GFB Respons TMS + MAF doesnt run ritch??

[Aurai]

Just doing some general reading, I know that running a BOV VTA instead of Recirc will mess with the AFR due to the MAF sensor, GBF claim their Respons TMS doesn\'t affect cars with MAF sensor due it being adjustable.

How much air can the valve dump to atmosphere before it starts to cause an issue? Im suspecting its alot less than GFB are letting on (almost nothing).

(http://www.gfb.com.au/products/blow-off-and-diverter-valves/respons-tms)

[Kiwi_Fozze]

the 50% that they are hinting at is a good midway point between recircing and VTA. recircs enough to minimise the rich spike, whilst still giving the chu chu, but tbh if you want to avoid all the running rich issues, stick with stock or recirc only

[Timmah]

 kwi_fozze said:

the 50% that they are hinting at is a good midway point between recircing and VTA. recircs enough to minimise the rich spike, whilst still giving the chu chu, but tbh if you want to avoid all the running rich issues, stick with stock or recirc only

Alternatively you can remove the intake shorkel for some \'just\' audible chu chu.

I\'ve found with my GFB respons is that on 50/50 the car is fairly happy. Idles nicely and doesn\'t get all weird compared to 100% vent.

[Kiwi_Fozze]

hks ssqv on my v7 and no weird idle issues, but i do get backfires and on very hard rapid shifts it seems a little hesitant as the foot goes back down.

50/50 on a v8 sti is quite nice. and thats as far as i can compare, becides a full vta on a v6 era forester is a c**t

[Aurai]

Ahhkay, I would of thought that as soon as any air as dumped it would cause issues as the engine isnt getting what it expects. How audible would 25% atmo 75% recirc be?

Would that also mean that the car pretty much runs as normal re fuel ratios etc?

[Timmah]

 Aurai said:

Ahhkay, I would of thought that as soon as any air as dumped it would cause issues as the engine isnt getting what it expects. How audible would 25% atmo 75% recirc be?

Would that also mean that the car pretty much runs as normal re fuel ratios etc?

Very audible. I\'ve tried that setting too. However the pssscchhh starts to sound like a choked chicken.

[nickch]

Could be me growing old, but I have a GFB hybrid, and I much prefer the sound it makes full recirc with the snorkel taken off

[Aurai]

 Timmah']

Very audible. I\'ve tried that setting too. However the pssscchhh starts to sound like a choked chicken.

Haha, that sucks.

[quote name='nickch said:

Could be me growing old, but I have a GFB hybrid, and I much prefer the sound it makes full recirc with the snorkel taken off

Hmmm, I like the current sound my factory valve makes, just wish it was a little louder so that someone next to the car can hear it and not just me inside it

Gonna wait till my next car to do any of this anyway.

How loud is yours full recirc?

[nickch]

 Aurai said:

Hmmm, I like the current sound my factory valve makes, just wish it was a little louder so that someone next to the car can hear it and not just me inside it

Gonna wait till my next car to do any of this anyway.

How loud is yours full recirc?

Not sure how it sounds from outside as I\'m sole driver. But from inside the cabin it is quite distinctive..

[Marky]

You know that "rich" moment is for a fraction of a second, just as your foot comes off the pedal and it\'s venting

After that fraction of a second, there\'s no fuel going in (0% throttle) until it returns to idle anyway.

The only reason you should get idle issues is if the BOV is staying a bit open when it shouldn\'t be - for example as it\'s returning to idle, big manifold vacuum can hold the valve open when it should be snapped shut - which is why tightening the valve can fix stumbling idle issues. The factory one stays open a lot longer than most aftermarket ones will, it just doesn\'t matter since it is a closed system

[Aurai]

 Marky said:

You know that "rich" moment is for a fraction of a second, just as your foot comes off the pedal and it\'s venting

After that fraction of a second, there\'s no fuel going in (0% throttle) until it returns to idle anyway.

The only reason you should get idle issues is if the BOV is staying a bit open when it shouldn\'t be - for example as it\'s returning to idle, big manifold vacuum can hold the valve open when it should be snapped shut - which is why tightening the valve can fix stumbling idle issues. The factory one stays open a lot longer than most aftermarket ones will, it just doesn\'t matter since it is a closed system

Ive heard that the rich even only for a fraction of a second can cause issues eventually? Damage the engine quite severely?

[Rosssub]

 Aurai']

[quote name='Marky said:

You know that "rich" moment is for a fraction of a second, just as your foot comes off the pedal and it\'s venting

After that fraction of a second, there\'s no fuel going in (0% throttle) until it returns to idle anyway.

The only reason you should get idle issues is if the BOV is staying a bit open when it shouldn\'t be - for example as it\'s returning to idle, big manifold vacuum can hold the valve open when it should be snapped shut - which is why tightening the valve can fix stumbling idle issues. The factory one stays open a lot longer than most aftermarket ones will, it just doesn\'t matter since it is a closed system

/quote]

Ive heard that the rich even only for a fraction of a second can cause issues eventually? Damage the engine quite severely?

It\'s more the Carbon and Crud left behind when running rich. Like Black Sooted Plugs/Caked Valve Seats/Coated Combustion Chambers/Clogged Catalytic Convertors.

Fouled Plugs/Burnt Valve Seats/Raised Compression causing Pinging/Failed Cats...

Also it\'s staying Rich, long enough to cause Hesitation when first back on the Gas. I found changing from my HKS Seq VTA to OEM Recirc, the hesitation during fast changes disappeared instantly.

All for a noise. :-\

[Aurai]

Yeah im not willing to have all the problems for a noise. :-\ Which is why i hoped a hybrid valve might get around it.

A good aftermarket recirc, eg the gfb listed when set to full recirc, shouldnt cause any issues right?

