LFX Tuning Questions

[TXBDan]

Hi all,

I have an LFX swapped into an RX8 using Andrew Keisler's excellent kit. The kit includes the E39 ECU already configured and tuned. The only part of my swap that is unique is that I'm running a Gen6 V6 Camaro TR3160 transmission instead of the usual AY6. This has a different pulse wheel for VSS but I believe i'lve configured it correctly in the VSS settings. I'm now digging around the tune a bit to learn more about it.

The car is up and running and I have about 100 miles on it. A few thoughts so far:

• The revs hang a bit which makes shifting a little clunky. Because they drop slowly, each shift pulls the rpms down to the next gear's rpm. This causes some synchro meshing issues at times.
• the throttle response seems a little sluggish for the first half of the travel and picks up a lot more in the last third, even last 25%

Question 1: I noticed in the Engine/Driver Demand section, my tune has "Use Calculated VSS" Enabled. It says that this means with this on, it'll calculate VSS based on RPM and the NV Ratio. My NV Ratio is set to 2.73. I can't see how an RPM divided by this number will produce a current speed. I'm also not sure which gear it assumes to be in for the calc. Either way, if I have a properly workin VSS, should I disable this and let it use VSS directly?

Question 2: While I'm in the Driver Demand section, I see there is Map A - Normal, Map B - Winter/4wd, and Map C - Sport/Tow/Eco. It seems that my tune just set them all to the same values since I don't have a button to switch modes. What would it take to rig a button up? I would be helpful to have selectable modes.

Question 3: In the Engine/Fuel/Cutoff/DFCO under RPM limits, Manual Gear Type is set to "Clutch" which it says means it uses the clutch switch to determine neutral. We don't have a clutch switch so maybe we should set it to "NV Ratio" which determines neutral by rpm and VSS and ignores clutch switch?

Question 4: How is NV Ratio figured? It's simple rpm/VSS, but wouldn't it also need gear information?

Question 5: I don't have a clutch switch connected. What "features" does the ECU have that might make connecting one interesting? I wonder about what happens during shifts with the manual transmission and if there are any benefits to installing it. A CPP potentiometer would probably be a pain to install on the RX8 pedal, but I could easily setup an on/off switch if that could work.

Thanks a lot,
Dan

[04silverado6.0]

Post your file up and get a log as soon as its rolling.

[Scott02]

I somehow accidentally deleted my post... but i had a screenshot of it for other reasons...

Hello Dan,
I also have a Keisler LFX swapped RX8 and I am also interested in fixing some items in the tune (rev hang, accel pedal mapping, etc.), so I am glad that I found your thread!
This will be my first time diving into HPTuner / Chevy tuning, so this will be a learning experience for sure. I've self-tuned other platforms in the past though.

EDIT: My transmission is the MV5 6 speed manual, and your comment about the clutch switch got me to thinking to go look at mine, and I am missing a clutch switch in my build as well. I could easily envision that causing some rev hang if the ecu does not know that I pushed in the clutch. Interesting. Much to learn.

[Scott02]

Does anyone have a stock read of a 2012 Camaro LT 3.6L LFX manual trans?

Since I'm new to tuning Chevy with HPTuners, I'm interested to know what the stock parameters are to compare to my tuned file so that I can learn what was already changed vs stock... then I can start over with my own tune from the completely stock starting point as well. Thanks!

[gtstorey]

Have you checked the tune repository?

[Scott02]

Apologies as I'm quite new to HPTuners. I was looking for such a thing as a repository exists in the NC Miata tuning world.

Can you provide a link to the repository? Thank you in advance for your time/help!

[gtstorey]

https://www.bing.com/search?q=hp+tun...p=1&ghc=1&lq=0

[Scott02]

There was no 2012, only a 2013, so I downloaded that and am comparing now. Thanks for your help!

[TXBDan]

Keep in mind that the 2013 is an E39A ECU.

[Scott02]

Keep in mind that the 2013 is an E39A ECU.

Crap, what other year can I start with to compare as my ECU is from a 2012 Camaro manual (which was not in the stock tune repository)?

