Im reading .5 bar on the vacuum at idle and I was wondering what the norm is.
The engine is a stock ported (atleast from what I know) jdm engine. Compression when warmed is all 95 front, 95, 80, 80 rear.

I hope im right but, .5 bar converted to in/hg is 14.6in/hg??

 

I hold like 18lbs of vacume, what rpm do you ide at? Is it a stable idle?

 

You mean 18 inHg. That's equal to about 9 psi of vacuum.

Vacuum on my S4 NA was about 15-20 inHg. Never checked it on my turbo engines, but it should be the same.

 

the reading from my first post was 2 days ago.
i just started the car and warmed it up, now im at .5-.6 bar at 900-1000 rpms

so thats about 17-20 in/hg?

 

14.8 to 17.7 in Hg by my count.

1 bar = 29.53 in Hg

Sounds good to me.

 

I know on a good healthy (motorcycle, but that shouldn't really matter) piston engine you should be somewhere around 20 in Hg, so yes, that sounds about right to be as well. Your compression plays a key factor in this, as does RPM.

 

i have a question. i have a 91 TII and at 900 rpm idle it sits anywhere between 14 and 16 Hg does this sound about right or is there a vac leak somewhere?

 

sounds right to me. on my phantom2 guage i sit at about 14-15 for vacuum on my stock port atkins motor.

 

ya its a stock s5 stock port