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Rawze · 06-15-2018, **(Subject: Fuel Efficiency differences 870 vs 871 )**

(06-15-2018 )Chamberpains Wrote:
(06-15-2018 )Rawze Wrote: I think your over-thinking it a bit there.

Last I checked, there was hot inert gases and and an EGR valve restricting flow though the venturi portion getting in the way of that effect, therefore there is no real efficiency gain. Block the EGR pipe (just commenting on what most 870 owners do) and all you end up with is a bit of unnecessary turbulence.
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Without the EGR nozzle in the way (completely removed) wouldn't this pipe act as a de Laval nozzle?
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With no air flow to supply it and it blocked off, it will not do anything but cause some turbulence in the intake. If you re-routed to a clean air supply, did provide a pathway for clean air, it would have to be post air filter, pre turbo,.. and there is already a slight vacuum at this point, I would suspect there would still be no gains there either. If it is unused for EGR gas, the only gain would be to remove it from restricting the intake. I have seen ppl doing just that in countries where such things are legal.

Chamberpains · 06-15-2018, **(Subject: Fuel Efficiency differences 870 vs 871 )**

I know extremely well of 1 guy that completely removed that nozzle in a country that deems such modifications illegal. He claims the authorities don't know or don't care thats it's not there anymore. And I've seen 1st hand this guys truck get looked at really hard at least 8 times by the authorities (puc and dot) in many different states and not so much as a mention of something wrong there. ;-)

DLC · 06-16-2018, **(Subject: Fuel Efficiency differences 870 vs 871 )**

I'd hope they'd be more concerned about the condition of said persons brakes,tires, lights etc.

It's too bad they don't have a cost effective way to lower NOx. It's not a problem in rural areas but in some urban areas it needs help. CNG engines would certainly help in local delivery trucks.

Rawze · 06-16-2018, **(Subject: Fuel Efficiency differences 870 vs 871 )**

(06-16-2018 )DLC Wrote: I'd hope they'd be more concerned about the condition of said persons brakes,tires, lights etc.

It's too bad they don't have a cost effective way to lower NOx. It's not a problem in rural areas but in some urban areas it needs help. CNG engines would certainly help in local delivery trucks.

There are ways to lower NOx without sacrificing fuel efficiency or all the problems with soot. Engine makers have no interest in developing it.