Soo..Voith’s DIWA or ZF’s Ecolife?..Cummins ISBe or Volvo D5/8K?

Gingerbus1991 · 29 Jan 2019

Curiosity killed the cat...

Why does the same Cummins 4.5 with a Voith attached, installed on a “200 MMC” handle not too badly...but the same combo in a Wright Streetlite is feeble and unreliable?

Why have Voith’s latest offerings degraded in smoothness and responsivness compared with there predecessors...when(in my own opinion) the change from ZF Ecomat to Ecolife have improved from reduced noise and smoother changes?

Discuss(an engineers thought would be appreciated).

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hassaanhc · 29 Jan 2019

(Definitely not an engineer, just a passenger and enthusiast!) My observation is that the E200MMC and StreetLite with those gearboxes are programmed to change up too early, and this appears to be worse in the StreetLite. It also makes them feel underpowered on the flat, and although they generally do have the power for hills, their gearbox also changes up early there. But put an Allison gearbox in the E200 and it becomes really fast!

At least the gearboxes are smooth enough compared to the ZF AS Tronic or Volvo I-Shift!

Gingerbus1991 · 17 Feb 2019

If everyone thought that 6 gears for a bus transmission is too much you might soon be finding 8 or 9 speed Autos here!! Allisons readying replacement for there current 6-speed 2000 series as well as ZF having an 8AP Powerline in the works with 8 forward gears, madness.

Voith is also on the cusp of adding a 5th gear to there long standing 4-gear ethos.

https://www.oemoffhighway.com/drive...ansmission-expanded-electrification-portfolio

https://www.zf.com/products/en/lcv/products_50821.html

https://newpowerprogress.com/news-from-iaa-show-voith/

Jordan Adam · 17 Feb 2019

I find our Cummins ISBe (4 cylinder) / Voith E200MMCs up to the job and quite smooth vehicles while they do under normally acceleration change up early it's pretty easy to get them to hold the gears and accelerate at quite an impressive rate, the Streetlites on the other hand are programmed different and to put it bluntly rancid.

Engines: Cummins ISBe wins
Gearbox: ZF Ecolife wins.

Still they'll never beat the glorious Ecomat :lol:

richw · 17 Feb 2019

I find the Voith on the E200MMCs we’ve got to be a nice program. The E400MMCs seem to shift a lot and pick a higher gear than perhaps would be ideal. Fuel economy wins that way though.

Gingerbus1991 · 17 Feb 2019

richw said:
I find the Voith on the E200MMCs we’ve got to be a nice program. The E400MMCs seem to shift a lot and pick a higher gear than perhaps would be ideal. Fuel economy wins that way though.

400 MMCs are certainly improved with an Ecolife!

Like ive said before Voiths hold 1st gear for far too long on up hill starts.

I find the Voith in Glasgows 200MMCs to he very boggy when they shift into second, but the little 4.5 engine is a strong little unit.

Jordan Adam · 17 Feb 2019

Gingerbus1991 said:
400 MMCs are certainly improved with an Ecolife!

Like ive said before Voiths hold 1st gear for far too long on up hill starts.

I find the Voith in Glasgows 200MMCs to he very boggy when they shift into second, but the little 4.5 engine is a strong little unit.

The E400MMCs are "useless" with Voith.

I agree that the change in to second can take too long with the E200MMCs, but i find they preform generally good, especially when compared to the Streetlites!

delticdave · 18 Feb 2019

Jordan Adam said:
I find our Cummins ISBe (4 cylinder) / Voith E200MMCs up to the job and quite smooth vehicles while they do under normally acceleration change up early it's pretty easy to get them to hold the gears and accelerate at quite an impressive rate, the Streetlites on the other hand are programmed different and to put it bluntly rancid.

Engines: Cummins ISBe wins
Gearbox: ZF Ecolife wins.

Still they'll never beat the glorious Ecomat

How does a driver "hold" a gear ratio?

