Boost gauge flutter in vacuum

[jdmr_neil]

I realise it's because my engine has a chipped seal and CHUFF CHUFF chuff but, what causes the needle to bounce at idle?

Just interested to know tbh.

 

[GAVBEY]

Pulsation of intake stroke generaly, If you put a little inline filter on it can smooth it out,

Most expensive boost gauges tend to have a smoothing filter or a litle bulb that smoothes out pulsations built in