Abarthisti

Tuning & Modifications => Abarth Grande Punto => Topic started by: John501 on December 11, 2008, 08:09:31 pm

Title: Dump Valve
Post by: John501 on December 11, 2008, 08:09:31 pm
On the G.P. Abarth there is a small vent that is capped off to accept a dump valve that will make your car make the "woosh" noise when you change gear. Chunky has had a quick look into this but the e-mail he sent to Turin appears to be a bit "lost in translation".
Has anyone looked into this and if you have, did you manage to find one that would do the job?
We are a bit busy to do any thorough research into this at the moment, but if there was any interest I may be able to get the service department to dig a bit deeper.
Before you get too excited, bear in mind that it may well cost between £350-£500 for the upgrade and wont make a huge difference to the performance.
Let me know if you've got any interest?
Title: Re: Dump Valve
Post by: chunkymonkey on December 11, 2008, 09:05:57 pm
only on the esseesse kit garrett turbo though.

i cant really make out what hes trying to say in the e-mails, my best guess is hes saying its not sold/available yet as a genuine abarth product, and when i looked on the garrett website i couldnt even find the 1446 listed last i looked..
Title: Re: Dump Valve
Post by: magicmole on December 13, 2008, 06:39:12 pm
Here you go..

http://www.bonalume.com/auto_prodotti_en.asp?marca_id=7&modello=Grande%20Punto%20Abarth%201.4%20Tjet
Title: Re: Dump Valve
Post by: chunkymonkey on December 13, 2008, 07:19:37 pm
ideal.

i dont think it will fit the esseesse though.

also, if we fit non-genuine, weve voided our warranties.
Title: Re: Dump Valve
Post by: JKDesign80 on December 13, 2008, 07:52:05 pm
Aren't recirculating dump valves better for performance though, as with a atmos valve you get more lag between gear changes?

That was alway the case with Punto GTs anyway.
Title: Re: Dump Valve
Post by: chunkymonkey on December 13, 2008, 08:14:00 pm
ok, now im learning!

whats the difference between the two please?

where would the item mole pointed us to fit on a t-jet?

on the GPA SS, it looks as though the excess pressure comes through the bypass hose and back around into the inlet tract between the air filter and turbo. looking at the garrett turbo, there is an airway machined into the casing just after the throat the air inlet pipe fits on to and just before the rotors. this airway leads to the port we blank off with a triangular shaped plate with two seals inside it. in the ss kit its marked dump valve kit.

a couple of lads who are into their glanza's and silvia's and are into modding a bit more than me said its a strange way of doing it and theyd never seen it before?

also our local motorsport place didnt seem to have heard much of it either.
Title: Re: Dump Valve
Post by: JKDesign80 on December 19, 2008, 06:17:54 pm

Not great videos, but it shows its been done!...

http://uk.youtube.com/watch?v=SyBbFeuSaeQ
http://uk.youtube.com/watch?v=lxlcyK4EBmc
Title: Re: Dump Valve
Post by: punto_matt on January 15, 2009, 07:24:55 pm
Recirc puts the air back into the induction to help the turbo spool up faster where as an atmospheric dump valves just dumps it into the atmosphere. Best place to install an atmospheric dump valve is up on the top right of the engine cover where the pipe joins into the pipe that runs along the top of the engine cover and back into the induction. On the right there should be a Tshape piece i think it is which the Recirc valve is part of. If you pull the pipe off which comes from the turbo and rev your car then you will hear the air if you rev the car and let off the throttle. You can then fit a DV up in place of the recirc blocking off other pumps. Forge motorsport do a atmos and recirc DV in which you can alter how much air gets recirced and how much gets dumped.
Title: Re: Dump Valve
Post by: chunkymonkey on January 15, 2009, 07:43:57 pm
that was the strange thing though, the GPA has a recirc system, like you said the excess turbo pressure deflects off the throttle butterfly, up the bypass hose, and then there is an electric recirc valve. once this is opened the pressure is guided back into the turbo air inlet pipe by way of the pipes that run around the top of the engine cover.

what i couldnt understand is right next to the air intake pipe/intake throat on the turbo there is a triangular hole, vented to atmosphere, with a drilling that leads into the throat. this triangular hole has to be blocked off when the ss kit is fitted by a triangular plate with a couple of seals on it. this plate is marked dump valve kit in the ss kit.

is it possible then that the gt1446 is designed for a system that had a dump valve venting to atmosphere, and because the GPA has a recirc system, its blocked off as its not required? could you still fit a dump valve to the turbo to make it go ptchh between gear changes, or is this impossible on a recirc system unless you want to start leaving pipes disconnected and block others off?

