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#113 |
![]() ![]() Drives: 2017 Camaro SS 50th Anniversary Join Date: Apr 2021
Location: Missouri
Posts: 950
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Ok! So I got the TQ mgmt issue solved. At least I think I do. I assume it's what I changed, and not just some weird temperature and moon phase imbalance making it go away now.
The first bump, where the vertical line is in my last image occurs only when I artificially hold it in 3rd at low rpm and WOT to get a full rpm range log. After some experimentation, it just doesn't occur if I am not manually holding it in that gear. The second blip (the very next one after the line) at around 5K rpm took some experimentation, but I think I've got it nuked. The canned tune had adjusted the virtual torque tables from stock, but just not enough. So first run today... verified TQM was still there at 5K-ish... it was. Bumped the VTT per KingLT1's instructions he had previously provided in a PM. Didn't want to bump them until I had a reason to since canned tune already bumped from stock. Honestly, it was a shot in the dark, didn't know if this was going to fix it, and it was something I hadn't tried yet. So for second pass, I bumped the final row in VTT up by 10% (multiply last row of each section by 1.1), then select whole range of cells (all of them from first row to last row, with cell linking turned on) and interpolate the middle rows. Made another pass, still there, but it was a little better. Decided to go an additional 15% by the same method. The low 3rd gear thing is still there, but honestly dont care. I am chalking it up to something with unlocking the TC, or a downshift or something... again, doesn't occur unless holding that gear manully. The TQM at the higher rpm was gone, and it runs great! I may have overdone it a bit by going addl 15% on that second update to VTT. I may back that down a bit. But.... then again... it really runs like I want it to now. It holds gears quite a bit longer at part throttle, which not good for fuel economy, but I have always thought the "track mode" was too tame to be a track mode. So now it's using CJPerformance track mode . So, now if i'm applying steady or increasing throttle, it holds lower gears for longer, just what I want if I'm going to roll out through an intersection and punch it after I'm clear.At this point, I feel like I've got the tune pretty much nailed down from what I can tell. Runs incredibly strong now. I've done so much incremental tuning, I had thought about going back and applying the original canned tune to compare by seat of pants... but honestly, that tune scares the **** out of me now. Would never run that tune again. Going to put together a summary of all the changes between the canned tune and current and post it later. Cant wait to get this to a track and see if my perceptions match reality. |
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#114 | |
![]() ![]() Drives: 2017 Camaro SS 50th Anniversary Join Date: Apr 2021
Location: Missouri
Posts: 950
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Quote:
The graph in the upper right is max values per rpm of the Engine Torque/RPM calculated hp. Again, I dont want to assume anything based on these numbers. I'll have to correlate that with a 1/4 mi run in the near future. Hoping Oct 8th. |
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#115 |
![]() ![]() Drives: 2017 Camaro SS 50th Anniversary Join Date: Apr 2021
Location: Missouri
Posts: 950
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Again assuming nothing in the tune I changed (like VTT) altered how the base calculation works... Here's a before and after of canned tune, versus where its at now.
A gain of 100 hp in the mid rpm ranges. At the top end, gains vary from around 35-50 if you throw out some of the outliers. That midrange improvement will hopefully help with the 60 ft times. Last edited by cjperformance; 09-27-2021 at 08:27 PM. |
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#116 |
![]() ![]() Drives: 2017 Camaro SS 50th Anniversary Join Date: Apr 2021
Location: Missouri
Posts: 950
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Even used excel to generate a graph of canned vs now.
![]() I'm having too much fun with this. lol... It official if it looks like dyno sheet right? |
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#117 |
![]() ![]() Drives: 2017 Camaro SS 50th Anniversary Join Date: Apr 2021
Location: Missouri
Posts: 950
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That flat spot between around 4800 RPM and 6200 RPM is bugging me in the "now" graph. I feel like that should be more of an arc. Maybe I'll play around some more with timing in that area. It's in the region where I start backing off the timing due to boost. I bet it'll take a bit more timing there.... maybe a different timing falloff curve?
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#118 | |
![]() ![]() ![]() ![]() ![]() Drives: 2017 Camaro 1SS Join Date: Aug 2016
Location: NH
Posts: 1,713
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Quote:
Obviously the basic formula for hp is correct, and the reason that this is happening is because the Engine Torque and Delivered Engine Torque channels are reporting higher values at higher rpm than reality IMO. |
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#119 |
![]() ![]() Drives: 2019 2SS Camaro Join Date: Apr 2012
Location: Al
Posts: 834
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Its heavily based on the maf curve. That will change the hp reading dramatically
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#120 | |
![]() ![]() Drives: 2017 Camaro SS 50th Anniversary Join Date: Apr 2021
Location: Missouri
Posts: 950
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Quote:
Latest update. I squeezed a bit more timing into that flat spot. Feels stronger, no knock in that area. HPTuners is showing slightly over 600 hp from 5400 RPM and up. I'm feeling really good about the tune now. Cant wait to get it to the track. An interesting note... I was having the A8 shudder with the canned tune... once I bumped up the VTT values... I no longer have torque shudder. There's still a constant 200-300 rpm up-down every few seconds, which I think is the lockup clutch slipping? But the rumble-strip vibration is gone. I think what's happened is that now it unlocks the converter at lower pedal input before the shudder happens. Going to look at doing fueling and torque conv over the winter when I wont be driving it much anyway. |
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#121 |
![]() ![]() Drives: 2017 Camaro SS 50th Anniversary Join Date: Apr 2021
Location: Missouri
Posts: 950
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Good info. Makes sense. After I get it to the track, I'll see about getting it on a dyno. I'm determined to do the tuning myself, but I'd like some "numbers" to give me a warm fuzzy... or to tell me I'm off.
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#122 | |
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Drives: 2022 Lt1 A10 Join Date: Nov 2015
Location: clark, mo
Posts: 8,882
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Quote:
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#123 |
![]() ![]() Drives: 2017 Camaro SS 50th Anniversary Join Date: Apr 2021
Location: Missouri
Posts: 950
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When i go, i usually get there early, do about 3 runs and leave before it gets too crowded.
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#124 | |
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Drives: 2016 1SS NFG A8 Join Date: Aug 2017
Location: 46804
Posts: 7,666
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Quote:
__________________
2016 NFG SS A8/Whipple 2.9/Fuel System/Flex Fuel |
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#125 |
![]() ![]() Drives: 2017 Camaro SS 50th Anniversary Join Date: Apr 2021
Location: Missouri
Posts: 950
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Cool. I will try that as soon as i get tcm unlocked. I dont have tcm unlocked yet, but plan to get than done one winter sets in and im not driving as much.
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#126 |
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Drives: 2016 1SS NFG A8 Join Date: Aug 2017
Location: 46804
Posts: 7,666
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Oh well shit yea you need to do that asap. Turn off AFM, Zero out the TCC slip tables and disable part throttle Converter lockup until 8th gear and she will drive sweet.
__________________
2016 NFG SS A8/Whipple 2.9/Fuel System/Flex Fuel |
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