Should I be BOV'red?

[robp]

Spiel sounds as if this is a good thing - reduced turbo lag; increased turbo-life at a minimal financial cost - although you do pay by having to listen to that 'whoosing' noise (some like - I don't). So what's the story, guys? And if so cheap to install with such benefits why are BOVs not fitted as standard on all cars? (Simon, interested to hear Noble view)

[washy]

Hi Rob - I'm having one fitted next week along with the intercooler upgrade. I'll let you know what I think. I understand the noise isn't to bad but we'll see soon enough.

[actech]

Washy, did you get my emails?

Anthony

[ahaughton]

Rob,

I've had the BOV and IC fitted as Washy is about to and it DOES make a big difference to the drive. The turbo lag has almost disappeared on the up shift and thanks to the IC I'm no longer loosing (as much) BHP through heat....

Well worth the change IMHO :-)

Adrian

[sjc]

washy said:

Hi Rob - I'm having one fitted next week along with the intercooler upgrade. I'll let you know what I think. I understand the noise isn't to bad but we'll see soon enough.

Washy, are you having it all done at NobleLondon as I was talking to Skippy and Martin this week about various mods and they said they are doing one at the mo'. If so, when is it likely to be ready?

[AMG Merc]

Seeing as we are on the BoV issue again, there seem to be two types (one had a diaphram and the other has a spring thingy - don't quote me!) - can anyone comment on the difference?

[LaurenceFrost]

I think the difference between the piston type and the diaphragm type is durability.

The piston type are not prone to splitting like the rubber versions, and can consequently handle more boost pressure.

[chillidog]

This looks useful - www.gto3.com/components/engine.htm#bov

and also the section "How Blow-Off Valves Work" in this link - http://autospeed.drive.com.au/cms/A_2188/article.html
plus the stuff Laurence has already said on PH.
--
Richard

[ahaughton]

sjc,

Skippy's been using my M400 to learn I think :-) I was the first customer at NobleLondon (IIRC) to have the BOV and IC fitted, he's using that experience to carry out the same work on Washy's.

Mind you, I think I'm sending Skippy to an early grave, he's been trying to sort out a rattle at ~3000RPM for weeks, poor bloke is slowly going mad because of it.....

Cheers,

Adrian

[broad]

robp said:

...if so cheap to install with such benefits why are BOVs not fitted as standard on all cars?

A basic diaphragm recirculating type is fitted to the majority of turbo production cars. The fact that it recirculates into the air intake (i.e. a sealed system) as opposed to vent to atmosphere means you never hear them doing their job.

A reirculating dump valve could be fitted to a Noble with a little extra work to get the 'performance' benefit without the noise. Its the noise a lot of people seem to like though.

Suprised the factory didn't install a recirc type as standard though.

Hope that helps

Graham

>> Edited by broad on Sunday 18th September 13:46

[lucozade]

I got the Faulks BOV a couple of weeks back and fitted it in 20 mins.

The noise does grow on you - I didn't want to "max power" my car but the noise seems acceptable IMHO

Performance-wise I certainly notice a difference going through the gears. Much better.

Apart from anything else it adds a little bit of "bling" to the engine bay and if fitted where mines is you can easily see it through one of the engine vents.

[LaurenceFrost]

broad said:

Suprised the factory didn't install a recirc type as standard though.

Most manufacturers do fit recirc valves to refine the car, because chirps and wooshes are generally unacceptable to a mass-production car. It has to appeal to a lot of people.

I've lost count of the amount of people I have spoke to about their cars who are totally clueless about them. I spoke to one lady about her Ford Focus RS...I asked her how she found the diff for road use expecting her to know about the car she had purchased (as you would), and her reply was, "I don't really know...I only got it because it was the best one!"

My point is that if this car wooshed and chirped upon gear changes she would probably suspect something was wrong with it and take it back. The recirc refines it.

However, the Noble has a very specific range of customers. They are those who typically have a huge passion for cars, a bit of an idea of how cars work in general (and what makes them go fast), and as such will actually enjoy the odd woosh and chirp instead of worry about it.

And that's why I think the Noble doesn't have a recirculating dump valve.

[AMG Merc]

LaurenceFrost said:

"And that's why I think the Noble doesn't have a recirculating dump valve."

I think it's due to cost - if Noble couldn't fit an air-horn (in place of that Noddy-sounding joke!) then I doubt they'd have costed in anything else -IMHO!

>> Edited by AMG Merc on Sunday 18th September 15:41

[paulcundy]

AMG Merc said:

LaurenceFrost said: "And that's why I think the Noble doesn't have a recirculating dump valve." I think it's due to cost - if Noble couldn't fit an air-horn (in place of that Noddy-sounding joke!) then I doubt they'd have costed in anything else -IMHO! >> Edited by AMG Merc on Sunday 18th September 15:41

But it is a bit odd. There seems to be a general view that BOVs are a good idea on turbo cars on theoretical grounds and a general view that when fitted the cars are better for them. Given that the Noble is clearly in the performance car bracket not fitting one does seem to be an oversight.

I bet the M14 comes with them.

Regards
Paul C

[chillidog]

paulcundy said:

But it is a bit odd. There seems to be a general view that BOVs are a good idea on turbo cars on theoretical grounds and a general view that when fitted the cars are better for them. Given that the Noble is clearly in the performance car bracket not fitting one does seem to be an oversight. I bet the M14 comes with them. Regards Paul C

Paul, have you got the FP BoV fitted?
--
Richard

[paulcundy]

chillidog said:

Paul, have you got the FP BoV fitted? -- Richard

Yes and his IC.
Regards
Paul C

[robp]

OK, so general consensus seems to be that this is a worthwhile mod and the FP BOV seems to get the thumbs up. One other related query - should you also change the current large bore hose from the intercooler outlet to throttle body to a more solid item? I've heard that when things get hot under the clam, this pipe can 'collapse' under negative pressure (or is this irrelevant and/or just a load of ol' b******s?)

[jipsom]

Apparently, the collapsing of the pipe is only a problem if you're using really high turbo settings, like 1.0 bar...I think. Can someone confirm my pot-holed memory?