80 replies to this topic

[EricF]

Look, they're about the most simple device in your engine bay, they don't need to be there for any reasons relating to performance, so any questions regarding their installation, sound, or look, will be moved to the appropriate forum (maintenance, cosmetic, cosmetic, respectively).

Before you lash out in "That's not fair! My question is important too!" see if this answers your question:

Blowoff Valves, and YOU

Blowoff valves do not increase performance.

Blowoff valves release air from your intake system when the throttle is suddenly closed.

Your stock CBV located on your turbo does the same thing.

Blowoff valves simply need to be plumbed into the intake between the turbo and the throttle in some manner, and given a vacuum source behind the throttle body in order to function and be fully installed.

They all sound stupid on an automatic Volvo.


Sorry, but this has gotten out of hand in here! If you have a question about a blowoff valve that isn't answered in this post, please post it in the appropriate forum, NOT performance

[Zaitz]

I dont have a CBV on my turbo.

[EricF]

I dont have a CBV on my turbo.

You are special. If you have upgraded turbos to a different family without integrated CBV and have a question about a BOV, I should reach through the computer and slap you upside your head

[Jaxx]

CBV does NOT do the same thing. the CBV routes the air back into your intake.

If you're running higher boost than stock, a BOV is good because it won't fall apart after 3 15psi lifts (see cbv)


sure they sound stupid, but they're cool too

[EricF]

CBV does NOT do the same thing. the CBV routes the air back into your intake.

If you're running higher boost than stock, a BOV is good because it won't fall apart after 3 15psi lifts (see cbv)


sure they sound stupid, but they're cool too

OK, so the CBV does the same thing but better.

Oh, and please educate me about running higher boost than stock I don't think I've run a 15G at less than 15 psi in the last 4 years, and I have had 15G/16T/19T on: black 855, yellow 854, silver 745, 242 gt, silver 854, platinum 854, white 244... Have probably put like 150k combined miles on Mitsubishi turbos with stock CBV's running over a bar of boost, and have never had one tear in *all of those different cars* ... Note, some of those cars have had replacement used turbos with other used CBV's..

Anyway. If your CBV tears at 15 psi, it was about to fall apart anyway, or it was installed incorrectly or damaged before installation.

[Che'_Moderator]

CBV does NOT do the same thing. the CBV routes the air back into your intake.

If you're running higher boost than stock, a BOV is good because it won't fall apart after 3 15psi lifts (see cbv)


sure they sound stupid, but they're cool too

CBV Job: Protect the Turbo From Surge
BOV Job: Protect the Turbo From Surge

Sounds the same to me

[Jaxx]

CBV Job: Protect the Turbo From Surge
BOV Job: Protect the Turbo From Surge

Sounds the same to me

okay okay, the job is the same, but the way they go about doing it is different. how about that?

[Che'_Moderator]

okay okay, the job is the same, but the way they go about doing it is different. how about that?

I'll be sure to call my girlfriend a hooker later just for you

[Zaitz]

You are special. If you have upgraded turbos to a different family without integrated CBV and have a question about a BOV, I should reach through the computer and slap you upside your head

WOOT!

[VS Legend]

okay okay, the job is the same, but the way they go about doing it is different. how about that?

BOV = PSSSHHHHH!
PSSSHHH != Performance
Unless you are creating some sort of performing BOV orchestra.

In which case, I love you.

[exexpat]

BOV's are stupid and belong in my cosmetic forum, exactly like how all wheels/tire changes ever are only for cosmetic reasons.

[gdizzle]

BOV's are stupid and belong in my cosmetic forum, exactly like how all wheels/tire changes ever are only for cosmetic reasons.

exactly!

[Trunks850R]

well my Turbo XS RFL isnt blowing off at all, what the hell?????im going to take it apart here in a minute, someone enlighten me before i start a new thread!

[ErikS]

Are CAI next then?

[Zaitz]

Are CAI next then?

The argument is there is already a system present that serves a similar purpose - the CBV. Switching to a BOV will not offer any performance increase. However I do agree performance is a better section then cosmetic, purely for the fact that the stock CBV fails and more people are turning to after market turbos where a BOV or diverter valve may be necessary.

[EricF]

well my Turbo XS RFL isnt blowing off at all, what the hell?????im going to take it apart here in a minute, someone enlighten me before i start a new thread!

Am I to understand then that it was working before and now it is not? That would mean basically either a siezed valve or a fault in the vacuum source. These are some of the most simple contraptions you will encounter in your automotive tinkering days

[v4lve]

wow you guys must hate mk4 vw shows

[bdimag]

I'll be sure to call my girlfriend a hooker later just for you

so.. what if we install a BOV and have the gas it expells hooked up to a hose that points to the back of the car... that way when it hits, it pushes the car a little... then can we call it performance?

[BuDeKai]

that will definately work.

[kildea]

... purely for the fact that the stock CBV fails and more people are turning to after market turbos where a BOV or diverter valve may be necessary.

i have an early pierburg cbv now, one of the metal ones from an early redblock turbo (garret) that can be mounted independently anywhere along the pressurized side of the intake.

it cost me a whole $12, and the return hose can be vented to atmosphere like a bov, in the event that the user wants to sound like a pansy.

there are solid stock volvo options that are immune to the "it'll tare" argument and that can be remote mounted (i use a kkk turbo with no integrated cbv), so i think that leaving this discussion OUT of performance makes sense, since it offers only bling + meow to the volvo turbo motor.