Do turbos need exhaust backpressure?

The turbos don't the need back pressure the EGR system I believe need some back pressure. The EGR needs back pressure to force air in to the system. I believe. Just opening the EGR valve is not enough pressure to force air in to the system. So it need some back pressure to force air into EGR sytem when the valve is open.

Like other said the DPF need some back pressure also. The computer know when to Regen the DPF by monitoring the pressure from in front and back. When the filter fills up with soot the pressure goes up since air is not passing thru. The computer then says it time to Regen going down the road. It lights it on fire burns the soot off the back pressure drop and everything is good to go again.

 

I'll assume your talking about a isx... with the correct programming no back pressure wouldn't be a problem. The only reason dpf engines need to see back pressure is so the Ecm knows the dpf is functioning correctly...,

 

Less restriction in the exhaust and intake, the better. Engine doesn't waste energy trying to push the dirty exhaust gasses out.

 

Ding! Ding! Ding! We have a winner!

To get there, that is why many modern diesel use VG turbos. The exhaust spool vanes can be modified electronically to generate the back pressure needed. But also, they are moderated to spool up boost quicker also. It is a two for one thing. The ECM controls the variation via the actuator to get the desired result. Adds a stack of complication and when that turbo or actuator need replaced, it lightens the wallet quite a bit. And they don't last as long typically compared to asymetric turbos of days gone by. And the benefit of those asymmetric turbos is that we could free flow the exhaust behind them, reducing EGT's and lightening the load on the engine and getting better performance and efficiency.

 

100% @Brandt was right, back pressure is only used for egr. As far as the oil in the intake pipe, the seals gone and it will get worse. You can either buy a new one of find a turbo rebuild shop who can do it... alot cannot and some who say they can, fail.

I found a place in Acheson AB Canada called Dave's diesel who did mine for $2500cdn after another shop f'ed up. It's been flawless ever since.