I have been battling KR issues, mostly at low RPM in boost. I decreased the timing table from 18* in the affected areas to as low as 12*, and it seems like the more I take out of the spark tables the more KR I get.....it's gotta be false knock, but how do I fix it? Happens mostly when I transition from vacuum to boost quickly, like going from a cruising at 25% throttle in 4th to trying to accelerate at like 50% throttle in 4th. Goes from vac to 2-4 psi quickly.

 

Torque converter still locked up at that point? I've been fighting with KR as a result of the same exact issue you are seeing. It's induced by lugging the motor, and no matter how little timing you run there, seems that it'll continue to knock...

 

Yes, TC is locked. When I do the same thing with it unlocked I don't get KR. So there's no good solution that you have found?

 

Yep. It's not false, it's real, lugging engine... Radix builds boost too fast.

And I assume that if you get into boost above 2400rpms with TC locked it doesn't do it, right? Just in the 2000-2200rpm range.

 

Interesting. I have a small amount of KR and it's always at about 2000-2200 rpm and 20-30% throttle. I haven't messed with the timing much yet in that area thinking that it might work it's self out as I get the fueling dialed in but I would say that you are onto something about lugging the engine. I may look at shift points and converter lock-up before I pull any more timing.

I logged this morning and didn't get any but that was done at 50deg and with IAT of 80. It loves this weather.

 

Ive found the same thing on my NA engine with the converter locked at low rpm I think alot of it is attributed to my cam just not being in its operating range with the converter locked.
The only real solution Ive found is just changing TC lockup so I can control when it locks with how much Throttle I give it. So that say going onto the highway on an entrance ramp the converter doesnt lockup too early to avoid the trouble area of low rpm and high load before Im up too speed, once Im at cruising speed in a constant state if Im still getting Kr I pull timing.

 

You are correct sir

OK cool thanks for the input guys, sounds like the solution is to change the converter lockup/release tables to keep the engine out of the problem area.

 

That's the solution, best one. I did the exact same to avoid it awhile back. But recently I went back to stock converter tables (and shifts) to do some experiementing. In 2bar, fueling will kill this for the most part...if you are 2bar. I can lug with no knock now. I hate lugging anyway, so I will ultimately fix it right (IMO) with what you are doing once again. Nothing like getting on that on ramp giving it 20 to 30%tps and it locks and goes brrrrrrrr...LOL even with the power and it pulling, I hate it, kr or not.

 

Anyone mind sharing their TCC apply/release settings?

 

I am 2 bar, but I still get it, even though my AFR's are correct. I think the problem is that when you transition into boost the bypass valve closes so quickly that the computer can't compensate fast enough......when I transition into boost quickly I usually go way lean (like 15-16:1) then quickly drop back into the 11.5:1 range.