Ok my brother inlaw has a Astra GSI Turbo 03 Plate he has a DV but its Very Quite so we tried the one of my cossie and it was alot better (louder) But the car nearly died on tick over when it was start idling

So whot i want to now Is Why is this doing it is it some thing to do with single piston or the Twin piston DV

His Baily one you can see the spring in the bottom and my one you can so which 1's which

Ps dont reply JUST REMOVE IT AS THERE SHI!T as it we'll just get icnored

CheeRS Alan

 

think thats the reason mate. you need a twin i think it is. Also, could be something to do with the air hose you put on the top as if that leaks or anything the car wont idle properly. Think thats why cossies have twin Dv's. Think im right anyway.

 

Mike its not leaking at all its just a very quite and short relise
Its like its dumping all the air and staving the engine

I know my cossie will run with a air leak as i have had that happen

 

fook knows then alan! get rid of it. gay anyway.

im off to bed! night!

 

But he Likes it

Night m8

 

hello alan what you been at?

 

the twin piston dumpvalve allows the DV to be closed at idle. this is needed on cars that measure mass air flow to calculate fueling (ie RST and your mates astra) single piston (or diaphragm etc. etc.) valves are open at idle and work with cars that use mainfold air pressure based metering systems (ie cossies)

ps DVs are shit, dont use one.

pps you mate can get the spring changed in his dumper to make it louder, however when he takes it off he'll realise the car drives a SHITLOAD better and uses less fuel

 

Mouse not alot m8 been busy with little lewis since he's been born he's well into cars already I'll pop over soon m8

Jim Spot on m8
But how the hell can you save fuel ??? Ps you dont but a sports car for Fuel consumpton (sp)

 

Never mind about dump valves, your brother in law needs to get rid of you as you are gayer than ben the bendy bender from Bentley.

 

ok m8 look forward to seeing you

 

Jim is correct.

 

when the dumpvalve is dumping, the airthat its letting our the management system thinks the engine is using, so it puts in the fuel to match, this makes the car overfuel whilst it is dumping.

ever noticed that RSTs with dumpvalves work better with flamerkits than those without DVs?

also if youre on part throttle and th car is boosting but the dumper is open (ever got it where its hissing on qtr throttle?) then the car will over overfueling its tits off.

MAF based cars aren't designed with dumpvalves in mind... if youre gonna use one, use a re-circ one

 

I see