this may be a bone question but i want to get a dump valve that flutters like **** as opposed to just one big woosh! (if that makes sense) anyone know what the absolute best one for that is? not to everyones taste but hey! someone told me you need a re-circulating dump valve, any truth in this? thanks j

Fraid I dunno which ones flutter as opposed to ones that go whooosh, but you deffo don't want to fit re-circulating ones, cos the Zed already has this type as standard and re-circulating means no noise.

hth

cheers

smithy

You mean this one

Try the HKS sequential ones they chatter quite nice???

It's not the dumpvalve that causes that noise it's air being forced through the wastegate backwards, that's why it's called wastegate chatter.

ok, so what can make air be forced backwards throught the wastegate? i want it to sound fierce!

anyone got any answers? need it explaining!

anyone got any answers? need it explaining!

a turbo :D

very usefull! youve made it crystal clear 2 me! the z im getting has 2 trubo dynamics stage 3 turbos one, so thats not a problem! or does no one actually have an answer to the question?

so you want wastegate chatter ?

 

The sounds is pressurised air bouncing back off the closed throttle plates and exiting the intake system via the impellor blades (backward) and then out through the air filter. The ch-ch-ch-ch noise is the air being "cut up" by the impellor blades as it stalls the turbo on it's journey backward out the system.

Cossie's and some other Turbocharged cars give off that noise as they dont have recircs or BOV's as standard like the zed does.

Basically, all you need to do to get the sound is remove & cap the standard recirculating valves and turn the boost waaay up. It is bad for your turbos - will reduce their life, and if you're unlucky, shatter the impellor. Not to mention the MAF getting confusd when the throttle is shut and causing fuellin issues.

ah, i see. hmm suddenly dont want it as much now!..

yup, if your recircs are blanked off it stalls like a bitch everytime you boot it and lift off, the air stalls in the MAF and it assumes there is no air flow so cuts the fuel.

my standard Charade GTti has a lovely ch ch ch ch ch on the lift off, as it doesnt have a dump valve fitted as standard. but as the RHB5 is only a tiny turbo the inertia would be less in the shaft so less likely to shear or shatter than the Z's.

 

Fraser