Im not sure if this fits in, but I am the proud new owner of a HPI RS4 EVO 3, but it came with the crappy outdated 15FE. I had many options on which engine to replace the old crapper, but I wanted it to have a taste of Redcat. So I just swapped out the old mill for the underdog SH .18 Some may think this is obscure but to us Redcat enthusiasts, its wicked cool. I wanted more oomph from it so i ported and polished it, added a tuned pipe and header and a custom boost bottle. Now I am still a Redcat fan because after all my first nitro RC was a Volcano, which i severely molested into a Volcano that looks like a 1/8 scale with a big-block. Now here are a few pics of my new baby with the heart of a Redcat

Ohh, and if you're wondering, 85% of the car is Carbon Fiber including the chassis.

that thing is sick, diggin the cold air intake. And do you notice effects with the boost bottle

Well, with the boost bottle (made from a Sharpie actually) the idle is a lot smoother and the low-end seems to have more punch. Drilling the hole and tapping it was the hardest part.

I'm just wondering... how the boost bottle work and how its made?

A boost bottle is an empty chamber that is used to store vacuum. When your engines running and you close the throttle, the piston sucks most of the intake mixture out of the bottle (leaving a vacuum). As soon as you open the throttle again , the bottle naturally tries to refill itself (thru the carb), thus pulling more air and fuel for an instant. More air and fuel should = more power or better throttle response. I made mine out of a sharpie marker cut in half, with the end sealed off.

Thats awsome, i bet it flies!