I did a head cam swap (TF and similer to LT4) we also have somewhat of a modified chip. With timing at 6* with stock and modified chip we get about 2-3 degrees of knock at a 0-60 run and about 30 degrees knock retard at a 3rd to 2nd downshift which makes the car basically just sit still and rev. I accidently moved the timing to 14 Base and the car screams and runs very powerful even with the same amount of knock. what gives? 02 volts are .900 at WOT

 

As long as it doesn't knock audibly, you could just leave it there.

Sounds to me like you need to program yourself a chip though; no commercially available "custom" chip AFAIK does very much to de-brutalize the factory knock retard curve. Check the DIY PROM board for info; Glenn in particular has done alot of experimenting with that set of tables.

 

either that or your balancers outter ring has slipped.

 

Thats why my car hasn't had a knock sensor on it since i bought it. Unless the system is working perfectly, it will probably find a way to screw up your whole day.

In your case, you're probably just barely getting into some transient knock with the timing at stock 6'. So the ECM just pulls a bunch of timing and leaves you with a slug.

With the timing at 14' it may knock so severely that the ECM just ends up ignoring the KS (which from what i've heard is what happens) and you actually have full timing when you aren't in the transient region where the problem is. Or it could just be that the extra timing is helping to cancel out the KR and letting you run half decently.

Do you know what knock sounds like? If so, feel free to bypass the knock sensor and see what's up. Or at the very least determine if you have a real knock problem and correct it.

BTW, fat O2s don't mean anything. You could easily have a lazy injector on the passenger side leaving a hole lean and detonating on you. I had such a problem a while back. I was getting knock right on the torque peak that was so nasty that i actually had the timing retarded 4' or so relative to the rest of the powerband. I figured that it was getting just lean enough right there on peak VE/cylinder pressure that it was setting a hole off. I even tried just making things way fatter in the chip but still no dice. A set of cleaned and flow matched injectors later and it was a completely different engine with a completely normal timing curve on it again. WAGs work sometimes

 

I don't have any computer gear on my car and I am currently running my 305 at 18* of advance. Runs fine with no knock at all.