LE5 Tune questions

[noorjSS]

Hey everyone, I'm new to the forum just picked up HPT pro for my 2006 cobalt ss/na with the LE5. I have full bolt ons and currently have a trifecta tune I will soon get rid of. Anyways I have been logged said tune and am pretty sure it isn't good. I'll attach a log but I am seeing up to 5 degrees of knock retard at points and constant knock throughout each pull. Also the knock usually starts after the car leans out to about 13.5 AFR. The first log is without my AEM wideband and the second I finally got it hooked up. But on a good note I am seeing almost 20 lb/min, that's pretty good right?

Also I was wondering how I can log commanded AFR as the one I tried in the second log didn't work. Also is there a way to log the cam positions? Like intake and exhaust advance/retard? I thought I saw a couple logs with it but cannot figure it out.

I will start tuning once I can get the Trifecta flashed back to stock, so any info/ suggestions you have I'll gladly take! I've been reading alot of the VVT info but haven't found much good info on NA tuning. Also I need to learn how to MAF tune haha.

[dtabbs]

Without you posting your tune and config, I can really only sumise two things from your logs. It does appear that you have larger than stock injectors in your LE5 since your IDC does not ever get over 50%. The second thing that I see is that you must be using pretty crappy fuel. Your tune only has timing bumped about three degrees, but you are getting all kinds of knock retard on hard acceleration.

Pull your tune and post your config.

[|V3nom|]

or lose the trifecta first and make with your own tune from scratch.

[noorjSS]

That's what I'm thinking. It isn't letting me read the current tune. Does anyone have good info on NA LE5 tuning? Searching hasn't yielded much.

[dtabbs]

The two threads that I already pointed out to you are about the best there is here. The E67 ECM is actually used on several V8 applications, so you can look at those as well. It is the ECM that comes with the LS3 and LS7 crate engines. It has no limitations for boost since it uses Virtual VE and not a two dimension table. Of course it also has all of the controls for VVT, DOD and AFM.

[noorjSS]

Does anyone have a stock LE5 tune handy? I can't seem to find this tune repository people are talking about. Trifecta dealer tells me that although I cannot read his tune I should be able to write over it, so would it be fine to just "write calibration" over the Trifecta tune once I get the stock one?

[silverbullet08]

Does anyone have a stock LE5 tune handy? I can't seem to find this tune repository people are talking about. Trifecta dealer tells me that although I cannot read his tune I should be able to write over it, so would it be fine to just "write calibration" over the Trifecta tune once I get the stock one?

I have never had luck with this when dealing with a trifecta tuned car. 99% of the time I end up taking the car to the dealer for a factory flash before I can tune it. Trifecta flashes seem to screw with the vin and OS numbers that Hptuners uses for crediting. I have a factory LE5 on my other laptop il post up later if someone doesnt by then.

[cobaltssoverbooster]

Dude save yourself and get it flashed through gm with the tech2 scanner. The trifecta flashes have problems and the only way u get the cleanest of starts is to get a reflash.

[Freakotec]

I've never had any luck with just doing a full write over a trifecta tuned car. You can do like silverbullet said and go to the dealer but you can also just flash the stock file back via EZFlash if you have access to the cable. Once that's done you can pull the file off the ecm via hpt with no issues.

[bonylad]

I had the same situation......lost credits and got pissed off so heres my suggestions.


1. Best way is to get cables from Trifecta, flash back to stock

2. Try a Tech 2...my dealer said it would not communicate

3. You can try a complete write, but when I did it I lost credits and wouldnt write entire

4. Do what I did, but a ZZP 1.0 PCM from ZZP....send your comp back in. Costs 100.00....and you get a ZZP base tune unlocked with HPT with your mods. Easiest way, as all you have to do is swap pcms.......

Dont give up!

[noorjSS]

Well it all worked out good. I got the cable from trifecta and am now tuning!


Anyways more noob questions:

I am calibrating/adjusting my MAF right now and am wondering if I'm doing it right? I have been using LTFT+STFT vs. maf freq. in a custom PID, copying and paste special% into the respective low/high maf frequency table on the tune. Should I be using AFR error instead?

hhrfreak has been helping me a lot and said that I shouldn't do a MAF only tune because my VE will be close to factory having only simple bolt-ons. So my dynamic airflow is set to 7000, should I move it down or does PE make it run on only maf?