[TXBDan]

Crap, what other year can I start with to compare as my ECU is from a 2012 Camaro manual (which was not in the stock tune repository)?

Only 2012s have E39s as I understand it. The rest of the Gen 5 V6 Camaro years are E39As.

[[email protected]]

I think I have a stock 2012 stock file, as-flashed to a E39 Serv# 12643248. If not, I can flash another one and read it

[Scott02]

Hello John,
If you're able to share, I'd certainly appreciate it! Then I can send it to hptuners to put into the repository as well.

[flatpick13]

Understanding I'm resurrecting an old thread, but I have an LFX swapped Miata and was wondering if you ever got any of your questions answered. I'm also having some throttle hang that makes shifting sketchy, it also doesn't give me the expected engine brake when I left off throttle which makes me use more brake to prep for corners. I'm sure I can probably adapt my driving style, but right now it's slowing me down and making it difficult to balance grip in the corners...

My "Use Calculated VSS" is disabled, and there were several folks talking about changing the adaptive idle max vss from 4.3 (stock value) to 300 as a fix to throttle hanging around 2k rpms on it's way down, which i've done. When I go to WOT, or really anything over 5k RPMs, and then let off throttle to shift I can see my pedal drop to closed (or relative, it doesn't seem to drop below 23% ever...) but my throttle position lags around 31% before dropping back to 23ish% (which also is mostly closed, verified this with vehicle on but not cranked). Short log attached for reference.

[SiriusC1024]

Need to dial in MAF. Fueling is way off. VVE should be fine if the motor is stock.

[flatpick13]

I have MACE cams and aftermarket coils, cams should make a difference but not coils. Valves have been refreshed, but otherwise motor is stock. At the risk of sounding ignorant, because I am and am very new to tuning this platform, where do I need to start on fixing my fueling and dialing in my MAF? Right now I'm trying to "stare-and-compare" with another tune I assume is from a stock 2012 Impala, the tune I have was tweaked by a fellow LFX swapper, I'm using it as a baseline but would like to understand how to change what I need to in order to get my engine to behave how I would like.

[SiriusC1024]

Go to Engine>Airflow>Dynamic. Set High RPM disable to 200rpm, Re-enable to 100rpm. This forces full-time MAF. Tune with fuel trims that are logged. Include the Mass Airflow Frequency channel in the log. If you post a log of the tune with those settings I'll show you how to do it if you want.

VVE is going to be a real pain. Probably should do the torque model, but at least it's a manual transmission. See how it does with MAF-only to start off.

[flatpick13]

Awesome, thank you, I will give the MAF change a go tomorrow and follow up, I really appreciate the help!

[flatpick13]

Changed the dynamic setting, did a few runs with logs, attached the latest. Still getting throttle hang, also had an issue with the car stalling when I pulled in the driveway and put it in neutral to coast down the hill into the garage, you can see the stall in the log... Timing is at -11 degrees, not sure if it's something with my spark tables? Also not sure about filling the entire VVE table, I checked another tune I pulled from a different thread and it had a blank VVE, too. My ST and LT tables still showed quite a few areas over 5%. I'm very new to tuning these, but there are a bunch of comments on LFXs being weird to tune.

[KillboyPowerhead]

Which VVE table did you look at? There are four, and all but one is zero'd out (don't have HP Tuners with me, but believe it's the Manifold Switch Closed table, or whatever the bottom table is that the E39A uses). Someone in the V8 Gen V forum mentioned an easy way to tune the VVE table and it seems to have worked fine for me as well: just dial in the MAF first (using STFT, or a wideband if you prefer, but STFT is better since it combines both banks, unless you're using two WB's), and then compare the MAF Airflow to "VE Airflow" and adjust the VVE table so that VE Airflow matches MAF Airflow. No need to fail the MAF to tune it or the VVE; and make sure you set both cams to 0 at all times since you can only adjust the VVE table for both cams at 0 (there are 441 tables, for each intake and exhaust cam angle combination, from 0 - 20, but you can only adjust the 0/0 table directly; changing this base tables will change the rest of the tables).