Exhaust BGM PRO Big Box Touring -
The BBT V2 is a further development of the well-known Big Box Touring exhaust system. In the revision, we placed great emphasis on covering the widest possible range of usable engine concepts. Our prototype was driven over 3000 km to ensure that the final product lives up to its promises. It was tested on an original (untouched) Rally200 Femsatronic engine with stock crankshaft and Malossi 210 Sport, just as it comes out of the box. In our tests, the engine produced just over 17 HP. Due to the higher power and torque, a straight-toothed 23/63 BGM primary is installed (3% longer than stock). The base plate of the Femsatronic was modified with a slotted hole to adjust the ignition timing from the fixed 24° BTDC to 18° BTDC. The squish clearance was set as specified by Malossi at 0.9 mm and the air filter was left unmodified, without holes. The scooter runs reproducible 120 km/h (according to GPS) on the highway while sitting upright, corresponding to 7000 rpm with still 16 HP at the wheel. In this diagram, we show the BBT2 (blue) compared to a Polini Box (red), measured in third gear:


The header pipe, the contour of the exhaust shells, the damper chamber, and the selectable diameter of the tailpipe are the detailed changes made. The header pipe itself has been changed in shape and for performance increase, and the new exhaust shells have been optimized for more ground clearance. In the damper chamber, we have added components to allow higher revving and increased torque. The tailpipe can be adjusted to the engine's displacement and rpm range by removing an insert. The tailpipe with insert (d=18 mm) is suitable for touring-oriented engines such as Malossi Sport, Polini 210/211 and Quattrini 232. After removing the insert, the new BBT runs with a tailpipe diameter of 20 mm very well on Quattrini 244-252 and Malossi MHR and also offers significantly more performance and revving capability there without thermally stressing the engines too much. In summary, the BBT V2 delivers more across the entire rpm range than the previous version on currently common engine concepts. In addition to my daily ride, Maryzabel's Platonika also had to be used for testing. You can read about the exact equipment of the Platonika with our bgm177 cylinder here in the blog
Link to the blog: Here is the comparison on the engine of the Platonika:
My daily ride, equipped with a Malossi Sport 210, Set primary incl. clutch, Clutch gear + primary + rep kit and via reed valve with a YSN30 carburetorLink to the blog: Carburetor YSN30 feeds air into the engine, making it a powerplant of the current generation.

Shape changed - the header runs closer to the exhaust body and is additionally supported by a brace The insert can be removed depending on the engine concept The BBTV2 is now available for PX80, PX125, PX150 and the like as well as for the PX200 and Rally200: bbt2
Autor
Uwe Schneider