I was wondering if you guys could post your compression numbers with your ITR's and the area you live in.. or better yet, your altitude if you know it. Atmospheric pressure...

Of course we all know that what matters is variation... but I'd like to see how high up some of you dudes are getting in different parts of the country..

I did a compression test on my 00 JDM R engine a couple months back and I got 185-190 as the biggest variation between cylinders.. as I was guessing. But just as I thought, that gauge was a POS. :thumbsdown:

Today however I got myself a snap on compression tester and I got:

215, 210, 208, 205

I might edit these because I'm going to do it again as soon as I'm done typing. I think the O-ring that was on my kit fell off, so I don't remember if it was on.

My atmospheric pressure is 14.7.. which is basically sea level.

 

atmospheric pressure wont affect your gauge reading, as its gauge pressure and not absolute pressure you are measuring.

 

Well I just redid it..

And it was all the way off the gauge over 255 on the first cylinder I tried.. so I couldn't read it.

Anyways, are you sure it doesn't have anything to do with atmospheric?

I have some books at my school (here we go again lol).. and the formula for aproximating your compression test numbers without a gauge includes the atmospheric pressure and your compression ratio. I don't know it off hand, but I remember this because my instructor informed me about it when I told him I thought my numbers were really low...

I'll check my book again.. I've been thinking about that lately.

 

225, 225, 220, 215

 

I got 200 across all four cylinders, I think it varies because the different kinds of compression gauges