Removing D/V

[richybigman]

Good news

 

[chriswilks]

all i can add to this is my recirc pipe came of my dv the other day and got that great sounding chattery noise!!performance was what can only be described as poo tho!!!!

 

[RobDon]

Very NOT recommended to run with no DV - you WILL destroy your turbo in a very short time, and possibly more when it does let go!

 

[Skorchio]

RobDon is the man. Probs got one of the most Modded Leons. Listen to him!!!

 

[Big_daddy]

I agree! All turbos come with a standard dv and its there to help the turbo. They would have suggested this before of removing the dv but they never!

 

[richybigman]

So how come most Evo specialists say to run them without d/v's, even on a standard Evo?
Don't get me wrong i know my car isn't an Evo but there can't be that much difference in the way the turbo works.

 

[DPJ]

Why can't I run without wheels, those guys with aeroplanes seem to manage it most of the time........

 

[G2232]

The boys in the scc do not run a dv as it is not allowed.
but obviously this does have its reprocutions as like robdon says it will destry your turbo in no time and also result in the turbo stailing not sure how the racing team get around that bit though.

 

[richybigman]

Why can't I run without wheels, those guys with aeroplanes seem to manage it most of the time........

Slight difference between a plane and a car than a car and a car! The way i see it is that the turbo is doing the same job in both cars so why would it be so much worse in mine?
I'm just looking for an explanation.

 

[BCM]

I think thats a fair point, what is the diff?
as i said, i know it isn't good, thats why my DV is back on!

 

[richybigman]

I'm not trying to start a debate or anything i just want to know why you can run some turbo's without a d/v but some have to have a d/v.

Surely you would feel if you had turbo stall? The way i see it is that it's the turbo stall which causes the problem so if you don't get it the car should be fine.

 

[Big_daddy]

Well if you think about it, diesel turbo dont come with any dv at all. asume they must have something similer!

 

[RobDon]

Anything running a turbocharger MUST have some sort of excess pressure release, or it is forced back through the turbo (hence the chattering noise) which puts immense strain on the blades, bearings, seals, etc. Race cars get away with it because they have the budget to change turbos after every race!

Most EVO tuners do NOT remove DV's on street cars, first time I've heard that one - lol! I have a large collection of EVO engine bay pics (for inspiration!) and not one has the DV removed, even the AMS drag EVO runs a big Tial BOV!

 

[richybigman]

I regulaly go to Evo meets with my brother and a mate and they say not to run with d/v's. Even cars that Norris Designs modify say to run with no d/v.
Surely the pressure goes through the wastegate to release?

 

[RobDon]

All I can say is 99% of all tuned EVO's I've ever seen all have a DV or BOV fitted. Maybe this is why so many EVO's and Scoobys blow their engines with alarming regularity ... by doing dumb things like running with no DV or BOV.

I mean if the likes of AMS, RC Developments, etc. all use BOV's then it has to be for a reason. Andrew Gallacher's fire-breathing 650bhp Focus Cosworth race car runs a Bailey DV30!!!

http://www.b7srl.com/Andrew/FocusMkIIimages/images/engine_fitted.jpg

 

[DPJ]

I regulaly go to Evo meets with my brother and a mate and they say not to run with d/v's. Even cars that Norris Designs modify say to run with no d/v.
Surely the pressure goes through the wastegate to release?

It can't if the wastegate is closed.

The moment you back off on the throttle from a full boost situation, the car would normally dump (or recirculate) relieving the pressure in the intake system.

Without the pressure relief, you've still got the exhaust turbine running hard, driving the compressor hard. Air is effectively backed up on the compressor side, going nowhere for a short while. The compressor blades are chopping through that air, putting great strain on them, shaft and bearings........

 

[richybigman]

As far as i know on the Evo's the wastegate deals with the pressure which is why they get wastegate chatter.
Please don't think i'm being argumentative

 

[DPJ]

As far as i know on the Evo's the wastegate deals with the pressure which is why they get wastegate chatter.
Please don't think i'm being argumentative

Think about how and when a wastegate works.

 

[skahigh]

anyone who is not a mechanical expert and wants more info on how turbos work see here for a good read:

http://en.wikipedia.org/wiki/Turbocharger

 

[richybigman]

Ok so i've just read this, i won't be removing my d/v :

Anti-Surge/Dump/Blow Off Valves
Turbo charged engines operating at wide open throttle and high rpm require a large volume of air to flow between the turbo and the inlet of the engine. When the throttle is closed compressed air will flow to the throttle valve without an exit (i.e. the air has nowhere to go).

This causes a surge which can raise the pressure of the air to a level which can be destructive to the engine e.g. damage may occur to the throttle plate, induction pipes may burst. The surge will also decompress back across the turbo, as this is the only path with the air can take.

The reverse flow back across the turbo acts on the compressor wheel and causes the turbine shaft to reduce in speed quicker than it would naturally. When the throttle is opened again, the turbo will have to spin-up for longer to the required speed, as turbo speed is proportional to boost/volume flow. In order to prevent this from happening, a valve is fitted between the turbo and inlet which vents off the excess volume of air. These are known as anti-surge, dump or blow-off valves. They are normally operated by engine vacuum or by electronic control.

The primary use of this valve is to prevent damage to the engine by a surge of compressed air and to maintain the turbo spinning at a high speed. They can also be used as a bypass valve to control boost in a similar fashion as a waste gate, but this is rarely seen as it is impractical. The air is usually vented to atmosphere, or can be recycled back into the turbo inlet. Recycling back into the turbo causes the venting sound to be reduced but as the excess volume of air is not removed problems may arise.