short dump

[brett craig]

How do your dump valves sound for loundness and length ?

the piston dump valve i have on mine although very well made and identical to a dv26 is a little quiet and dumps very short and quick, i am only running standard boost pressure at the minute with the re-circ valve removed.

is this normal or will it increase with my remap next week ?

[t5_monkey]

you'll get more noise with higher boost - as there'll be more air to vent.

try removing the soundproofing from under the bonnet if you want more DV noise? :)

[gmain1967]

And like most dumpvalves, spring strength has a bearing on things.

The Forge one on my T4 needed an uprated spring when the boost pressure was upped (fortunately I got the spring tuning kit with the valve from a forum member), otherwise the valve would vent pressure before peak boost was reached.

If you cant source a stronger spring then try and fit a shim into the valve seat, to effectively shorten the spring length, and increase tension, or have a machine shop make up a heavier duty one. The yanks do this and call it the "nickel trick" I believe.....!

[brett craig]

i did wonder about the spring strength, only problem is how to tell if its to strong or to weak ?
there certainly seems to be some good resistance to it when compressed

[gmain1967]

Not sure what valve/spring you have, so difficult to say, other than trying it.

Do you have a boost gauge fitted? If so, try shifting when hitting peak boost, and off boost (before or after it is hit). If the vent to atmosphere is shorter and quieter at lower boost, then it shouldn't be too far off.

The Forge one was easy, as the springs are colour coded and correspond to psi though be aware, that the quoted psi of the spring, does not translate directly to the reading you get on a boost gauge, there is a correction.

[brett craig]

its certainly louder at higher boost levels, will start dumping around -1 to 0psi not before, and does gain volume dependent on the pos boost, maybe its just a quiet/short dumpvalve but did expect more.
304's going in next week so if theres no significant improvment then may move over to a DV26 with correct pressure spring.

[the-man-that-can]

mate t5_monkey is 100% right my hks ssqv is like the best 1 can have i think and mine was very quiet till i upped the boost. now an EG of how loud ok i can do 120 and realease the throttle and its like u got earphones on playing a hks blow off valve whoooosh lol :D its amazingly loud and ive angled it so its below the cold intake pipe (standard airbox 1) its hid away from prying eyes yet blasts out such a powerful blast. on the hks ssqv's u can buy difrent inserts to change the sound i have the gold fin and it gives an agressive loud whoosh. so so happy with it id never ever have any other make dump valve really and kept this HKS ssqv back as it was off me WRX :P

[gmain1967]

That does seem low.

I can't hear mine unless boost has been up around 10psi min, though the cone filter and wastegate chatter could possibly just drown it out at lower boost...

But when peak boost is hit, there's a loud psshh, followed by a very brief chirp, right at the end. It does seem a unique sound and certainly makes folk look twice. Or possibly that's just the colour...

[brett craig]

how long does it dump for mate ? mines dead short and swift.

[brett craig]

That does seem low.

I can't hear mine unless boost has been up around 10psi min, though the cone filter and wastegate chatter could possibly just drown it out at lower boost...

But when peak boost is hit, there's a loud psshh, followed by a very brief chirp, right at the end. It does seem a unique sound and certainly makes folk look twice. Or possibly that's just the colour...

ive still got the noise coming back through my cone filter but no chirp, its almost as if the recirc is still inplace if you understand what i mean ?

[the-man-that-can]

and my god these are cheap hks ssqv's and in black too :P

MORE THAN 10 available grab em wile u can lads trust me these are the best in my eyes and normally are £250 ish give or take

http://cgi.ebay.co.uk/HKS-DUMP-BLOW-OFF-VALVE-SSQV-2-BLACK-LIMITED-EDITION-/250653821537?cmd=ViewItem&pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3a5c21ca61

[the-man-that-can]

http://www.youtube.com/watch?v=mYEA3i3b3mI&feature=related

[gmain1967]

Those are cheap - had one on my STI and that set me back over £200...

If you want noise at virtually any boost pressure, it's the one to go for, IMO...

