Quick quest? My oem guage on my evo are reading 48hg/cm at idle. Isn't that not normal and if so what could be the problems... Mods are filter, dp, hfc, cbe, and dtm tune if that matters.

 

Help

 

Mine reads the same. IIRC even my Defi gauge reads at 20 inHg which is roughly 49-50 cmHg which is the unit the oem gauge uses.

 

Okay I was getting both readings confused. I thought there was only 1 measurement.

 

There is only 1 unit of measurement per gauge but I have 2 boost gauges in my Evo lol and mine is bone stock so I think yours is fine.

 

I'm gonna glom onto this and ask a question rather than start a new post since it's on topic, not to HJ or anything.

I just did a compression test yesterday and had 160+ on all 4, but my vacuum at idle when warm is about 15-17 in/hg.

I would think the answer to my question is yes but, could aftermarket cams cause a lower vacuum reading than stock?

I have HKS cams on both sides and the vacuum seems low to me especially considering the compression readings. Even after working on cars for 2 decades now, I would without a doubt say cams are the thing I know the least about.

/brox

 

Yes, different cams will cause different vacuum readings at idle depending on how aggressive they are.