Safc II (Knock Monitoring)

[Nartanian]

Can the Safc II be used as a knock monitor for the gvr4s? I have heard both yes and no. Some clarification would be nice. Thanks.

 

[Brianawd]

no

 

[steve]

+no

 

[Nartanian]

No it is then... Why does it say it can though? /ubbthreads/images/graemlins/dunno.gif Or better yet, why not?

 

[steve]

It can on some cars, where there is a knock count to give it. In a DSM/VR4 the knocksum is determined inside the ECU based on the signal that comes from the sensor. The sensor does not output "10 knock", "35 knock" etc, it outputs a signal that needs to be interpreted first.

 

It does something but its not really accurate. When my lifters got loud my ecu would pull timing and the SAFC would should the knock going all over the place. It flips out when there is something obvious but I'm not sure what its reading from. Get a keydiver chip and turn that boost gauge into knock.

 

[Nartanian]

That what I did. I have the chip but was just curious. I guess with a keydiver chip, getting an safc would be a waste of money?

 

^No it can help you fine tune on a dyno to get things even closer. Measure battery voltage, karman, etc... So not totally worthless at all. I get by with my safc/eprom combo pretty well.

 

[steve]

No, the SAFC will still allow you to make adjustments (tune).

 

The SAFC can also be used to monitor 02 voltage, which can be handy if you don't have your logger in the car (the safc will also record data for up to 30 sec. I believe). This is the so-called "blue wire mod," and while not something I'd recommend tuning with, it can give you something to compare against if, say, your knock gauge lights up like Christmas. If the 02 isn't showing a lean condition then it could very well be phantom knock.

 

[Nartanian]

Ok, I will be getting one in conjunction with a wideband and keydiver chip. Is it possible to wire in the Safc II without having any settings from the get go?

 

Yes. You wire it in, turn it on, go through the setup, then turn the car on. Pretty simple. IDK if the SAFC can monitor a WBO2; in the above post I was referring to a factory O2 sensor.