Never timed my dump, if you'll pardon the expression, but it probably lasts between one and two seconds! LOL

[brett craig]

mines approx half a second

[p fandango]

who needs a dump valve lol

http://www.youtube.com/watch?v=fuwtr9NefDg&feature=related

[the-man-that-can]

i paid over £250 for mine have had it a wile there still over £250 in sum places it is really so so loud and i assure u now them black 1's are a steal at that price £100 or best offer lol musta came off the back of alorry but who cares :D BUY BUY BUY lads i assure u now ur never be disapointed hehehe ;)


PS nice 1 there p fandango :) i recall getting a gt tuning huge spec turbo for my old
reno 5 and i bought a t3 actuator which was huge and thats exactly how it use to sound
:P thing is the hks jobee's arent dump valves there blow off valves hehehe and there gona save the turbo life i guess where as blanking off the recirc and having none just the actuator/waste gate chatter aint gona do ur turbo no favours when uppin ya boost pressure is it?

[brett craig]

who needs a dump valve lol

http://www.youtube.com/watch?v=fuwtr9NefDg&feature=related

i take it thats with no dv, the recirc blanked and the turbo stalling ?

[brett craig]

i paid over £250 for mine have had it a wile there still over £250 in sum places it is really so so loud and i assure u now them black 1's are a steal at that price £100 or best offer lol musta came off the back of alorry but who cares :D BUY BUY BUY lads i assure u now ur never be disapointed hehehe ;)


PS nice 1 there p fandango :) i recall getting a gt tuning huge spec turbo for my old
reno 5 and i bought a t3 actuator which was huge and thats exactly how it use to sound
:P thing is the hks jobee's arent dump valves there blow off valves hehehe and there gona save the turbo life i guess where as blanking off the recirc and having none just the actuator/waste gate chatter aint gona do ur turbo no favours when uppin ya boost pressure is it?

if i could afford it i would mate, paying for my 304 ecu next week and the exhaust from nads the week after

[p fandango]

i take it thats with no dv, the recirc blanked and the turbo stalling ?
:biggrin: spot on

[brett craig]

:biggrin: spot on

now thats tempting !!!!!

[johny the monkey]

i love that sound my mate had a cossie that made the exact same sound, he said it was his actuator that did it... how do i do this and how much does it effect the turbo.

My old man is a big rallycross fan and he would love it, even if it just for one day, as a treat to him..

[brett craig]

you need a forge blanking plate, remove the recirc valve and fit blank plate. then go make turkey noises !

[p fandango]

i love that sound my mate had a cossie that made the exact same sound, he said it was his actuator that did it... how do i do this and how much does it effect the turbo.
the actuator is part of the system which helps control the boost level, as said you need to remove the recirc valve

[johny the monkey]

were can i get a blanking gasket from and how much of a job is it to do, and can it reversed easly..

Think it would be woth it for the smile on mine and my old mans face

[brett craig]

forge motorsport, about 1-2hrs dependent on how good you are with spanners, same for the reversal.
do a search on the search bar at the top of the page, theres many threads and how to guides on here.

[p fandango]

were can i get a blanking gasket from and how much of a job is it to do, and can it reversed easly..
LINK (http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=0016&product=FMBPVRM)

from what i've read a ratchet spanner will make the job so much easier, & reversal is simply done by refitting the original recirc valve

[johny the monkey]

cheers brett craig wil have a look.


you sound clued up so i have a ques for you....

i was told my car was chipped when i bought it but have no paperwork to say so. It does have a Rspec boost control on it and boosts at 12psi and holds it. Is there anyway or someone local to me that you know of (grimsby, north east lincilnshire) that can identify that what chip (if any) or what software my car is running

[JelT5]

You will definitely need a 10mm ratchet spanner- get as many of the boost and vac hoses near the turbo out of the way too- makes it a lot easier to get at the bolts securing the recirc valve. HTH

[p fandango]

i was told my car was chipped when i bought it but have no paperwork to say so. It does have a Rspec boost control on it and boosts at 12psi and holds it. Is there anyway or someone local to me that you know of (grimsby, north east lincilnshire) that can identify that what chip (if any) or what software my car is running
the easiest way to tell if an ECU has been chipped is if its been opened. Not sure what year your 850 is, but from about 96 the ECU had a securing strap over the top (the ECU box is behind the drivers headlight), which was fixed down with a black pop-rivet anything else is a good clue its been tampered with. To go a bit further if you remove the lid off the ECU box the engine management ECU will be in the middle slot out of the 3, on close inspection you might be able to see if the tabs on the ECU case have been folded to gain access to the internal boards. Some companies even put stickers on the ECU once they'd remapped them so you might be lucky

[johny the monkey]

p fandango its a 98 V70 T5 does that make a big diff from the 850

[p fandango]

p fandango its a 98 V70 T5 does that make a big diff from the 850
near enough lol, will defo have the securing strap over the box then

[johny the monkey]

cheers lads.