So I have a 2014 Mustang GT. My mods are Airraid synthaflow intake. Boss 302 Intake Manifold. American Racing Headers. I have a bench tune.

I have been having transmission flares. SO when I am driving and my car shifts from 3-4 gear I get a transmission flare of around 300-500 rpm.

I can not figure out what the problem is or how to fix it. The place I got my tune has went over the logs 5 times and says its all fine. What could be the issue and what could be a fix?

 

After the tune, did you reset your ECU?

 

It was an emailed tune I used a SCT x4 tuner. I plugged it in and reloaded it. Does that not count??

 

No cause your ECU needs to re-learn. Just take off the negative (-) black line connected to your battery for 2mins and plug back in. Start your car in ON position not engine running, keep this for 5mins and smoke test all electronics like windows up/down, door locks, radio, nav system, AC, seat heaters and so forth...then crank on the engine and go for a drive.

 

this started happening since the tune?

 

Well it was just fine about 2 weeks after. Then all of a sudden it started doing it.

 

How many miles on car? It sounds like there is a trans problem. Do you have the ability to scan for codes in the trans? You can also try to reflash, engine and trans. It MIGHT fix shift problem. You can also try a battery reset, connecting both battery terminals together, terminals off the battery!! Read!! keep connected for about 5 minutes, that will clear any capacitors charged. and try that again. If you have faults, you most likely have a solenoid going bad.

 

Okay, So I tested this and I did about a 5 -8 minute drive and I did not have any of the issues I was having. Could it really be that simple of a fix? Also, since I reset that computer the tune that I had put on the car will still be active right? I wont need to reinstall it or anything?

 

No you won't lose your tune, but I bet its tune related with your transmission line pressure at shift change.
I had a flair on 2-3 shift when I was stock, but once I installed my tune the flair was gone.
I assume when you did your data logging you also had the transmission PIDs select. I can't recall all of the tranny PIDs but it sound like your torque converter is locking up at gear change. I would hit the tuner back up or go elsewhere.

 

I had a shift flare under light throttle when shifting from 5th to 6th gear, both with the stock tune and the Steeda tune. Upping the line pressure helped a little. Problem went away with the ProCharger tune when I installed the supercharger last year.

 

Yes, it's the ECU re-learning process. Tune still stays, it doesn't reset to original settings. You'll know once you get up to 100km of driving mileage.

 

So what exactly is a transmission flare? The RPMs just jump up after the gear changes?

 

Kind of a "slip" in the gear change. The trans doesn't keep connected during the shift, and the engine kind of freewheels during the shift. All of this is a bad description of basically a bad shift, from the automatic trans. Does that help?

 

Okay well new update is that the ECU reset did not do it. The place I got my tune from is saying that all the numbers are just fine and he doesn't know why. Sorta at a loss of how I can fix this. I am sure it doesn't hurt the car but it annoys the crap out of me when it does it. It only does it from 5th to 6th gear and when im at 14-1700 rpms. If am above or below that it seems to be okay.

 

Did they try putting original factory tune back and see if that fixes the issue?

 

I didnt think they could since I have all those mods. I wouldnt be able to run the original.

 

Why not? They should at least have a backup of your original factory tune.

 

It won't run with the different air frequencies and engine modifications it is a totally different ride

 

Alright...I'm out of ideas.

 

Thanks for trying man. Appreciate it. When I figure it out I will post and explain how to fix so everyone can have the knowledge in the future.