I will need to get one if i go past 20 psi?

[Rosssub]

 Aurai said:

Yeah im not willing to have all the problems for a noise. :-\ Which is why i hoped a hybrid valve might get around it.

A good aftermarket recirc, eg the gfb listed when set to full recirc, shouldnt cause any issues right?

I will need to get one if i go past 20 psi?

50/50 GFB Recirc - $400.00 -Shiny

OEM Recirc BOV - $0.00 -Not so shiny

Money better spent on things that make it go faster... ;D

[Johnnynz]

 Rosssub']

[quote name='Aurai said:

Yeah im not willing to have all the problems for a noise. :-\ Which is why i hoped a hybrid valve might get around it.

A good aftermarket recirc, eg the gfb listed when set to full recirc, shouldnt cause any issues right?

I will need to get one if i go past 20 psi?

/quote]

50/50 GFB Recirc - $400.00 -Shiny

OEM Recirc BOV - $0.00 -Not so shiny

Money better spent on things that make it go faster... ;D

Agree.

V7 BOV handles 20 PSI on my setup just fine.

[Rosssub]

 Johnnynz']

[quote name='Aurai said:

Yeah im not willing to have all the problems for a noise. :-\ Which is why i hoped a hybrid valve might get around it.

A good aftermarket recirc, eg the gfb listed when set to full recirc, shouldnt cause any issues right?

I will need to get one if i go past 20 psi?

/quote]

50/50 GFB Recirc - $400.00 -Shiny

OEM Recirc BOV - $0.00 -Not so shiny

Money better spent on things that make it go faster... ;D

Agree.

V7 BOV handles 20 PSI on my setup just fine.

I\'ll be trying my OEM TT BOV out to around that too. ;D

If worried about BOV sneaking open or not holding shut. Make sure there is no OEM Restrictor Pill in the BOV Vac/Control Hose.

Or fit Bigger/Thicker Vac Hose, that wont Compress under Vac, or Expand under Boost.

I\'ve just fitted a length of 3/16" Reinforced Fuel Hose to mine ;D

If the Valve has 20psi Pressure on it from the TMIC, then it also has 20psi Pressure on it from the Manifold holding it shut. Same goes when in Vac both sides.

Small I/D Hoses or Restrictor Pills, slow the Response of the BOV.

[Johnnynz]

FYI the V7 BOV is open at idle so needs to be recirced or AFM delete and a Map sensor used. Not sure about the TT one.

They look similar but not identical and thats about all the insight I have for you lol.

[Marky]

That momentary rich is reeeeeeally pushing it to say it will cause long term damage. You\'ll do far worse keeping a top mount cooler and cooking the intake than you will from BOV noise

If you want the noise, get the noise, don\'t spend several hundred when any valve will do the same job

For what its worth most early mitsi valves did (do?) leak under reasonable boost so the solution was to reverse them so they functioned like an SSQV, pressure holding the valve shut rather than pushing against it. Can be a thought. Some WRX ones can do the same? There\'s something you can do with chucking a grub screw into the little hole just around the top edge, I\'ve read the metal wrx valve (non sti) has a softish spring which can do the leaky under boosty thing

Or just run no BOV for maximum zututututu

[WRXONP]

How rich are we talking ? Does anyone actually have a wide band and watch what happens when the valves venting ?

I have a venting valve in my drift car - and a wide band - I pull 11.0 afr on wot and as soon as I let off it spikes up real lean because as soon as you lift the ECU initiates fuel cut

Call me dumb but I\'m confused as to how the car can go rich when the injectors are turned off - is it because the maf is still reading too high when you first put the gas back on ?

[boon]

 WRXONP said:

How rich are we talking ? Does anyone actually have a wide band and watch what happens when the valves venting ?

I have a venting valve in my drift car - and a wide band - I pull 11.0 afr on wot and as soon as I let off it spikes up real lean because as soon as you lift the ECU initiates fuel cut

Call me dumb but I\'m confused as to how the car can go rich when the injectors are turned off - is it because the maf is still reading too high when you first put the gas back on ?

It goes rich because you\'re dumping metered air (in an AFM setup)

AFM saw x litres of air, told injectors to add y cc of fuel.

Instead you only get 0.5x litres of air, so you can\'t burn all the fuel, so it goes crazy rich.

Solution, run a MAP based setup

[WRXONP]

Your missing a big point - when you let your foot off and tps hits idle contacts - the ECU turns injectors off (fuel cut on decel)

So my question again is how does it run rich when the injectors are all turned off

[Rosssub]

 WRXONP said:

Your missing a big point - when you let your foot off and tps hits idle contacts - the ECU turns injectors off (fuel cut on decel)

So my question again is how does it run rich when the injectors are all turned off

It\'s the split second of non-adjustment that does it, (the time it takes to vent). Just enough extra fuel to stop clean ignition, to stop clean combustion etc.

The extra fuel is enough to cause backfires under deceleration as the un-burnt fuel hits the hot exhaust.

Also enough un-burnt fuel, that it leaves a sort of un-burnt residue/vapour inside the combustion chamber that stops clean ignition when back on the gas.

Both of which foul plugs and clogs the combustion chamber with carbon/sludge deposits. Eventually causing pinging from increased compression and possibly burnt valve seats from hot spots as the carbon burns.

Edit: Excessive use of capital letters removed for Marky.

[Marky]

That\'s A Lot of Capital Letters

Just run no BOV, zutututu is where it\'s at

[Aurai]

 Marky said:

That\'s A Lot of Capital Letters

Just run no BOV, zutututu is where it\'s at

Don\'t tempt me :

[Kiwi_Fozze]

i wouldnt... you\'ll be replacing turbos as often as the auto bp leggy owners