Straight pipes vs muffled pipes and jake brake effectiveness

if your going to go with strait pipes you give up your right to idle next to me in a truck stop at 1 am

 

Truck with dpf has poor performance and usually about 1 mpg harder on fuel.

 

A DPF filter on your exhaust system catches all the black soot (particulates) and traps it in a ceramic filter. It's similar to trying to run a marathon with a thick sponge duct taped over your mouth and nose. When the built up soot backs up enough exhaust gas and affects performance, raw fuel is sprayed onto the hot ceramic filter- this lights the carbon soot on fire and burns it off.

It'll get better mileage with no ceramic filter for the exhaust gas to squeeze through, but trapping black exhaust soot is the point of the filter.

 

And how are you gonna stop someone from idling next to you, I'm curious, as I feel the answer is gonna be very funny...

 

Construction barrels to the right and left of you or just use police tape do not cross even a radioactive sign stating to stay back 20 feet at all times.

 

So many areas of the country do not even check the emissions on autos like they do in major cities or CA. I might show some concern over the green police plugging up my truck and checking ECM stuff when all states jump on the auto emission testing game. Of course California is always the major issue. But only if one runs there.

Back to OP. Reducing the restriction on the exhaust side of the engine is always a plus. How you go about it, you can keep jake brake noise down and get good exhaust flow. But there is no real way to reduce exhaust restriction without some increase in the decibel level. There are really good high flow mufflers from Donaldson, Walker, PP, etc that get that exhaust moving and still keep the noise down to a tolerable level.

 

Jakes dont work on your exhaust. If I remember correctly the Jakes on a larger engine work off the cam shaft. Your popping your compression stroke with out the combustion. So stack size has no bearing to what the jake does. However..... If you reduce too much back pressure you can damage your valves by allowing cold air in when you let off the fuel.

Out of curiosity? Why not sleeve the existing pipes with larger ones?

As to going to straight pipes. The louder noise will destroy your hearing. It may look and sound neat for about 5 minutes. On my own antique, a neighbor said he loved the sound of straight pipes. I let him try it on my antique. In 5 minutes he didnt like it anymore. Fortunately for me it didnt cost anything to be able to go back to a muffler. For a class 8 rig, you will be paying for it over a long time.

Do it if the truck is for show. Dont do it if you want to work it.