My car has a 6-speed auto, which can be left to shift as & when the computer thinks fit, but also has a manual hold mode.
This allows the driver to shift or hold any gear at will, albeit within the engines upper & lower RPM limits.

Do you have any similar facility on any of the current bus transmissions?

TIA, DC.

richw · 18 Feb 2019

delticdave said:
How does a driver "hold" a gear ratio?

My car has a 6-speed auto, which can be left to shift as & when the computer thinks fit, but also has a manual hold mode.
This allows the driver to shift or hold any gear at will, albeit within the engines upper & lower RPM limits.

Do you have any similar facility on any of the current bus transmissions?

TIA, DC.

No such capability on the new MMCs here,

Some of our older Tridents have this functio, some don’t.

Jordan Adam · 18 Feb 2019

delticdave said:
How does a driver "hold" a gear ratio?

My car has a 6-speed auto, which can be left to shift as & when the computer thinks fit, but also has a manual hold mode.
This allows the driver to shift or hold any gear at will, albeit within the engines upper & lower RPM limits.

Do you have any similar facility on any of the current bus transmissions?

TIA, DC.

In the "days of old" the kickdown function would have allowed the driver to "hold a gear" (Or downshift if at a lower RPM).

These days Voith and ZF both have topography based systems which tell the bus when to change gear based on the terrain. The ZF Ecolife uses their Topodyn system, it has two settings effectively a "Eco" and "Power" mode. Eco means the bus will shift up early and only hold gears on hills, while Power in theory means that pressing the accelerator fully down means the bus will hold its gear (or downshift if it's at a lower RPM) - much like what would happen on a bus fitted with a kickdown switch. ZF are also working on a GPS based system which will allow buses to "predict" a hill before it actually gets to it.

The Voith system is very similar and known as "Sensotop", the difference between Streetlites and E200MMCs is that most Streetlites are in the Eco mode and are mapped to change really up early where as most E200MMCs are not.

It's very rare now, however some buses also used to be fitted with "hold gears", these are buttons next to the main "DNR" gear selector which allow the driver to force the bus to stay in one gear. In most cases the gear selector pattern would be "1|2|D|N|R", however if the driver knows and understand how the system works you can actually use the selector buttons to hold any gear.

Here is an example of a gear selector switch with the "hold gear buttons".

Gingerbus1991 · 18 Feb 2019

Volvo still offer a Kickdown switch option for there own iShift gearboxes, Stagecoach Fife's B11R's at aberhill have them working, I'm certain that if operators wanted ZF/Voith could have a properly funtioning switch on the accelorator.

As per the ZF friedrichshafen brochure for the Ecolife it is still available, but fuel economy wins as many driver overly exploit such a feature.

Jordan Adam · 18 Feb 2019

Gingerbus1991 said:
Volvo still offer a Kickdown switch option for there own iShift gearboxes, Stagecoach Fife's B11R's at aberhill have them working, I'm certain that if operators wanted ZF/Voith could have a properly funtioning switch on the accelorator.

As per the ZF friedrichshafen brochure for the Ecolife it is still available, but fuel economy wins as many driver overly exploit such a feature.

It is indeed still offered. The 67 plate B11Rs with North Scotland are fitted with ZF Ecolife and have kickdown fitted.

GaryMcEwan · 18 Feb 2019

The newer that McGill's got last year appear to have kickdown anyway. At the slightest touch of the accelerator and as it starts to pick up speed, it goes right down the gearbox.

I certainly miss the old days where the Tridents and older E400s used to get a good thrashing. Probably didn't help the gearbox in any way shape or form mind you.

Gingerbus1991 · 18 Feb 2019

The Mcgills E6 citaros have kickdown switches I am laid to believe for there frequent use on faster roads.

RJ · 20 Feb 2019

delticdave said:
How does a driver "hold" a gear ratio?

Kickdown function, use of gear range selector buttons or paddle shift, crude pumping of the throttle pedal or more delicate throttle pressure sequences which produce the same effect.

