30 Nov 2016, 6:04 pm
#764
(30 Nov 2016, 4:17 pm)G-CPTN The difference between a coach and a bus (apart from the body and seating) is the gearing.
It is perfectly possible to build a 'bus' with coach gearing (double overdrive ratio gearbox or lower numerical axle ratio) using standard transmission options - ie no special parts other than spares if you need to rebuild the transmission.
The disadvantage would be running in lower gears in urban areas, but the advantage would be less stress on the engine on 'fast' parts of the route (and, probably lower fuel consumption).
Of course, the compromise would be when you need to transfer vehicles onto other routes which are either hilly or congested.
Its not as possible as you think.
First of all the chassis needs to be able to accommodate the Big, Strong Transmissions such as the Coach/Truck I-Shift ( or similar ) , Which a Small length double deck chassis wouldn't.
Secondly, Most of the markets engine's are not compatible with such a strong transmission, The Daimler OM934LA in the Streetdeck, The Cummins ISBe in both 4 and 6 cylinder formats,
While Scania's DC9 is half available depending on Which HP and Torque model you purchase, The Bus Spec DC9 is not in this range however, With max torque coming from the 280 hp Spec DC9, Which will fit in with ZF Ecolife 6HP-1400 as the engine produces 1400nm torque according to the spec sheet.
That's why id recommend buying a high performance bus as opposed to a coach for the TTX, The 280hp model of the Scania N250UD is the highest powered 2 axle Double Decker on the market, So would be as near performance to a coach as you can get, It will be more robust, And will be more suited to the demands due to the higher Power configuration and a higher Torque gearbox as opposed to the 250hp option which comes with the lesser 6HP-1200 Ecolife, So will not be as capable.
Another thing people haven't noticed is that the Scania chassis comes with a higher powered 6.7L Cummins ISBe option, It produces only 10hp less than the highest rated Scania ( Which is 280hp ) and produces near the same torque as the Scania, Despite being 2 litres less than the Scania.
Id heavily suggest getting the Scania Chassis E400MMC on trial before making decisions on what to buy.
