Reveiews - Manifold spacer, TB and Chip

[MagiTEK]

By blocking the valve it stops exhaust gas from recirculating back into the manifold (hence EGR = Exhaust Gas Recirculation valve) Its required to pass emission laws.

So no without the egr, you have normal air (instead of heated exhaust gas) entering the engine and it runs cooler.

 

[vxcalais_01]

THanks MagiTEK. The plenum runs cooler, but i meant the extractors and exhaust, wont that run hotter ?

 

[MACE]

Hows this one going ???

By blocking off the EGR valve, doesn't the engine and exhaust heat up more that it should ?

Mace, what is the purpose of the blanking plug on the vacuum hose to throttle body ?

Makes a negligible difference to blocking it up to engine and exhaust temps. The idea behind blocking off the EGR valve is to keep inlet temp normal.

By blocking the valve it stops exhaust gas from recirculating back into the manifold (hence EGR = Exhaust Gas Recirculation valve) Its required to pass emission laws.

So no without the egr, you have normal air (instead of heated exhaust gas) entering the engine and it runs cooler.

I’ll be quick to add that EGR is definitely a good thing if you want to improve fuel economy as it reduces the pumping losses associated with a petrol engine and potentially power, provided the exhaust gases entering into the inlet manifold were cooled.

 

[vxcalais_01]

Below is from Holden service manual, they claim egr helps lower intake temps ??

PRINCIPLES OF OPERATION
The Non Supercharged V6 engine is equipped with
an Exhaust Gas Recirculation (EGR) system. The
EGR system is used to lower Oxides of Nitrogen
(NOx) emission levels, caused by high combustion
temperature.
A linear EGR valve feeds small amounts of exhaust
gas back into the combustion chamber. This dilutes
the air/fuel mixture and combustion temperatures
are reduced.
The linear EGR valve is designed to accurately
supply exhaust gas to the engine independent of
the intake manifold vacuum. The valve controls gas
flow from the exhaust to the intake manifold
through an orifice with a PCM controlled pintle.
During operation, the PCM controls pintle position
by monitoring the pintle position feedback signal.

 

[Immortality]

EGR would reduce combustion temps simply because if you pollute the intake charge (air/fuel) there is a non combustible material present during the burn phase, less fuel and air(or more precisely oxygen) = less heat. just reducing the fuel doesn't work as it leans out creating more heat. increasing fuel reduces heat but increased fuel usage.........

 

[MACE]

Emissions aside,

I'm much more excited about using EGR to reduce fuel consumption, by reducing pumping losses under part throttle.

For a better understanding of pumping losses check out the link below

Part Load Pumping Losses In A Spark Ignited IC Engine

Cheers
Steve