question on datalogging knock retard/timing

[silver2ssrs10]

I was playing around with my car today and was doing some datalogging, and noticed I had some knock retard on a WOT 2nd gear pull. Does the pid "spark advance for #1 cyl" show the timing before the knock retard and you need to subtract the knock retard value from the timing advance value? My car logged 20 deg timing with almost 7 deg knock retard from 5300rpms to 6200rpms. So was the actual timing I was running 13 deg instead of 20? I am running 93 octane fuel, so I don't see how I could be getting so much knock retard. I only have an airaid cold air intake, jba mid pipes, and factory stock tune.

[Badbubba]

It would be nice if someone could provide some info and tips on the SCT. I just figured out last night how to change some of the units to English from Metric. With no mods and stock tune, I had about 4 or more deg of knock retard. I believe there are at least 2 pids dealing with knock. I chose the one that Ted had in his list of pids for logging for a custom tune.

[Swytch]

My tune isnt stock, so i cant speak directly to what a stock tune should do. That being said, the mail-order tune i got from Ted over at Jannetty Racing never, ever, ever shows more than 2-3 degrees of timing retard from knock. I have watched that gague on my Diablo Trinity for over a year and only seem to see knock when i get a bad batch of gas or am nailing it WOT and not in the right gear, under load (i.e. 3rd gear @ <40 mph). Even then its very rare and usually more like 1 - 1.5 deg being pulled. I personally would be very concerned with that much knock, check to make sure your exhaust is not hitting the tunnel brace. I know that was a common issue with aftermarket exhausts and it has been shown here to set off the knock sensors incorrectly. Other than that, fill er up at a reputable station with the highest octane (91 here in ME, hopefully you can get 93) and maybe some dry-gas just in case. Also, i would check to make sure all the connections are tight on our CAI, if air is making into the system post MAF (i.e. unmetered) you could be leaning the engine out and causing pre-detonation..

Take all that advice with a grain of salt please, im an amateur gear-head at best.

[bmorecam]

Originally Posted by silver2ssrs10

I was playing around with my car today and was doing some datalogging, and noticed I had some knock retard on a WOT 2nd gear pull. Does the pid "spark advance for #1 cyl" show the timing before the knock retard and you need to subtract the knock retard value from the timing advance value? My car logged 20 deg timing with almost 7 deg knock retard from 5300rpms to 6200rpms. So was the actual timing I was running 13 deg instead of 20? I am running 93 octane fuel, so I don't see how I could be getting so much knock retard. I only have an airaid cold air intake, jba mid pipes, and factory stock tune.

no, your ignition timing should show exactly the final value, which mean after kr been calculated out. I know that's how my ecm show timing.

[silver2ssrs10]

Originally Posted by bmorecam

no, your ignition timing should show exactly the final value, which mean after kr been calculated out. I know that's how my ecm show timing.

I dont see how that could be though because my car commands 20 deg at the rpm point i had the knock retard kick in and it still logged 20deg with 7 deg knock retard. I would think it should be logging 13 deg because im not comnanding 27 deg at 5800rpms according to the high octane spark table

[bmorecam]

Originally Posted by silver2ssrs10

I dont see how that could be though because my car commands 20 deg at the rpm point i had the knock retard kick in and it still logged 20deg with 7 deg knock retard. I would think it should be logging 13 deg because im not comnanding 27 deg at 5800rpms according to the high octane spark table

well if you are commanding 20* and got 7* of kr but still seeing 20* then your ecm must don't display calculated final value. I thought you must of have been commanding 27*.

Sent from my LG-P500 using Tapatalk

[MA2010SS]

Even though the timing table will command (X*) at (Y)RPM there are other tables to think of: ECT will pull timing if too high, IAT will pull timing if too high, knock sensors are very sensitive on LS3, there are other tables that will pull timing that I can not think of, tuners chime in as to what else pulls timing

[silver2ssrs10]

Is there anything that adds timing on top of what the base table uses? I will post my datalog when i get home to see if anyone else can make more sense of it.

[MA2010SS]

Power enrichment rate will increase how fast added timing and added fuel will be introduced, if I remember right stock PE is .02 which is very slow in my opinion

[silver2ssrs10]

Here is my datalog file, the 2nd gear WOT starts at 2min 36sec mark.

datalog1.csv

[Wizard1183]

I noticed you guys trying use "*" for degree symbol. Use Alt+248 and you'll get °

[bluetorp]

Originally Posted by silver2ssrs10

I dont see how that could be though because my car commands 20 deg at the rpm point i had the knock retard kick in and it still logged 20deg with 7 deg knock retard. I would think it should be logging 13 deg because im not comnanding 27 deg at 5800rpms according to the high octane spark table

That's just the base map for spark advance. There are various spark adder tables that you're not taking into account. The AFR correction table by itself is adding 4 degrees of advance in PE mode from 5200 to 6000.

PE spark advance in the stock tune is actually fairly aggressive.

