Help with tuning out KNK

[Quick]

I wish someone from Diablo would be more help how to read and interpret logs and KR. They obviously have the knowledge. Their absence of help is really noticeable.

This isn't really fair. They have tunes for your average, relatively stock car and they're assuming good quality fuel. There are a whole lot of variables in just the fuel and seasonal additives, etc. Then there can be some difference between cars.

They could look at a tune to see if your base was different but without at least a wideband a/f gauge to see where you're at on your car you're pretty much shooting in the dark and at best, making educated guesses. There is always a possibility of false knock although I've yet to hear of anyone that actually had that without using different valve springs or something like that. One way to eliminate the possibility is to dump a whole lot more fuel in there and if the knock doesn't change then maybe it's false knock. If it goes away then it's pretty sure it's not false knock. How much fuel? Well... hard to say without a wideband.

Before I got my CMR tune I spent a lot of time tweaking my 9r04 CAI tune. I ended up adding a bunch of fuel and pulling a degree of timing (maybe 2 degrees in the middle?). How much fuel I'm not sure but it had to be close to 20%. The reason I'm not sure is that I added like 5-7% and then saved the tune and reloaded it as a custom tune. So when I added 5% again I was adding 5% of 107%, etc. I did something like that a couple of times. Somewhere in there I got my PLX wideband installed and did it by that. The canned tune had me up in the high 12's afr. I tried 12.5, then went to 12.2 and finally ended up around 12.0 with 17 to 18* timing. I was pretty happy with the results and it was a whole lot of fun going through the process getting there.

So DS can look in a tune file for most things but they can't look at your A/F on your car which is a fundamental factor. They can't really look at your car to see what's different about it. Interpreting knock retard is pretty straight forward. When the PCM detects knock it pulls timing to eliminate it. Why you have knock on your car when the one they developed the tune on didn't is not so easy. They have said that you want to see it about 3* or under and drop off fairly quickly.

[slip]

I wish someone from Diablo would be more help how to read and interpret logs and KR. They obviously have the knowledge. Their absence of help is really noticeable.

This isn't really fair. They have tunes for your average, relatively stock car and they're assuming good quality fuel. There are a whole lot of variables in just the fuel and seasonal additives, etc. Then there can be some difference between cars.

They could look at a tune to see if your base was different but without at least a wideband a/f gauge to see where you're at on your car you're pretty much shooting in the dark and at best, making educated guesses. There is always a possibility of false knock although I've yet to hear of anyone that actually had that without using different valve springs or something like that. One way to eliminate the possibility is to dump a whole lot more fuel in there and if the knock doesn't change then maybe it's false knock. If it goes away then it's pretty sure it's not false knock. How much fuel? Well... hard to say without a wideband.

Before I got my CMR tune I spent a lot of time tweaking my 9r04 CAI tune. I ended up adding a bunch of fuel and pulling a degree of timing (maybe 2 degrees in the middle?). How much fuel I'm not sure but it had to be close to 20%. The reason I'm not sure is that I added like 5-7% and then saved the tune and reloaded it as a custom tune. So when I added 5% again I was adding 5% of 107%, etc. I did something like that a couple of times. Somewhere in there I got my PLX wideband installed and did it by that. The canned tune had me up in the high 12's afr. I tried 12.5, then went to 12.2 and finally ended up around 12.0 with 17 to 18* timing. I was pretty happy with the results and it was a whole lot of fun going through the process getting there.

So DS can look in a tune file for most things but they can't look at your A/F on your car which is a fundamental factor. They can't really look at your car to see what's different about it. Interpreting knock retard is pretty straight forward. When the PCM detects knock it pulls timing to eliminate it. Why you have knock on your car when the one they developed the tune on didn't is not so easy. They have said that you want to see it about 3* or under and drop off fairly quickly.

I see Diablo responding to numerous threads on this forum and other forums.
But when it comes to solving KR and basic tuning, Diablo seems to be fairly quit.
Maybe this is because they do not want to share their approach to tuning to keep their proprietary methods from the competitors.

There should be at least a layman's thread on tuning and how to read datalogs, or another Forum section dedicated to understanding tuning/logs, or maybe more info in a Owners Manual.
Example - My simple question about what is the maximum timing/Spk I should see on my stock 5.7 300c at WOT at peak RPMs (5600) on the 91 tune has never been answered. I often see 23.5 as max spark/timing on the 91 tune during peak RPMs, but not always. Not once in this forum or other forums has Diablo ever answered this simple question.

I am first to admit I am a complete rookie to all this and may be asking dumb questions.
But I am willing to look stupid and keep asking dumb questions to broaden the knowledge base.

[Quick]

I see Diablo responding to numerous threads on this forum and other forums.
But when it comes to solving KR and basic tuning, Diablo seems to be fairly quit.
Maybe this is because they do not want to share their approach to tuning to keep their proprietary methods from the competitors.

There should be at least a layman's thread on tuning and how to read datalogs, or another Forum section dedicated to understanding tuning/logs, or maybe more info in a Owners Manual.
Example - My simple question about what is the maximum timing/Spk I should see on my stock 5.7 300c at WOT at peak RPMs (5600) on the 91 tune has never been answered. I often see 23.5 as max spark/timing on the 91 tune during peak RPMs, but not always. Not once in this forum or other forums has Diablo ever answered this simple question.

