Question about vacuum at idle
#1
Question about vacuum at idle
I have an Evo IX that only has a manual boost controller (set for 23 lbs) and an AWD tune, other than that it's the way it came from the factory. I've never paid attention to what the boost gauge reads at idle, but after I was reading through a random article online it said that typical boost vacuum at idle should be around -10 to -12 lbs? Sometime after reading this article I was in my car and noticed that my boost gauge reads at -40 lbs at idle. It idles smoothly, no issues, it boosts to 23 lbs under full acceleration like it's supposed to, is something wrong or is it okay to have that much vacuum at idle? I went through and checked all of my hoses for vacuum leaks, couldn't find anything that seemed like it was loose, checked the fittings on the boost controller, etc. It idles smoothly at 800rpm when it's warm.
Do I need to be concerned about this? Or is it fine as long as it's running well?
Thanks for any input!
Do I need to be concerned about this? Or is it fine as long as it's running well?
Thanks for any input!
#3
Evolved Member
iTrader: (5)
Ever think it may be your boost gauge? If it idles smooth and there is no stumbling or hiccups, you're fine. BTW, vacuum is in in/HG on gauges and not PSI. My gauge usually sits between 12 to 14 in/HG at idle. If you get a loggable map sensor it is actually around -7psi at idle.
#8
You do realize that the stock boost gauge measures vacuum in cm/HG instead of instead of in/HG, and that the boost is in bar instead of psi right? So these are metric measurements and not the standard (U.S. measurements) your used to.
Find a converter online and convert cm/HG to in/HG and i'm sure your vacuum reading will seem more reasonable.
Find a converter online and convert cm/HG to in/HG and i'm sure your vacuum reading will seem more reasonable.
#9
You do realize that the stock boost gauge measures vacuum in cm/HG instead of instead of in/HG, and that the boost is in bar instead of psi right? So these are metric measurements and not the standard (U.S. measurements) your used to.
Find a converter online and convert cm/HG to in/HG and i'm sure your vacuum reading will seem more reasonable.
Find a converter online and convert cm/HG to in/HG and i'm sure your vacuum reading will seem more reasonable.
#10
Evolving Member
I've got a D1 Spec aftermarket gauge.I actually had to reset my gauge when i bought it because Japan is at a different altitude.
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mattchan99
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Jan 10, 2014 04:28 PM