I have been working on my tune and recently installed a CAI. The tune is attached along with a log file. The issue is the under hard acceleration it feels as though the car is lean or torque management is engaged. The setup is 90lb injectors, Fore Fuel twin pump return setup, BTR 3 PDS cam, Airraid intake, ported nose and supercharger. Car runs fine cruising around. It starts and idles fine. The most recent change is the CAI. Any help or suggestions will be greatly appreciated.
Steve
Going by "feelings" won't get you much. There is a difference between feels lean and is lean. You need a wideband on this stat to know what you are dealing with.
Outside of PE you are rich, the fuel trims are pulling 18-20% worth of fuel most of the time. Then in PE I can only guess at this but based on the o2 sensors nearing and going over 1,000mv, it's way way rich at full throttle.
Something is also pulling a massive amount of timing, it starts at 10 degrees and spikes to mid 20's where it goes to following your timing tables. Possible that you have burst knock yanking that 10-12 degrees out because that is still enabled in the tune, I'd personally disable that. You could add burst knock to your logs and see if that indeed is what was pulling it before you make any changes to that table.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
5FDP I appreciate your insights. I will check the burst knock. The tune prior to CAI install my fuel trims ran -5 to +5. The fuel trims are way off and it goes pig rich. So where would you suggest beginning to help in clearing up the tune? Here is my original tune.
Use the wideband to create and error graph from the commanded AFR (or lambda) to the actual AFR (or lambda) value that the wideband is showing.
The error that is given can be applied to the airflow model (MAF/VVE or VE) to add/remove fuel where is it required to fix your issues. This kind of calibration would be done is open loop with fuel trims and closed loop disabled.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
I appreciate your insights and help. I made some adjustments to my tune and logged the car. The LTFT are better as well as STFT. I have a wide band coming and will work on it more to get it more defined. Check the log and tune.Originally Posted by 5FDP
Thanks,
Steve
Well, I removed the CAI and reinstalled my stock air cleaner. I worked on the tune and have average +3 LTFT and +6 to -4.5 STFT. I updated my maf and got it into a better range and worked on the timing. Please take a look at my log and tune. Any suggestions to better tune or anything you see that needs changed? I am thinking of increasing my maf. Thank you for all help.
Steve
Why did you switch back to a stock intake? Do you have a wideband? That's going to be the only thing that will tell you if you need to "increase your maf". You are commanding a fairly rich PE but again I wouldnt mess with it unless you have a wideband. Turn off DFCO, put the intake back on and log the car. if you are getting to around */- 5% make a small adjustment in that area.
Where do you see DFCO enabled? I thought it was disabled. I was having trouble with my fuel trims. They were running LTFT -18 and STFT -10 running pig rich with the CAI installed. I will put it back on next week and work on the maf. I am thinking I may have a bad 02 sensor. It seems the fuel trims are off and not balanced. Is this affects of the tune?
Steve
You need to read about injector tip temp. Tune your MAF when injector tip temp is at a normal running temp. Usually 122F or 131F. On a Vett it can be 140F.
Last edited by jsllc; 09-18-2019 at 01:19 AM.
2012 ZL1 - Maggie Heartbeat, Port & Polish Heads, Custom Cam, Custom rotating assembly, steel sleeved LS9, No NOS and No water meth. 16psi
810rwhp and 820rwtq 91 Octane 6400 rpm
948rwhp and 951rwtq 105 Octane 6400 rpm
999rwhp and 997rwtq on 60% Ethanol 6400 rpm
I would add, roll into the throttle a little smoother when tuning. You are timing limited when you first roll in, either torque management or traction control limiting your timing to 10deg. Once you get your timing in (20) things start moving. Much better log than before. Also, let your engine warm up a bit more. It's not just coolant temp that needs to be up before you floor it, it's oil temp. Your engine will last longer if you let those temps come up as well. Also, I second for you to read about ITT.
I also notice your fuel pressure is a bit low at WOT, but you mentioned you have an aftermarket system. I don't know enough about that to advise you, but most V's run in 68-72PSI range at WOT.
Cheers!
