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View Full Version : OMG its a dump valve question!


raj
20-12-2009, 18:10
:cooter:

ive decided i fancy fitting one to the volvo 460:p
to be honest im not very clued up on dump valves, im sure i heard there are different types for certain cars:scratch: are they?
im just after a cheap dv, possibly an ebay special. its not something i want to spend big bucks on, just something to pass the time youuuu knowww:D
raj
22-12-2009, 17:31
anyone? :wasntme:
clee
22-12-2009, 17:33
You can have a recirc one I have off a GTA . Just leave the recirc pipe off and there ya go :agree:
HULK
22-12-2009, 17:36
If the volvo runs a maf sensor you will need a recirc type dv
reevio
22-12-2009, 18:21
ive been running my 480 with an atmospeheric but when i put the bigger turbo on will be going back to a recirc
raj
22-12-2009, 18:40
ahh, thats what i was trying to get at.! so does the b18ft have a maf sensor:confused: and if it does,what issues would arrise from running an atmospheric dv as reevio has done?
mlb123
22-12-2009, 18:46
airflow meter cars require twin piston dump valves and it can be atmospheric, its only advised to have recirc due to returning the measured air, if you havnt got an airflow meter pretty sure anything will go :agree:
reevio
23-12-2009, 18:39
as i said ran mine not any issues as yet but will be going back until as sometime i can go standalone and rid that maf
mlb123
24-12-2009, 17:13
as i said ran mine not any issues as yet but will be going back until as sometime i can go standalone and rid that maf

yeah i run an atmospheric on my nova turbo and thats got a afm, never had any issues, although it is twin piston, never ran it with a single piston type but i've heard a few people say they have idle issues.
reevio
24-12-2009, 20:32
mines an rspec one 1 piston works great and she idles fine i think the other issues people have come across are that the recirc put the preesure back in the system which some turbos need to function correctly
Scoff
24-12-2009, 20:44
mines an rspec one 1 piston works great and she idles fine i think the other issues people have come across are that the recirc put the preesure back in the system which some turbos need to function correctly

The problems arise because the air flow meter no longer see's the correct air flow at idle, if the dump valve is open. With a strong enough spring to ensure it stays shut at idle you won't have a problem.
rs250nut
24-12-2009, 20:51
I as got the main dump valve on me 5 turbz it be proper blou at full rinse out 37psi innit. Me car proper flys and de dump valve gives it an extra 30 brake cos k-tec says innit:cooter:
raj
24-12-2009, 20:58
The problems arise because the air flow meter no longer see's the correct air flow at idle, if the dump valve is open. With a strong enough spring to ensure it stays shut at idle you won't have a problem.

is this something a twin piston type solves:confused:.
Scoff
24-12-2009, 21:19
is this something a twin piston type solves:confused:.

only if it's closed at idle :)
raj
24-12-2009, 21:29
only if it's closed at idle :)

forgive me for lacking knowledge in the dv area.
arent dv's shut at idle anyway? or would you need a stronger spring to keep it shut at idle if it already isnt?:scratch:
rs250nut
24-12-2009, 21:39
forgive me for lacking knowledge in the dv area.
arent dv's shut at idle anyway? or would you need a stronger spring to keep it shut at idle if it already isnt?:scratch:

No hence why with no boost they are open. When you are on the throttle you are building boost, when you let off the valve opens.
reevio
24-12-2009, 23:56
yeah mine closes shut on idle a treat sucks the piston up shut