I have one of these i bought from towerhobbies it's a great planes velocity stack for 25-45cc engines

And i have it on my side carb DLE30 and have noticed no difference, except I see less high speed fuel spray in the cowling now its barely nothign at all..

Though I haven't noticed any difference in the engine's performance but it's something I highly recomend it if you have a side carb.