ianshad6

hi all peeps
write iknow this has prob been on here loads but im new and still trying to get to know how this works
my question
we have a westy that we fitted a cossy into??know we have also got a t34 hybrid stg3
we want to run with out a dump valve is this safe and can we do it as i hate them get on my nevers everytime you let of throttle so dont want it on.
what benifits do you get if you have one and if not???

thanks all any info pls

sailorbob

The dump valve is there to prevent the turbo stalling due to the build of pressure when the throttle is shut. You can get away without one if your induction system is large enough between the turbo and throttle (e.g. having a large intercooler), as this acts as a 'reservoir' preventing the boost spiking too high. If you don't like the sound the dump valve makes you could fit a recirculating type that's much quieter.

ianshad6

so having a 500 cooler for example is ok? and a big air filter?
dose this depend on boost where runing around 25 pound max?but we are having a boost control also for weather conditions.droping ithink as low as 12 pound?
dose this mean we have the chatter sound as of the dump sound?
thanks for info

sailorbob

I expect a RS500 intercooler would be 'plenty big enough', the filter makes no difference. The higher boost you run then there is the greater potential for higher spikes. The chatter sound you are referring to is probably the wastegate fluttering, which is pretty much unavoidable.

Incidentally I have remembered an old magazine article where they fitted a dump valve to a Silvia turbo (which doesn't come with one as standard I think) and when they did before and after pressure monitoring the boost spikes were higher with the dump valve fitted! They were at a loss to explain why but it all adds to the confusion

ianshad6

intresting stuff there?
we have made an aggrement that we are not going to run a dump valve and keep boost to 20psi or there abouts hopfully we should be safe?how do you know if there a spike???

sailorbob

Ideally you need some way of logging pressure vs throttle position so you can see what happens relative to throttle input.

mike72168

Ive removed the dump valves from all the cossies ive had including a 450 bhp escos running 32 psi boost pressure,never had a problem

C.Lyon

rrrrrrrrrpppppppttttttttttsssssssshhhhhhhhhhhrrrrr rrrr
I like them ones
Not the ones that go rrrrrrrrrrrchchchchchchchchcrrrrrrrrr
or rrrrrrrrrrrrrrrrblblblblblblrrrrrr

Escos Jam

Just take it out mate. It wont cause you a problem