you punch it ALA it's only around +0.25-0.5 during that instant you put your foot to the floor you are ok can't do anything about that. After that instant in time it should go back to 0 and start registering - #'s (like -1 or 2 maybe even more if fuel is good).

When you did your hard pulls in 3rd and 4th and you saw 2.00 of knock did you see +2 or -2? So you have a 94 octane tune and 91 from Lund? Do you actually have 94 octane fuel where you are? I thought most gas stations in the US has 93 octane fuel only up here in Canada we have 94 (it's mixed with up to 10% ethanol though).

Best thing to do is throw your 94 tune back in and add some octane boost to your "94" fuel and see if you have - knock when you do some pulls. If it doesn't show + knock with your 94 fuel plus octane boost keep running the OB or have Lund do a tune revision so you can run the fuel you want without it.

I did some logs for Lund a while back when I wanted them to check my tune after my ORX pipe install. With the fuel I use up here (94 octane) I get that little + knock on the initial hit (+0.25) then it goes to 0 and gets to -2 as I go through each gear during the log, my tune from them is bang on.

 

[efroeh]

It was a positive 2 deg yes it's 94 with the 10 percent ethanol from husky dealer. Tomorrow I'll be adding some octane booster and go from there. Is there any damage that could occur with +2 knock and it didn't bounce around once floored in 3rd and 4th 2nd was negative knock.

 

[JPs2013GT500]

Also:
Make sure you're running oil separators or catch cans. Usually the passenger side is the main one to have. Driver side is optional IMHO (mine is always dry on the drivers side). EDIT: I see you already have these. I'll leave the comment in for future searches.
Make sure there's nothing to cause a false reading, like an exhaust bolt. Example:
[video=youtube;lO_xQWRb6Vk]https://www.youtube.com/watch?v=lO_xQWRb6Vk[/video]

More helpful information can be found here:
http://www.svtperformance.com/forums/showthread.php?1071822-Knock-Retard
http://www.svtperformance.com/forums/showthread.php?1077176-How-To-Tell-If-Knock-Is-False

 

[Cman01]

If it's showing +2 knock when you do the hit it's pulling timing so you aren't getting the best use of the fuel you are using to make the power you should. The ECU is doing it's job pulling timing so you don't damage the engine but I wouldn't go flooring it all the time....................find the cause of the + knock and get it sorted out before you continue to do the hits.

 

[efroeh]

So if it's pulling timing it means the fuel does not have enough octane?

 

[Cman01]

Possibly. I prefer to use either Sunoco or Shell fuel when I'm in the states (even though they are 93 octane fuel), but again lots of other factors can result in the ECU pulling timing (+value for knock).

Spark plug heat range and gap, loud or abnormal engine noises, and like the video above bolts or other solid items hitting or banging into the chassis of the car can be picked up by the knock sensor resulting in engine timing being pulled since the ECU thinks it's real knock when it isn't. There's probably a few other things but off the top of my head that's what I came up with, others here probably can chime in with the other reasons that cause real or false knock.

 

[efroeh]

The only 94 octane fuel is husky. Im also in canada so the ethanol is 10 percent or more. After waxing the car today i dumped full bottle of vp octancd boost in a full tank amd went for a drive. Like cman said initial hit had .50 .75 once i seen 1 then went to a negative reading. After a few hits iat2 were at 130 ish i then wouod see some knock but let off gonna set up the aeroforce gauge to light up when seeing more then 1.00 knock. Also was seeing 15 to 16 psi boost. This was a done with my 91 tune from lund.