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

CrabbyMilton · February 26, 2018, 05:31:30 AM

MCTS does operate what they call "Freeway Flyer" service so they'll need to go 50-60mph with that so I get that part so it may have been standardization with GM and the RTS which is a good thing
My point is that the 740 was never offered in overdrive which would have been logical. Later transit buses had the T drive and the ALLISON 747/748 which was based on the 740.

chessie4905 · February 26, 2018, 05:49:00 AM

The design wasn't an actual "overdrive transmission in today's sense. They overdrive everything to provide a compact package that would work best with what they had as parameters, especially room to get it to fit.

buswarrior · February 26, 2018, 06:54:49 AM

There was no bus engine power that could pull an overdrive gear back then, and barely for the big truck engines.

Direct 1:1 was all you needed, and all you wanted.

The real "transit bus slow" stuff died with the 2 speed transmissions, last seen in the mid 70's.

Everything since then is capable of 60 mph or better.

If it wasn't for the internet interfering with busnut creativity, there would have been tons of capable high floor transit conversions built over the last 20 years. Great chassis, low profile and with good drivetrain, but into the scrap yard they went...

Happy coaching!
Buswarrior

luvrbus · February 26, 2018, 07:05:23 AM

The HT 70 Allison was found in buses with OD ,the MCI 7 had those problem was they were wet torque converters and leaked it was a good transmission for it's day with the over drive and being a 6 speed

CrabbyMilton · February 26, 2018, 07:10:18 AM

Thanks for the perspective guys.
I remember the old GM NEW and OLD LOOK transits around here with the old 2 speeds. Sometimes I would wonder how they would get up some hill around here being that the 6V-71 with 170 HP straining for all it was worth then it finally shifted into 2 second.
Then going more than 35 or 40 in those seemed like you were about to take off from the sound of the engine.

olebusman · February 26, 2018, 08:40:49 AM

Bill Gerrie and myself have a V730 with a Teal o-drive. I would NOT part with mine. I get 8.2 mpg since installing. I have a 6V92 with 9A90 injectors, 4 1/8 rear end and a power tech 8 kw 3 cyl isuzu gen that runs from the time I start the bus till I shut it off, plus all the time I am at the nascar races. usually 5 days. I run between 70 and 80 most of the time. Top speed

but I love it. I shift into o-drive at about 65 and out going up a hill at 70 mph. I can run at 60 in o-drive but I don't like the oil pressure at that low of a rpm. By the way I have a 4106. O-drive forever olebusman

chessie4905 · February 26, 2018, 10:36:14 AM

How many miles have you put on it since installing? Have you had any issues? Are you using the VS2-8 planetary for overdrive or the planetary from the VS2-6? Thanks.

luvrbus · February 26, 2018, 11:35:43 AM

So what is the final drive with a extra O.D on a V730,the 0.875 is there no way to change it when the 2 planetary and sun gears are locked together as 1 unit that I know of anyways,you an change torque converters for stall ratios but it will not change the final ratio on a v730 or the HT 740.

chessie4905 · February 26, 2018, 02:10:49 PM

It makes the final overall ratio 3:60 instead of 4:12. Of course the first and second gear are also lower numerically, instead of the second and third ratios of the 740 because the angle drive years are overdrive to .875.

luvrbus · February 26, 2018, 07:50:20 PM

Quote from: chessie4905 on February 26, 2018, 02:10:49 PM
It makes the final overall ratio 3:60 instead of 4:12. Of course the first and second gear are also lower numerically, instead of the second and third ratios of the 740 because the angle drive years are overdrive to .875.

That transmission (V730) if Allison could have made it as durable as a 740 it would have probably been ok,but man they give a lot of problems,they did make it easy to remove though

olebusman · March 03, 2018, 05:55:46 PM

Hey Bill, Did any of these guys see that your tranny, on ebay, was built for odrive? oldebusman

belfert · March 03, 2018, 09:21:07 PM

Quote from: chessie4905 on February 26, 2018, 10:36:14 AM
How many miles have you put on it since installing? Have you had any issues? Are you using the VS2-8 planetary for overdrive or the planetary from the VS2-6? Thanks.

If you're asking the OP he hasn't been active for over four years so you'll likely never get a reply from him.

chessie4905 · March 04, 2018, 06:39:08 AM

I asked him about that last week when I noticed the fittings on the bell. I wanted to know if he had the rest of the od parts. He said only the trans. He has had the od in his transit for several years. Works great with no issues.

kjurkic · April 16, 2018, 03:29:18 PM

Howdy

I would be very interested in the VS-2 parts list and details, if someone has them on offer.

I run a lot on a stretch of freeway that is 120kph (75mph). My RTS (1994/S50/Vr730r) maxes at 90kph with me running against the limiter the whole time. The one benefit is that I have done better than 22l/100km (about 11mpg) - was a shoulder season trip, so don't know if I was running winter or summer blend. On highway I always get better than 10mpg.

The RTS is so stable and comfortable at speed that I would like to be able to run about 70-75 without the roughness that comes with banging off the limiter.

cheers
Ken

buswarrior · April 16, 2018, 04:06:14 PM

Have you been into your engine computer to be sure you aren't at the mercy of the transit company's governor setting???

90 kph sounds exactly like it is held back.

As for your experience at the governor, that sounds strange?

Should accelerate to governor setting and then just cruise there?

happy coaching!
buswarrior