So I've had my 04 MT 8 for about a year and a half and just got a compression test. I know, should have done that a long time ago. Flame on. The tech who preformed the test said it came back with good compression on both rotors. Being of a suspicions nature I figured I should confirm his assertion here and true to form there are several threads of results and how to interpret them. When I bought the car it has 85,000 miles on it and its now at 94,000.
Results:
1 8.3 8.2
2 8.2 8.2
3 8.3 8.3
RPM 243 247

While I was there I did get a printout of the warranty work and I found out the
previous owner replaced the engine and cat in Nov-06 at 29,000 miles. Which was good to know.

 

Yup
I would say those are great numbers.

 

Yes, those are fantastic numbers, especially after 65,000 miles. You got a really good build on yours

 

I always forgot to Ask! Is the graph u use for fd engine or rx8?

Cuz I'm sure the fail for msp is 6.8 @ 250 rpm

 

RX-8. I used the Foxed CA calculator, Renesis option. There are a few points on it that make me wonder a bit, like the normalization is actually apparently normalizing to 260rpm not 250.

The RX-7 service manual compression chart has failing at 5.9
The RX-8 service manual compression chart has failing at 6.9

Edited for incorrect information

 

Where did they get 5.9 for s1 from then?

COMPRESSION INSPECTION

I was like hmm, no way! Cuz as far as I remember 5.9 is for rx7

 

The one u show came from rx7 manual, someone probably mistaken and upload the wrong stuff.

Does the one u post said to do the test from the trailing plugs and floor the pedal to do the test? If it is then yes it's from rx7

When u dl the PDF for 2004 rx8, it shows the same thing I sent you. Which makes more sense since msp does have higher compression rotor in the first place

 

Understood. That is the first reasonable explanation for the various charts floating around that I've seen. Makes a lot of sense.

Might have to do a bunch of adjustment and chart cleanup it looks like. Until now, I would have sworn that I had seen the 5.9 chart in the OEM documentation, but I've been hunting since your previous post and haven't found it.

 

I just double checked ! Yep, it came from rx7, in fact those numbers match up with fc3s fsm

 

Alright, thanks. I've been thinking I need to overhaul the new owner's thread anyway to get some sections updated that will need a complete re-write. Probably time for it, and can dig back through past posts for where I've used that chart.

 

Damn ... Thats gonna take a while.

 

I hear envy in your voice. :p