I find all the concern about whether there is a big difference or not, kinda ridiculous. To me, there is really only one question to ask..."does it run better". The answer is yes. I found NO lack in top end power when compared to other 'box stock' engines and neither did anyone else at my track.

One factor that no one seems to take into account is gearing. MANY, MANY, nitro racers think of engines as simply 'drop in and go' equipment. But engines are no different than electric motors. Some require different gearing to make their best performance. I wouldn't gear my original P2K the same as I would a Monster Stock. It just wouldn't work. So why drop in one engine with the same gearing you would another.

For example: I knew that my Sirio wouldn't produce as much bottom end as my TR, so I went down a tooth to help it when I started using it. And I went back to my normal gearing when I put in the R-Spec. I also knew that the R-Spec would reach its optimum power quicker, so I went up on the high end gearing to help its powerband be more useful for top end purposes.

End result...this engine puts out more power out of the corners than my Sirio and matches or suppases it on top end. Just think, if we weren't supposed to change the gearing, they wouldn't make the pinions and spurs removable.

One things for sure, if you don't believe its any different than the standard TR, just keep your original, theres nothing wrong with that. Its a damn good engine! BUT, if your in the market for a new engine, rather than try to 'put together' an R-spec by buying parts, just drop the $139-$159 to get a brand new R-Spec. Not many of us are engine experts, so who knows what may be different that we don't know about.

Like JLock said, its the little things that make these things work better, and I for one don't really care to learn about all of them!