APR Polo - How much boost should I see?

[Petrina Polo]

I installed my Auto meter boost gauge. Straight off intake plenum.

I noticed the following...

First gear boost to about 15 psi,
Second gear boosts to about 15psi

Third gear boost to about 17.5-18psi and occasionally boost spikes to about 20psi.

Is this normal?

My vaccum sits at about 20 at idle..

My mods as follows..

APR V1 software
APR Downpipe and diverter valve
Full 2.5 inch exhaust system
SEAT intake and BMC filter.
FMIC

[RhysQ]

I installed my Auto meter boost gauge. Straight off intake plenum.

I noticed the following...

First gear boost to about 15 psi,
Second gear boosts to about 15psi

Third gear boost to about 17.5-18psi and occasionally boost spikes to about 20psi.

Is this normal?

My vaccum sits at about 20 at idle..

My mods as follows..

APR V1 software
APR Downpipe and diverter valve
Full 2.5 inch exhaust system
SEAT intake and BMC filter.
FMIC

To be honest I would have thought 1st and 2nd would have been around the 19-20psi with those mods.

[Joe Chu]

I believe V2 APR software has a little more boost mid range?

[h100vw]

You see less boost in first and second as the engine accelerates fast enough that it doesn't have time to build up.

Think of boost as a measure of restriction. Pressure builds up in the manifold behind the valve, when the valve opens the pressure drops. This is happening many times a second.

In forth gear the engine is accelerating slower and the valves are open for a shorter duration, then the boost has chance to peak higher.

Better to think of the turbo producing airflow. Volume is more important.

You can blow 20 PSI into a straw or a hosepipe, which will flow the most air in a given time period???

Gavin

[mikepologti]

You see less boost in first and second as the engine accelerates fast enough that it doesn't have time to build up.

Think of boost as a measure of restriction. Pressure builds up in the manifold behind the valve, when the valve opens the pressure drops. This is happening many times a second.

In forth gear the engine is accelerating slower and the valves are open for a shorter duration, then the boost has chance to peak higher.

Better to think of the turbo producing airflow. Volume is more important.

You can blow 20 PSI into a straw or a hosepipe, which will flow the most air in a given time period???

Gavin

i like that analogy (still learning the whole car engine thing), i think ill steal it

[h100vw]

Sorry Mike every time you use it, you have to mention me and send me 50 cents. I just patented the sentence!!
Gavin

[Petrina Polo]

The car revs out pretty fast in first and second gear. Third gear there is more load on and more time for boost to peak..

But are others getting similar amounts of boost? About 15psi in 1st and 2nd and around 17.5psi in 3rd, spiking up to 20psi?