Hey I was just talking to a fellow S owner and he mentioned that Japanese spec S2000's make 10 more hp. I think I have heard this before but was wondering what the difference is, and if it would be possible to get that extra 10hp out of the US spec car. I assume its a air/fuel ratio or something like that, andone know?

 

higher compression

 

higher compression, possibly better fuel available, ecu with different settings.

 

I think they're at 11.7:1 compression. You could probably use the JDM head gasket to achieve that, right? Maybe there's something else, but yeah, their ECU would probably be setup differently to account for all of it.

 

Probably better fuel over there too. A good 70mm single exhaust will probably give you that 10hp you're looking for too.

 

Headgasket, different pistons, 100RON fuel, compression.

 

A large portion of it is that our fuel sucks.

 

especially california with it's emission nazis.

 

Are the Japanese horsepower ratings measured on the same standard as the US horsepower ratings?

 

AFAIK, the head gaskets are the same. the higher compression comes from the block itself not just the gasket. you could however get a Spoon Thin head gasket, and its supposedly gonna give you a bump in compression. and yes, the ECU settings are hella different here. stock JDM spec ECUs/F20s experience knocking even at 93 ron. Also unlike in the US, (I read somewhere that the US ECUs can't be interchanged that easily because there's a security/key recognition) the JDM counterpart ECU is just plug and play to any S2000 regardless of year model.