Acceleration "boomerang" effect - Trying to figure it out

[[email protected]]

Hi all,

I have been chasing this issue for a while now and know I am missing something.

The Car: 2010 Challenger V6 swap to a 5.7L with 6.1L heads and Cam. High Hoarse Performance TCM (so I don't write to that). 6.1L fuel injectors, 90mm TB, K&N CAI, SRT shorty headers, 2.5: exhaust to Magnaflow mufflers then 3" the rest of the way, 180 degree thermostat, 3.06 Getrag LSD, coil overs, all BMR rear suspension, Front upper arms with Camber adjustment. Wideband is installed.

I have got the car running better than ever it feels like but my issue is when I get into the throttle it ramps up and downshifts I feel like it should but I get the "Power to the ground" feeling when I back off the throttle like a boomerang effect. I don't know if it's throttle "lag: exactly as I get revs ect. I'm thinking to much air, not enough? fueling maybe? I'm just at a loss.

My latest tune is attached as well as a scanner file (I know, I need to work on my charts, please excuse this). I am running the latest Beta Suite 4.86 I believe is the version.

Please, any help or thoughts are more than welcome.

Thanks so much

Dan

[GHuggins]

You might want to check displacement settings and maybe even just start with a 5.7 OE tune file.

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Displacement settings have to be set that way so I don't get an error because the car is a V6 so has a V6 VIN number if I set displacement both to 5.7 I get an error. Also a stock 5.7 tune runs like crap because of my cam. Believe me I've been tuning on this car for about 2 and 1/2 years 3 years this is the last thing that's pretty much hanging. Definitely a little bit more advanced I think on what my issue is.

[GHuggins]

Make a short log showing your specific problem while logging torque management pids and basically anything else you can add in there.

I just got through tuning a dang near identical setup in a ram two weeks ago. It rips the tires off anywhere under 55mph... Ported 6.1 heads, cai, straight piped and a tsp cam with 15 degree limiter. Are you not running a limiter? Tune doesn't show it - also still shows all limiters in place for trans. My tunes running considerably more timing in places while running less in others and has already been raced quite a bit. He actually just dropped it back off for nitrous even though I'm not sure it'll be useful as the tires already don't hook. There's voltage scaling and other things in your tune that's stock in a say 17 ram for instance that I think you would benefit from - even something like a 11ish ram would work better for the cam... 17ish ram idle settings would work really good and then get the VE table possibly smoother or better would also benefit - just some thoughts...

[[email protected]]

Right on! I'll do a log file tonight. The place we had do the motor swap messed it up on so many level it was like we kicked their dog or something. They gave me the car back tuned with HP Tuners and a pretty jacked up tune. The tune I posted is basic where I'm at after almost 3 years of learning and adjustments. I paid for a remote tune with a shop but I don't think his heart was in it or understood what I was saying. He helped for sure but I was starting from bad data so if you see something off more than likely it is.

All the shop told me was it's a 5.7 from a 2013 Charger police edition with 6.1 heads and cam. It had 3.91 diff in it but I swapped that back down to 3.06 for gas mileage. I'll do a full pcu and TCM read today as well so the transmission section reflects the Hemi Fever TCM settings, they told me not to overwrite that so I have just left it alone.

[[email protected]]

Hi, sorry for the delay but the weather has been horrible here. I made a couple of quick pulls, not quite the full effect I'm describing but wanted to get something posted. I will try to get a full pull in the next few days when the weather breaks. Also attaching a full read with the HHP TCM.

Any insight is so welcome.

[GHuggins]

Are you referring to it being SO low on power? Looked at log 2 - never went into PE even with 100% throttle and actually thankfully is only running 4 degrees of timing. Log 1 went into PE for a brief second then comes back out falling on it's face I imagine the "boomerang effect" your talking about... SOoo fix those two alone and this will feel like a completely different car... If that's what your talking about...

[GHuggins]

Something to try... Just copy all differences. If you don't like it you can go back to what you had.

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The falling off was me pulling my foot out of it as I didn't have much room orchard road. Typically on power it builds on a steady Pace but if I lift out of it like 1/8 of a beat or so you actually feel those slingshot of the power kicking in. That's odd about the pe. I'll definitely check this tune out, hopefully tomorrow, and let you know how it goes. You're the man. Thank you so much.

[GHuggins]

Sounds like it's going into different fueling and spark tables. Let me know how these changes goes. You'll still probably notice some "boomerang" just because of your spark tables, but your overly rich PE tables and/or MAF cal is a lot of it. Hemi's don't need to be that rich unless boosted and even then I typically do general rule of thumb ls fueling for them... I would almost be willing to bet that'll you'll benefit from new plugs after fueling was that rich.

[GHuggins]

OK, had to change tune file name as it wasn't uploading the correct file when I selected it as I hadn't changed the name of the file. That one has the corrected axis. Wish it would let you put in the correct axis, but apparently your OS won't.

