BOV early turbo

[trackmagic]

Does anyone have experience adding one of these to the Dellorto equiped turbo Esprit.

Thanks,

Jeff

[Splashout]

not done it yet but have looked into it what you after.

[nicksoldies]

I have recently fitted one to a Stephens carb'turbo which I think is the same. There is a post under BOV in the Stephens technical room. I can't see how to list a link to it but a search for Forge will find it.

Here is an extract I posted with what I learnt but it is worth reading the whole post, Dermot and others have very useful input:

I finally received all the components from the various suppliers and fitted it. I tried a few T pieces but the T has to be shortened to 70mm to fit a carb' turbo. It doesn't leave a lot of room for the clips. The bevel where the 25mm part joins the main hose was too large on some hoses to allow enough room for the clips. I found one from Forge Motorsport which does fit OK (

[WayneB]

As your modified dump valve setup is exhausting the pressure back into the pre-turbo inlet tract it will silence the whoosh noise.

You could probably put some rubber hose off the standard BOV and exhaust it closer to the drivers compartment if you really want to make a WHOOSH!

I am keeping mine stock, as I like the big whoosh and all this messing around doesnt really add any power (might improve drivability a bit IMO)

Edited April 25, 2006 by WayneB

[nicksoldies]

Wayne,

I couldn't hear anything when I had no pipe on , just the metal outlet stub from the valve. I haven't recirculated it the intake hose, just down the side of the gearbox to the road. I still hear no whoosh at all. I am going to check the BOV to see if that is working. It was brand new but you never know.

[Evil_Dr_Fish]

Wayne - Errr I thought the whole BOV thing wasn't for power but for

1) Perceived reduction in lag when changing up (disputed)

2) Improved Turbo longevity - especially when starting to play silly buggers with the boost!

[WayneB]

Evil collegue, thats what I said it doesnt add any power

Is it the language difference thats baffling you?

[Evil_Dr_Fish]

Your inital reply made it sound as though you had the impression OTHERS thought it did!

(Ok this is going around in circles!)

However it is seen by some (eg. ME! ) as something to fit as an 'enabler', prior to increasing the power (ie boost) to help posptone the onset of Turbo poppage!

[Joey]

Okay excuse my ignorance, but I thought the carb versions of the Turbo Esprit came equiped with a BOV.

[WayneB]

They do Joey

What this thread is on about is fitting an aftermarket type which is designed to vent the expelled boost pressure back into the inlet tract to hopefully keep the turbo spinning somewhat.

The standard one is mounted on inlet plenum towards the rear of the car, and vents pressure directly to the atmosphere.

The reason you need a BOV is to vent pressure build up from the turbo , when the throttle blades angle is reduced or closed(or else boost pressure would rise uncontrolably as the turbine is still spinning away)

[nicksoldies]

Not all the carb' turbos are fitted with a BOV. Mine certainly never was, I suspect at least the HCs didn't have one and maybe some other later examples. I think it was only the early ones that had one fitted. I didn't think it was a BOV in the sense we are talking here (one controlled by mainifold vaccuum and boost pressure), just a safety valve which opened when the boost hit a set pressure in order that a stuck wastegate and associated high boost couldn't scrap the engine.

[dodgy]

i agree with nick, my valve was blocked off by the previous owner( in order to get extra boost i think ? )

i have removed that blanking plate now as i would rather save the engine!

Dodgy

[USAndretti42]

Is this the same as the anti-twitter valve as on a Cosworth Sierra? It's purpose was to stop the noise from the compressor as it stalled when the throttle is closed (hence the name) and to stop the compressor stalling and damaging the blades.