[QUOTE]Originally posted by Luis

 

interesting...oh well.

 

[QUOTE]Originally posted by jurgento

 

Is CR not the dominant factor of Cylinder Pressure??? I agree that there are many other factors, but I can promise you that changing the CR would be one of the simplest ways to reduce cylinder pressure. Besides, I was answering a simple question on CR, informing others that 12 CR would work on 91 octane gas and 13 CR would work on 93 octane gas...

The JDM would probably pass emissions and so would European versions of many cars we do not get. But Honda has set a standard of LEV, ULEV, etc and being several years ahead of the curve as far as emissions goes. So for all intensive purposes, the detune engines (just a bit) for the US market.

So to refine my earlier statement, the JDM S2000 would not be as clean on emissions as the USDM S and this is not tuned as much for the US..

 

I can say for a fact that the 11.7:1 compression WILL work with 91 octane. Runs like a champ matter of fact ...

 

it has higher compression due to the head gasket doesn't it?

 

Horsepower is a measurement of the engine's ability to perform work. One SAE horse is the ability to lift 33,000 lbs one foot in one minute. One DIN horse is the ability to lift 450000 kg one cm in one minute. For the same power the SAE measurement is thus 98.629% of the metric DIN measurement.

so, 240 SAE hp = 243.4 ps or DIN hp

The other 4 is due to compression.

 

Actually 11.7:1 will run with 87 octane. The computer just senses the knocking and retards the timing. The REAL question is what is the MINIMUM octane the car requires to develop full power (computer not retarding timing). Any octane higher than that is wasted. Also just because car A will run with a certain CR and a certain octane doesn't mean car B will. There are other factors than CR as stated in a couple of threads.