[[email protected]]

Thanks, I got it loaded up last night and it was running amazing, even saw a huge increase in gas mileage. I was on a longer trip and towards the end running constant RPM on the freeway the car cut out and went into limp mode. I pulled over and saved the log file (I was logging the whole trip) and read error codes, it showed a P2173 - Throttle Actuator Control System - High Airflow Detected. Quick forum searches pointed to a vacuum leak or faulty TB. I shut the car down and fired back up and everything was cleared and good. Made it to my destination. Leaving hours later I am on the freeway about a 1/4 into my trip and the same error hits again. I pull over, capture reflashed to the old tune, and continued. No other errors the rest of the way. I've never had this error or issue. I have a 90mm TB but it is new (within a year and a half I would say). Check out the attached log files, the 1st and 2nd files are big but the error happens right at the end. Let me know what you think, has to be something a little off but other than that this tune is money! lol

[GHuggins]

I'm not at my computer right now. Sounds like it just needs the airflow number's adjusted back slightly until the issue no longer persist. May even want to set the dtc to no error if it will allow it. Ill look at the log later and see where it's having the problem.

[GHuggins]

This one should be better as far as the cars calcs goes. Also made "some other" changes for you

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1 orig tune example

[GHuggins]

Copy all differences and let me know how this one goes. Made sure all axis right. Do a throttle reset if it'll let you in the scanner before starting too.

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When people comment on my car I am humbled but know it's pretty badass. That being said I usually tell everyone the same thing. My Challenger is like that single Mom's 13-year-old daughter you have like 7 or 8 dates in with.... "F**k you, you're not my real Dad!!" is the first reaction to anything you try to do for her. Oh, she'll finally, quietly accept it, but not until she's made it as difficult as possible.

In true form, she did the same thing with the tune. Idle shot way up and was surging. It looks like my injector pulse widths are really up and down and fuel pressure at idle is way up there. Tune applied was GHuggins Latest v1, which is the straight copy of your last, scan file also attached. I did some editing going back to the more original cam profiles and old VE tables (I've done a lot of work on those but could never get them to smooth out, the smoothed versions in the new tune had me back up in the 20's), all to no avail. Had the same surging etc. That edit is labeled v2 and the scan I took right after is also attached. So needing to get on the road not realizing Lowes changed their hours from 10 pm to 9 pm for some unknown reason lol. I went back to the Full Read 12_25 baseline but for kicks and giggles turned NN back on. Why I don't know, hate NN. The car seems to run smooth but if I put my foot in it I get big-time boomerang and watch my WB Lambda drop to 6.4-7 and just hang there. I didn't capture that but did do a reference scan after applying it as that brought my fuel pressure, idle and everything back down.

I am hoping you are the type that loves Rubix cubes or a good Scooby-Doo Mystery because this has been a MoFo for me for a long time now. I've got the tune down where the car runs good, I mean anyone first driving it would be all giggles, but I know this little bitch inside and out and I know it's just not there and really never has been, I would guess 70 maybe 75% of it's potential.

CAI, 90mm TB, 2013 Charger Pursuit 5.7 with 6.1 heads and cam, SRT shorty headers, 2.5" pipe to mid car Magnaflow mufflers then 3" the rest of the way back. NAG1 tranny fresh rebuild a little over a year ago, HHP TCM, New matching ECU, 3.91 Getrag diff was just swapped 7 months or so ago for a 3.06 Getrag (Gas mileage). HHP TCM was bought to make the gearing change as HPT couldn't get it to take so that is all on point. NGK Irridium plugs and new could last May or so. SRT Brakes all 4, Eibach sway bars, SE Coilovers, all-new front suspension (3rd round messing with that) full camber adjustment. Subframe connectors, with complete BMR rear on car adjustable suspension. Directional tail lights led everything, 8000+ watts of ground shaking stereo, and a million little customized details done out of the love (or be it curse) of not being able to drive anything stock. Hell, even my golf cart is lifted with chrome exhaust tips lol, and this continues to haunt me. I've threatening for years to get rid of her but it started as the wife's car so was desperately trying to get it right for her (I should have gotten ger the boob job instead, lesson learned). All I know is my next car (my 16 Camaro got T-boned and totaled last month) will be pre-'72 old school

Rant concluded lol

[jtroiano]

My flat spot is what you call the boomerang effect. I hasn't been 3 years... I'm going to check out GHiggins tunes tomorrow. To late tonight. My logs and tune are in this post. Its like it just missing something. Let off the gas a touch and it takes off. I dont know how to tell if its in PE mode??? It goes open loop and full throttle.

https://forum.hptuners.com/showthrea...-Bog-flat-spot

[GHuggins]

Well, she's definitely being a big pain - that's for sure, but you did say you've been tuning on it for 2ys, soo... I still think the solution is in the spark and throttle tables. Wish I could just make some quick changes and test If you want to run your stock cam tables then that's fine - just don't copy these over. I really don't think you have much of a cam anyway as it's not requiring locks or anything plus it's running on stock idle settings. Maybe a stock 6.1 cam?

[jtroiano]

I fixed mine by changing my max airflow to 100lbs/min. Maybe try it???

Jon