Bar pressure on turbos

[john purdie]

My Bar is showing 0.7 on my display at max should this be more or is this right, by the way it is a standard turbo (Non X50).

Cheers

[nevetas]

Taken from Porsche website:

The boost pressure in each turbine is automatically regulated using a valve device known as a 'wastegate'. These are integrated into the turbine housings from where they can vent excess gas back into the exhaust system downstream of the turbo units. On the 911 Turbo, a maximum boost pressure of 0.8 bar is available from as low as 2,700 rpm.

[nevetas]

Taken from Porsche website:

The boost pressure in each turbine is automatically regulated using a valve device known as a 'wastegate'. These are integrated into the turbine housings from where they can vent excess gas back into the exhaust system downstream of the turbo units. On the 911 Turbo, a maximum boost pressure of 0.8 bar is available from as low as 2,700 rpm.

[verysideways]

0.7 at the top end or 0.7 is the highest you ever see?

Best test is to start at 3k rpm in 3rd or 4th and floor it and see what the boost registers - not unusual for it to go up to 0.8 and then come down again towards the rev limiter (i.e. 5k rpm you may see 0.8, but it might have dropped to 0.7 by 6500 rpm).

[silver993tt]

depends on weather, hot temps, more boost (less O2 in the air, less dense). Cooler temps, less boost since the density of O2 is greater

>> Edited by silver993tt on Monday 14th November 13:12

[craigturbo2]

Mine never shows above 0.7 and thats running a 1bar spring,could go aftermarket its finding a place to put it.The only one i have seen was in a RUF, were they remove the clock.

[dazren]

My X50 regularly always goes to 0.8 and occasionally shows 0.9. I've been told the 420bhp turbo should regularly easily show 0.7 and occasionally 0.8 when conditions etc suit.

DAZ

[rumplestiltskin]

Standard 996 TT here, always see 0.7, sometimes 0.8 if cold, never 0.9
I was under impression that standard = 0.7/8 & X50 = 0.8/9

[cyrus1971]

Consistently 0.6 sometimes 0.7 and once or twice 0.8 and only then when I did something very iffy in my technique. Humid weather makes a big positive difference to the felt power but I have no numbers on actual power

[jj996]

I run upto 1.1 bar, but mine isn't standard 500bhp+++

[robinm]

I posted an almost identical question about 3 months ago when I first got my turbo. I was (and still am) seeing 0.7 momentarily and then settling at 0.6

I raised the question with the Technical department at Porsche Reading, and they explained it like this:

The electronic engine management system is designed to produce 420 bhp upon demand. It only provides as much boost as is necessary for the ambient conditions to achieve this, up to a max of 0.8 bar for standard 996tt. An engine in good condition, on a cool day, at sea level, should not need 0.8 bar to achieve full power.

The proof of the pudding for me was when I went to the Alps and at 5000ft was reassured to see 0.9 momentarily, settling to 0.8

[bluesatin]

Mine does 0.7 in lower gears and 0.8 to 0.9 in fourth. I hope it is working ok!

[egbert]

I have a 470 bhp upgrade and my pressure shows 0.9 bar.

I should know because i set all available displays to boost pressure.

[vpr]

If the management system is designed to dial in just enough boost to give the 420bhp what happens when you fit an exhaust system that supposedly gives a further 20 odd horses?

It should theoreticaly (?) mean a lower boost?

I'm sure I'm going to hit something soon....you guys have got me accelerating hard watching the readout. Not advisable. 0.8 on a couple of points today.

With Tubi-style