"Cé hé sin" (michael-m-mouse)
04/11/2015 at 15:09 • Filed to: iShift, Volvo
1
7|
"Cé hé sin" (michael-m-mouse)
04/11/2015 at 15:09 • Filed to: iShift, Volvo | 1
| 7 |
Above we find, in a fetching shade of blue, a long distance bus.
Urban and suburban buses here usually have ZF automatic transmissions because no clutch to wear out and they're smoother in stop-start driving. National ones tend to have automated manuals because they're cheaper and more efficient and as the majority of them are built on Volvo chassis they use Volvo's iShift automated gearbox. So, what's the relevance of this?
You can tell by the sound that they have iShift. There's an unusually abrupt kind of gearchange. The engine slows down rapidly, there's a slight pause and then it accelerates quickly to arrive at the new gear. Because it's all being done by electrons and compressed air each change is exactly the same as the next so if you see a Volvo bus heading off from the lights you hear a rapid sequence of identical gearchanges.
If the bus isn't a Volvo it's probably a Scania and they don't have the characteristic sound despite having the same kind of gearbox.
So, there you have it. Today's educational post. You're welcome.
Svend
> Cé hé sin
04/11/2015 at 15:17 |
|
'Aircoach' sounds like the typical 'train replacement service' we have in the U.K. when the trains have stopped for one reason or another (working on the line, broken train, etc...).
|
Cé hé sin
> Svend
04/11/2015 at 15:19 |
|
Not this one though, it's an airport bus service.
Aya, Almost Has A Cosmo With Toyota Engine Owned by a BMW.
> Cé hé sin
04/11/2015 at 15:19 |
|
Yeah, i notice it with some Volvo buses we got in Indonesia as well, especially when you ride inside. It kinda feels like very short gearbox. Plus they are normally shifting somewhere arround 1500rpm isn't it?
|
Cé hé sin
> Aya, Almost Has A Cosmo With Toyota Engine Owned by a BMW.
04/11/2015 at 15:23 |
|
Yes, big diesels have a very narrow power band.
Look at this tachometer with a green band from 1,100 to about 1,600.
|
Aya, Almost Has A Cosmo With Toyota Engine Owned by a BMW.
> Cé hé sin
04/11/2015 at 15:31 |
|
Yeah. When i learn how to drive a bus, i thought those green speedometer area is where to shift if you want to drive economically, and shift* at redline instead. I was an idiot.
*Most buses in Indonesia has 6/7-speed manual gearbox, except the ones with double rear axles.
Satoshi "Zipang" Katsura
> Cé hé sin
04/11/2015 at 15:57 |
|
Some of the buses here have Allisons considering the touchpad-style shifter seen with Allison-equipped vehicles.
|
Cé hé sin
> Satoshi "Zipang" Katsura
04/11/2015 at 17:03 |
|
That's probably a national thing. American vehicles (assuming if that's what you have in mind) tend to have Allison boxes because they're American and they've always used them, buses on my side of the pond have ZF, Voith, Mercedes or whatever the engine maker prefers/makes. Same with engines, Americans like Cummins and other American makers, here it's all Volvo, Scania, DAF or whoever.
I looked up VanHool's website (they supply buses on both sides of the Atlantic) and they have different drivetrain options for each market.