does the 6.2 need backpressure ?

[Keith_J]

Diesels have little to no valve overlap. There is little clearance between the piston and the head at TDC. Valves are just 10 to 15 thousandths below the planed gasket surface.
Mufflers work by providing an expansion volume, then a slight restriction or a flow path variation. Some have louvered inlets which act as reversion preventers.
The best mod for the least cost are mandrel bent head pipes from the manifolds to the mufflers. Any stock muffler is not going to add any significant back pressure compared to the crimped and necked stock head pipes.
This engine flows a theoretical 400 standard cubic feet per minute of air at maximum speed, 3600 RPM. And in actuality, it is just a bit over 300 cubic feet per minute at this high speed. Even at 950°F, dual exhaust means flow velocity is barely 200 ft per second in the stock system. Not a problem with smooth bends.

 

[MTVR]

Dude -

This thread is ELEVEN years old.
But since you brought it back from the dead -

NO - you do not need back pressure. This topic has been beat to death for years. This subject has caused irreparable harm to close lifelong friendships. I know of one divorce and two shoot-outs this silly backpressure debate has caused. I promised my current wife and both my near-miss friends that I would never be drawn back into the debate again. Don’t even think about trying to get me to respond further on the backpressure subject, as I will not. This tape will self-destruct in five seconds. Good luck Jim.

AMEN!!!