My new Series 50, 4.11 geared "RTS" got 10.75 mpg in short test yesterday

[chessie4905]

Surprising they went to all that trouble since they spent most of their life running 30 to 45 mph.

[Geoff]

Surprising they went to all that trouble since they spent most of their life running 30 to 45 mph.

The RTS came in a variety of platforms and sizes.  The suburban model came with overhead luggage racks and lower center isle, and was geared for highway speeds.  The rear door was an option to be ADA compliant with a wheelchair lift.  Wanna race?

[chessie4905]

I imagine they spent all that design money as a spin-off replacement for the 4905 design. Also there are similarities with the GMC motorhomes.

[TomC]

If only Allison had made a V740-it would have been perfect

[chessie4905]

A few years back, a guy named Teal put together a V730 with overdrive, using a planetary from a VS-2 transmission. I have the booklet he sold to modify the V730.

[buswarrior]

Bill Teal.

Bill Gerrie built one too. He will chime in...

Finding the donor parts is not easy, all that stuff had to survive too many waves of high scrap prices...

Happy coaching!
Buswarrior

[luvrbus]

Why in the world would you want 2 overdrives on a V730 they are already .875:1 in third,it's the 2nd gear to 3rd gear wide range that kills you on a V730 going from 1.121:1 to 0.875:1 is large gap to fill,I believe that is what TomC is referring to that since a 740 does not have that gap.The V730 is not much in the mountains   

[buswarrior]

1600 rpm highway cruise in a V-drive?

Happy coaching!
Buswarrior

[chessie4905]

The V730 is .875 through all 3 gears. The angle drive is where it is overdriven. The gears are just like a 740 without a 1st gear. Since the tallest differential ratio is 4:12, it is like a MCI with 3:70. 4:12x.875 gives you 3:60 final drive. The torque converter used assists in takeoff since 1st is higher. The overdrive setup would lower cruising rpms at today's interstate speeds to 1750 to 1850 instead of 2300. Also with the penalty of the 315x80x22.5's slightly shorter tire would help compensate

[gg04]

Most common transmission with series 50 was the Voith...

[luvrbus]

Never saw a Voith behind a series 50 in a RTS before interesting,  I have seen plenty of ZF's and R V731 lol or is the R after the V731  I forgot   

[Geoff]

The RTS used a ZF transmission in their later years after GMC sold the assembly line. 

[HB of CJ]

I think the drop between 2nd and 3rd with the V730 automatic is the same as the 3rd to 4th gear percentage drop with the 740?  About 37% or 38%?

About the same as a 13 speed manual shifted like a common 9 speed without using the splitter?  The 7th to 8th gear percentage drop    Takes torque.

If such a 37% rpm drop is horrible in a 35,000 Bus Conversion imagine how bad it must be in a 80,000 or less logging truck?  Bad.  Thus the needed splitter? 

[CrabbyMilton]

Here in Milwaukee, the MCTS had 150 RTS's built in 1980. All but 6 had the 8V-71/V730 and 6 had the 6V-92TA/V730.
Anyway, 2 of the 8V-71 versions were selected to receive a CUMMINS L10/VOITH combo an experimental program for a few years after which, they put the original powertrains back in.
So it may be safe to conclude that later RTS's could accept other trannys besides the stalwart V730.
My only bugaboo is why in the world did the V730 which were used in buses that normally didn't get above 45 on a regular basis need an overdrive while the 740 never had overdrive which would have made perfect sense in a MCI or PREVOST?

[Oonrahnjay]

... why in the world did the V730 which were used in buses that normally didn't get above 45 on a regular basis need an overdrive while the 740 never had overdrive which would have made perfect sense in a MCI or PREVOST? 

      As Geoff frequently points out, there's a difference in "highway/suburban" transit buses versus those that only run 40 mph urban routes.  Maybe Milwaukee (and other users) felt the need for mixed-service buses that were at least capable of highway travel as part of their routes???