What would be the effects of a different manifold on a VX?

[mkiVX]

well i have a question
our vx's have a catalytic converter on th exhaust manifold
if i would install a si ex manifold which has no cat
besides the whole smog thing, would my car run any better
the reason why i ask is because i heard that lowering your back pressure is no good PLEASE HELP
i am itching to install this manifold and i don't want it to affect my mpg
thanks!!

[GasSavers_Ryland]

often the aftermarket manifolds are to large for the lower volume of exaust that the vx engine has, so unless you are running your engine at 4-5,000RPM it is going to expand in that manifold to much and act slightly like an expantion chamber on a 2 stroke, where you get waves of back presure feeding back in to the engine... not something you want on a 4 stroke engine.

[mkiVX]

Originally Posted by Ryland

often the aftermarket manifolds are to large for the lower volume of exaust that the vx engine has, so unless you are running your engine at 4-5,000RPM it is going to expand in that manifold to much and act slightly like an expantion chamber on a 2 stroke, where you get waves of back presure feeding back in to the engine... not something you want on a 4 stroke engine.

an ex manifold is pretty much stock with the exception of no cat

what o you think

[GasSavers_TomO]

You could swap out the manifold if you catalytic converter is shot and you son't feeel like getting the expensive OEM replacement.

The EX/LX/DX one wouldn't harm mpg noticably. You would still want to get a catalytic converter to put in there though, for noise reasons as well as emmision reasons though.

[StorminMatt]

You can get the manifold and downpipe for next to nothing at a wrecker. You could always pick the stuff up and see how it works. If it doesn't work well, you can just go back to the OEM stuff without taking too big of a hit money-wise.