Im a bit curious to what vacuum you guys pull at idle... Car idles at about 900rpm+-

according to my apexi gauge im pulling 200mmHG which to me seems a bit low considering some guys pulling 350+..

Vacuum leak maybe ?..All the vacuum hoses seem to be in good condition

Car goes awesome though.. Destroyed a wrx and an audi s5 lastnight

 

That is only around 8 inches of mercury for us non-Metric guys. I pull around 18 inches at idle with a moderate street port, or around 450mmHG.

 

I run about 15 in HG (~380 mm HG) with a large (race) port at 1010 rpm.

 

Stock with non-sequential, pulling 18inhg

 

stupid question, but is inhg when psi is negative? For instance, when my boost gauge reads 15psi in boost and then idles at -18 thats really inhg instead of psi?

 

It really depends on the portwork of the motor and your idle setting. I am at 16-17 inhg w/ a big street port @ 900 rpm.

 

17-18 inhg stock port 900rpm idle

 

yes, mm mercury, or the US equivalent inches mercury is used to measure vacuum, PSI is used to measure pressure.

 

11 inches at 1100 rpm with a half bridge with 400 miles.

 

In the summer, idling at 800rpm, -21. -18 during the winter.

 

I have a funky idle but its always around 20in, sometimes 21in.

When my idle actually sets at the correct 850rpm, then its around 18-19in

 

17-18inHg, i've seen it as high as 20 though.

 

I'm around -450 to -500 mmHg / 18 inHg at 1200 RPM, moderate street port, stock twins.

 

my stockport cosmo was 17 inHG

 

19

 

I get -15 at 850 with a street port and 3mm seals. I was told the seals would cause lower vac and comp readings.

 

My motor is stock!.. Why am i pulling such weak vacuum then

 

15 in at 1050 with large street port. Around 115 compression on all sides

 

15 at 800 rpm. I think anything lower that 10 is due for a rebuild.

 

~16.5 @ 850 warm idle. Stock ports.

 

Malloy Reman 4 years old 27K
fully warmed up 900 rpm 468-480 mmHg.

 

So much variance in vacuum readings with the rotary. IMO. You have big variance based on RPM, idle timing, AFR, and porting... I think the health of the engine is much better gauged with the dyno (specific to your engine). Dyno when you get it... then comparable dynos on the same dyno, across varying time frames.

My street port pulled about 425-450mmhg at ~ 900rpm. Timing was retarded quite a bit at idle....AFR was around 13.5:1

 

15 at 900 rpm for me.

 

Mine is 16 inHG at 750 RPM. If you were truly pulling only 200 mmHG (~8 inHG) due to the engine condition, you would never be able to start the car because the compression would be too low. Something else (bad gauge, kink in vacuum line to the gauge, etc.) is wrong. A vacuum leak of that magnitude would make it idle too fast.

 

Mine sits at 12 in. @ 950-1000rpms... Streetport with non. seq. stock twins.