touareg

So never really paid attention to my boost gauge in the car.

I noticed on WOT it pegs the gauge at 0,8 bar.

I thought I read that max boost is 1.9 bar on an 06 Turbo S (Can't find specs for my year) which is 0.3 bar higher than a regular Turbo. I assume ~1.0 bar is atmosphere and the gauge measures over that.

So am I reading this right? The max the gauge reads is 1.8 bar or is it 0.8 bar over current atmosphere, which could be 0.957bar for example ?

Or is my boost too high.

Thanks!

From Porsche for 2006, I dont see 2009 specs:
To provide such performance, Porsche engineers revised the engine control system’s throttle map, and installed larger intercoolers that improve volumetric efficiency by lowering the temperature of the air entering the V-8 engine’s intake tract. Thanks to the increase in the system’s cooling efficiency, engineers increased turbo boost pressure by 4.3 psi (0.3 bar) to a maximum of 27.5 psi (1.9 bar).

http://press.porsche.com/news/release.php?id=295

kmagnuss

1 bar is not atmosphere. 0 bar is atmosphere.

As for the cause of your issue... I haven't the slightest. In my previous turbo cars it could be any of the following: boost leak, computer holding back boost, faulty gauge, wastegate stuck, blow off valve faulty, and on and on.

touareg

Hmm, then I don't get this gauge.



Clearly says 0.4 0.8 and bar(well a , instead of a .)
I think my boost is fine, just don't get the readings on this.

kosmo

Wheres the oil pressure gauge ?

mcbit

You are correct, 1bar is average atmospheric pressure at sea level, and your boost gauge measures over pressure (pressure above atmospheric) in the same way as a tyre pressure gauge does.

Boost numbers for 955 CTT and CTTS are about 1.6 and 1.9 bar respectively, however I too have not been able to find the numbers for the 957. I know that my 957 TT also pegs FSD on the boost gauge until about 5000 rpm.

Lightningmcnulty

1 bar is atmospheric pressure and presumably the gauge reads pressure over atmospheric while Porsche record their absolute intake pressure in their literature
1 bar is 14.503 psi 1.8 bar is 26.106 psi per googles conversion, it would seem that is the maximum that the factory gauge reads
With the information you have your gauge should go past its maximum.

kmagnuss

Sorry guys... looks like I need physics class from 30 years ago again.

Where's my facepalm smiley?

imalek

Hi all,

so shall we consider the 1.8 bar is the maximum that can be configured?
this has an effect on the V8 naturally aspirated engine as well or only turbo engine ?

deilenberger

Exactly HOW would a normally aspirated engine exceed 1 bar?

imalek

To answer your question, I a, not a mechanic, but at least should have same as the atmospheric pressure which is around 15psi.
If we increase the pressure boost to 1.6 or 1.8, what are the consequences on the V8 naturally aspirated engine?

jeff spahn

There are no consequences on a naturally aspirated engine. It has no boost, that's why it is naturally aspirated.

imalek

There is no MAP sensor on the naturally aspirated?
honestly speaking, I increased the pressure to 1.6, the car seeems accelerating much easier and downsHifting differently, I can feel a boost in the car.

deilenberger

Exactly HOW did you increase the ambient pressure to 1.6? I'm sure the car manufacturers would love to know how to avoid having to use those expensive turbos to do that..

imalek

I just modified the parameter max boost pressure and I am realizing the difference.

hopsis

I call bs.