tonychan1224

I don't know how to do the calculation, can someone please help me? Thanks very much.

1st one: 96, 96, 97 MPa 261 rpm
2nd one: 88, 89, 88 MPa 259 rpm

test was done at 459 feet elevation.

Thanks again.

Andrew5190

iTrader: (1)

An easy Google search would lead you to the calculator.

tonychan1224

Thanks, found them. 2 questions:

1. is MPa the same as PSI?
2. Not sure what engine I got, it is a 05 stick shift. I think it is stock.

Thanks again.

Andrew5190

iTrader: (1)

1. I don't think those readings would are in MPA. They're likely already in PSI. If that's the case, the engine is borderline failing on rotor 1 and failing on rotor 2 (according to this sheet)

2. If it's a 6 speed, it's a 6-port. If it's a 5 speed, it's a 4-port. Also, you can tell by the extra intake runners on the upper intake manifold.

NotAPreppie

1) Those numbers are definitely not in MPa. 96 MPa would be just shy of 14,000 psi. The only units those numbers would reasonably match up with would be psi.

2) If you're using the Foxed.ca calculator, select the "13B Renesis 04-11" for your engine.

If you really want the details, USDM 2004/2005 models got either a 6MT/6-port or a 4AT/4-port.
USDM 2006 and later models got either a 6MT/6-port or a 6AT/6-port (though still lower power than the 6MT/6-port due to lower redline).
Regardless, all RX-8's regardless of year have a "Renesis" engine with the same 10:1 compression ratio.

You can use this table to see how healthy your engine is. Just pick the correct column for RPM and the correct row for pressure. Where the two meet is your "score". A score of less than 7 is failing. So, if you normalize your results to 250 RPM at sea level, then your column would be "250". Lets say your normalized pressure was 90 PSI; you're somewhere between the 89.5 and 90.9 rows so just follow that to the right until you reach the 250 PSI column. That would give that rotor face a score between 6.4 and 6.5. Time for a rebuild.