what hp do you need dual exhaust?

I ran a 515 for a while, went back to 435. I didn't experience any issues, but that's just me. It will be interesting to hear from others....

 

He wants to go higher with his HPs.... I also have no idea if you need dual exhaust, but i did see lots of trucks with CAT 550 hp with single exhaust.

 

A single larger diameter is often better then duels as it is about restriction.
One 6" pipe has 12,5% more area then two 4" pipes.
Then if you factor in the Y or T piece needed for duels as well as the extra bends and extra friction from more surface area you are way better off with a larger single.
What is very important is the muffler , this is where sometimes duel pipes have an advantage as you can use 2 mufflers.
A good free flow muffler is very important if you are concerned about this.

 

have 3 515 detroits... all have single exhaust ... been doing this along time and I love the old dual exhaust trucks... I mean I love them.. would take a 359 or 379 pete over anything.. but there is no need for dual exhaust.. it just looks better.. I am getting 6.6 mpg on all 3 as an avg and never have a power issue..

 

With duals all your power is coming straight out.

 

That not true. Cascadias come out the factory with 600hp and single exhaust sometimes.

 

FWIW, I've tried a high flow muffler on my previous 01' S60 and now my MBE4000, neither time did it make a measurable difference in power or economy. Both times it made more noise and lightened my wallet.