bigger converter like a 2800 with a trans cooler
3.55 gear will wake it up and work great when you convert to stick later too. Bigger crank makes a huge difference...pay no attention to #s posted when you drive it youll see
Or sell it all and get a blueprint 406 crate

 

sorry for the newb questions, but the EGR...that has to do with the spread bore flange right?...but what does it mean? is the EGR how I will know the Qjet will work with it as well as my edelbrock carb? and they will both work with out an adaptor right?...

Thanks again.

 

EGR is exhaust gas recirculation. It is a valve that is part of the emissions equipment. Not related to carb type.

The Q-Jet is a spreadbore carburetor, secondaries are bigger than the primaries. The Edelbrock is a squarebore carb, secondaries are the same size as the primaries.

Most aftermarket spreadbore manifolds are drilled for both types of carb. You just need to use the right gasket. The difference is why you had to use a adapter spacer to put the Edelbrock on the stock manifold.

Edelbrock also makes Performer manifolds without EGR as well as Performer RPM squarebore and the RPM Q-Jet which is a spreadbore.

 

I knew that as well!...maybe if I engaged my brain!...Ive heard the EGR reduces performance? Whats the benefit in that rather then a non EGR intake?

Got yeah, ill have to make sure I get the right gaskets.

 

EGR does not reduce performance if it's working correctly and offers some benefits. Look up the EGR Wikipedia page. A benefit is that it will keep your car (at least apoearing) emissions legal.

If your heads don't have the heat riser crossover passage, you won't be able to have a functional EGR system.

 

If you are looking for more power without changing lots of engine components to get there, I would skip the intake and go for a more aggressive roller cam assuming you have the compression to support the change. Which magnum cam do you have and what compression pistons as well as the CC on the heads? The gear change suggestion would be noticeable as well.

 

 

Sorry but EGR's do NOT improve or have no effect on performance...This is bantered about often but the EGR is an emissions device designed to reduce NOx..period. It is not a free ride..never has been and never will be. Show me a performance engine builder who uses an EGR valve?

 

Considering there are only two aftermarket intakes I know of that have EGR provisions (Performer EGR and ZZ4), using the non-use of EGR valves on performance engines as an argument against them isn't really a strong one.

Combine that with the lack of functional heat crossover passages in aftermarket cylinder heads (AFR, Edelbrock Performer, and Dart Iron Eagles 165cc are the only ones I've been able to find that don't require modifications to make it functional, and I've looked).

A final point, most race cars wouldn't benefit from EGR. Most performance cars before the mid-70s didn't come with EGR, so adding one probably isn't a high priority. Most cars that did come with EGR have had all of the "emissions junk" removed to simplify the engine compartment. Laws in most states make these cars emissions exempt now, anyways. One of the (theoretical) non-emissions benefits of EGR is improved MPG. With most people having these as limited use fun cars, MPG isn't a concern.

 

Exhaust gas recirculation


From Wikipedia, the free encyclopedia


Jump to: navigation, search




This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (March 2009) (Learn how and when to remove this template message)





EGR valve the top of box on top of the inlet manifold of a Saab H engine in a 1987 Saab 90
In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide (NOx) emissions reduction technique used in petrol/gasoline and diesel engines. EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders. This dilutes the O2 in the incoming air stream and provides gases inert to combustion to act as absorbents of combustion heat to reduce peak in-cylinder temperatures. NOx is produced in a narrow band of high cylinder temperatures and pressures.

In a gasoline engine, this inert exhaust displaces the amount of combustible matter in the cylinder. In a diesel engine, the exhaust gas replaces some of the excess oxygen in the pre-combustion mixture.[1] Because NOx forms primarily when a mixture of nitrogen and oxygen is subjected to high temperature, the lower combustion chamber temperatures caused by EGR reduces the amount of NOx the combustion generates (though at some loss of engine efficiency).[2] Gasses re-introduced from EGR systems will also contain near equilibrium concentrations of NOx and CO; the small fraction initially within the combustion chamber inhibits the total net production of these and other pollutants when sampled on a time average. Most modern engines now require exhaust gas recirculation to meet emissions standards. Chemical properties of different fuels limit how much EGR may be used. For example methanol is more tolerant to EGR than gasoline.[3]



Contents [hide]
1 History
2 EGR
3 In diesel engines
4 See also
5 Sources 5.1 References

6 External links


History[edit]

The first EGR systems were crude; some were as simple as an orifice jet between the exhaust and intake tracts which admitted exhaust to the intake tract whenever the engine was running. Difficult starting, rough idling, and reduced performance and fuel economy resulted.[4] By 1973, an EGR valve controlled by manifold vacuum opened or closed to admit exhaust to the intake tract only under certain conditions. Control systems grew more sophisticated as automakers gained experience; Chrysler's "Coolant Controlled Exhaust Gas Recirculation" system of 1973 exemplified this evolution: a coolant temperature sensor blocked vacuum to the EGR valve until the engine reached normal operating temperature.[4] This prevented driveability problems due to unnecessary exhaust induction; NOx forms under elevated temperature conditions generally not present with a cold engine. Moreover, the EGR valve was controlled, in part, by vacuum drawn from the carburetor's venturi, which allowed more precise constraint of EGR flow to only those engine load conditions under which NOx is likely to form.[5] Later, backpressure transducers were added to the EGR valve control to further tailor EGR flow to engine load conditions. Most modern engines now need exhaust gas recirculation to meet emissions standards. However, recent innovations have led to the development of engines that do not require them. The 3.6 Chrysler Pentastar engine is one example that does not require EGR.[6]

EGR[edit]



This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (August 2014) (Learn how and when to remove this template message)

The exhaust gas, added to the fuel, oxygen, and combustion products, increases the specific heat capacity of the cylinder contents, which lowers the adiabatic flame temperature.

In a typical automotive spark-ignited (SI) engine, 5% to 15% of the exhaust gas is routed back to the intake as EGR. The maximum quantity is limited by the need of the mixture to sustain a continuous flame front during the combustion event;[B] excessive EGR in poorly set up applications can cause misfires and partial burns. Although EGR does measurably slow combustion, this can largely be compensated for by advancing spark timing. The impact of EGR on engine efficiency largely depends on the specific engine design, and sometimes leads to a compromise between efficiency and NOx emissions. A properly operating EGR can theoretically increase the efficiency of gasoline engines via several mechanisms:
Reduced throttling losses. The addition of inert exhaust gas into the intake system means that for a given power output, the throttle plate must be opened further, resulting in increased inlet manifold pressure and reduced throttling losses.[7]
Reduced heat rejection. Lowered peak combustion temperatures not only reduces NOx formation, it also reduces the loss of thermal energy to combustion chamber surfaces, leaving more available for conversion to mechanical work during the expansion stroke.
Reduced chemical dissociation. The lower peak temperatures result in more of the released energy remaining as sensible energy near TDC (Top Dead-Center), rather than being bound up (early in the expansion stroke) in the dissociation of combustion products. This effect is minor compared to the first two.


Lots of compromises and theorectical assumptions. Early EGR systems like on our C3's have zero benefit but to reduce NOx emissions. Modern cars with sophisticated ECU's are a completely different story.....Almost all emissions components from the 70's/80's were junk with the exception of PCV valve.... As for the claim that an EGR valve on a non computer controlled vehicle like a C3 corvette will INCREASAE MPG...not a chance....sorry.