iam not trying to bash the tr-r in anyway , but i am one who likes to know the differance in a up dated motor , not just , oh its better trust me, ive heard that many times from mod engine builder to stock engine manufactures, not very many live up to the hype, i have many mod and stock engines at this point but am always looking for a better one, power is never a problem but fuel millage always seems to be the down fall, i have raced agianst many tr in the past and to be honest thay just can compete with most nova based motors, and thats just the facts,
maybe on a very tight parking lot track they can compete but even then all thing being equal a nova based motor will useually win.

the reason i say the only differance looks like between the tr and the tr-r is the turbo button is the replacement part #s for
crank, rod,piston ,sleeve,block,are all the same between the two,
now yes the turbo will give it a slight incress in power but not enough to compete with a ns12 for instance.

maybe they super seeded the old part # with the new ones i dont know but that not likly.
there use to be a guy on here that worked for os or somethin like that maybe he could give us some hard facts on the motor.
also i think there was someone who said they modified a tr-r who was sponsored by OS maybe he could let us know what he did to make it run good on top end(specificts)