LSWHO

iTrader: (1)

It's starting to really **** me off. I have pulled my timing tables well below the stock tables and that isn't right in a cammed car. I've pulled a significant amount and it goes away, but why do they have to be SO DAMN LOW!? What's the deal? Anybody have any insight?!

quik95lt1

iTrader: (7)

its probably insanely lean in that spot........a lean condition WILL cause detonation........and excess cylinder heat......fix it dont drive it.......

LSWHO

iTrader: (1)

My wideband was reading richer there than anywhere else in the power band. I tuned it richer there to try to cool the charge and reduce knock. It helped some, but it's still there.... and I JUST fried my PCM so I won't be driving it much.

nitrous2fast

iTrader: (2)

I shouldn't be doing it there. well at 2k at least. Almost every LT1 i have tuned i have and to keep timing conservative around the 4k spot because that is where the most VE typically is.

By richer there than than anywhere... what are we talking A/F wise. also timing wise.

trilkb

iTrader: (4)

knock knock knockin on heavens doooooorrrr.

(not helpful, but fitting i thought with the fried pcm)

stevo9389

Goldschläger in your oil?

LSWHO

iTrader: (1)

Exactly what I am thinking. 4k is normal. But 2k is stupid. Timing is in the 16-18 degree range in the 2k range. I can't get up above 30 degrees timing until 4500 rpm. I keep lowering it and it's working but it's getting ridiculous. I have no midrange because there's no timing.

A/F has always been half a point richer in this area than the rest of the rpm band. In the 12.7 range. And if it's not reading accurately then I should see MORE knock up top from being even leaner, but it isn't the case.

05HD

How about a little info on the setup? Auto? Stick? Cam size? Converter? Gears? Other ****?

gregrob

iTrader: (8)

Overly rich can cause it to knock as well... I would tune it conservative there, and turn down the KR functionality there as well tip it stops reporting and call it good..

05HD

What I was thinking is, if he has a cam that comes on at 4k and a 2k stalled auto with 2.73 gears, he may be lugging the ever living **** out of it.

Telling him to turn down the KR sensitivity at this point would be bad, unless you have further knowlege of his setup and the actual conditions of the knock occuences (2k in 6th @ WOT?).

speed_demon24

iTrader: (6)

gregrob

iTrader: (8)

Stalled auto + 6th at WOT? ??

Knowing he has a stalled auto, there should be very little load on the engine at that point.. Get the fueling right and it will help, then time it conservative there and if it doesn't go away its probably false. It will be fine to tune it out.

gregrob

iTrader: (8)

Its a misconception that rich will cure knock and its simply not true. If you're loading up the cylinder combustion will never happen predictably or when you want so to speak. I have tuned cars that wouldn't take anyore timing than stock but were super rich. Fix the fueling, and then the timing. We were able to increser it significantly with no knock, after fueling was close.

Another thought is you may be getting some reversion from the cam at that point.

If its false knock it could be a harmonic resonance in the valve train as well.

gregrob

iTrader: (8)

Stall size, gear, cam specs, valve train? What have you done in the tune or otherwise to address false knock?

gregrob

iTrader: (8)

BTW overly rich to "cool the charge" is a myth... Don't do that

05HD

Those were (I hoped obviously) 2 different statements. I only know as much about this dudes car as what he has posted here.