Compression Test Intepretation Help Please
 

Had compression test done today on '04 RX-8 MT, with 99xxx miles on the clock. The temp was in low 60s, with elevation at 324ft per http://veloroutes.org. Here are numbers:

front rotor: 6.7/6.5/6.7 @239rpm
rear rotor: 6.7/6.6/6.7 @238rpm

Tech mentioned that these are healthy-looking figures, with cars needing engine replacement typically reading in 4s when calling techline and needing decarb treatment in 5s. My car sometimes cranks longer than normal when hot, but otherwise felt ok (subjective thus why I paid to get it tested).

Please help with conversion to sea-level @ 250rpm, which I thought mine falls within replacement guideline absolute-number-wise. Thanks!

Those are out of spec numbers according to my Android compression test app.

And according to this:

http://www.flickr.com/photos/9krpmrx8/4497702781/

Interesting graph you got, since it looks different than than sticky copy: http://www.twistedrotors.com/images/..._Comp_Test.jpg

I downloaded the Android RX-8 Compression Calculator mentioned (cool!), and it does say out-of-spec for 2nd chamber. However, it doesn't correct for elevation. I did find another calculator which does correct for elevation: http://foxed.ca/index.php?page=rotarycalc

In that case, the front rotor (weaker of two) has 101.7, 98.7, and 101.7 normalized. Minimum is 98.6 with standard at 120. So it seems I'm on the lower-end range-wise, but not low enough to warrant a new refurb engine?

Looks close

I use this chart;
https://www.rx8club.com/attachment.p...6&d=1266716801

^ I concur that is a better chart (more legit)

Just past 100k now. Did the test prior to 100k. For an engine with no premix regimen, a few engine flooding throughout its lifetime, I guess it's not too bad.