Originally Posted by 1QwkSport2.5r

Generally, single chamber pipes will aid the low to mid part of the powerband where multi-chamber systems are for mid to high rpm power. The shorter the whole system (header, coupler, pipe) is, the higher the rpm potential. If the engine doesn't have enough exhaust timing though, too short of a "system" will have erratic running behavior. Short system - fast pressure wave return - high exhaust timing. Long system - slower wave return - lower exhaust timing. Generally. Some multi chamber pipes work a bit different though.

FWIW, most guys with monster trucks will opt for an 086 variant as the engines for monster trucks often have a decent low end to start with. An 086 won't hurt the bottom end much, but helps the top end a bit. On some engines it helps a lot. It is said that an Ofna 086 and the Dynamite 086 are very different pipes with the Dynamite being the better of the two. The barn burner pipe to have is a Novarossi 51021/9886. That is the pipe that many other 086 variants are based from. The Novarossi 9853 is said to be 98% "close enough" to the 9886.