Alright chaps,
Sold my Integra to buy a 2004 231 a couple of months ago - very pleased with it to be honest. My RX8 starts up a little slow (it has the old weak starter motor) so when taking it to Mazda for its 60k service last week I asked them also to compression test it (£96!)

Results as folllows;
Rotor 1
5.3 / 5.4 / 5.3
Rotor 2
5.7 / 6.1 / 5.8

The cranking speed was only 180rpm (slow start as said) - and Mazda have written "Good healthy test results - PASS" on my reciept for the compression test.

My question is - I know the minimum's are meant to be 6.9 @ 250rpm - to I extrapolate as if the graph where linear?

I.e - I calculate the above at 250rpm to be;

Rotor 1
7.3 / 7.5 / 7.3
Rotor 2
7.9 / 8.4 / 8.0

Is this right or wrong? I would have thought that the graph isnt linear in that compression doesnt keep increasing with rpm - making my extrapolation misleading...

Any opinions?

I've already forked ot on new leads, coils & plugs which I have hear and will swap over this weekend. Im considering ordering one of the 2KW starter motors (since mine is obviously total *****), but am hessitant untill I am sure that the compression test results were good.

For clarity - I bought my car privately and have no warrenty - I am however an obsessive car detailer and my Rex is absolutely mint :D

Any help apprciated!
Cheers!

Tom

 

Are you looking for this?

https://www.rx8club.com/attachment.p...6&d=1266716801

 

Hi - yes that is exactly wat I needed!

Cheers for your help - it seems that my readings are right on the borderline at that RPM which makes me worry.