how much timing are you seeing? how much boost? what kind of fuel(octane)?

11-1 is a great place to be for now, dont mess with that at all.

i just noticed you have a 99, it is posiable that you are seeing some false knock, common in 99's, we can look at that posiability later but for now answer the first question above.

you shouldn't hear any pinging, that is what KR is, it hears the ping before you do and pulls timing to get rid of it. if you hear pinging then it is very serious and you need to let off imeadiately. problem is once the pinging starts it is hard to get rid of so the computer has to over compensate to get rid of it and that kills power. it is best to tune so you dont get any KR at all(especialy at WOT).

 

FWIW we have 90 octane here for premium which is crap. My KR shows pretty good too, at WOT. Usually, if I stomped on it and let it rev, it will go to 5-7 degrees of KR which is way too much. I have not started on my timing tables either.
When I put the blower on, I had a superchips tune stuck in my pcm, so I was just happy to get the stock table back, so I didn't blow it up.

 

90? THAT SUCKS!!

time to log some timing numbers for us. with only 90gas you have to pully back or run low timing. could be false knock too, what are the temps up there now?

 

Ok, I have 92 oct gas(Eagle river chevron sam). Ambeint temp is in 40s and IAT was only like 102 degrees last night when the motor was good and warm. I have not really run it up high enough to get a lot of boost. I probably let it off when I got to 4psi. The procharger really has to be spining fast to make any power. Since I was seeing some KR, I just let off. The other thing is that I know one or two factors are not quite right, becasue it was rally hesitatant. It should have had WAY more power at WOT than it did last night. I had more power with the stock injectors, which tells me that I am rich somewhere in there.

I would not be suprised if it is this false knock stuff. Cause I don't hear any pinging at all! I don't remember how much advance I was showing, but when it there is KR, it definatly pulls timing.

What if I put a couple of bottles of octane booster in to see if the knock goes away?

Like I said earlier though, It shows knock at really wierd times. Like at part throttle, low load. But when I am at 60% throttle and say 3000 rmp... no knock. I am confused. What are the signs of false knock and what is the cure, besides the resister method? I need this engine to last until christmas and I get a new 6.0L.

Suggestions??? Please respond. You guys are great. I will go and do a log of some timing numbers.

 

Ok, I put a whole bottle of oct booster into 10 gal of gas hoping that some of the KR would go away. But, it is still there.

I did some short WOT runs. AFR looks pretty steady at 11.5-12.00, I guess that is fine for now. Ltrims are 0 at WOT. There is anywhere from 2* to 6* of knock showing but is not very consistent. Yes, there is still the same amount of knock with the oct-boosted gas. I didn't pay too much attention to the timing advance, but it dropped bigtime when KR appeared.

Now what? I kind of hate to pull timing if it is false knock. Ideas???

 

first, log the timing, dont try and watch it, just log it. then you can look at it later and report back. we need to know how much it is asking for and how much is geting pulled back and how much KR.

not sure what you used for octane boost but the word is that stuff dont work, i full bottle is worth less than 1 octane point. maybe even just a few tenths of a point. get us some timing numbers before you test for false knock. in order to test for false knock you need some GOOD gas in there and you need a good feel for what your timing is doing. there are 2 ways that i know of to get good gas, run your tank low and put in some 100+octane unleaded race gas or run some xylene with that 92.

here is how you mix the xylene, have about 10galons of gas in the truck, add 5 gallons of xylene along with about 15oz of tranny fluid, the xylene cost me $20 for 5 gallons. that mix will give you 100octane. i ran alot of this stuff thru my truck, just dont get any on the paint.

now go out and log again, if the timing seems prety much the same you probably have false knock, if it is better than it was real knock.

if it looks like it was false knock i will tell you what i did on my truck to get rid of it but dont hold me responciable if you blow up your motor, my truck had false knock and ran like mad once i got rid of it but if you try and ignore knock that is real it will break a piston.

 

Ok. good grief that took a long time. I finally got my usb port adapter so that I can run efilive and the wideband at the same time. I logged about 20 min worth of data. The knock shows up several times in the log. Would you guys mind if I emailed the files to you so that you could give me suggestions on the next step tuning wise? Thanks in advance. Also, where can you pick up xylene?

 

i always got my xylene at a local paint store, sherwin williams is the name. they sell it here for $20/5gallons. the tranny fluid is because the xylene is really "dry" whatever that means, i was told to do it so i did.