I came in 2nd place in the B main with my OS .12TR in a mostly stock HPI R40. If the car did handle better I would expect to place better. I got dusted on the straights, but on the infield I did perfect. No way it keeps up with a Ninja on the straightaway or so, but maybe on the infield with good driving skill it will match. However, it's still a tick slower in terms of HP and RPM compared to the Mugen MT12. Now that is a real low end motor of the past. During it's time one of the best and most powerful .12 to get. Today it's still a great beater motor if you can find one. BTW this was the layout for my track. It's roughly 205' x 108'wide
Depending on the track and layout if it's more technical you can get away with a weaker motor. Though on a larger track you might want to consider. Don't forget a weaker motor if you find yourself peaking it out run time will decrease being you are running almost WOT. Therefore it won't last as long on a tank of fuel like a faster engine.