Re: Fire in the hole... Ross please read

[Orin Eman <orin@WOLFENET.com>]

> In a speed density setup, when the blow off valve opens, the mass-air sensor
> is still reading X amount of air flowing into the engine, while the engine
> is actually using Y amount of air.  X-Y = amount of air flowing out the
> blowoff valve.  The computer doesn't know they the engine is only using Y
> amount of air, it thinks the engine is using X amount and dumps the
> corresponding amount of fuel, much more than it actually needs.

> Audi uses a combination of these two.  It could go one way or the other, but
> by Scott's posts, assuming he's correct, the computer must continue dumping
> fuel into the cylinders (Continuous Intake System??).  By routing the
> blowoff valve back into the intake of the turbo, you no longer need air from
> an outside source, slaming the air flow sensor shut, reducing the fuel
> delivery, keeping everything happy inside.

One tiny little extra... the decel valve... 

The 5kCSTQs at least have one.  It is computer controlled when the throttle
closes and bypasses the air-flow sensor, allowing the sensor plate to fall
and cut off fuel.

Whether this happens fast enough to make a difference is a different matter.
It'll probably keep us amused for a while discussing it though.

Orin.