JimC you make a good argument. One last thing before I go drop the car off tonight. Your 2013 Convertible was a 3.7l V6 or the V8?

 

It was a 3.7 like yours.

 

Just picked up my car from Ford for an airbag recall. While I was there I was asking about gears. They recommended the 3.73's haha. They said, "don't fear the gear." They also thought my 2013 3.7 had 3.15's in it already so they didn't know the cars off the top of their head which is why you have to question their recommendations at all lol. Anyway, I'm going with the 3.55s. I'll let ya know how it all turns out. Thanks again, everyone!

 

There's only a 5% difference between the 3.55 and 3.73 so I don't think you can go wrong either way.

 

Alright so I got the 3.55 gears put in yesterday guys and I loaded the BAMA tune that I called American Muscle to make up for me. My initial thoughts are.... MEGA DISAPPOINTMENT. The car slightly has better acceleration but its so minimal that it seems this wasn't worth all the money I just laid out. I mean every other modern car accelerates from a red light smoothly and quickly too, and they aren't supposed to have the power my mustang has. I've driven rental cars that are Fords Focus's and quicker than the stang to get going lol. I'm hoping that its because this tune just sucks and that I can correct this with a proper tune. The acceleration is barely noticible until I get up in speed. Its slightly smoother through first gear in traffic and parkinglots but after that it's still that jerky feeling the 2.73's always had. I really have to hit the gas to get the RPMs to go up on a short distance quick acceleration which is only something I would do hard if I need to do an emergency merge, which I did once today. I only drove around town today. Lots of in and out of the car at stores so I got roughly 14mpg which is pretty bad but I'm sure that will go up when I do real combined driving all week.

I thought once I did this I would get rid of the pedal commander too for the throttle body response sensitivity but right now it seems that I may need to keep that.

With all that being said it seems the install itself went well and the car is acting normal. No additional noise or anything, this is just a performance thing for me.

The tune could be an issue. I will look into it this week but any other recommendations. Is it me?

 

Go with MPT, that was the best tune on my 2013 3.7 convertible when it was NA with 3.55 gears..

 

Get a MPT tune

 

I'm going to look in to the MPT since so many seem to recommend them. I don't like the idea of laying out more money after a tuner with free tunes and gears but I want to finish this job and do it right and enjoy my last 2 years with this car. This bama tune is not only not that quick but its a rough shift on my auto too. I want the thing to be quick and like butter. My wife hates the jolt out of 3rd gear and I'm not fond of it either.

 

MPT tune!! Way better than Bama

 

If you have ever disconnected the battery, and did not go through the idle trim relearn process,
your off the line acceleration will suffer. There is a procedure FORD put in their cars to relearn
the throttle plate positions while idling, cold warm and hot, then with A/C on. Mine was sloppy, but I
had a battery put in, so while at Adavance Auto, I waited in the parking lot and went through the
process. HUGE difference...

Basically, after restoring power, you start the car and let it run for 10 minutes as it relearns the
idle trims. Then when at operating temp, turn on the A/C. You do this in PARK, idling. Idle
trim optimizes throttle plate positions. There is a video, with a guy using the FORD IDS
software, that shows it is learning the values, and when it rests on it's final values. Also
he explains the tolerance as to where it should be within when it's done.

Then you may not need that pedal commander, OR, will improve it even more. Doesn't matter how
fast the plate opens, it's what angle it's at. The plate only moves 45 degrees, from straight up
and down. If it's not at 45 degrees at WOT, you're losing some power, not a lot. If it opens passed
45 degrees, you may get more fuel, but less air. It is important the relearn is done after a TUNE or
removing battery power.