Guys, bear with me here, I'm not quite sure how to explain this lol

when I floor it, which isn't too often, and my rpm's get up to about 5000, right before it shifts, my exhaust goes from a healthy and deep rumble to like it throws up. The deep rumble goes away and I feel like it couldn't handle it. Anybody remotely know what I'm talking about? Any help on how to correct this is appreciated. I have flowmaster 40 series on there that came with the truck.

 

What engine do ya have?

 

5.7L hemi ... 2004 1500 QC

 

you need the 5.9

 

Mine does it too. I believe that just before the shift occurs the computer pulls the timing to cut power so the limp wristed 545rfe can make a shift without grenading. Mine makes a loud sort of pop when it makes the change to my belief its the same thing but I am not 100 percent on this. Anyone care to add?

 

Sounds about right for the stock shifts, get a tuner and it will firm up than shift. With an 04 get a superchips, the newest one that supports all the new stuff coming out, and you wont have that shift problem.

 

Why the Superchips programmer over the Diablo Sport Predator?

 

The Diablo does not support the trans tuning on the 04's yet, only the 05's up while the superchips is about to release some sweet tuning features for the trans fro the 04's up.

 

When I had my flow masters put on my truck the guy said that the hemi's sometimes do not accept the new exhaust so hell and it screws with shift points, etc. He said Flow master hasn't figured out a way to solve it but he said it is not uncommon for the new exhaust to cause problems. Thankfully I have never experienced this!

 

Flowmasters flow about as well as a brick flys...

At any rate, the source of your problem is most likely the PCM pulling timing and making sloppy shifts. Like Truckin' and others said, get a Superchips.