DSMlink logs-why knocks?

[MarsaGSX]

here are few logs I did today...
18°Celsius,sunny..

using Stock 2G timings,
Fuel..set to 11.1:1 threw RPM band
why knocks at low boost at stock timings??
any input will be great!!!

In that last log(its driven in the city...check only 79.63sec..
which other values I should capture?which change?
Iam confused why it knocks when got LOW boost on stock timing? WTF !!

Thanks

 

[CanadianTSi]

The Most Knock I see is 0.4 of a degree which is negligible. Anything under 2 degree's of knock is fine.

 

[MarsaGSX]

The Most Knock I see is 0.4 of a degree which is negligible. Anything under 2 degree's of knock is fine.

in log 04112007-3 at 14.47sec,there is 3.9deg knock....
Iam confused of my Timig curve...everybody got timing same as RPMs..Timing curve go with rpms. I don´t..
Do I have to subtract timing???

BTW..when runing lowest boost with stock timing..Not using MBC..its okay...



what about LTFT,STFT??which numbers I should get???

Thanks

 

[zippyshoe]

Looking at log 04112007-3, it looks like you have some of your RPM-based fuel sliders set awfully lean: the 2.5K and 3K sliders are set to -30%, and the 3.5K slider is set to -31%. I would expect to see these sliders somewhere around -10% for an 11:1 AFR. I am wondering if you may be running leaner than 11:1 based on those fuel sliders.

Concerning LTFT's, you want them to be as close to 0% as possible.

 

[MarsaGSX]

Looking at log 04112007-3, it looks like you have some of your RPM-based fuel sliders set awfully lean: the 2.5K and 3K sliders are set to -30%, and the 3.5K slider is set to -31%. I would expect to see these sliders somewhere around -10% for an 11:1 AFR. I am wondering if you may be running leaner than 11:1 based on those fuel sliders.

Concerning LTFT's, you want them to be as close to 0% as possible.

Yes,there was mystake..or how to say..Forgot I tune only WOT..(If MAF is reading more than2g per rev..).I wants to run Stoich threw cruising to get better gas milage...
Monthor so I set Fuel to my 850s injectors,deadtime etc..and today checked again cus of your answer..was okay...and checked A/F ratio too... A/F ratio/ props..and there was 450cc inj and stock dead time..changed and now my A/F seems to be okay...
But those knocks still here!
Today waspretty hot in here..22°C..did maybe 17logs!
did few with MBC off- 6PSI and then with like 12PSI
In logs with MBC off used stock timings and 1:0 A/F(from 5k)...no knocks all seems okay to me..
then turned up MBC to 13PSI and get knocks at 5.5k- 7k....
So in those "knock" rpms I substract timing...went to 13deg at 6k and...KNOCK!!

BTW Not able to do 3rd gear pull cus my freeway got curve after high second gear...have to take out my foot of gas pedal..Iam affraid go to highway

Any other input??
Thanks

 

[scottsee]

Maybe you could log a 3rd gear pull for us? Say 2000rpm at WOT to 7500rpm..

Edit: Holly crap! You need to fix your LTFT's & calibrate your GM MAF.

Scott

 

[turbodsm18]

You need to go make one clean 3rd gear pull all the way through..

You timing is all over the place and your .02 values are also.

 

[zippyshoe]

You definitely want to calibrate your GM MAF and fuel trims, as scottsee pointed out. If your airflow sensor is reporting inaccurate airflow measurements to the ECU, you will have all sorts of tuning problems. Also, an improperly calibrated airflow sensor will cause the A/F ratio reported by DSMLink to be inaccurate. I noticed that in your logs, the front O2 voltage never seems to go higher than about 0.7 volts - assuming your front O2 sensor is functioning properly, this may indicate a lean condition.

In your previous post, you mentioned that you wanted to run stoich while cruising. I didn't know if you were aware that the RPM-based fuel sliders do not affect fuel delivery while cruising - they only affect fuel delivery at or near WOT operation. If your fuel trims are reasonably close to 0%, then the ECU will automatically maintain your A/F at stoich by constantly monitoring the front O2 sensor voltage during cruising/idling conditions.

 

[biglady112]

Please post a third gear log for us. Or do a first through the top of third gear. The logs you posted don't have enough information for us to help you. Short shifting and lifting early will not help us help you. Everything seems ok so far.

Steven

 

[scottsee]

Actually if there is consistent knock in 2nd gear the knock sums will carry on over to the next gear skewing the results of a 3rd gear log. That will be fixed in DSMlink V3; Also, I want to see what everything looks like in 3rd gear at WOT from 2000RPM to 8000RPMs, you can't do that because of the gearing of 2nd, unless he shifts at 4500ish RPM...

 

[biglady112]

Right. But I like to see how exaggerated things get on the top of the run. Or what happens as heat soak sets in and load changes.

