What A Dump!

[CAMO]

I'm Concidering Fitting A Dump Valve To My 1996 850 T5. First Of All What Sort Is Best: Piston Or Diaphram? How Hard Is It To Fit One, And Are There Any Problems In Fitting/ Running/ Maintaining One Once Fitted? Suggestions Please!

[Wobbly Dave]

If you do fit one - then you will have to remove the recirc valve that is already on the turbo.

Personally - I wouldnt bother fitting an airleak to my car

[hamish]

camo,

Please don't do it ! I'm getting bored of removing those blanking plates that someone keeps selling ! They don't work and just cause problems. The volvo management system uses a MAF sensor to determine air taken in, and so a to atmosphere D.V. will ultimately confuse your ECU. They're alright on ancient history like: Renault 5, Escort / Sierra RS, 200SX etc. Fitting one, to a T5, usually end's up with a poor running issue ! Spend your money on making it fast not noisey !

Regards,
Hamish.

[CAMO]

I Have Been Assured That By Fitting A Twin Piston Type Dump Valve, This Ensures That There Is No Running Problems, Idle/ Ecu Problems?

[Pedro Fandango]

Bracers got a dump valve on his, where is he?

[CAMO]

Wow, He Must Be Good On The Stop Watch, To Time 14.557 Seconds! And I Bet It's All Down To The Dump Valve Fitted!!!

[Pedro Fandango]

Wow, He Must Be Good On The Stop Watch, To Time 14.557 Seconds! And I Bet It's All Down To The Dump Valve Fitted!!!

lol, it was timed at Santa pod. & i've still got the standard re-circ valve (for now )

[CAMO]

Twin Piston Is The One To Go For!!

[Bracer]

Sorry it took me so long.

Well as Cov said, I have one and I have no problems, infact it cured my boost leak and my compressor stall as the stock CBV would leak under the boost levels I'm running and then did not flow enough to relieve the system of boost during gear changes and causes serious stall

You will require a "Double Piston" or an "Adjustable" one.

I personally prefer the Adjustable type as this allows you full control over the set-up and gives you a better range of valves to choose from !

Anyway the key to the system is a "MUST" fitting of a block off plate for the CBV. Dont be tempted to do the quick way of fitting a washer check valve in the Vac/Pressure line to the CBV and its just a Bodge way of doing this mod.

Anyway here’s some pics





See the Full step by step fitting here

Any questions, please ask !

Regards

Steve

[CAMO]

mate, what is the cbv, and why do you need to blank it off. with the fitting kit that you get with these dump valves do they tell you to do this? i thought that the dump valve fits in place as shown on your photo, and the small pipe off the dump valve goes onto your engine block at the front?
sorry i'm a little slow when it comes to modding volvo's!

[Bracer]

mate, what is the cbv, and why do you need to blank it off. with the fitting kit that you get with these dump valves do they tell you to do this? i thought that the dump valve fits in place as shown on your photo, and the small pipe off the dump valve goes onto your engine block at the front?
sorry i'm a little slow when it comes to modding volvo's!

Yeah your on the right track, but T5's are fitted with a recirculating valve which does what a BOV does just that it shoves the air back into the intake.

The problem I found is that it starts to leak at high boost pressures and hasn't got a high enough flow to cope around those levels too thus causing compressor stall

If you leave it in place it will just screw the system up.

CBV Pic 1

CBV Pic 2

CBV Blanking Plate Pic

[CAMO]

Cheers Mate I'll Blank That Off The When I Fit The Dump Valve! (by The Way Did You Buy The Blank Plate Or Was It Custom Home Made?

[Bracer]

Cheers Mate I'll Blank That Off The When I Fit The Dump Valve! (by The Way Did You Buy The Blank Plate Or Was It Custom Home Made?

Yep I made it

[CAMO]

i have fitted the twin piston dump valve now, but at this stage without blanking the other device off. The valve appears to work ok without doing this, you can hear it blowing off when you change gear etc.How will i know if this device still requires blanking off, what symptoms will i encounter? how will it effect the car? is it possible that my vehicle does'nt require having this done?
bracer! your sugestions please?

[Bracer]

i have fitted the twin piston dump valve now, but at this stage without blanking the other device off. The valve appears to work ok without doing this, you can hear it blowing off when you change gear etc.How will i know if this device still requires blanking off, what symptoms will i encounter? how will it effect the car? is it possible that my vehicle does'nt require having this done?
bracer! your sugestions please?

Did you fit a washer check valve in the Vac line to the stock CBV just out of interest ?

The main difference you will find with blocking off the CBV is that the new DV will react quicker / be louder / and give better throttle response.

As for your car being different and not requiring the CBV blanking plate, lots of people dont bother cause of the inconvenience but then your only doing half the job in my book and will never reap the true benefits of your had earnt cash.

Just to recap, you've a Bailey DV yes ?

Regards

Steve

[CAMO]

Bracer:
I Purchased A 2nd Hand Twin Piston Dump Valve Off E-bay (ripspeed From Halfords), And A Brand New Fitting Kit Made By Bailey. This Came With All Fittings To Connect The Dump Valve Into The Plastic Hose From The Inter Cooler, With The Small Flex Which Goes To The Vaccum Side Of The Engine Block. There Was No Check Valve Or One Way Valve That Connects In This Line! That Came With The Kit. What Should I Do Mate. (looking For Your Experience On This One Chap!)

[Bracer]

Bracer:
I Purchased A 2nd Hand Twin Piston Dump Valve Off E-bay (ripspeed From Halfords), And A Brand New Fitting Kit Made By Bailey. This Came With All Fittings To Connect The Dump Valve Into The Plastic Hose From The Inter Cooler, With The Small Flex Which Goes To The Vaccum Side Of The Engine Block. There Was No Check Valve Or One Way Valve That Connects In This Line! That Came With The Kit. What Should I Do Mate. (looking For Your Experience On This One Chap!)

Ok that sounds all fine mate.

As I've said, by fitting the Blanking plate you will only improve the situation with quicker response / better high boost holding / lower charge temps (due to not recalculating pre charged air) and a louder sound from the DV.

Hope this helps ?

Regards

Steve

[CAMO]

i/ve had the bov removed, but in doing so its left me with another problem. it seems to be over boosting/ running with too much boost now. the ecu is cutting fuel off when max boost, and the turbo gauge is going over the registered mark. the boost has not been altered, only the bov blanked off as per your instruction. the vac pipe that went to the engine block has also been blanked off. i have even turned off the bleed vale in an effort to reduce the boost. can you assist (urgent!)

[Bracer]

i/ve had the bov removed, but in doing so its left me with another problem. it seems to be over boosting/ running with too much boost now. the ecu is cutting fuel off when max boost, and the turbo gauge is going over the registered mark. the boost has not been altered, only the bov blanked off as per your instruction. the vac pipe that went to the engine block has also been blanked off. i have even turned off the bleed vale in an effort to reduce the boost. can you assist (urgent!)

So let me get this right,

You've removed your BOV but left the blanking plate in place and not re-fitted the CBV ?

Or you've fitted the BOV and removed the CBV and blanked it off with a plate ?

[CAMO]

the new dump valve has been fitted for some while now, and run with the stock valve in place. today i have had someone remove the stock valve and put a metal blank plate to blank the space off. (is that clear mate, or do you want me try an explain more?)