Also it is very lean at WOT, will this change once I dial my MAF in? it's commanding 12.9 but seeing 13.8-13.5. I just bumped up the timing and am starting to see knock at only 2 degrees above stock so I guess I'll go back to stock timing tables


Sorry for all the questions, the guide I have been using haven't answered these questions.

[dtabbs]

To tune MAF, you should disable VE. Engine > Airflow > Dynamic > High RPM Disable set to 200, High RPM Re-enable set to 100. Since the engine will never operate between 200 and 100 RPM Dynamic Airflow will be disabled and will rely soley on MAF.

While tuning turn off LTFT's. There is no need to have an added factor. Engine > Fuel > Open & Closed Loop > LTFT Enable, Set Min ECT to 493, Max ECT -40.

Be sure to turn off other fuel adders like DFCO, CFCO and COT.

Use STFT vs MAF to tune MAF. My VE was not even close and I have been tuning it for quite some time now (months to years). I log everyday I am in town (travel for work about 75% of the time) to and from work. I create a new tune file and upload to my car before leaving work (parking lot) and then at night at home after dinner, yard work etc. to upload before I leave for work the next day.

[dtabbs]

For reference, here is what your VE looks like;



And this is what my VE looks like;

[noorjSS]

Haha wow yours is so much smoother. What is the vertical axis on that graph?


I have been using AFR error to adjust the maf and got the STFT within +-2% but the LTFT are around 2% lean.

[dtabbs]

The vertical axis on the left is Cyl Air Mass (g/cyl).

LTFT's are derived from what the STFT's are over a period of time. If your STFT's are reporting 2% lean, after a period of time that is transfered to the LTFT's and the STFT's will then report 0% if all things remain the same (will never happen). Therefore if you are tuning using LTFT's and STFT's you add the two together for each cell and make your change by that calculated number.

Since you are tuning and resetting your fuel trims (you are doing that right?) before each session, there is no need to have LTFT's enabled.

I would hope that you are not using AFR Error to tune unless you have messured the Ethonal content of your fuel and adjusted your stoich accordingly. A wideband gauge, although it has an AFR scale, does not report actual AFR. They report lambda and convert stoich of lambda 1 to an AFR of 14.68+-. The previous instruction was written in assumption you are tuning using fuel trim error (STFT and LTFT), which is not AFR error.

[noorjSS]

Yes I have LTFT's disabled. I am using AFR error for the high maf frequecy and have dynamic airflow disabled at 2600 rpms. I use stft to adjust low freq maf table, it seems to be working great as the stft are within +-2% and the afr error is almost there I still have some work to do.

[noorjSS]

Random question for you guys, how fast do you shift? I can't seem to get faster than .5 second from full WOT to back on it, I feel like that's pretty slow. Just curious

[cobaltssoverbooster]

not very fast in the lnf the cables break

[noorjSS]

Well after a lot of playing around I'm pretty stuck. Even at around stock timing my car will knock randomly. Not really dependent on timing or AFR at all. Almost every third gear pull it will knock, 4* and it's very annoying. It also seems very sensitive to IAT temps which is odd being an NA engine. I'm thinking about bringing the "dip" in timing higher into the rpm range(18* around 5k) then ramp up to max timing by like 6k to see if that helps. Any ideas/ guidance would be great

Edit: forgot to say this is not stock timing but only 1 degree advanced up top

[dtabbs]

Noor, you are lean according to your wideband where you start to have KR. As I suggested previously, convert over to Lambda because using AFR on a Lambda gauge you cannot tell where you are really at. It is very simple to do and only requires a very small screwdriver with your AEM UEGO and can be done while connected to the car and running (that is how I did mine). If you don't have the manual, download it here. You will be changing the rotary switch from P0 to P1 and swapping out the faceplate for a lambda scale.

If you are unsure of the AUX input set up I can help you with that and also setting up lambda error.

The location where you added 1° of timing is where you are getting KR, so you need to reduce that area by about 4°. Less timing does not mean less power, in fact too much timing causes cylinder pressure excess and actually fights the piston coming up on the compression stroke causing the oposite of the desired effect.