I think that may be a fair question. I can only speculate why they might be reluctant to answer.

As you said, they are very closed about their tuning. I think that's understandable. It's a large part of their market differentiator. They invest time and knowledge into their tunes. While I think the primary purpose of the included tunes is to enable sales of the tuner it is a very large part of the product. I'm sure their goal is for people to say "Get a Predator, their tunes are way better".

Another speculation is that they could say, given a car the same as our test car, same fuel, same ..., the max timing would be X. But that may not be very useful. I do know that the PCM will pull timing for a number of reasons. Only 1 of those being knock detection. I do not know if the PCM will add timing due to dynamic inputs. You see a max of 23.5. What if DS's answer was 25? Naturally your next question would be "then why am I only seeing 23.5?".

Apparently they do not want to be in the custom tuning business and have enabled CMR tuners to fill that need. I think they aim to include the very best generic tune they can for basically stock cars. This provides a complete "turn key" tuning solution for the greatest number of customers. For those who want to go further, the handheld provides a very limited capability to adjust a very limited set of parameters. For those who want to go further than that they have the CMR solution (which still requires the handheld to put the tune on the car).

I'm guessing that your first thought was the right one. They have a general policy of not divulging details of the changes made to produce their tunes.

[ywait]

I played with the Tuner as far as WOT but I went back to the default tune because of KNK in ST and LT… It’s a lot better now; I only get KNK when I’m really getting on it... I have attached the log from this morning but I installed the default 93CAI and need to give it a few day to adapt.. I need someone smarter than me to have a look at the log file and tell me what they think.. Thanks in advance…

The Screen shot is from a 5mph roll w/ auto shift

[ywait]

09ChallyRT ST, LT and Fuel KNK 93CAI Valero
I played with the Tuner as far as WOT but I went back to the default tune because of KNK in ST and LT… It’s a lot better now; I only get KNK when I’m really getting on it... I have attached the log from this morning but I installed the default 93CAI and need to give it a few day to adapt.. I need someone smarter than me to have a look at the log file and tell me what they think.. Thanks in advance…

The Screen shot is from a 5mph roll w/ auto shift

[ywait]

Here is the complete log file from this morning.. Thanks

[mikel]

To see how much timing you 'should' be getting, log the commanded spark, that is what we are requesting for timing.

If your actual spark cyl 1 is different, than there is something pulling timing.

We have stated on more than 1 occasion that these motors have bad oil consumption issues, causing KR with even the stock tune, meaning there is no real 'tuning' solution to solve this, but rather a neeed for a catch can and a cleaned out intake manifold.

Thanks
Mike

[ywait]

Thanks Mikel
I have a catch can on order.. and I'll get the cyl 1 spark loged and have it tonight.

Thanks again, I love this stuff !!!

[ywait]

I could not find commanded spark in any of the lists.
Would someone please tell me where it is???

Thanks

[sohfast94]

It's under Spark and Actual Spark cyl 1 is what you're looking for.

[ywait]

Hey Thanks I logged that in that PID in that run.
I set the marker right at the top of 3rd gear

Thanks

[ywait]

and her is +5 fuel -1 Spark w/ 0 to 60 time.in the next post.

[ywait]

This +5 Fuel and -1 Spark in from the run I did Last Night.
0 to 60 Time.

[ywait]

I think I'll leave her the way she is until my catch can come in.. Unless someone thinks running at +5 fuel and -1Spark is bad for it.
What's the SRT8 Stock 0 to 60 Time I think they said 4.9sec????
Remember I only get KNK when I'm WOT.. Other than that she runs like a Bitch in Heat!!!

Thanks

[QuickRT2SRT]

That's some serious knock. First try a different gas station and add a healthy dose of fuel in modify parameters. The difference in the CAI tune and the non-CAI tune is more fuel in the CAI tune. Go into Modify Parameters and try adding 6%, 10%, 10% (that's low rpm range, mid rpm range, top rpm range) and see what that does. If the knock goes completely away then you might try backing it off a little at a time in each range until it just comes back after the shift points. I think what you want to see is NO long term knock retard and maybe up to 3* of knock retard momentarily right at or immediately after a shift.

If adding 6% 10% and 10% doesn't do it, add some more. Maybe another 5% in the ranges where you're still seeing constant knock retard. If that still doesn't do it then try pulling (retarding) a degree or two of timing in the rpm ranges that need it.

That's a lot of knock you got there. You might want to refrain from racing until you get this sorted out.

Quick... I'd like to ask a related question regarding your advice to add fuel. This is exactly what I had done with my tune - added fuel in small portions with a bunch of data logging and got rid of all the unwanted KR on my 93 CAI tune. (2007 SRT8 Charger) I ended up with 8, 10, and 12 added fuel. Problem was even though I removed my KR problem, this made my AFR to be 10.8-11.2 which was way too rich and undoubtedly costing me HP. Oh, and I also took out 1 degree of timing across the board as well... Any suggestions or wisdom you can share that can help me keep my afr good without unwanted KR?
TIA!