Dump/blow off valve

[MART3R]

Being new to nobles and not knowing about the management system yet i thought I'd pick your brains.


Rite I fking hate dump valves lol are they on the cars just to give the blowers a break or do they need them do to the management? I'm guessing it's just because they run GT turbos as it looks to use a map sensor not a maf sensor?

Cheers guys I need chatter lol

[patsrocket]

I wondered the same thing?
I don't have a Blowoff and I am Still running stock.
I have read good and bad so I said heck with adding them.
Did they come stock on UK nobles?
I am in the States.

[andygtt]

Stock noble doesn't have a dump valve, and it doesn't need one.

[D_G]

andygtt said:

Stock noble doesn't have a dump valve, and it doesn't need one.

It does benefit the turbos though as you don't get the back pressure and stalling of the turbo when the throttle is snapped shut on boost. As Andy said you don't need one but I put a HKS SSQV on mine as they don't leak on boost and it helps the turbos.

Oh, and with the filters on the bulkhead it sounds pretty good too

[patsrocket]

Thanks for the info. Andy, Always looking to learn everything I can about them.

[andygtt]

The trouble with a dump valve is it dumps the air ie the boost.... So when you go back on the throttle the turbo has to build the boost back up.... Back pressure on high boost applications can start to slow a turbo, however a stock noble has tiny turbos and low boost pressure and massive amount of pipe work.

Back in the Cassie days I had a dump valve on my modified car running 1.8bar because it was the done thing... Later I removed it and the car then had a better response for the above reasons..

So IMO only fit a dump valve if you love the noise or have a huge turbo running high boost like mine lol

[D_G]

I found with my track car (small turbo / lowish boost) the dump valve improved response from off/on throttle applications. It's not a lot but a definite improvement. Same with the Nob. As it also takes the stress off the turbos it's worthwhile IMO.
The only issue you can have is leaking from a poor quality valve so just buy a suitable one.

[Hollowpockets]

As you can imagine ... On my car the forge BOV packed in at SPA and caused a number of issues, took a few weeks to realise what happened.

Never noticed a difference when I fitted it, now it's gone, still don't notice any difference.

My advice - It's something else which can break and you don't need it, so don't bother!!!

[2.5bluenob]

Hollowpockets said:

As you can imagine ... On my car the forge BOV packed in at SPA and caused a number of issues, took a few weeks to realise what happened.

Never noticed a difference when I fitted it, now it's gone, still don't notice any difference.

My advice - It's something else which can break and you don't need it, so don't bother!!!

Graham was yours a diaphragm or piston type?

[Hollowpockets]

Alright matey,

my one was a piston type, broke two yellow springs so just gave up and plugged the boss with a threaded alloy bung I made up at work.

Think I might have another bov repair kit lying around if anyone wants it.

[2.5bluenob]

Im guessing that im the same spec engine as you graham so im going to try without a Bov. As i like the sound how it is with the filters on the bulkhead. As you say its fine without a Bov, im going to try it and if needs be i will weld a boss in the the hard pipe at a later date.
Cheers
Steve

[patsrocket]

I'm getting the Pro Alloy hard pipe kit and they have the option for a dump valve opening.
I might want to add a dump later since I currently don't have one.
Is the threaded boss easy to plug or cap?
Why type of cap or plug does it need?
Would Pro Alloy have one or can someone direct me on what I need.
Thanks for the help.

[2.5bluenob]

patsrocket said:

I'm getting the Pro Alloy hard pipe kit and they have the option for a dump valve opening.
I might want to add a dump later since I currently don't have one.
Is the threaded boss easy to plug or cap?
Why type of cap or plug does it need?
Would Pro Alloy have one or can someone direct me on what I need.
Thanks for the help.

Pat if you look on ebay for a weld on boss it will prob bring up some bungs as well! they are just a bolt basically.
Steve

[Blu3R]

I have a ProAlloy hard pipe with the weld in boss and a Forge BOV which I've plugged because I'm not running 250BAR and I'm not 18. If anyone wants it I'd sell it but would want a PA hard pipe in exchange.

[simonx50]

mine already had the dump valve fitted so I have a good excuse to be 18

[AverageMPH]

I want to be 18, does a dump valve make you feel younger?

[LazyRoss18]

I'm 22 and have a dump valve, is this acceptable? lol

[wessexrfc]

AverageMPH said:

I want to be 18, does a dump valve make you feel younger?

O-yes, 18 at least !!!
Great sound IMHO!! Sure my Forge DV was fitted as standard.

[AverageMPH]

I've got to have me one of them then, O to feel young again LOL.

[Blu3R]

Excellent! Any of you youngsters want to p/ex then with an old man??