Question concerning Knock sensor readings

[mattsplat72]

I have a safc2 installed into the Supra.
Mods are . BC 264 cams ,Port and polish of manis and head Standard BHG fix
Running 9 Psi on a stock ct26
Question is what should I set the Knock warning feature on the Safc2 too
I searched and all I found where threads on Rod KNock nothing concerning this

Thanks In advance

 

[jdub]

The knock sensors "listen" for 7 kHz signal. The voltage output is 2-4 volts as this signal peaks.

 

[mattsplat72]

So I should set it for that or for the volt spike? It just moniters at 650 1550 3500 rpms
it gives me the option of settingit at a certian level to warm me ( of what I am unsure) .

 

[jdub]

I don't have a SAFC, so I don't know what input from the knock sensor it's looking for.

The TCCS documentation I have is not specific as to exactly what level the ECU retards timing due to knock....but, it does look at peak levels.

 

[grimreaper]

damn i wish we had a obdII port to hook a stinking scan gauge into and watch kr and ks voltage.....

7khz huh? i wonder if any body has permantly wired some test leads in line with the oem harness to be able to watch for that stuff.... how do they do it on a dyno, or do they?

 

[mattsplat72]

damn i wish we had a obdII port to hook a stinking scan gauge into and watch kr and ks voltage.....

:sarcasm: totally helping

 

[grimreaper]

sorry, no safcII or anything, just thinking out loud, how are you wiring the safc to the ks?

 

[mattsplat72]

from the ecu
it is wired perfectly
just wondering what to set for a warning level

ie x reaches y level and i get warned that it just happened

 

[grimreaper]

you might want to find out if the stock sensors actually read accurately in the higher rpms. a few cars i have seen actually ignore ks after 5000 rpms or so.

also a good thing to have that will set the kr limit before it gives you a warning is find out how many degrees it can pull max, when it detects knock.

 

[jdub]

Grim - it's not that the ECU is ignoring the KS. Timing is retarded a max of 10 deg due to the KS.

The TCCS looks at 3 levels of knock: Strong, medium, and weak. It retards appropriately for each...that leads me to believe the threshold is 4V, but the book is not specific.

 

[grimreaper]

good info, thanks for clearing it up!

 

[mattsplat72]

Totally on target for the question that I asked . The exact information I ask for .