Compression Test Results
 

Just got compression test results from dealer on a 2009 manual. It's out of state, so I haven't been able to check it out myself.

Rotor 1: 730, 740, 730 kPa @ 250 rpm
Rotor 2: 810, 800, 810 kPa @ 250 rpm

I don't know a lot about compression tests, but is it normal for the results to be at 250 rpm from the dealership? The other ones I've seen have not been, so I just thought it seemed a little odd.

They're normalized to 250 RPM.

The dealership normalizes to 250rpm?

Unless the starter was spinning the engine at exactly 250 RPM, they normalize the results to that speed. The link below goes into more depth.

https://www.rx8club.com/new-member-f...2/#post4533734

https://cimg7.ibsrv.net/gimg/www.rx8...dc599599a0.png

I think I'm doing a bad job explaining. I thought on the photo above the RPM should be the actual RPM and the formulas would normalize and deposit the result in the "Good" columns. I didn't think the RPM values should be normalized.

I'm doing a bad job explaining.

https://imgur.com/0x8PnQL

The 2-3 other results I've seen from that same Mazda spreadsheet have put the actual RPM in the RPM boxes on the left. I'm guessing that the "CLICK HERE" normalizes the data and outputs "GOOD" or "BAD" on the right side.

But, I really don't know. Would the dealership normalize the RPM before putting it into that spreadsheet?

I don't think the starter should be running at 250RPM, as this is a series 2 and they're supposed to have stronger starters.

Depending on what dealership you go to, they might give you the data based on whatever RPM they got the rotors to spin to. But the good/bad compression scores are always judged based off of 250 RPM. So yes, I would say most dealerships would normalize the RPM and compression score before giving you the readout.