Jordan Adam said:
In the "days of old" the kickdown function would have allowed the driver to "hold a gear" (Or downshift if at a lower RPM).

These days Voith and ZF both have topography based systems which tell the bus when to change gear based on the terrain. The ZF Ecolife uses their Topodyn system, it has two settings effectively a "Eco" and "Power" mode. Eco means the bus will shift up early and only hold gears on hills, while Power in theory means that pressing the accelerator fully down means the bus will hold its gear (or downshift if it's at a lower RPM) - much like what would happen on a bus fitted with a kickdown switch. ZF are also working on a GPS based system which will allow buses to "predict" a hill before it actually gets to it.

The Voith system is very similar and known as "Sensotop", the difference between Streetlites and E200MMCs is that most Streetlites are in the Eco mode and are mapped to change really up early where as most E200MMCs are not.

It's very rare now, however some buses also used to be fitted with "hold gears", these are buttons next to the main "DNR" gear selector which allow the driver to force the bus to stay in one gear. In most cases the gear selector pattern would be "1|2|D|N|R", however if the driver knows and understand how the system works you can actually use the selector buttons to hold any gear.

Here is an example of a gear selector switch with the "hold gear buttons".

Yes, I had my Euro 2 Trident fitted with a 5 button selector, replacing the 3 button selector it had. They had 5 buttons from new but the engineers replaced them because some drivers abused them way back in the early 2000s!

On a recent trip to Hong Kong I noticed many buses, even the newer ones had at least 4 button selectors. The most overkill were the 4 speed Voith Tridents which have 6 button selectors fitted. Speaking to some drivers over there, they mused the workforce likely consisted of the following;

- 95% "D" drivers
- 4.5% "12" drivers
- 0.5% "12D2D2D2" drivers :lol:

Jordan Adam · 20 Feb 2019

RJ said:
Yes, I had my Euro 2 Trident fitted with a 5 button selector, replacing the 3 button selector it had. They had 5 buttons from new but the engineers replaced them because some drivers abused them way back in the early 2000s!

On a recent trip to Hong Kong I noticed many buses, even the newer ones had at least 4 button selectors. The most overkill were the 4 speed Voith Tridents which have 6 button selectors fitted. Speaking to some drivers over there, they mused the workforce likely consisted of the following;

- 95% "D" drivers
- 4.5% "12" drivers
- 0.5% "12D2D2D2" drivers

The main reason Hold Gears and Kickdown are less common now is down to drivers abusing them. Of course if a driver knows how to use them properly they can be a massive bonus.

In the case of Hong Kong many routes there have really steep gradients where you need to force the bus to stay in the same gear in order to not stall.

- 95% of drivers are lazy
- 4.5% don't know how to use hold gears
- 0.5% know how to use hold gears
Just kidding!

GusB · 20 Feb 2019

I recall, some years ago now, being on a MCW Metroliner climbing out of Inverness on the A9, and the thing slowed to a crawl very quickly because the kickdown didn't work. I wonder now if they'd had the feature disabled.

Gingerbus1991 · 20 Feb 2019

GusB said:
I recall, some years ago now, being on a MCW Metroliner climbing out of Inverness on the A9, and the thing slowed to a crawl very quickly because the kickdown didn't work. I wonder now if they'd had the feature disabled.

Generally speak, driving modern voiths back to back with lothians 2016 B5TLs, they dont have a kickdown switch, even though there somewhat sluggish too pick-up they move ok on the move, however when you do hit the slghtest inclines the Ecolife on them is quick witted to pick a lower gear even at the slightest incline, many modern boxes should really need to reply on kickdowns, epecially as turbo chargers have became more responsive in recent years.

delticdave · 20 Feb 2019

richw said:
No such capability on the new MMCs here,

Some of our older Tridents have this functio, some don’t.