Jason
Jason,
My running fuel pressure at idle on the Fore fuel regulator holds steady @ 55 psi. The regulator is vacuum referenced for boost and am not certain what my driving pressure is under boost. I may need to look into hooking the Fore fuel management system to the factory power source and wire in a reference so the computer can regulate the pressure. I am also thinking I may need to richen up the fuel @ cruise: LTFT are 7-15 positive and my STFT are running close to -1.2 to +2. I just don't want to run to lean. I have done some more logging and use dashCommad to log when not tuning.
Steve
Steve,
Is that last tune and log still current? Do you know how to adjust your maff to get your LTFTs closer to 0? Also, if you don't have one already, get a wideband so you can better tune your WOT fueling. The AEM wideband that connects to your OBD2 port is a nice addition and can be data logged with HPT along with all the other parameters making it easy to tune WOT fueling. There are better WBO2s out there, but the AEM is pretty nice and comes in around $220.
Cheers
Jason
Steve,
I just went though your last log. I noticed your oil pressure was low during the WOT session in that log. At almost 5,000 RPM your oil pressure was 33psi. IMO, this is a bit concerning since you should be in the 60-70+ PSI range at that RPM. Your idle oil pressure is also concerning. At 1K RPM your oil pressure is just over 10psi. If I were you I'd hook up a mechanical gauge to the oil pressure port and verify your idle pressure. If it is indeed that low, you need a rebuild.....very, very, soon.
I see over on ctsvowners.com you were going to check the oil pump pick up tube. I think that's a great idea, please give that a check since you have a cam and the person who installed it may have pinched the oring.
Last edited by Jason Austin; 09-22-2019 at 12:59 PM.
Jason,
What tuning changes do you think I should start with? I know tuning the maf 5%, 10%, 12%, 15%, to do this requires highlighting area or all of maf and multiply by 1.05 for 5%, 1.10 for 10% and so on correct? Give some thoughts to help with the LTFT being out.
Thanks,
Steve
Don't you have a Histogram for MAF Error so you can adjust the MAF curve by % for the area you need.
2013 OBM A6 CTS-V Coupe
Mods: Headers back Billy Boat Exhaust, GripTec 2.65, 8.6 PowerBond Lower, LSX Innovations Solid Isolator, ID850's, NGK TR7IX's, Accel 9070CK Wires, Spectre CAI, SRI Ported Throttle Body, SRI Catch Can, NGK AFRM, 160* T-Stat, 0fx2gv Brick, Hard Line Delete W/3/4" Lines, FB 101 FMIC, Pierberg CWA50, Stoptech Drilled/Slotted Rotors, EBC Redstuff, Cut Stock Springs, Flat Bottom Steering Wheel
2006 Black Raven STS-V (Traded In)
Fully Modded: 459RWHP@5888rpm/451lbft@4696rpm
Yes, I made some adjustments and the LTFT are running 0 to +3 in cruise areas. I am going to add 1% to see how it goes. Trying to get the LTFT to 0.
Steve
What I am saying is use the results from your histogram and copy the areas you want to change and use the multiply by function in the editor. Use either % or half % of you are close.
Last edited by PGA2B; 10-12-2019 at 02:44 PM.
2013 OBM A6 CTS-V Coupe
Mods: Headers back Billy Boat Exhaust, GripTec 2.65, 8.6 PowerBond Lower, LSX Innovations Solid Isolator, ID850's, NGK TR7IX's, Accel 9070CK Wires, Spectre CAI, SRI Ported Throttle Body, SRI Catch Can, NGK AFRM, 160* T-Stat, 0fx2gv Brick, Hard Line Delete W/3/4" Lines, FB 101 FMIC, Pierberg CWA50, Stoptech Drilled/Slotted Rotors, EBC Redstuff, Cut Stock Springs, Flat Bottom Steering Wheel
2006 Black Raven STS-V (Traded In)
Fully Modded: 459RWHP@5888rpm/451lbft@4696rpm
Here is a good video on tuning MAF using LTFTs.
https://www.youtube.com/watch?v=kaRL3vSA-JI
You should do the Multiply by 1/2% or else you will be overshooting alot of times. You really need to get the wideband in and installed so you can make some better progress.
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