mechanical boost control valve?

[corraptor_evo 0]

Hello to everybody!

Does anyone know something about mechanical boost control valve?

I found this description which I quote:

"The G-Charger (G-Lader) produces more boost than the engine can efficiently use. Excess boost pressure is controlled by a mechanically operated boost control valve and the idle stabilizer.

The mechanical boost control valve is bolted to the throttle valve housing and operated by the throttle linkage. The boost control valve moves in the opposite direction of the throttle valve. As the throttle valves opens, the boost control valves closes.

The mechanical boost control valve is open idle and part throttle. This directs the majority of the boost pressure back into the intake side of the G-Charger.

The mechanical boost control valve closes approx. 5 degrees before full throttle. This directs boost pressure direct into the intake manifold for maximum engine performance.

The boost control valve linkage is located on the underside of the throttle housing and is adjusted at the factory. Before making any attempts to re-adjust the linkage consult an expert.

Boost pressure in excess of 0.8 bar is controlled by the idle stabilizer. The idle stabilizer will open when the intake manifold pressure is above 0.8 bar and vent the excess boost pressure to the intake side of the G-Charger".

I'm interested about the readjusting the linkage between the boost control valve and the throttle valve and if I will gain something (boost, power) and with what price (increasing of the consumption maybe or something else).

Thanks to all!

[flusted 0]

Thats just the boost return butterfly on the throttlebody.

Think if you mess with with it,you make your charger suffer

[corraptor_evo 0]

Thank you for your quick answer!

That means there are two boost control systems: mechanical and electrical (ISV). Why?

I thought if I will readjusting (by shortening) the linkage between the boost control valve and the throttle valve, I will close earlier the control valve and so I will gain boost earlier.

I have a '89 Corrado G60 and I have done some modifications too:

- a Bar-Tek Tuning kit: 70 mm pulley, 12 mm charger belt, bypass valve (after ISV), RS 3 Powerchip (they said I gained up to 190 HP).

- larger intercooler (the water-alcohol sprayer system is under construction),

- In.Pro. (angel eyes) frontlight,

- FK Automotive "Lexus" tailights,

- Weitec (KW) adjustable shock absorbers and adjustable coils (Hicon GT+Tx Series),

- a Syncro system from a 92'Passat (6 months of hard work)

Next:

- I am starting (this week) to give Lambo Style Doors to my "Corraptor".

- I am waiting (next week) for a G-Lader rebuilding kit.

- an oil air-cooler (under construction)

- 16v head (thank you again for your advices-very pretious!)

And I want more!

So, please, tell me more about the boost return mod and knife edged rsr outlet.

Thank you again.

Eduard - Romania

http://autos.ph.groups.yahoo.com/group/ ... rowse/c87c

[GazzaG60 0]

the mechanical allows a smoother transition to and from boost. as the charger is providing enough air to be in boost at any given point ytou need to vent some off for normal driving. the flap provides a very smooth transition. fit a BOV and you will see what an on/off delivery is.

 

the isv only vents boost on certain code's apparently. i was told IIRC by sam at SNS that the euro variety doesn't have this boost bleed-off only US where itll bleed when knock or overboost is detected hence the jiro/isv reroute mod.

[corraptor_evo 0]

Thanks Gazza,

But I ask again:

If I will readjusting (by shortening) the linkage between the boost control valve and the throttle valve, I will close earlier the control valve and so I will gain boost earlier?

Can you give me an answer, please?

[flusted 0]

yes you will gain boost eralier but think it puts alot more strain on charger

[corraptor_evo 0]

Hmm... that mean you allready told me about. Sorry, I didn't read your post well enough. Thanks a lot.

But I insist with another previous question... Can you tell me something about boost return mod and knife edged rsr outlet ?

[GazzaG60 0]

boost return mod basically blocks the return of the charger or vents with twin filter. the pipe off the throttle body is removed. basically boosted air then goes to atmosphere rather than returning to the charger. this in turn lowers intake temps and helps with intercooler heatsoak. makes more noise though.

 

the outled edging is to alllow more flow to lower internal charger pressures and flow air more efficiently.

[corraptor_evo 0]

Ok. Thanks.

If you want to see my Corraptor, search on my album :)