Title: Re: Dump Valve
Post by: Missing in Action on January 15, 2009, 07:48:21 pm
all well and good BUT.... wouldnt it irritate the HELL out of you every time you changed gear!?
Title: Re: Dump Valve
Post by: chunkymonkey on January 15, 2009, 07:54:08 pm
it seems to float quite alot of peoples boats though doesnt it?!
Title: Re: Dump Valve
Post by: magicmole on January 15, 2009, 08:35:26 pm
It would keep me amused for a while
Title: Re: Dump Valve
Post by: Scrogg on January 15, 2009, 08:59:33 pm
Before you get too excited, bear in mind that it may well cost between £350-£500 for the upgrade and wont make a huge difference to the performance.

£300-£500 just to sound like a 1993 Impreza? I'll pass thanks!
Title: Re: Dump Valve
Post by: domc on January 15, 2009, 09:02:29 pm
It would be amusing for about 20 min then would become a little tiresome.
Title: Re: Dump Valve
Post by: Missing in Action on January 15, 2009, 09:13:07 pm
It would be amusing for about 20 min then would become a little tiresome.

agreed... maybe the first time in a town to show off and the it would get annoying and you'd start looking like a t*t... its not something id want on my car but as you say chunky it does float quite a lot of peoples boats...
Title: Re: Dump Valve
Post by: punto_matt on January 15, 2009, 10:52:32 pm
It can be bypassed easily. All turbo cars come with recircs fitted as standard so putting an atmos dump valve on shouldnt cause any problems but a side effect is it can cause more turbo lag as it takes longer to spool up. The only pipe i think that needs to be blocked up is the one recircing into the induction as obviously this is now redundant and you dont want to leave it open for obvious reasons. The other alternative is to fit an open air filter on an induction kit like i have. Because its open air you hear the recirc dumping into the induction which gives the noise of a dump valve. Its not really that chavvy as you can control it. If you are in a town centre you arent really gonna be spooling the turbo up and if you do its not going to be much so its going to be relatively quiet. The induction roar is what gets people looking not the dumping noise )
Title: Re: Dump Valve
Post by: Old Boy on January 16, 2009, 08:06:52 am
It's the psssst noise that gets people tutting and thinking CHAV !!

 ;D
Title: Re: Dump Valve
Post by: punto_matt on January 16, 2009, 11:45:16 am
The noise can be dependant on the type of dumpvalve. You get different types of dump valves which can offer slightly different noises.
Title: Re: Dump Valve
Post by: 1mmortal on January 16, 2009, 02:39:25 pm
It would be amusing for about 20 min then would become a little tiresome.

Yea it wouldnt be long before you started trying to drive around everywhere in fourth.
Saying that though, i quite like them, but not when theres about 10 round near me and they're all at about 260,000db.
Title: Re: Dump Valve
Post by: Missing in Action on January 16, 2009, 09:29:35 pm
theres 1 scooby around here and every time i see it hes gunning it down the main street in my town - which when its busy just makes me think what a dick... its probably that, that gives me the bad inpression of it. although again the noise would get on my t*ts after a while.
Title: Re: Dump Valve
Post by: maccy. on January 16, 2009, 09:31:08 pm
It can be bypassed easily. All turbo cars come with recircs fitted as standard so putting an atmos dump valve on shouldnt cause any problems but a side effect is it can cause more turbo lag as it takes longer to spool up. The only pipe i think that needs to be blocked up is the one recircing into the induction as obviously this is now redundant and you dont want to leave it open for obvious reasons. The other alternative is to fit an open air filter on an induction kit like i have. Because its open air you hear the recirc dumping into the induction which gives the noise of a dump valve. Its not really that chavvy as you can control it. If you are in a town centre you arent really gonna be spooling the turbo up and if you do its not going to be much so its going to be relatively quiet. The induction roar is what gets people looking not the dumping noise )
well said, I couldnt agree more and its what im looking into at the moment.
Iv'e never liked a dump valve (Iv'e tried a few) the best option is the right induction kit.
Title: Re: Dump Valve
Post by: fishbone on January 17, 2009, 10:19:51 pm
i prefer the 'chattering' noise.... my Smart Roadster is chipped and got a KN filter so the chatter is a little louder, never fails to raise a giggle.. I avoided thr dump valve cos as has been said... the WHOOOOOOSH sounds so neddy!!! (sorry, Chavvy!)
Title: Re: Dump Valve
Post by: maccy. on January 18, 2009, 10:32:41 am
i prefer the 'chattering' noise.... my Smart Roadster is chipped and got a KN filter so the chatter is a little louder, never fails to raise a giggle.. I avoided thr dump valve cos as has been said... the WHOOOOOOSH sounds so neddy!!! (sorry, Chavvy!)

its not chavvy, its fantastic I ran a venon induction kit in my smart along with lots of other things! sounded amazing. Have you still got the roadster?
Title: Re: Dump Valve
Post by: punto_matt on January 19, 2009, 12:43:17 am
If i fit a BOV this is going to be the one that gets fitted  8) :thumb:

http://uk.youtube.com/watch?v=iQxQAr3cMi8