Thanks for the info, DC.

flymo · 20 Feb 2019

RJ said:
On a recent trip to Hong Kong I noticed many buses, even the newer ones had at least 4 button selectors. The most overkill were the 4 speed Voith Tridents which have 6 button selectors fitted. Speaking to some drivers over there, they mused the workforce likely consisted of the following;

Sorry but I have to ask, where on earth did you see them here in HK ? as the Trident is all but dead. Just curious. Can't remember the last time I was on a Trident her but they do live on with the non-franchise dept. Wonder if KMB still have some ??????

Customer spec here drives the button fitment, each to their own etc. On the kickdown subject, one operator for example still insists on a 'kickdown feel' for the pedal even though no switch is fitted.

delticdave · 20 Feb 2019

Jordan Adam said:
In the "days of old" the kickdown function would have allowed the driver to "hold a gear" (Or downshift if at a lower RPM).

These days Voith and ZF both have topography based systems which tell the bus when to change gear based on the terrain. The ZF Ecolife uses their Topodyn system, it has two settings effectively a "Eco" and "Power" mode. Eco means the bus will shift up early and only hold gears on hills, while Power in theory means that pressing the accelerator fully down means the bus will hold its gear (or downshift if it's at a lower RPM) - much like what would happen on a bus fitted with a kickdown switch. ZF are also working on a GPS based system which will allow buses to "predict" a hill before it actually gets to it.

The Voith system is very similar and known as "Sensotop", the difference between Streetlites and E200MMCs is that most Streetlites are in the Eco mode and are mapped to change really up early where as most E200MMCs are not.

It's very rare now, however some buses also used to be fitted with "hold gears", these are buttons next to the main "DNR" gear selector which allow the driver to force the bus to stay in one gear. In most cases the gear selector pattern would be "1|2|D|N|R", however if the driver knows and understand how the system works you can actually use the selector buttons to hold any gear.

Here is an example of a gear selector switch with the "hold gear buttons".

Thanks for the very detailed info. I do remember a B R DMU being fitted with a Self changing Gears adaption to the standard 4-speed epicyclic box, but it wasn't terribly liked.......

The use of topography based systems is interesting, some hi-end cars link the sat-nav mapping to the transmission, but my humble Skoda relies on an inclineometer (?) to hold a ratio up or down hill.
If I'm not happy, I can use the paddles or the shifter to keep the engine in it's useful power / torque band.

I'd guess that today's bus drivers have a reduced workload re. gear shifting & probably braking & steering too, but modern traffic + much bigger buses must make for a somewhat demanding experience.

I do use some of my local buses, (Ensign in & around Thurrock) + First Essex route 36 to & from Chelmsford.
Similar buses, (Wright bodied s/deck Volvos) do seem to perform differently, maybe differing driving habits, but more often, very odd sounding (& feeling) shifting points.
As for the Volvo 7900 hybrids on the 100 route, they seem to use only 3 or 4 ratios out of the 12 in the 'box.
Parallel Hybrids really don't make sense on a 2 hour cross-country route with very little recuperation available.

Thanks again, David C.

RJ · 20 Feb 2019

flymo said:
Sorry but I have to ask, where on earth did you see them here in HK ? as the Trident is all but dead. Just curious. Can't remember the last time I was on a Trident her but they do live on with the non-franchise dept. Wonder if KMB still have some ??????

Customer spec here drives the button fitment, each to their own etc. On the kickdown subject, one operator for example still insists on a 'kickdown feel' for the pedal even though no switch is fitted.

KMB still have a load of them - I was in the Diamond Hill area looking for 10.6m Volvo Super Olympians and they were running alongside them on the 91M/92.

The switch under the pedal is pretty useless where I am as the majority of the buses engage the kickdown without depressing the switch.

Gingerbus1991 · 22 Feb 2019

ZF making sure they’ve got it right!

https://www.route-one.net/articles/Drivelines/ZF_Services_continues_to_focus_on_customer_support

Soo..Voith’s DIWA or ZF’s Ecolife?..Cummins ISBe or Volvo D5/8K?

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