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superman wrote:a dump valve wont make your car or bike go bang ainyway. they make the performance better and to have the turbo you need to make critical changes to certain things dont you?

a dump valve WILL NOT improve performance, this is getting silly now.

going a long lost memory here so tell me if im right or not...

when the turbo has to release the presure its built up (ie changing gear) it normaly realises though a tube back into the system, all the dump valve dos is vent it atmospheric so you get the his noise? If im correct then theres no reason why it should make more power, just clear the charged air quicker?

rene wrote:going a long lost memory here so tell me if im right or not...

when the turbo has to release the presure its built up (ie changing gear) it normaly realises though a tube back into the system, all the dump valve dos is vent it atmospheric so you get the his noise? If im correct then theres no reason why it should make more power, just clear the charged air quicker?

thats pretty much it yes.

im not gonna argue wiv rover anymore, cus he's rite anyway, dumpvalves just drop the built up power 4 ur turbo rite rover?

zxr_maniac wrote:im not gonna argue wiv rover anymore, cus he's rite anyway, dumpvalves just drop the built up power 4 ur turbo rite rover?

when you shut the throttle after being on boost, there is still some pressure in the turbo pipework, a dump valve releases this pressure, either back into the air inlet or to atmosphere, hence the terms re-circ and atmospheric dumpvalves.

^^^^

Better discripton of what i ment...

without some way to bleed the excess pressure off the inlet tract, when the throttle is shut and the engine drawing little air, the pressure tends to stall the turbine blades if not released.

so.....in english so all can understand, then yeh it keeps the power built up in the engine, or re-circulates it yeh

zxr_maniac wrote:so.....in english so all can understand, then yeh it keeps the power built up in the engine, or re-circulates it yeh

neither type keep the power built up no.

when i was running mine with no dumpvalve, it was fractionally quicker when re-opening the throttle after closing it as there was still positive pressure in the system. by no menas a massive amount, it just menat you didnt have to wait for boost to shut teh dumpvalve.

im sure they do more than just make a nice noise...... ill look it up when i get some time... im off out on the RAZ now at last aint been out for ages

superman wrote:im sure they do more than just make a nice noise...... ill look it up when i get some time... im off out on the RAZ now at last aint been out for ages

no, they dont.

like Northern ANdy said they remove presure from the turbo, if you dont remove the presure then the turbo will continue to pump compressed air into the intercooler putting much more strain onto it, the pipe work and the turbo its self. So when you power off the bump valve lets the presure go

again this is all from a long lost memory so dont take is a gossball

rene wrote:like Northern ANdy said they remove presure from the turbo, if you dont remove the presure then the turbo will continue to pump compressed air into the intercooler putting much more strain onto it, the pipe work and the turbo its self. So when you power off the bump valve lets the presure go

again this is all from a long lost memory so dont take is a gossball

if you dont remove the pressure, you get compressor stall, this is not a bad thing however some will argue it is, i ran for a year plus with compreesor stall and it caused no damage to the turbo. if it was that bad, the ford cossie boys would all run dv's wouldnt they.....

i think it deepends on turbo size and how much boost your using...Surly if its not using the boost it will keeps forceing more into the intercooler what will only take so much before somthing gives up?

rene wrote:i think it deepends on turbo size and how much boost your using...Surly if its not using the boost it will keeps forceing more into the intercooler what will only take so much before somthing gives up?

it doesnt force more into teh intercooler or other pipework for that matter, the undumped air just chops against the impellor blades causing it to stall hence the fluttery noise you get when running without a dumpvalve

theroretically, it could damage the turbo bearings but ive never seen this happen and as i say, ive done it so have many many others.