SAFC II Knock Sensor, and a 2G

[focusedrage]

I have searched, mind you... "Safc Knock" and "safc Knock sensor" I have gathered that the knock sensing feature of the safc II, doesnt work with 2gs? I am wondering why? It is pretty lame if it dosent.

Again I would like to know why, and if anything can be done about it.

 

[Toshiro]

Check out this thread, there's some talk about the SAFCII and knocks and such.

http://dsmtuners.com/forums/showthread.php?s=&threadid=95671

 

[focusedrage]

thanks i read that thread, so basicaly, timeing advance is just as useful as knock when tuning?

i am still unsure as to the physical reason why the knock wire will not work. i think some one mentioned that a resistor or somethign was needed. or what would make the sensors inaccesable?

 

[Tallen]

It's not the SAFC's fault, its Mitsus. It has to do with it being OBD2 and reading a difeent type of signal from a diff type of sensor.

 

[Larry L]

I did the knock sensor led mod on vfaq. It required me using a 600 ohm resistor. this taps into the knock wire (#11) on the ECU. I only lights up when you start the car or if you get knock substantial enough for the ecu to cut boost at the BCS. however, it is enough...If the light comes on I shut down...It is not good for tuning though. I still rely on wide band o2 sensor and dyno tuning. Good luck.

P.S. Try a 600 ohm resistor with the S-AFC...Maybe that will work. Or maybe not!

 

[nine5raptor]

The knock sensor is sending out a raw signal and the ecu is filtering it to determine what it thinks is actual knock and what is other noise. The afc does not have this capability.

The reason DSMLink can read knock is because of it's direct interaction with the ecu.

 

[Scrymerr]

Originally posted by nine5raptor
The knock sensor is sending out a raw signal and the ecu is filtering it to determine what it thinks is actual knock and what is other noise. The afc does not have this capability.

The reason DSMLink can read knock is because of it's direct interaction with the ecu.

How is this different with 1gs? I feel like i've been jipped j/k

thanks,

--Dan

 

[nine5raptor]

Originally posted by Scrymerr
How is this different with 1gs? I feel like i've been jipped j/k

thanks,

--Dan

From what I understand the 1g knock sensor sends out an already filtered signal as opposed to the 2g one that just transmits everything it hears.

 

[Scrymerr]

Originally posted by nine5raptor
From what I understand the 1g knock sensor sends out an already filtered signal as opposed to the 2g one that just transmits everything it hears.

Well, would it be possible then to run 2 knock sensors? The stock 2g one functioning normally, and the 1g sensor hooked directly to the AFC?

Thanks,

--Dan

 

[Mr96GSX408]

for 2g's you're pretty much screwed unless you have a dsmlink.

the vfaq knock led light is useful, but it's not accurate. The ecu does activate the bcs thing when there's enough knock detected. But the problem is not knowing how much knock you have...

Using timing can also be a way to detect knock. Unfortunately many variables could pull timing (such as for me, everytime i shift, the automatic used to pull timing), so I find that inaccurate also. That's rather like using your hands to tell if there's a chick in a dark room and feeling if she is hot or not....

A good way to detect knock, probably as good or better than reading the knock sensor is to bulid a microphone on a headset, attach it to the engine, and drive it on the dyno.
You'll hear it start making odd noises. The place where i went to dyno did it. Works rather well, I remember a page showing how to build one using radio shack parts for under 20 bux... haha

 

[focusedrage]

yo guys, what about this: http://www.i-m-racing.com/hksafknockamp.html
i also belive there is a an older model. Infact mitsubishi rally team uses this thing to tune thier engines.

 

[white 2g awd]

Originally posted by focusedrage
yo guys, what about this: http://www.i-m-racing.com/hksafknockamp.html
i also belive there is a an older model. Infact mitsubishi rally team uses this thing to tune thier engines.

i emailed horsepowerfreaks.com about that, they said that they aren't going to sell them any more, cause hks will only sell them to hks pro dealers that can install them also.

Dustin

 

[pickens]

What ever happened to the idea of using a 1G Knock sensor and connecting it straight to the AFC? Sounds feasible to me. It may be difficult to mount two knock sensors in a location and have them both accurately detect knock.

 

[focusedrage]

i heard that if you coil thin copper turbing around a bolt close to the head/block and lead it away from the car, you can hear the knock through the tube... just a thought

 

[steve]

I wouldn't spend too much time on this, my conclusion is the SAFC II knock feature is pretty much worthless on 1g's too. on a 1G your better off with a datalogger since it reports what the ECU actually counts as knock vs the meaningless numbers the SAFC produces.

Steve

 

[RuBiCaNT5X]

If you are worried about knock on a 2G and don't want to use O2's or Timing, you might want to check out the Keydiver ECU from DSMchips.com. They just started selling 2G ECU's with injector compensation. They also rig the stock boost gauge to read knock. I have this feature and it works great! I also had them trip a CEL when my knock count exceeds 5.