what's the difference between the two

 

same thing?, think the Americans call them Blow Off Valves though

i could be wrong

 

as far as youre concerned theyre the same thing...

people incorrecly refer to them anyway, and literally speaking they are different

but everyone calls em the wrong thing anyway

 

how are they different then Jim?

 

blow off valve limits boost in champ cars bit like a bleed valve i think but doesn't allow pressure to raise like a bleed valve.

dump valve dumps the boost on gearchange.

 

as per edd...

you'd use a bov on something like a supercharger... bit like a wastegate, but works on the air side not the exhaust side... lets off excess boost and is constant

but i've never heard anyone refer to one correcly... and all these blow off valves you see for sale are infact dumpvalves incorrectly named

 

ah fair play, i thought it was an american term to