So I put a deposit down on a 2005 RX8 GT with 61k km on the odometer, sale pending compression test results. Compression test results are as follows:

rotor 1: 6.5, 6.7, 6.3 kg/cm2 @ 229 rpm
rotor 2: 6.8, 6.8, 6.8 kg/cm2 @ 230 rpm

I got photographs of the compression test results from the testing unit itself. I don't believe these have been normalized at all.

So if I read the compression testing guide correctly, here's what I end up with (I got the altitude of the dealership from Google Earth :P):

Rotor 1
Foxed.ca Rotary Compression Calculator Results

************************************************** **********
Initial Data:
Face 1: 6.5 PSI
Face 2: 6.7 PSI
Face 3: 6.3 PSI
Cranking RPM: 229
Altitude: 440 Feet
Engine: 13B Renesis 04*11
Compression Ratio: 10
************************************************** **********
Corrected Values:
Face 1: 7.16 PSI
Face 2: 7.38 PSI
Face 3: 6.94 PSI

Rotor 2
Foxed.ca Rotary Compression Calculator Results
************************************************** **********
Initial Data:
Face 1: 6.8 PSI
Face 2: 6.8 PSI
Face 3: 6.8 PSI
Cranking RPM: 230
Altitude: 440 Feet
Engine: 13B Renesis 04*11
Compression Ratio: 10
************************************************** **********
Corrected Values:
Face 1: 7.47 PSI
Face 2: 7.47 PSI
Face 3: 7.47 PSI


It looks to me like the one rotor is borderline, but not sure how serious it is.. Experts of the interwebs, please tell me if I should buy this car!

Thanks in advance!

 

Looks like pretty borderline results to me, even normalized. I would pass on this one, depending on the price of course.

 

The price is a big variable.

However, these engines run well at much lower levels. I was tracking mine with all but one face failing, and 2 failing massively (like not even on that chart, about 3.5 BAR). The car ran, started and drove fine. I only really noticed things at the track. I was absolutely amazed when I took compression numbers.

What this means is the car may be OK, if the price is right, then start putting money away for the eventual re-build when you decide it is time. Those low numbers should be good for a great negotiating position.

BTW, we know what you are talking about, but those are not PSI, likely BAR

 

Thanks very much.. the car's absolutely beautiful aside from the numbers, so I'm thinking just like you said: get it now and budget/plan for a rebuild (street port? ) in a year or two.

 

Is it the white one from Infiniti?

 

yes!

 

I sent you a pm...not sure how helpful I was though.