[silver2ssrs10]

Originally Posted by bluetorp

That's just the base map for spark advance. There are various spark adder tables that you're not taking into account. The AFR correction table by itself is adding 4 degrees of advance in PE mode from 5200 to 6000.

PE spark advance in the stock tune is actually fairly aggressive.

Ok so what is the stock timing i should be seeing during pe with no knock retard?

[Tampa Tuning]

Originally Posted by silver2ssrs10

Ok so what is the stock timing i should be seeing during pe with no knock retard?

That's what tuning your car is. There's no set number you can use. You have to see what the set up of the car tolerates. There is going to be certain areas of the RPM band of the set up that will allow more spark and areas that allow less. You can't just set it at 25 in the WOT area and walk away. Get your fueling right with a wideband, then see how much spark it will tolerate. Don't set the main spark table to at WOT to 25, then drown it with fuel to kill the KR.
In the stock configuration, six degrees of retard is common at WOT. I like to take out some spark before the knock comes on to see how it flows through the effected area.
So when I'm tuning a car and the car is breathing in 70 degree air and I get 1 or 2 degrees of knock, I want to take that out because in the summer' hot air, that's going to be 4 + degrees of KR.
Phil

[JANNETTYRACING]

Originally Posted by silver2ssrs10

I was playing around with my car today and was doing some datalogging, and noticed I had some knock retard on a WOT 2nd gear pull. Does the pid "spark advance for #1 cyl" show the timing before the knock retard and you need to subtract the knock retard value from the timing advance value? My car logged 20 deg timing with almost 7 deg knock retard from 5300rpms to 6200rpms. So was the actual timing I was running 13 deg instead of 20? I am running 93 octane fuel, so I don't see how I could be getting so much knock retard. I only have an airaid cold air intake, jba mid pipes, and factory stock tune.

Is your Car Custom tuned for the Airaid?

If not it is 10% Lean.

Other things that cause Knock retard are Rattles in the Chassis, engine compartment or Exhaust system.

Ted.

[silver2ssrs10]

Originally Posted by JANNETTYRACING

Is your Car Custom tuned for the Airaid?

If not it is 10% Lean.

Other things that cause Knock retard are Rattles in the Chassis, engine compartment or Exhaust system.

Ted.

No it has not been tuned yet. I am still on the factory tune. I will most likely be contacting you soon though for a custom tune. I dont want my car running lean and i've heard you are the best.

[JANNETTYRACING]

Originally Posted by silver2ssrs10

No it has not been tuned yet. I am still on the factory tune. I will most likely be contacting you soon though for a custom tune. I dont want my car running lean and i've heard you are the best.

I appreciate the Opportunity and will Do My Best Every Time.

Ted.

[FRANK121]

You can't go wrong with Ted.

I sent my log files in the morning and He had my adjusted tune back to me that afternoon!

You won't be disappointed

[dekan513]

ted is a class A guy has always answered any question i had and has done all that u can ask for in a guy. i always check his site for something i may want first cause of this. he is not just out for a sell he is there after the sell unlike alot of ppl ive bought from in the past

[silver2ssrs10]

Just ordered my custom tune from Ted

[f5journal]

If this is a more or less totally stock car, I would be interested in detailed results. I too suspect gross KR on mine and am considiering the same

[f5journal]

I'd also consider driving to Greenwood to check out

[thebeast916]

Since we are talking about kr, iwas cruising at 45mph and then floored it. I was in 6th gear, then the tranny shifted to 2nd wot. I saw 6*kr. Air fuel was 11.4. A little rich.

Tune is getting ther, but can traction control, when kicking in, pull timing to slow down the motor?
I let off immediately after I saw the kr Guage.
Current mods are d1 on 13lbs, stage 1c cam from Livernois, 1 7/8 headers, zr1 injectors at 91% idc at wot. Fuel pressure 52psi at wot. Timing at wot is set at 17 for now.

Any help from the knowledgable would be appreciated

[silver2ssrs10]

Originally Posted by f5journal

I'd also consider driving to Greenwood to check out

Come on to wareshoals dragway fri night. If i have my tune by then, i will be testing it out and doing some more datalogging.

[bluetorp]

Originally Posted by thebeast916

Since we are talking about kr, iwas cruising at 45mph and then floored it. I was in 6th gear, then the tranny shifted to 2nd wot. I saw 6*kr. Air fuel was 11.4. A little rich.

Tune is getting ther, but can traction control, when kicking in, pull timing to slow down the motor?
I let off immediately after I saw the kr Guage.
Current mods are d1 on 13lbs, stage 1c cam from Livernois, 1 7/8 headers, zr1 injectors at 91% idc at wot. Fuel pressure 52psi at wot. Timing at wot is set at 17 for now.

Any help from the knowledgable would be appreciated

Traction control can pull timing, but it wouldn't show up as KR. I'd pull a few degrees of timing and see if it effects your KR readings.

Also, I wouldn't advise running injectors past 80% duty cycle. I'd recommend an upgrade.