RS_Matt

It's ok it's a £70 TD05 and by 5,100ish it's fully venting. I've run it for 5 years on a TDO4 and that chattered (poor man's compressor surge) from as low as 2,000 revs. I had to tighten the spring initially as I sounded like a bus every time I changed gear, not cool when you aren't actually going fast.

joshnosh

iTrader: (1)

the overfuel could be a little benfical for the reasons you stated. however the car is likely to get this amount off fuel with no air going through the maf.
with vta and deleat the engine is likely always getting "over-over fuel" if that makes sense lol

yes it would be good to know that! the vacuum isnt very strong though and the pressureised air will force its way through the recerc pipework quite quickly. even on a NA car the vacume will draw in air very quickly though the filter and the vacuum will drop off.

you defiantly wouldnt be able to change gear in that time put it that way!

joshnosh

iTrader: (1)

the turbo will be fine yeah
but its going the wrong way is all. the vanes are very light but to spin them up to 100,000 rpm takes lots off energy. when the turbos chattering its losing its kinetic energy and charging it back up will take longer. ie turbo lag. chances are it wount make a massive difference bit that's the point of the valve

RS_Matt

No I mean, as soon as you lift off fully the MAF ignores the vacuum of air that still pulls air past the MAF until the effect stops. Not being able to change fast would make this feat applicable as changing impossibly fast would mean no fuel was being injected due to the paused MAF and there would be det. It'd probably be too dangerous for the engine though as if you lift off then apply without changing - boom! I'm not sure how fast an ECU/MAF/Injectors could work with fast throttle data.

joshnosh

iTrader: (1)

unless the software tells it to react slowly they can react almost instantly.

problems is how do you know whats real air flow and whats the air flow you want to ignoor? im sure its possible to rewrite the ecu to do this but your rewiteing it not just changing parameters like most mappers do

this is the valve im probably going to get
http://www.scoobyparts.com/acatalog/..._9003_BOV.html

set it up for mostly recirc and a tiny bit off vta

RS_Matt

Shame there isn't one that does all 3! It'd be a restrictive DV for starters. Too small to fully vent and re-circ so the rest of the pressure hits the fins.

joshnosh

iTrader: (1)

just make the recerc pipe smaller?

RS_Matt

I've just read on another thread that a lad fabricated and placed a blanking plate with a small hole in front of his recirc to get to a bit of chatter whilst he re-circs. As we know there are dv's that part vent part re-circ so all 3 could be viable using his trick.

joshnosh

iTrader: (1)

i like it

The Pink Ninja

iTrader: (23)

What have i missed, Is it time to come back yet??


Air enters via the airbox, past the maf, through the turbo intake, Into the turbo where it becomes pressurised into the intertercooler, Then recirculated back into the intake between the maf and turbo... for the air that is not used into the T/B that is. That is the direction of it

If your turbo is spinning its under pressure to some degree....the faster it spins the more pressure

With A DV delete the air cant escape so goes back through the intercooler and turbo which will give a bigger pressure drop...Compressor stall...Cha cha cha

A recirc has a continuing one directional flow which keeps the turbo spinning the same direction resulting in less of a pressure drop.

Wether its right or wrong thats how i see it

RS_Matt

Yeah that was the gist of it before the thread, the real confusion was how the pressure ect caused or didn't cause over-fueling and when, how long for? It was not so much the air metered has to be used then frigs off, it was more the Turbo vacuum effect draws extra air past the MAF on lift off which causes that momentary injector madness.

Jury still seems out on why a DV Delete causes rich running. It has been suggested that air gets read whilst it leaves the MAF backwards, so to speak, but I've also read elsewhere that Newage MAF's are exempt from that kind or reverse reading capability/flaw.

EssexJamie

iTrader: (5)

I understand how DV work and what they can do to the engine etc!

My question is on My Type RA it had a D/V run like a pig, changed to recirc ran spot on!
My UK300 had a D/V on when bought it and it ran perfectly anyway I put a recirc one!
I've always had turbo cars and my Sierra Cosworth I had one as it was heavily modded and was recommended to help the turbo! Ran perfect!
Golf GTI 1.8T ran like poo with a D/V kept going into limp mode
Pulsar ran better with one but again was very modded!
MR2 twin entry turbo ran better with a up rated recirc!

So why does it effect different cars differently and some it's fine on and others it's not?
Also why did the UK300 run fine with a d/v?
Just curious as I don't want to run one lol!

RS_Matt

Decent question, I had a VTA on an RS Turbo, car ran fine but DV spat oil and it initially fell off after a mile. (mentioning no names as tuners like to bandy legal action)

I then had a VTA on an EVO IV car seemed ok but would occasionally cut out when going down gears off boost.

Got a VTA on the WRX and all seems fine apart from occasional lights pops on overrun.

