Whats the difference
 

I have heard that there are differences in the RX7 Rotaries and the Cosmo's. What are they?

2 rotor vs 3 rotor?

Manual/Auto option vs Auto only?

One's a luxury sports coupe whereas one is only sports?

Not sure, but is that what you want?

In general the Cosmo motors are tweaked for more power.
You see things like bigger intake passages, bigger AFM etc.

not all cosmo motors are 3 rotor. some are 13b, but bigger intake passages and the such are what i was looking for. Are they worth the extra effort to get and money?

the only USDM cosmos were in the 70s and are only worth the money for the collectability, not for the sport. If you lived in Japan, the cosmos have the 13B-RE which is different, has a bigger intake, bigger ports, bigger turbo, etc or the 20B-REW which is a twin turbo 3 rotor, which is worth it.

Thanks, that is what I was wanted. Cool