Pros and cons to blocking the EGR valve
- Thread starter YoungyD22
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ST-R
Member
Pro's
Minor turbo spool up and low RPM Improvement, Less soot in oil, Less Exhaust smoke, Minor Economy improvement and soot build up in inlet manifold greatly reduced. Possibly increased timing chain life due to less corrosive acids in oil.
Con's
Nothing to my knowledge.
Regards
Greg
Minor turbo spool up and low RPM Improvement, Less soot in oil, Less Exhaust smoke, Minor Economy improvement and soot build up in inlet manifold greatly reduced. Possibly increased timing chain life due to less corrosive acids in oil.
Con's
Nothing to my knowledge.
Regards
Greg
Teleman191
Member
Cons - car is now unroadworthy for tampering with emission systems.
I change the plate back to stock when I get Nissan to service it.
I change the plate back to stock when I get Nissan to service it.
Apart from the emission control tampering (which does technically render the car not only unroadworthy but worth a fine in excess of $10K), what you're doing to the combustion process is removing a dampening agent, allowing the combustion to be more complete. This reduces unburnt particulates - which you see as soot, in both diesels and unleaded cars. Check the V8s next time off the start grid - in fact, look at around 1:20-1:25 in this video at the cloud along the main straight, much of which is fuel (some of it is tyres!).
More complete combustion means better (more efficient) use of the fuel going in, which means more power and better economy. What you're also doing is increasing the amount of NOx (oxides of nitrogen) that your engine is producing. Your CAT is going to collect about 15% or so of that, but you're contributing to the creation of the superhighway into our planetary atmosphere that allows races like the Vorgons to have unrestricted access to the resources on this planet.
Oh what? Maybe I just meant a hole in the ozone layer. Either way, many people say either is total BS, so choose the BS you want, it's all free!
More complete combustion means better (more efficient) use of the fuel going in, which means more power and better economy. What you're also doing is increasing the amount of NOx (oxides of nitrogen) that your engine is producing. Your CAT is going to collect about 15% or so of that, but you're contributing to the creation of the superhighway into our planetary atmosphere that allows races like the Vorgons to have unrestricted access to the resources on this planet.
Oh what? Maybe I just meant a hole in the ozone layer. Either way, many people say either is total BS, so choose the BS you want, it's all free!
Chris_in_Ravenswood
Member
Doesn't apply to turbo diesels. Because of the turbocharger, there's no vacuum in the chamber (or not often, anyway) and thus no "vacuum to work against".
Vacuum in the cylinders is (can only be) present at ONE point in the combustion cycle (for a turbocharged engine) anyway: just after the piston rises with the exhaust valve open, as the valve closes, the piston reaches the top, then starts to descend and the intake valve opens to allow fresh air to be drawn into the motor. There might be a small fraction of the cycle (in either diesel or petrol engines) where the piston is just starting to travel from the top of the stroke (TDC) to the point where the piston has left enough room for the valve to open that there's a vacuum present.
Once the valve opens, any turbocharged engine will have air pumped into it (same for supercharged engines). Normally aspirated engines will draw air in, but that's such a small amount of effort required - consider when you take the glow plugs, or spark plugs out, and try to turn the engine over by hand. You can do it!
His theory that the EGR replaces all of the air (removing the vacuum) contradicts his earlier statement that EGR is only used in minute amounts, and doesn't make sense then that at full throttle, when you want the most power available, the EGR system is turned off - by his measure, to overcome the vacuum, you'd want as much EGR as possible!
Nice try, but it's a shame that this misinformation is getting exposure, especially for those of us with turbocharged engines.
Vacuum in the cylinders is (can only be) present at ONE point in the combustion cycle (for a turbocharged engine) anyway: just after the piston rises with the exhaust valve open, as the valve closes, the piston reaches the top, then starts to descend and the intake valve opens to allow fresh air to be drawn into the motor. There might be a small fraction of the cycle (in either diesel or petrol engines) where the piston is just starting to travel from the top of the stroke (TDC) to the point where the piston has left enough room for the valve to open that there's a vacuum present.
Once the valve opens, any turbocharged engine will have air pumped into it (same for supercharged engines). Normally aspirated engines will draw air in, but that's such a small amount of effort required - consider when you take the glow plugs, or spark plugs out, and try to turn the engine over by hand. You can do it!
His theory that the EGR replaces all of the air (removing the vacuum) contradicts his earlier statement that EGR is only used in minute amounts, and doesn't make sense then that at full throttle, when you want the most power available, the EGR system is turned off - by his measure, to overcome the vacuum, you'd want as much EGR as possible!
Nice try, but it's a shame that this misinformation is getting exposure, especially for those of us with turbocharged engines.
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I'll go back and edit my post a little. I just noticed a few language transgressions (nothing racist, of course) - just need to make it a little clearer.
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