Total removal of a Dump Valve?

**Niles** · Monday 23rd February 2009, 21:17

Is there a benefit or is it 'kill a turbo early'?

**1996 850 T5** · Monday 23rd February 2009, 22:01

youll risk compressor surge when you shut off with isnt healthy for turbo life

stalling the turbo due to massive back pressure repeatedly will inevitable cause something to give (twisted/snapped turbo shaft or worse)

joe

**t5 pete** · Monday 23rd February 2009, 22:12

by doing this wouldnt you be getting turbo chatter as well

**timbo_1975** · Monday 23rd February 2009, 22:30

And hugely pronounced lag after gear changes.

**thebadger** · Monday 23rd February 2009, 22:37

It'll make the car sound like Darth Vaders death scene... Scraping & painful!

Don't do it man!

Save the Turbo! Kill an environmentalist! (well plant one!)

**Saaamon** · Monday 23rd February 2009, 23:16

The boost levels we run wont really cause much damage if you run without a recirculating valve and you would, if running a cone type filter, hear the turbo stalling. There's alot of people on here that slate members who remove the recirc valve because they like the sound of "chatter", but its a pretty common thing.

**AndysR** · Monday 23rd February 2009, 23:21

Mine's been removed for a while now and I love the noise, lag hasn't changed at all but then mine is auto so might not notice lag so much anyway..

**kevin 850t** · Tuesday 24th February 2009, 00:43

You lot are clever, what you talkin about?

**p fandango** · Tuesday 24th February 2009, 02:16

Originally Posted by Niles

Is there a benefit or is it 'kill a turbo early'?

[ame]http://www.youtube.com/watch?v=3rQAYXfmhco[/ame]

i'm running a 19t with no dump valve or recirc valve & would say its got less lag than when i had my 15g on (because of other mods tho)

**kevin 850t** · Tuesday 24th February 2009, 05:40

Originally Posted by p fandango

http://www.youtube.com/watch?v=3rQAYXfmhco

i'm running a 19t with no dump valve or recirc valve & would say its got less lag than when i had my 15g on (because of other mods tho)

That sounds well nice, thanks for the vid, i still don't know what's going on here!!, i'll learn though

**p fandango** · Tuesday 24th February 2009, 06:50

Originally Posted by kevin 850t

That sounds well nice, thanks for the vid, i still don't know what's going on here!!, i'll learn though

thanks, i'm happy with it

with either a recirc or a dump valve when you back off the throttle (either to change gear or just slow down) the turbo is still spinning creating boost, with a valve fitted the air is let out & the turbo is allowed to carry on spinning. But without one the air created from the turbo is trapped in the system & stopped by the throttle plate, backing the air up until it the system is full & eventually stopping the turbo & creating lag as the turbo has to start spinning back up again once you step back on the gas

**kevin 850t** · Tuesday 24th February 2009, 07:39

Nice explaining, can i take off my plate for a week or two till i can afford a blanking plate for my dump valve as i've spent all my money i havn't got yet?, (i like that sound)

, thankyou for the pipe and clamps by the way

**shaun850** · Tuesday 24th February 2009, 07:54

I havent run a DV for over a year.. 1.2 bar, no (extra) lag and no hint of any problems.

We dont run enough boost imo to do any real damage.

**p fandango** · Tuesday 24th February 2009, 07:57

Originally Posted by kevin 850t

Nice explaining, can i take off my plate for a week or two till i can afford a blanking plate for my dump valve as i've spent all my money i havn't got yet?, (i like that sound)

i don't quite get what you mean tbh mate, do you mean remove the recirc valve & then fit a blanking plate later? if so then no, you'll just have a nice big hole in the side of your turbo till its blocked which isn't good

thankyou for the pipe and clamps by the way

is it fitted yet? pictures

**thebadger** · Tuesday 24th February 2009, 08:02

you can have both an external (dump valve) and a recirc valve (whats in the car as standard) But removal of both causes reverse pressure on the blades of the turbo, which can eventually damage said blades or damage the spindle core.

Do recall that a turbo works at a much higher operating tempreature than most engine components, and as the metal gurus will know, heat will make metal brittle over time.

So..... it is something you can do, but it's like a baked alaska, very nice, but it won't last very long either way!

No recirc, with a BOV will give a small amount of chatter below 3-3.5k revs, where as above this you will get normal external dump of hot gasses (TSHHHHH...).

Recirc & BOV will give no noise (other than standard pipe whoosh) below 3-3.5k revs, but a much quieter dump of gasses (tshhh..) above.

Nither of the above options (no recirc or BOV) gives that chatter sound, which as I have said is not really healthy to the turbos lifespan.

Best choice is ext BOV, or recirc only. Not both, or nither as these are exersises in futility!

My opinion & I'm sticking to it!

HTH

**kevin 850t** · Tuesday 24th February 2009, 08:09

Superb, thankyou, my cars just two quiet, the wife likes it quiet, she's going to go mad when she hears the dump valve and the powerflex upper engine mount sending race tunes through the dash, i'm going to get beats!!!, hehe i laugh now!, thanks for expert advice.

Kind regards, kevin.

**kevin 850t** · Tuesday 24th February 2009, 08:12

This is the one i wan't.........................

No recirc, with a BOV will give a small amount of chatter below 3-3.5k revs, where as above this you will get normal external dump of hot gasses (TSHHHHH...).

**kevin 850t** · Tuesday 24th February 2009, 08:14

Originally Posted by p fandango

i don't quite get what you mean tbh mate, do you mean remove the recirc valve & then fit a blanking plate later? if so then no, you'll just have a nice big hole in the side of your turbo till its blocked which isn't good

is it fitted yet? pictures

not fitted, waiting for the reducer still, 7-10 days

i don't quite get what you mean tbh mate, do you mean remove the recirc valve & then fit a blanking plate later? yes, that's what i meant i think

**p fandango** · Tuesday 24th February 2009, 12:18

Originally Posted by thebadger

you can have both an external (dump valve) and a recirc valve (whats in the car as standard) But removal of both causes reverse pressure on the blades of the turbo, which can eventually damage said blades or damage the spindle core.

Do recall that a turbo works at a much higher operating tempreature than most engine components, and as the metal gurus will know, heat will make metal brittle over time.

So..... it is something you can do, but it's like a baked alaska, very nice, but it won't last very long either way!

No recirc, with a BOV will give a small amount of chatter below 3-3.5k revs, where as above this you will get normal external dump of hot gasses (TSHHHHH...).

Recirc & BOV will give no noise (other than standard pipe whoosh) below 3-3.5k revs, but a much quieter dump of gasses (tshhh..) above.

Nither of the above options (no recirc or BOV) gives that chatter sound, which as I have said is not really healthy to the turbos lifespan.

Best choice is ext BOV, or recirc only. Not both, or nither as these are exersises in futility!

My opinion & I'm sticking to it!

HTH

turbo's are developed & made to cope with the high temperatures, even as standard they run at very hot temperatures & would of thought with the high-mileage Volvo's we've got would of had blade failure of a few by now if they got brittle considering the RPM's a turbo spins at. & as mentioned we're not talking high boost levels here

**Loadsamiles** · Tuesday 24th February 2009, 13:37

Originally Posted by p fandango

http://www.youtube.com/watch?v=3rQAYXfmhco

i'm running a 19t with no dump valve or recirc valve & would say its got less lag than when i had my 15g on (because of other mods tho)

I thought you had a "fart valve" on your DP.... I don't hear it, Or isn't it connected yet?