I thought that I had it all figured out and was going to go with a Roush Legal SI/DO Exhaust for my truck.

Now I am questioning if I want to go with the dual tips out the rear, or single out the side?

I am also undecided on the Legal or Off-Road Systems (I want no interior noise) as I do not want to buy the Legal system and have it be too quiet outside.

These are the systems that I am considering so please do not suggest me buying Magnaflow or Flowmasters, etc.... as I want a complete T-304 Stainless system.

Borla SI/SO
Roush Si/DO Legal
Roush Si/DO Off-Road

 

I think the SI/DO would look very nice on your FX4. I have the Roush off-road and it does have some interior resonance around 2000 rpms. I absolutely love the way it sounds though...to me a little interior drone is worth it. I wouldn't classify it as loud per se, it's more of a deep, tough sound which sounds great Quite noticeable, and I've received many compliments from both men and women.

I've had this exhaust system for about 8 months and I still enjoy listening to the exhaust EVERY time I drive my truck. Like I said though, there is some drone inside at around 2000. I thought about the legal system too, but I didn't like the way the tips on the legal system look. I'm very glad I went with the off-road.

 

E-Mail sent

 

I went with the Borla SI/SO and love it. Nice deep rumble (not set off car alarms loud), you definitely hear it when accelerating but can't hear it at all when just cruising. Improved my highway mpg by 1.8 also..

 

Returned

 

SI/DO would look good. It's funny that you mention the Borla, because I think the Roush exhaust is a rebranded Borla. If someone has proof otherwise, let me know, but here is why I think this:

1. I have an Airaid CAI, which other than the branding, is identical to the Roush for a 5.4.
   
2. I just did a "stare and compare" at the SI/DO Roush Off Road (rear exit) and the SI/DO Borla. The pipe bends, clamps, and hangers appear to be identical.

I was looking at Flowmaster, but if the Roush truly is a Borla, for the price, I'm going Roush.

 

The Roush exhuasts are made by Borla..

 

That is why I am going with the Roush if I go SI/DO. It is about $250-300 less than the Borla Si/DO.

 

Can't go wrong with that! Shoot some pics up whichever way ya go..