just a random question that popped into my head, right now I am seeing 16-17 of vacume at idle, but what would be a point that is bad

 

Mine runs somewhere around there, sometimes it'll dip down to 22-23psi when I release the throttle, but usually around 17-18psi........


-Dan

 

Vacuum at idle depends on port size, rpm, altitude, etc...

If you are on stock ports, you shouldn't see less than around 16 inHg. Usually less means vacuum leak or worse, low compression.

My car idles around 750-800rpms with vacuum of 19 inHg.

 

stock ports fresh rebuild basic add ons ecu etc.. i see about 550 mm at a 850 idle

 

My car idles around 900 RPMS with the tune it has on the PFC (car tuned by Don Marvel of marvelspeed) with 16-17 inHg, does this sound appropriate? Am I just being paranoid

 

Yes, you are. Just drive the car and be happy.

 

mine was between 18-20 before it blew on stock ports. Now with a large street port it sits around 14 or 15
-Nic

 

that's where my car is at also. If I idle at 800 - 850 rpms with no electrical load, I get 410 - 430 mmHg
(16 - 17 inHg). I get 380 - 390 mmHg (15 inHg) with electrical load on the engine. I think these are average numbers for sevens with stock, higher mileage engines.

 

well my motor only has 24K original miles but I think I am just being paranoid I find myself checking everything I can all the time. But I kind of like checking stuff all the time, keeps me busy

 

Pineapple Racing Large Port, 5500ft altitute, 1000rpm idle, 11in vacuum. Been this way since the motor was put it.

 

my car idles at about 550 - i know that is low - but my vac is 17hg - aboutg 21-22 when i let off the throttle (23 when I let off at higher RPMs)

 

Hmmm, my car has 30k original miles and idles around 750 with only about 13-14 vaccume. Could something be wrong?

 

I've got a vac leak that's getting really ******* loud these days, and I get 17 at 850 RPMs. I get 26 when I let off the throttle at higher RPMs.

 

i usually get around 17 when idling with parking lights on. At night when i turn the lights on and rest of the accessories, plus the fan, i get 15. I don't know what's up with that, but it doesn't bother me.

 

anybody else have an opinion on safe vacume levels?

 

If the engine runs well, and there are no other signs of a problem don't worry about vacuum levels so much. I've seen guys on here with 12 on old engines. As long as a compression test shows consistent numbers across the board, you don't need to worry.

 

I get 16 at idle 800 rpms and 18 when i put the car in fisrt gear. I asked my mechanic and he said that's what they show when a new remanufacture engine is put in.