Picked up a new commute vehicle this week

[STEvil]

Dunno why you want to remove NOx. We're developing systems to inject the tractor exhaust into the ground around here because plants like NOx...

[zanzabar]

Dunno why you want to remove NOx. We're developing systems to inject the tractor exhaust into the ground around here because plants like NOx...

it destroys the ozone layer, but of course that also helps stop global warming even if it dose it by making sure the ozone is not there to absorb uv radiation.

[dengyong]

Your understanding of the EGR Valve is completely wrong too. High combustion temperatures are efficient with low hydrocarbon emissions, but very, very high in NOx emissions. NOx emissions are what cause acid rain and smog. The EGR valve's job is to lower combustion temperatures to the point where the catalyst can effectively take care of the rest. As a side effect, combustion efficiency drops slightly creating more hydrocarbons, which the catalyst will also take care of.

It is a trade off. You get slightly more CO2 out the exhaust, but almost no NOx.

Right on.

[chinaguy]

My new VW has Direct Petrol Injection and works more like a diesel then a normal petrol car. It has a very high torque for a 1.4lt in line four, its more like a V6 or small block V8. It has the supercharger that works up to 3500rpm and then a KKK turbo cuts in from 2500rpm to the engine limiter at 7000rpm. The 7 speed DSG box is in top gear at 80kmph and the engine is only going 1500rpm.

The engine pushes out around 140bhp at 6000rpm but can give me 45miles/gallon(I have the GT TSi engine spec, I only got it for the electronic stablity control and the EPS breaking((not for the reason the car is seriously HOT))). So the same kind of performance as a BMW 323i but the fuel consumption of my old mini clubman 1100cc. At a steedy 100kmph with the auto cruse on I dont think the car would ever run out of petrol, it must hit 12-14km/1lt of petrol.

Diesels only work as an option when the Devils Piss costs half as much as Petrol. 25 years ago in the UK diesel engines cars sounded like tractors but people would buy them and put up with slow performance as diesl was 30-40pence cheaper then petrol. When more people bought diesles the TAX went up and now diesel cost more then petrol!

No taxation without representation.

[[XC] Lead Head]

im 99% sure that carb mandates it for gas vehicles, and isnt it a servo unit stuck inside the intake manifold from ford and a passive unit for new vortec. u dont need the valve buy u do need flow.

Nope, we tore into a brand new 3.7L V6 Mustang for a competition for school. There is no EGR valve for the 3.7 and 5.0. The only emissions controls on the new engines are the evap system and a PCV valve. Like I said, they alter the camshaft timing during cruise to create a self-EGR effect. In addition, the latest generation of mustangs come from the factory with wideband oxygen sensors, giving the ECU even more fuel control.

The GM Vortec 4200 I6 is the same way, it has no solenoid, no servo, no EGR valve, no anything. Alters cam timing at cruise.

for the cat, dosnt the egr make more hydrocarbon emissions so old cats can work (the ones from way back in the 70's), and for the nitrogen emissions dosnt the use of ethanol in the fuel lower the temp enough already to negate the high combustion temp now and previously mtbe. and it dose not change that most cars will pass smog tests without the egr but then will fail if its disabled or cloged or dead and shut on the visual inspection.

The EGR only has one purpose, to reduce combustion temperatures to reduce NOx. As a side effect, it increase hydrocarbon emissions. Ethanol is cleaner, but E10 is not clean enough.

what i know about egr in practical terms is that with smog test units that i got to use back in shop like 8 years ago, both my cars based with the egr disabled out the pipe (the same nitrogen and no hydrocarbons until deceleration, just like with the egr) and both get much be mileage with my truck getting alot better power.

Three way cats are getting better are being able to reduce NOx into its components, so you do not need as much EGR.

Dunno why you want to remove NOx. We're developing systems to inject the tractor exhaust into the ground around here because plants like NOx...

Oxides of Nitrogen in the ground are different than NOx in the air. NOx in the air forms acid rain and smog.

[Dave_Sz]

Yeah, EGR and most technology related to exhaust emissions just hurt efficiency and/or power efficiency thus creating more emissions and more fuel use.. DPF (Diesel Particulate Filters) are an example of this. Sure they help with particulate matter a bit, but so would turning up the turbo pressure or injecting water/methanol or water/ethanol..

Hmm, I completely eliminated my EGR system during my last engine swap, only left the egr temp sensor connected to not trip the cel and have gained maybe 2-3mpg. Same goes for most of the people I've read about or know, who have done the same egr delete.

[STEvil]

Oxides of Nitrogen in the ground are different than NOx in the air. NOx in the air forms acid rain and smog.

Yes, however, they tend to settle on the ground when talking diesel.

In a city there is an issue. Anywhere else it goes to the plants and is good for them.

Wasting more fuel to decrease NOx emissions doesnt seem like an efficient method of reducing NOx output for consumer vehicles to me.

[chinaguy]

In the late 80's and 90's if a car engine was under 1400cc it did not need to have a CAT converter fitted as the CO2/NOx equation was deemed to costly in the amount of petrol it would take to reduce the NOx. The tree huggers won the day and all cars needed a CAT fitted no matter how small the engine. This was in the UK so this is why you will see a lot of cars of this time advertised with 1400cc engines instead on the usual 1300cc(the 1300cc limit came from the old TAX bands on cars <999cc, <1298cc, 1798cc and >2200cc.)

So lossing 8-12bhp on a small 1000cc engine that is only producing 70bhp in the first place cost a lot in extra petrol for little improvement in the enviroment IMHO.

My mothers 1300 Morris Marina pushed out 75bhp comapred to a Smart Cars 60bhp from an 800cc turbo engine, but with a CAT taking its share on the power.

[[XC] Lead Head]

Yes, however, they tend to settle on the ground when talking diesel.

In a city there is an issue. Anywhere else it goes to the plants and is good for them.

Wasting more fuel to decrease NOx emissions doesnt seem like an efficient method of reducing NOx output for consumer vehicles to me.

They are more likely to react in the atmosphere and form smog before they settle to the ground. Just like people that say Diesel soot settles to the ground. Diesel particulates can stay floating around for weeks before finding their way to the ground. NOx particles are much lighter than solid chunks of carbon, and would probably stay in the air for months.

More "clean" emissions are better than less "dirty" emissions.