urS6 - Not always full boost ?

[macspring]

When squirting between junctions, my urS6 sometimes shows 1.8 on the dash boost readout, and sometimes 2.3. 2.3 is the max it ever shows.

There's no rhyme or reason to it, just wondering what I need to check to ensure that it boosts to 2.3 every time.

It's an auto. I can feel the difference without looking at the readout, and the 2.3 every time would be nicer.

Thanks for any input.

[stocious]

overboost ?

[UrS4boy]

Are you chipped or stock? Not that it matters too much. The ECU via the chip set decides on the max boost for the given situation, it isn't always FULL AHEAD (2.3 Bar), just what is appropriate (based on the inputs it receives AND the particular chip set).

Otherwise, you would just have a big ON/OFF switch, which is hell to drive that way.

[ChrisAudi80]

Are you chipped or stock? Not that it matters too much. The ECU via the chip set decides on the max boost for the given situation, it isn't always FULL AHEAD (2.3 Bar), just what is appropriate (based on the inputs it receives AND the particular chip set).

Otherwise, you would just have a big ON/OFF switch, which is hell to drive that way.

Let me tell you that it could make a difference. I had 034MS stg1 chip set on my S6 auto for some years. This chip set is really for the manual.
Recently switched to prj's AAN auto chip set.
Day and night difference. Spool up is much faster, the torque and boost much more reliable/predictable.
However, I do agree it depends on the situation. Depends on throttle opening, RPM and vehicle speed.

A boost leak test would be an idea, too.

[prj]

When squirting between junctions, my urS6 sometimes shows 1.8 on the dash boost readout, and sometimes 2.3. 2.3 is the max it ever shows.

There's no rhyme or reason to it, just wondering what I need to check to ensure that it boosts to 2.3 every time.

It's an auto. I can feel the difference without looking at the readout, and the 2.3 every time would be nicer.

Thanks for any input.

An intermittent signal from the baro pressure sensor could cause it...
Or if the ECU does not read that you are WOT every time - throttle cable catching on something.

[ChrisAudi80]

An intermittent signal from the baro pressure sensor could cause it...
Or if the ECU does not read that you are WOT every time - throttle cable catching on something.

Don't know about the first.
However, there is no throttle cable. The TCU gets a TPS signal.
If the throttle is not exactly the same, could happen.

[prj]

However, there is no throttle cable.

There very much is a throttle cable, this is how the throttle butterfly is actuated on these cars. DBW cars did not make an appearance until 1998 or so.

The TCU gets a conditioned signal from the ECU. And the ECU gets a signal from the TPS.
Thus if the throttle cable is jamming somewhere or hitting something, the car will not be at full throttle.

[ChrisAudi80]

There very much is a throttle cable, this is how the throttle butterfly is actuated on these cars. DBW cars did not make an appearance until 1998 or so.

The TCU gets a conditioned signal from the ECU. And the ECU gets a signal from the TPS.
Thus if the throttle cable is jamming somewhere or hitting something, the car will not be at full throttle.

Of course. I am sorry.
I was confused in the previous post. I was thinking of a cable/rod going to the trans from the throttle body. You know, old style.

I know there is a throttle cable to the butterfly. Played with it many times.