Steven

 

[MarsaGSX]

Okay..will do 1st - 3rd gear pull, will need turn down my boost..should be on full gas right..
Will use stock timings and 11:1 A/F fuel sliders acros the bpard..
We got 11am..going to run within 5hrs..If is something I should do or log some other values ,let me know..

BTW yesterday played with LTFT...on 150Hz slider I wasn´t able to get "0"....!!

Thanks guys

 

[scottsee]

if LTFTlow and LFTmid are both with in +/-5% of each other thats fine. Getting 0 is impossable. You may do a 1st through third if youl like, but would you also just do a 3rd gear log from 2000 to 7500..

 

[MarsaGSX]

Here are todays logs..again wasn´t able turn 3rd more than 7k..Hope will help to you guys I was on public higway..there was lotta cars..Its Friday ..So Islower the whole trafic and wait until some distance befor me..then pushed on 2nd little bit..
Fuel set to 10.9 A/F from like 3k...acros board,stock timing,
again was like 22°C..hot!
checked airflow 29lbs at 11PSI..sounds good to me..
Thanks
Venca

 

[scottsee]

Airflow and LTFT still off. You didn't even touch the airflow sliders.. Now that we know hes not heat soaking his extremal small 31x12x3 FMIC at 11psi with his 50trim can we move on?

Venca, I'm just going to come out and say it... You're doing this all wrong dude.. You need to get your LTFTlow and LTFTmid closer then that. You also need to get MAP/BoostEst to match up throughout your MAF HZ points. Please "0" out your timing sliders, and add "MAF" to your Captured Values list.

Try changing your Deadtime to 330 from 315 to see if that brings LTFTmid down closer to LTFTlow.

Logging STFT, MAF, LTFTlow, LTFTMid take your car on a nice strait, highway drive while keeping the speed as steady as possible for about 10 minuets. Then pull off into a parking lot and let the car idle for about 10 minuets. Compare the MAF signal from the cruise (150hz/250hz) with the STFT/LTFTmid and adjust the HZ Airflow sliders accordingly. Just get it within +/-5% of each other.. Don't worry about 0.. Just get LTFTlow and LTFTmid close.. You don't want LTFTlow to me -5% and LTFTmid to be +5%, you want both to be either on the -% or +% side. That should clear up your fuel settings.

As for getting airflow accurate Log GM33bar & BoostEst at 3rd gear from 2000rpm through 8000 rpm. Use this formula to readjust each MAF HZ slider (from 400hz+) to make airflow metering accurate. You can find more one these to things from the link I provided in my last post.

(14.7 + MAP) / (14.7 + BoostEst) - 1

Once you do that, you should be ready to tune WOT. You really need to turn up that boost dude, your running way under the efficiency of that turbo and are not even close to running in the top fuel/timing map (over 2.1g/rev). You should really turn that boost up to at least 17psi, your car is setup very well, I don't see any reason not to turn the boost up to 20psi and start tuning from there. I, personally would turn the boost upto 20psi before you do anything, then calibrate your MAF.

Log that stuff, and post it up, we'll go from there..

 

[biglady112]

Dead on Scott. Marsa, please do us a favor, DO NOT TRY TO TUNE USING DSMLINK FUEL ESTIMATES. They are just that, estimates. From most of our experiences the estimates are way off and generally actual fuel ratios will be leaner than estimated. Right now you have two tools that you can use to your benefit. The MAP sensor and the knock sensor. Just pay attention to both and you are golden. Oh, and turn the boost up.

Steven

 

[Rice Over Wheat]

if LTFTlow and LFTmid are both with in +/-5% of each other thats fine. Getting 0 is impossable.

I second this, chasing trims is a waste of time outside of 5%. Even stock cars aren't ever zeroed out.

 

[MarsaGSX]

Sorry for that late reply..had some issues with new babe and her old boy..

So..need to re-Calibrate my GM Maf..thats the Alpha and Omega for me right now..

Will work on at weekend,and give you some logs..
BTW give me some points where start/in which HZ sliders add or subtract .....50hz slider (idle) should be okay...

and got new Date. 5.5.07 is the DAY "D" biggest Czech drag day... wanna break 12sec..

Thanks
Venca

 

[MarsaGSX]

Another IDEA..

Got Keydiver chip..(bought befor my DSMlink)and never run..of course my ECU is socketed..

..if I will be really Lazy or I don´t calibrate my MAF..may I run this chip and push 25PSI of boost on my 50trim??

that chip is burned for my 850cc inj,95AWD,no fuel cut,No airfloew cap,Knock sum Gauge,8k rev limiter,800rpm idle,
MAFT!!,
5step stutter,11:1A/F,No boost cut,enhanced closed loop

as for MAFT feauture on keydiver chip..I don´t need calibrate GM MAF when run only this chip???

BTW can borrow dataloger from my 1G friend...to be safe wiht keydiver

Thanks
Venca