Dump Valve

[ahaughton]

Hi, I'm going to have a dump valve fitted to my M400 once it's completed it's 1000 mile service. Is there anything other than physically fitting the new pipework and valve that needs to be done to complete the work?

[obes]

Hi Adrian,

I see you're in Northants. If you can make it to the Northants meet on sunday you can have a look at mine.

Details here:
www.pistonheads.com/gassing/topic.asp?t=183278&f=65&h=0

Owen

[ahaughton]

Hi, I'd love to but we're away for the weekend. Who did your install by the way and was there anything else to do other than physically fir the new pipework?

Where in Northants are you, perhaps I could trundle (officer) over one evening?

Cheers,

Adrian

[obes]

In Northampton (Abington). Send me a mail through my profile and we'll sort something out

Matt Faulks did the plumbing.
www.faulksperformance.com/

[lucozade]

so whats the real benefit in getting one fitted then?

[obes]

Lawrence explained it far better than I ever could...

LaurenceFrost said:

Dump valves come in to flavours: recalculating and atmospheric. Upon lifting off the throttle (after giving it some), the throttle plate is slammed shut so that very little air can get into the cylinders. This means that you have full boost pressure built up, and nowhere for it to go. Air will always try and uncompress itself, so it looks for the easiest escape route. This escape route is the turbo (where the air has just come from)! The air can now escape this way because there is no longer any exhaust gas driving the turbo (foot is off the throttle remember). Even though the turbo is not being driven at this point, it will still be spinning incredibility quickly, but the compressed air going back through it the wrong way will slow it right down (and can actually damage it in extreme cases). The atmospheric dump valve works by opening when the throttle is lifted (I’ll explain exactly how it knows when to open if anyone is interested). The easiest escape route for the air is no longer the turbo’s compressor housing, but the dump valve that has just opened. The woosh is the air escaping. The turbo will still be spinning nice and fast, and a lot of the lag between changing gears will be eliminated. The recalculating valve works just the same, but is much quieter (although some air still escapes back through the air filter). The excess boost is routed back to the piping just before the turbo, so the pressure goes back through the system, which eliminates more lag than the previous method, and still relieves the strain on the turbo between changes. Laurence

[Mr Noble]

I wanted one mainly for the fun of the noise. But instead I had the factory move the filters to the front for a minimal labour charge and have now got the most amazing sounding car in the world!!

The ppssssstttttssss and whoooossshhes and chatters as you lift off the throttle are grerat, as is the sucking induction noise as you accelerate. Its really made driving it much more fun an experience.

IMO the boost vale would do little to the performance. (or else there would be one as standard.)

GN

[matt_fp]

Nearly every turbo charged large scale production car in the last 10 years has been fitted with a Re-Circ BOV as standard, mainly to reduce lag and increase turbo life. There are no downsides to installing a correctly spec'd valve and even on a standard car the reduction in lag between gearshifts is noticeable, it is also a relatively inexpensive way of increasing turbo life.

Noise was a consideration when speccing and developing our valve and due to the filtered valve technology we employ it sounds very much like a louder standard car.

Best Regards
Matt - FP

[Mr Noble]

Mr Noble said:

IMO the boost vale would do little to the performance. (or else there would be one as standard.)

No offence intended there Matt, I am sure there are gains to be had with the addition of the BOV, not to mention the reduced stress put on the turbo's.

In my case I was only going for audio asthetics and not improved performance.

The BOV on Owens car did liik lovely, and sounded spot on too.

[adrian w]

while your fitting the dump valve fit a solid pipe as the samco pipe colapses, better still talk to Vegantune they know what there doing.

[ahaughton]

The 'ole M400 went in for 1000 mile service last week and also for a Vegantune Dump Valve. Got the car back Friday evening and it's totally different (IMO), less neck jerking gear changes 'cos the Turbo's are still on song. I've now found myself overtaking cars and changing gear as I'm level in order to scare the hell out of them with the spitting/hissing/farting Dump Valve :-)

But boys and girls, what's next (within the restrictions of the Warranty)?

Need more speed/power 'cos I'm normalising!

>> Edited by ahaughton on Monday 11th July 08:59

[gizard]

Wait till your warranty expires?! Or buy a second hand noble...