bov fitted need some advice.

[Tonks4x4]

I have run cars without either, you do get turbo stall but on quick gear changes it's noticeably faster. I know it's supposed to reduce the life of your turbo but by how much??? Also have monitored AFR in this state and not had any adverse effects.

[prj]

so on maf cars I think an open style bov causing loss of power is the least of your worries and its mostly theoretical buII s.h.i.t from over use of reading the internet.

Yeah, I'm really sorry.
All my accelerometer data, my AFR and boost logs and my experience mean nothing compared to your butt dyno

I have run cars without either, you do get turbo stall but on quick gear changes it's noticeably faster. I know it's supposed to reduce the life of your turbo but by how much??? Also have monitored AFR in this state and not had any adverse effects.

Without reduces the life of the turbo and you get more lag on gearchanges.
I don't think the AFR will get affected much, but I have never tried running without.
Venting air to atmosphere post-turbo is the issue, if you have no valve at all, you don't went to atmosphere and your AFR does not go pig rich.

[Rusty]

Having run my GFB item in various states it is my firm opinion that the car ran noticeably worse on the full vent to atmosphere setting than on fully recirculating. It was rougher, especially when applying WOT immediately after a dump You could hear the exhaust backfiring on gear change where there was excess unburned fuel going into the exhaust. prj might not sugar coat things the way some others do but we agree here and he's trying to help. On a car that's not running spot on and not running 98 fuel the effect wouldn't be so noticeable as the boost build up isn't as great and the AFRs are already a bit low. Much though we all like to think our cars are perfect, they rarely are, as I've found out just about every time I've done a boost leak test or connected to VAG com... frustrating You bet!

If you want the chirp then get something like the GFB item that can be adjusted to give mainly recirculating with a little air vented to atmosphere for good measure. I found that I was not able to identify the difference between the lower settings and fully recirculating (the port opened after 2 clicks from the 11 available and 3 or 4 clicks from fully recirculating was just right). For those after the woosh - the best of both worlds? I think so.

http://www.balancemotorsport.co.uk/p...h%20FX%20(1008)

I got mine for ~£70 secondhand and had to buy some adaptors. Still < half price. Build quality was something to behold.

[quattro]

Obviouslu prj you have taken my coment to heart, for any particular reason?.......... and your experience, I have no clue who you are so why would I trust you?

You may even be very good at what you do, I just posted my opinion, to which you took great offence to a small part of it. If you are a pro in the tuning world, you would at least agree with the rest of my post, would you not?

Theoretical perfection is not allways realistic perfection!

Dont take it so personal, its a public enthusiat forum......

[Rusty]

Happy enough for in depth discussions but this is in danger of getting a little heated and we don't want that

[newsh]

It seems pretty obvious to me that if you're running a maf and you dump a load of air to atmosphere thats been metered by that maf then you're going to end up with a load of excess fuel in the engine, its obvious, no bulls.h.1.t there dude.

My ur runs without a DV, you can hear it go chooka-chooka when you change gears, its a well documented fact that fitting a DV to a ur will get the power back on quicker after a gear change and make the car faster.

As far as air going back past the maf into the airbox, there may well be some, there's always some breather oil in the maf to turbo hose, but look at it this way, the turbine is spinning trying to make low pressure upstream and high pressure downstream, a diverter valve makes a short circuit across the coldside so the blades can keep spinning and the air just goes round and round in a circle. (probably imperfectly though )
The 3B is well designed in this respect as the return hose from the DV points straight back into the turbo impeller The ABY comes in a right angles to give more clearance behind the headlight..

[4WheelDrifter]

And without BOV it would be even faster.
I have tested this back-to-back on the same car. Logged AFR.
I am not talking out of my ***.

I have run a open bov since I had the car

Who is dealing with theory, and who is dealing with facts?

BOV's have never been a good idea on an S2.
I tried one once too, and with no DV. Personally I have never had a problem with the stock Bosch DV's, 710N & P's work fine IME.

[quattro]

Look maby I was a little abrasive in my last post, didnt really put down what Im trying to get over. What im trying to say is that a bov is not the end of the world, Im not saying its better or worse than a re-circ.

When I changed mine over it made no difference to performance at all, just gave me a nice noise (in my opinion).

[M_GORDON]

I just change my Forge 007 DV for a new APR R1 diaphram valve.

The change is very good. I´m very happy because it reduce the lag and turbo charge earlier.

[Rusty]

Right you two, I asked you nicely to calm it a bit. You're just ruining the thread.

Thread cleaned up.

[rj scotty]

@PRJ. Reading your responses to a lot of posts on this forum it's clear you know your stuff, however your attitude leaves a little to be desiered..........remember it's all just a matter of opinion.

[prj]

No. Everything is not a matter of opinion.
If I told you the world is flat (and I was serious), I would be going with my so-called opinion against the facts, and you would not take it seriously either.

This is exactly the same. What happens when you vent counted air into the atmosphere is exactly the same across all of these cars. No one's car is different.
Barging in and claiming to know best, and calling everyone else "idiots who sit too much online" does not make me want to take someone serious at all.

Just as if you would not take me serious, if I told you the world is flat.
Anyway, play the ball, not the player. If you have an issue with my attitude (and I agree, that it is not always the best) write it in PM.

[Rusty]

@PRJ. Reading your responses to a lot of posts on this forum it's clear you know your stuff, however your attitude leaves a little to be desiered..........remember it's all just a matter of opinion.

I was thinking the same thing I'm afraid.

This forum is 99% good natured and that sets us apart from many other forums where rudeness, bullying and aggression are the norm. Many on here are experienced and / or educated enough to discuss problems with a balanced opinion and even accept, on occasion, that we are allowed to agree to disagree However, we can all be sensitive souls at times and a sharp telling off is a good way of putting noses and egos out of joint! In fairness to quattro, I've not seen him react like that before so this is not a regular occurance.

Thanks for sharing your knowledge with us, I've been interested to read your posts on a number of threads and it's good to hear a new opinion that comes from both an experimental and theoretical POV. However, I'd suggest that a course in diplomacy 101 will make for an easier education for all of us.

[rj scotty]

Agreed. Rudeness is not the norm on this fine forum and I'd like it to stay that way