All I hear on here re: VTA's is 50% of the cars run crappy with them on and the other 50% are fine, how queer? I wonder if it's down to stiff springs not fully venting? Then again, some claim it's driving in general and not just when fooling with the spooling.

swaynie

iTrader: (6)

Imprezas are tuned from factory with a recirc

END OF

RS_Matt

...and a conservative map, quiet exhaust, 3 cats, restrictive air filter etc etc etc.

TBH if you don't know the full workings and the why's then don't post.

swaynie

iTrader: (6)

What are you on about your just looking to get the last word in.

Subaru invested millions into the Impreza during RnD and everything was put on the car for a purpose including a recirc dv aswel as all the other stuff.

Stop pretending to be smart because it ain't working. If you knew anything about Imprezas and the workings you wouldn't have a 4 page long thread about overfueling with VTA DV's and then question everything trying to be right when your not.

Just give it up

A mod should lock this thread just for stupidity alone

mickywrx

iTrader: (29)

How about you stop posting then?

3 cats.

Very few, in the grand scheme of things, Impreza's left the factory with 3 catalytic convertors.

FWIW, my own car ran perfectly fine with the OEM recirc fitted.

I had the car under a week, and it ran perfectly fine with a Bailey VTA fitted.

I fitted an FMIC + induction kit, retained the Bailey VTA - it ran perfectly fine.

Got sick of the noise, blanked the take off for the DV, it ran perfectly fine.

Got sick of that noise, went back to an OEM recirc, it ran perfectly fine.

I fitted a Forge recirc intended for a Newage, it wouldn't idle for ****. Turned out that the one I'd bought second hand 6 months prior was in fact fcuked.

So that meant over Christmas/New year I was back at the no DV stage, as I'd given someone my OEM recirc to help them out. It still ran fine though.

Yesterday, (Friday), I fitted a late classic OEM recirc that someone on here kindly sent me FOC, having knocked up my own adaptor and sorting the plumbing of it in the dark.

Guess what, it still runs as it did the day I bought the car 8 years ago. Well it's a bit hesitant 1st thing if it's damp or really cold, but then it always is when it's due a plug change.

What might go straight over your head about the above, is, it's only representative of my car. It's been used, abused, neglected at times, properly had the **** kicked out of it at other times; launching when you're near the limiter isn't one of the best things to do.

Some Impreza's will have a proper hissy fit when you change a panel filter, they are all different. Panel filter swap might be a bit extreme, but, I'd hope you'd understand what I'm getting at.

Just because mine has been fine, doesn't mean someone else's will be. Just because mine never appeared to be overfuelling with the VTA fitted doesn't mean it wasn't.

The fact remain's that the ECU has calculated how much fuel to inject based on the readings from the MAF etc, venting to atmosphere ruins that calculation. It also carries out these calculations a hell of a lot faster that you can change gear.....

mickywrx

iTrader: (29)

I'd ask Lisa, but, she's probably asleep.

RS_Matt

I didn't read the rest as it'll be the same erroneous BS that every (save for joshnosh) other clueless sheep has posted.

The fact not all Imps had 3 cats isn't the point the point is not all things bolted onto an Imp is to improve performance etc etc. I'd say 20% of a Newage's weight 10% of a Classic's wouldn't be there if Subaru had the choice. Some implementations such as comfier and less bucket like seats or softer ride are to attract a broader market. Not all aspects are for rapid point to point reasons.

Now get back to a sticker thread if you can't contribute to the thread...

Now back to the discussion, I just can't get my head around why a deleted DV would cause over-fueling on lift off?? Anyone know, anyone know why Subaru and the like ran the re-circ option? Stringent noise tests? Smoother running? Emissions? homologation reasons? MPG? Turbo life? Personal preference re: noise? Maybe more than 1 reason?

mickywrx

iTrader: (29)

Imp?

mickywrx

iTrader: (29)

Is he sucking you off? You do know that a nosh is a blow job, don't you?

Eh? How much have you had to drink, as that makes no sense.

Would you care to explain your implication?

I doubt you can get your head round daylight and darkness, but, I'll await the answer to my question.

RS_Matt

You answer mine and I'll answer yours.


...Someone on here must know how a bloody DV and all it's alternatives work (or don't) and what it is for.

RS_Matt

Sorry I meant Subaru Impreza WRX STI. Do you have Aspergers Syndrome?

joz8968

iTrader: (13)

Think Aus and NZ affectionately use the term, Imp.

As well as Rex, of course.

mickywrx

iTrader: (29)

No, the only syndrome I have is a serious intolerance to people using the moniker RS_Matt.

At idle, a DV is open, as the vacuum pulls it open, under boost pressure it's shut.

Now answer my question.

Aaron1978

iTrader: (12)

and 'great galah'

RS_Matt

What air fuel ratio would be considered dangerously rich for the time the ECU over-fuels and what is the length of that time?

mickywrx

iTrader: (29)

How about you answer my question Matt?

What was your implication?

joz8968

iTrader: (13)

lol

swaynie

iTrader: (6)