Anybody use an HKS SQV?

[Oranoco]

Mate has one I can have cheap, don't want it on my Escort as the MFi system doesn't like dump valves of any sort really, but was thinking I might grab it to stick on my A4

 

[hades-]

the a4 dont like them either
you can get away with the splitter R thats about it

 

[Oranoco]

I know atmospheric valves aren't the best idea on these but know a lot of people do it anyway. I have a Forge 007 on there at the moment but it just sounds a bit..... well..... like a camp sneeze if I'm honest. lol

 

[aragorn]

It screws up the fuel trims.

DV dumps already metered air, engine adds the fuel for it anyway as it doesnt know its missing, making it bog and go rich (just like the escort would), cept the more intelligent EFI system then notices its went rich, and tries to adapt for it by adjusting the overall fuelling.

710n is all you need.

 

[Oranoco]

With the Escort it's more a case of the Bosche KE-Jetronic seeing the DV as an air leak which allows the metering flap to close and killing the engine.

TBH It only highlights what I already knew really but the price I was offered it for made it attractive. Will leave the Forge recirc in there and accept the noise.

 

[ado66]

HKS SQV MFi OMG WTF?

ROFL

 

[aragorn]

Its exactly the same principle on the MFI as on the EFI though, it appears as an air leak to both systems.

Both engines use an air flow meter, which measures the amount of air flowing into the engine, and adds fuel accordingly. The MFI one is cruder sure, but exactly the same thing happens when the DV opens. A quantity of air is dumped (ie leaked) and never reaches the engine, but that air has already been measured, and so the injection system adds the amount of fuel required for the air that should have been there, causing the engine to momentarily go mega rich, at exactly the same moment that you've closed the throttle. This invariably means the engine with cough, splutter, flat spot or even stall if you happen to dip the clutch at the wrong moment.

Obviously the EFI management systems are more clever, and have more bells and whistles to try to keep the engine running when that occurs, and are also faster acting than K-Jet, so will likely manage to handle it a little better, but its still just as bad for the motor as it is on the escort!

 

[Oranoco]

Yes on the EFi on the Audi I understand this but that's not quite so on the MFi. With KE-Jetronic (which is a revision of the K-Jetronic found on the older Golf GTi's and Escort XR3i's) the flap actually closes completely as the pressure in the system is dumped out which cuts fuel completely. On the roll it's not much of an issue but when stopping at traffic lights etc the car can often die.

Anyways, thanks for the input. It kind of underlines what I knew so I shall stick with the 007 recirc and turn the radio up a bit. lol

 

[aragorn]

The flap closes anyway, as you've just shut the throttle and airflow has pretty much stopped Remember the flap is before the turbo, its not seeing any pressure, and infact the action of the DV will mean that more air is drawn thru the flap than would otherwise normally occur, as the engine should be running on recirculated air for a few moments, and instead has to draw in new air thru the meter.

Its the resulting rich mixture that causes the stalling/lumpy running etc!

I dont hear the recirc valve on our car at all, do you have a cone filter fitted?

 

[Oranoco]

I can sort of see your thinking but you're wide of the mark with that I'm afraid. The flap never closes once the engine is running. The further open the plate is the more fuel goes in. Trust me, I haven't got it to 260bhp by not knowing how it works . Even removing the dipstick or oil filler cap will stop the engine running (if the engine is on good health) on these cars.

Anyway, this is about A4's and I thank you for the info on that one