Valve On exhaust System , Whats it for ? any benefits , Louder ?

[madalex]

What does a valve do on an Exhaust system ??? I was told something to do with built up pressure , Any louder , Performance gain ect

Cheers :icon_thumright:

 

[dummi]

on a standard car its supposed to give back pressure at low engine speeds to give you a bit more instant torque when your engine is not loaded , it is always open when the car is under load accelerating. also reduces noise when cruising or sitting in traffic... if your car is modified just remove it for better flow

 

[LDoR]

I always heard that back pressure in the exhaust was good for low down tourque but that never made sense to me. Resistence will just sap power and i read something in evo about that which says this back pressure being good for low down tourque is not true.

 

[Prawn]

it depends on the type of engine.

on an n/a car, a small amount of back pressure really does aid low down torque.

in my 1380 mini, when i get an exhaust leak (often due to it being SO low) i loose lots of low down torque due to the lack of back pressure. when i fix it, the torque appears again

in a turbo car, its not the case, maximum flow is needed for power, with no back pressure at all.

although, low down off boost, the turbo engine just acts like an n/a anyway, so in theory at least, the exhaust valve could help.

although personally, i think thats just a gimick, id never bother.

the back pressure arguement is true though.