The tomos estoril is a totally different pipe, it's got a shorter stepped header and pulls way harder.
The blowdown on the cylinder 'powers' the pipe, essentially you are giving up trapping the energy in the cylinder to push the piston down, and blowing out that energy to get the gasses moving.
The header diameter will determine how efficiently the pipe uses that energy. If you have a small dia header the gasses will keep the velocity high and you don't need as much gas energy to light up the pipe, but it will choke on the top end. If you have a big header it will breathe up top but it will never hit on a cylinder with no blow down.
You can always cut it shorter but you can't cut it longer, so plan on using a radiator hose coupler (yes it will burn up but it's ok for tuning) and cutting the header back until you're happy.