I have a 04 4.7 4x4 and was thinking about getting a super 40 with 2in/2out. Has anyone tried this configuration before? Does anyone see any performance problems with this?

 

get a 3" out or dual 2.5's reduced to 2.25" and you'll be happy.

 

So you are saying to not get the 2in/2out setup? Because I could only find them at 2.5" diameters.

 

you dont want 2 inch because i think the stock pipe is 2.5 or 3 inch so that would be downsizing it

 

I am not talking about the exhaust haveing 2" in and 2" out, I am talking about having 2 inlet and 2 outlet ports that are 2.5" in diameter on a flowmaster 40.

 

It won't lead to any problems, but it will be loud as crap. I personally reccommend the Flowmaster 50 Series due to three reasons. Primarily, they are better built mufflers (made from thick guage steel as opposed to 40's aluminum frame). Secondly, one flowmaster 40 will make your truck quite loud, enough to be heard driving 1/4 mile away... but two in my opinion is overkill. Third, the interior noise produced by the 40 series is quite loud, almost as loud as being outside, while the 50 series is 1/3 the noise... Thus you could still listen to music where as the 2 40's would ruin that likely...

Good luck and enjoy your exhaust!

 

It is a huge misconception that true duals are "louder". In fact, most of the time, they aren't as potent. I run a si/do set-up, and it's louder than any other truck I know of around town. True duals are designed for trucks that are packing some serious horsepower, or race, you don't need one if you don't have much done to your truck. You'll most likely loose some torque actually. There are ways to make a si/do system lethal. My truck has long tube headers with the offroad y-pipe, a gutted cat, and a si/do super 44 muffler. It's as flowing as any other system, and extrmely loud. Don't be fooled into thinking true dual means louder..and in some cases like I said before, they loose potency because there is less air going through each muffler..

Now if you want to do dual in/dual out muffler...I'd say go with the 2.5 inlets/outlets..it will not hurt performance much, you may loose a little torque with this somewhat of a true dual set-up, but if your aching to give each manifold its own inlet, then you could go with this...but if you want it to be loud, this will not make a differance.