OK what does all that elaborate crapola of running weird ass tubes from the exhaust and into the funky valve thing and back into the manifold ... what does it do --- BTW its a virago 1100 not GS ... I got one busted from the rear cyl ... so I wanna cap that and break off the front and cap its ass too. Then toss the entire BS and cap the vacuum fitting and be done with it.
Anyone know what its real purpose is and do I have to jet up or down ...
Cool.
Srinath.
is it like a pair valve? pair is where it injects air in the exhaust to burn the unburnt mixure. Just take it off if its this and cap it all up. it has lines running to the head above the header pipes right? If so then cap it all.
EGR (aka Exhaust Gas Recirculation) Valve. What is does?.... It re-introduces some of the exaust gas back into the combustion chamber to lower the combustion temperature enough so that NOx (Oxides of Nitrogen) gases aren't produced (at least not in great quantities). If you cap off the vacuum line it will no longer function. If the EGR valve isn't working then the engine will be leaner, since the CO2 isn't being sucked back into the combustion chamber.
I believe it does the opposite ... inject the exhaust into the intake manifold and make it run leaner ... and hotter ... yuck ... like feeding shaZam! to someone ... OK not quite ... but close enough ... now real question is ... jet up or down ... cap it all ... yup ... but up 1 jet ... 2 ... 3 ... BTW its got cobra straight through pipes so doubt anything was getting into the thing anyway ... used to have a tiny header and large collector and tiny exhaust ... now huge ass cobra pipe.
Cool.
Srinath.
what a great site! Even virago questions!
when removing the egr on a car the mixture would have to be richened. I would guess on the bike- go up a jet size. that is what we would do with holley carbs on cars. the egr injects exhaust that contains un burn't fuel back into the intake track. That had the effect of making the engine " think" it was runing richer then it was. this was done to increase gas milage and cut down emmissions. remove = lean so up a jet . shouldn't need more then one size
It does lower combustion temps. It also helps mileage when working properly.
On fuel injected cars, removing it without reprogramming will cause a Check Engine Light as the computer will not see the vacuum change when it opens the valve.
Dunno what you gotta do for a carb'd car, as I've never really work on them :dunno:
EDIT: Wow, didnt realize they put those things on bikes too.
OK... the EGR valve was designed solely to reduce the emissions of NOx from internal combustion engines. NOx gases are always produced as a natural byproduct of combustion but NOx levels rise exponentially once the temperature exceeds 2800 degrees F (ie. during high engine load) This is why the EGR valve is wide open at WOT, and generally closed or only partially open during lower load conditions. The function of the EGR valve was to allow inert gases (ie CO2) into the combustion chamber during these high load/high temperature conditions to lower the combustion chamber temperature below the 2800 degree threshold.... so basically if you remove the EGR valve, the a/f mixture will be pretty much the same for low load conditions, but will be lean under high load.
OK then ... 2 sizes richer ... cobra = 1, egr by pass = 1 ...
Of course We wrote the book on self craburetion as well as general bike and automobile info ...
The virago site - Hands on means you personally hand over the keys to the mechanic ... :lol: - Its a great place to get your saddle bag questions answered ...
Maxim site is better but they are a mailing list - not discussion like we are.
GStwin is the best of the whole damn lot - no matter what bike you got.
Cool.
Srinath.