YotaTruck1986

Just a quick question about a vac gauge. If I hooked a vac gauge up to my N/A intake, would it be able to measure a noticable vacuum? Of course I'd run the gauge to the the throttle body, I was just wondering how much "vacuumness" there would be. Thanks.

mike_d

are you saying to mount the sensor to between the airbox and the throttle plate? i don't think you'd measure very much vacuum there. the vacuum that you care about is that between the intake valve and the throttle plate.

or did i completely misread your question

YotaTruck1986

Should connect the gauge after the butterfly valve or right before it? Aprox. how much Hg do you think it would measure?

mike_d

the sensor should be after the butterfly. the area before the butterfly should always be at almost atmospheric pressure (0 inHg vacuum).

I'm not sure what kind of vaccuum you'll see, I don't have a vacuum gauge on my truck, so I don't know what typical numbers are. But if I were to guess (and this is just a guess), I'd say you'd probably pull about 20 inHg of vacuum at idle and 0 inHg at WOT.

edit: it may be interesting to run a vacuum gauge before the butterfly. any vacuum there will show you how restrictive your intake is. but these numbers will be much smaller than a typical vacuum gauge reads, so you'd probably have to get a special vacuum gauge for that.

YotaTruck1986

Thanks for the reply. Where would I hook the hose up to? One of the small pipes coming off the throttle body? Thanks.

mike_d

check out roger brown's website (www.4crawler.com). i believe that he has a writeup on it.

i think this page has it. i'm not sure, i didn't fully read it:

http://www.4crawler.com/4x4/CheapTri...es/index.shtml

YotaTruck1986

Thanks. I'll probably just mount it on a pedistal on the dash. Thanks for the reply.

mike_d

also check our roger's site for where to hook up the hose. i know he mentioned it sometime, i read it a while ago. it's probably somewhere in the "cheap tricks" section.

Bigkahuna808

I got mine running right after the throttle body on my 3.4L I use it to determine when Im giving it to much gas. and to check for leaks and watch the idel