Knock and timing

gSIr · Post by **gSIr** » Sat Feb 10, 2007 10:11 pm

I have a 11.8:1 comp motor with cams. I started tuning today and have a pretty good tune going, but i'm getting 1.7v of knock randomly at every rpm, and its pulling 10 degrees of timing. I used a b16 basemap for timing, and pulled a few degrees to be safe does anyone have any idea if somethin is causing a false reading or do i have a problem on my hands

strider · Post by **strider** » Mon Feb 12, 2007 11:09 am

Do you have forged pistons? Those could cause a false knock.

I had the same problem with my 12:1 comp. The car was tuned on the dyno with 92 octane and the knock sensor disabled. No apparent problems. On the street with the knock sensor enabled I noticed it indicated random knock. I tired 100 octane and pulled timing and I still got a random knock indication. I think it was due to my forged pistons. I plan to take the car back to the tuner just to make sure all is good. (The car has been sitting during the winter.)

But I would try 100 octane fuel if it is available to you first and see if it changes anything.

gSIr · Post by **gSIr** » Mon Feb 12, 2007 3:24 pm

i'm runnin factory pistons, but i am tryin to do my own tuning, due to being broke. Next time when I go home i'm goin to pull a few degrees of timing and see what happnes, if it keeps pullin timing i'll just ignore it.

deafy · Post by **deafy** » Mon Feb 12, 2007 4:55 pm

You could disable knock sensor?

jdmspecdc5 · Post by **jdmspecdc5** » Mon Feb 12, 2007 10:16 pm

how about adding a little more fuel?

gSIr · Post by **gSIr** » Mon Feb 12, 2007 10:42 pm

i'm using the wideband and i have adequete fuel, maybe too much, i'm not goin to disable it, i don't want to ignore somethin that could prevent engine damage, i don't understand why people do that, not a good idea

nalude · Post by **nalude** » Sun Feb 25, 2007 7:47 am

I got NA H22A and my knock reading is jumping to 1,7 V as well.
Even before I did anything to the base map or upgrade the engine.
No driving problems, I'll probably try and check it on the dyno wit the knock desabled.

Post by **Spunkster** » Mon Feb 26, 2007 11:31 am

Knock boards are tuned for a specific frequency for the engine that ecu was originally designed. For instance if you have an H22 and are using a knock board that was for a b16a it may register more noise than there actually is.

Knock Board resistor locations:

(All resistors are 100 Ohms - Brown, Black, Brown, Gold)

US P61 - None
US P30 - R15
US P72 - R11, R15, R16
JDM P30 - R12, R15
JDM PR3 - R15 (OBD1)
JDM P72 ...

There are more, but I do not have them at the momment

strider · Post by **strider** » Mon Feb 26, 2007 2:08 pm

Spunkster wrote:Knock boards are tuned for a specific frequency for the engine that ecu was originally designed. For instance if you have an H22 and are using a knock board that was for a b16a it may register more noise than there actually is.

So is there anyway to get the knock board to work correctly with forged pistons? I know in my case you recommend that I disable the knock sensor due to the forged pistons.

My old topic: http://www.hondata.net/forum/viewtopic.php?t=4762

Thanks

Post by **Spunkster** » Mon Feb 26, 2007 3:13 pm

Forged pistons make noise, there is no way around this. You'll have to disable the knock sensor.

nalude · Post by **nalude** » Mon Feb 26, 2007 10:05 pm

Spunkster wrote:Knock boards are tuned for a specific frequency for the engine that ecu was originally designed. For instance if you have an H22 and are using a knock board that was for a b16a it may register more noise than there actually is.

Knock Board resistor locations:

(All resistors are 100 Ohms - Brown, Black, Brown, Gold)

US P61 - None
US P30 - R15
US P72 - R11, R15, R16
JDM P30 - R12, R15
JDM PR3 - R15 (OBD1)
JDM P72 ...

There are more, but I do not have them at the momment

So what would I have to do to fix it? If I have a P72 I need to replace resistors from P13 or something?
Thanks

monty · Post by **monty** » Mon Apr 23, 2007 9:38 pm

im having the same problem with my car but i dont have a forge piston ..
i have a LS/Vtec NA .. ITR piston .. can it be a bad motor ? help

Post by **Spunkster** » Tue Apr 24, 2007 9:36 am

You cannot go by voltage. You need to look at the actual degrees of retard.