i cant remeber excactly what i had last summer, i think it was around -18psi on my autometer boost guage. i just put my car back together and noticed its around -10psi. does a strong motor pull -20psi vac at idle? thanks

vacuum
idle vacuum
vacuum at idle

sorry, these are for the next guy using search.. i could find squat

thanks

 

I pull about 13" of Mercury at idle on a streetported TII. Not sure what stock is but its going to be more vacuum than that.

Just for information sake.... the unit of measurement for vacuum is Inches of Mercury or something like 13" of HG.

James

 

i do about 13-14 on my street port.

 

I pulled 16-18" on the old 88 TII motor, with 110k+. Another TII around these parts used to only pull about 10-14" at idle, but after some hose replacment and, basically some TLC, the car pulls 18" on a rebuild. I believe new motors pull 20-22".

 

thanks for the replies guys, i just relized where i might have a leak... i removed the twinscroll. i might have forgot to plue the vac line. thanks for the measurement tip. i didnt think psi was right. i would still like to hear others with a stock motor.. if they are different

 

Most gauges that read in PSI read vacuum in inHg. Stock port engines generally pull anywhere from 20-15, streetported is usually 17-12, and etc.

15inHg is roughly 7.7psi

 

Explain that one?

 

Google inHg to PSI conversions, that's what it came up with!

 

Yeah, but one is suck and one is blow...I know they both feel great but how can they relate?

 

man i have an atkins rebuild t2 wth stock port and 3mm seals and it has had around 10 to 12hg vac at idle. i broke the engine in correctly and i did the emissions removal and i know i have no vac leaks. whats the deal the engine only has about 6,000 miles on it is this right?

 

I pull 400mmHG on my greddy gauge at idle.

 

Well, if you read in absolute then it's easier to relate. (As then at 15inHg the pressure really is 7.3psi or so, versus atmospheric at ~14.5psi). But regardless, it's just a unit of measurement, which can be used either in vacuum or positive pressure.

 

My autometer phantom boost gauge reads 18 vac at idle....

that's good right?

 

18 is a perfectly respectable number.