I would say it depends on the engine. The grp .21 engines really like the 053 pipes the grp 2053 makes less power but a little better mileage and the dyn 053 opens the power up and cuts off a little runtime. The same dyn 053 pipe on an os speed engien did not perform at all it was ok but compared to the os 2060 te 053 chopped off the top end and was a little soft on the bottom. On the os speed engines the os 2060 or mugen 2042 (same pipe) works very very well. Well worth the $$ they get for it. I didn't like the 086 on either engine or a grp .28. The trinity bad boy pipe has a total of 2-3 laps on it and back in the box it went. It cut the top end off worse than the 053 but I know some guys who run them and like them. That's just my experience. So once again I think it depends on the engine. Any 053 pipe seems to be a safe bet for descent performance. That's what's in my pit box.