Boost

[verba1]

Hey guys took it for a drive today and my memory could be playing up in my old age but i can't remember anymore if it's right that the boost gauge drops to around minus 0.8 bar sometimes . I did hit +1 bar a few times giving it some so all is fine there .( car has had a remap )
Thanks in advance for any help .

[GTO600]

When you lift off the throttle it will go into a vacuum so sounds normal.

[Blu3R]

Perfectly normal mate, overrun at high revs will pull up to 0.8Bar of vacuum.

[Jarcy]

Mine never exceeds 0.5bar on full beans. I mentioned it to Jetstream but they were non-plussed about it. I guess I need to dyno it to know for sure. Perhaps the gauge is iffy, but yes, they go quite a long way minus, which I have never understood. But it is my first turbo car ('cept the company diesel).

[verba1]

cheers guys it must be old age then , i'm sure also depressing the throttle slightly when static it went to minus

[Hairsy16]

Jarcy said:

they go quite a long way minus, which I have never understood.

If you're decelerating under zero throttle then there are still 3 litres of cylinder space to fill every time the engine goes round a revolution.

If you're at 5,000 rpm then that's 15,000 litres of air per minute. Or 250 litres per second.

Hence a bit of vacuum!