SAFC-II knock question

[Red Devil]

Ok, gotta a question. Up until a day or so ago, I never really looked at the SAFC-2 in detail. Figured the previous owner, Ryan M., had everything squared away. So, going through and checked knock sensor settings. Page came up and had a number next to the realtime RPM. For the correction settings, 0 was displayed. My first question, was the correction even set before? After I performed the knock setting test, using the RPM-1 and -2, it starts displaying a knock number when idleing under no load. Once brought into load it reads zero except when near 1000 RPM under load(usually 0-10). Ambient temp is a nice 95+ degrees.
So,
1.Did the previous owner even perform the check, seeing as no numbers were set for RPM-1 and RPM-2 and no knock level number wes present, ever?

2. Is the knock number under no load/idleing, anywhere between 5-20, because of bad timing or just becaus its hot out?

3. Is any knock number bad for your engine under no load? Under load from 1500-Redline(many throttle positions and also under full boost) no number is displayed.

Another, "noob" question. What defines or is "knock level"? How does one correct it without messing with the timing or tune radically?

any help would be appreciated, seeing as I never played around with the SAFC-2 before.

[lagos]

The knock sensor is just a microphone. It picks up all kinds of engine noises even at normal operation. In the safc menu, you're supposed to highlight the specified rpm, rev the car to that rpm, and then set the current knock count fro that rpm. The idea is tell the safc to ignore anything below that knock value, since thats just normal engine noise for that rpm.

However, the knock setting in the safc doesn't work correctly at all. I've set mine up more then once, and even on light throttle inputs, it still registers some kind of count. They even ended up taking this feature out of the safc neo, because it never worked right in the first place. Its a shame, because it could have been a very valuable tuning tool, and it worked correctly.

So basically, just ignore any count that you get, because its not really knock.
If you want to know if your car has issues with knock, put it on the dyno and it will show up on your dyno sheet as sudden loss of 20hp or more in your power band.

[Red Devil]

Thanks. I really appreciate the information you've given me. Is that your car in the avvy? That probably one of the only badass Celica's I've seen.

[Red Devil]

Originally Posted by lagos

The knock sensor is just a microphone. It picks up all kinds of engine noises even at normal operation. In the safc menu, you're supposed to highlight the specified rpm, rev the car to that rpm, and then set the current knock count fro that rpm. The idea is tell the safc to ignore anything below that knock value, since thats just normal engine noise for that rpm.

However, the knock setting in the safc doesn't work correctly at all. I've set mine up more then once, and even on light throttle inputs, it still registers some kind of count. They even ended up taking this feature out of the safc neo, because it never worked right in the first place. Its a shame, because it could have been a very valuable tuning tool, and it worked correctly.

So basically, just ignore any count that you get, because its not really knock.
If you want to know if your car has issues with knock, put it on the dyno and it will show up on your dyno sheet as sudden loss of 20hp or more in your power band.

I get what you're saying. I reset it when it was colder out and drove it this afternoon, it was registering knock under load. When I reset it again during the day it just didnt occur. Is there any other way besides dyno tuning? I havent been feeling any hp loss under throttle. iMy exhaust has been popping a lot under 1400 rpm. It's just been strange that it either wasnt set, under the settings page it had a 0 for RPM-1 and RPM-2 before this knock issue occured, or that it's always changing even though I just added a bottle of octane booster.

Any further help would be greatly appreciated.

[TurboTagTeam]

I really never played with the SAFC settings but I get a bit of knock of my Power FC commander from my SR20. Anything under 60 is nothing to worry about.

Differnt systems value knock levels in differnt ways. Some go in degrees of knock, some use set numbers. Either way, if you get any kind of really noticable knock, the stock knock sensor should reconize it and retard the timming as necessary.

[Red Devil]

Originally Posted by TurboTagTeam

I really never played with the SAFC settings but I get a bit of knock of my Power FC commander from my SR20. Anything under 60 is nothing to worry about.

Differnt systems value knock levels in differnt ways. Some go in degrees of knock, some use set numbers. Either way, if you get any kind of really noticable knock, the stock knock sensor should reconize it and retard the timming as necessary.

Well it doesnt seem to be doing anything it never had anything come up before. When I first entered the page, it looked like this. Lets say the knock level on the set up page says 200

200 800rpm
0 1500rpm-1
0 3200rpm-2

Does this mean it wasnt set at all by the previous owner before I went and adjusted the sensor?

[lagos]

Let my try to explain this again.

200 800rpm
0 1500rpm-1
0 3200rpm-2

The 200 @ 800rpm is supposed to be just normal engine noise being picked up by the microphone (knock sensor).
Now, since you have 0 at 1500 and 3200, means that the last owner didnt bother setting up the knock feature. You're supposed to highlight the 0, rev the car to 1500, and press a button (Left or right i think?). Then do the same thing for 3200rpm. This will record some knock number to tell the safc that those values are just normal engine noise that it should ignore.

Now you get out of that menu, and look at what it says for knock under the Monitor menu to see your knock count.

HOWEVER.... Even once you set this up correctly, It will probably still show you a FALSE reading because the feature on the safc is not implemented correctly. So dont freak out by anything you see on there, because its most likely just false information.

Your exhaust poping under 1400 rpm is totally normal.

and yes... that is my car in the avatar.

[Red Devil]

Sorry, I just was confused about the whole feature. Thanks for explaining it to me though. So even if it doesnt work properly, if the number jumps really high I should probably look into my timing.

Yeah, thats a pretty bad ass Celica. I usually only see the final year and they are usually riced out. Its refreshing to see an earlier Celica thats as well put together.

[Tigawoods]

mine isnt calibrated and always generates random numbers. Only one time dod it actually work. i had driven it to pittsburgh and numbers started generating at idle which was the first time that had happened. idle felt real rough so i pulle dover and checked my oil and the dipstick was dry. other than that...it is useless flare