Hallo!
Bin mal wieder auf was Interessantes gestoßen.
Als ich das gesehen habe, habe ich sofort an einen sau kurzen AOA (Lochendkegel) gedacht, mit weiter hinten platzierten, geschlossenen Endkegel.
Was meint ihr?
http://www.pedparts.co.uk/blog/tecnigas-exhaust
"We can see something very interesting with the Yasuni R pipe here which is a little off-topic but worth mentioning because the graph demonstrates it well.
The more highly you tune a moped engine the powerband tends to get narrower (pointier) and occur at higher revs. To combat this larger 2-stroke engines may use exhaust valves which open and close to change the cylinder exhaust port height thus changing the powerband as the revs increase to effectively make one wide powerband out of 2 peaky powerbands.
If you cut open a Yasuni R exhaust you can see they've done something really clever to mimic this effect and get both high peak power and a wider over-run powerband.
In the front section there is an additional cone welded inside with holes drilled into it.
At a certain rpm/ exhaust velocity the gases no longer pass through the holes which effectively means the cone has changed size and the exhaust now starts to move into a different powerband at higher revs.
The advantage of this is that you get a much wider powerband which continues to make useable power at high revs. The disadvantage is that you lose a little bit of peak power (the peak is flattened off).
This can be seen perfectly in the graph above. The Stage6 Pro Rep and Tecnigas Triops pipes make identical narrow peaks whereas the Yasuni R peaks approx 0.3hp lower but has a much wider powerband which out revs all the other pipes as was its intention."
Grüße
