blow off valve??
 

whats the difference between them and dump valves?? do they do anything apart from blow off:razz: what there function on the car or is it just for the noise??

Dump valves literally 'dump' the 'pssssssshhhhhh' sound out of the bottom of the engine - whereas blow off valves literally 'blow' the 'psssssshhhhhh' sound up and out of the engine through the bonnet scoop.

I stand to be corrected but I believe d/v's only add about 20bhp versus a b/v which makes as much as an additional 30bhp.

They are the same thing, there are two types of dump valve, a recirculating type and a vent to atmosphere model. They prevent the turbo from stalling by dumping unwanted boost pressure, they add no bhp at all.

Andy

i knew they didnt add bhp i think mr blues was being funny:) are they worth fitting?? i see that hks blow off valves are £288!!!!!

They can cause slightly erratic running, and also a slight increase in fuelling as your dumping out air that the maf has sensed for fuelling.

nice noise though :lol:

they are the exact same thing, only yanks/japs call them blow off valves, ive the hks ssqv, great sound

ill have to wait till ive old my other car before i buy one though!