For all those interested, after installing my American thunder flowmaster kit with the 50 series dual out muffler, as expected, low end torque/power was lost. I wanted to get that back & keep the dual out exhaust, so today I visited the muffler shop and had 2 1/4" reducers installed on the output side of the exhuast, taking it from 2 1/2-> 2 1/4 -> 2 1/2. The results are... exhaust tone is the same and the low end power is back. But as expected the top end suffered a little. I feel that the balance between top end & bottom end is much better this way. This is a temporary setup, the muffler man is letting me leave it this way for a week to see how I like it, then either put it back the way it was or weld it as is.

This will give me a week or so to see how mpg are affected. I currently get a consistant 11.8 mpg average city/hiway driving. Before the install of the flow kit, I was consistantly getting 12.8 mpg. I check every tank. I'll know in a week.

 

Thanks for the informative post. I think this kind of post is what adds the most value to forums like this. You check results before you buy something... install it, check results after installing it... share results. Now hundreds of people don't have to go threw all the pain and money of trying something if they don't personally like the results... OR they can buy the stuff with confidance if they do!

Posts like this don't usually get much in feednack.. so I wanted to give credit.
*hats off!*

 

Thanks, I see SO MANY posts about people beetchin & complaining about their gas milage & when anyone mentions something that's not "intake, exhaust or software", you never hear any feedback. I have posted another mod that I did that added 6% better fuel economy and there were a couple of interested people... not sure if they tried the mod yet but, I figure when someone searches for better fuel economy, this thread will come up & maybe help someone out there.

I'm the type of person to tweek until I'm happy with it. I'm shooting for 15 mpg average... maybe not doable with the 360 & big tires, but I'll never know unless I try... I will post results on the next mod that I do.