I've heard the ecu sets timing to 17* at WOT but does it retard it when the knock sensor senses knock? In other words if you have less than 17* of timing at WOT, and you're not using a SAFC or ign control does that mean the engine is sensing knock? Can you feel knock? I've heard it sounds like a metal ball rattling, but I don't think I've ever heard it?

I still think I'm rich as hell. I have sub 1400 egt's, and sometimes hesitation through the rpm range if I'm not in a low gear and I go wide open (I'm certain I have a strong spark). I'd like to keep leaning it out till I know I'm experiencing a little knock then richen it back up some.

I thought we didnt have a knock sensor?? could be wrong but i swear i've read that a few times before.

edit: check out this thread, lots of info on timing retard.

http://forums.2gnt.com/dcboard.php?az=show_topic&forum=26&topic_id=451&mode=full

Originally posted by willmayo
I thought we didnt have a knock sensor?? could be wrong but i swear i've read that a few times before. edit: check out this thread, lots of info on timing retard. http://forums.2gnt.com/dcboard.php?az=show_topic&forum=26&topic_id=451&mode=full

We do have a knock sensor, directly on the back off the block. It's actual function is unknown, to me at least.

Originally posted by etx
We do have a knock sensor, directly on the back off the block. It's actual function is unknown, to me at least.

Who's to say it doesn't retard timing w/ detonation like knock sensors do on every other engine? A low timing logged would be a good indication of knock, which is what I've heard the most watched parameter by a good tuner on other engines is.

I've read that thread, it's more on how much you should decrease timing w/ boost, not the actual timing you're already getting before tampering w/ it.

Here's a WOT run in 3rd gear. Manifold air temp was around 115*F.

RPM Timing O2 1
2661 11 0.89
2885 13 0.87
3603 16 0.91
3861 16 0.91
4529 15 0.93
4739 14 0.93
4960 14 0.94
5137 14 0.94
5330 16 0.94
6289 16 0.94

Why is the timing so low? I have a logged run when I was N/A w/ manifold temps at 63*F, O2 was at .89, and timing was at 20*. I'm a '95 w/ nothing interfering w/ the MAP sensor signal (no missing link, safc, fcd, etc...). Do you think it's because my MAP sensor is seeing 1.05?

Well to answer your question above.....I know for a fact that timing does retard with Knock. I havent logged the timing to see how far mine advances.


Terry

I've logged the timing on both occasions..knock produced a whoping 1-2 degrees of retard, thats it. If you think about it, these engines were designed to never really see any knock. The pentroof combustion chamber design, mild timing advance at WOT, and a compression ratio that is not super high, stock. In NA form, it takes quite a bit for these engines to detonate at all. They were never designed to see boost, which GREATLY provides more conditions to have detonation. These findings were on my 98, so I suppose it's possible that the 95-96 may produce more spark retard with knock..Just trying to commment on what i've personally experienced anyway..

I just found in the service manual verifying that the sole purpose of the knock sensor on our car is just to pull timing w/ it senses knock.

That's great you actually were able to see how much it does XtremeRS.