I get conflicting info on this and I hope you guys can sort it out for me. Then again, the conflict is with the info here as this is the only place I go and there ain't no other place like this place anywhere near this place. You understand.
My instinct is to go with a stick. I didn't consider any other option till I read that a stick WILL NOT start out on a 6% grade. Info was that if you get stopped you back to the bottom and restart the climb. The Grapevine came immediately to mind and then all the hills in Pa. so the stick idea became a discard. Pulling me the other way was the decrease in MPG with the auto and some said it would be 1 MPG. Recently I read a post where the Nut said he absorbed a 1.5 MPG hit and that turned my head again. I know a 12 speed Road Ranger ( I say that like I understood what that really meant) has very low gears at the bottom and could theoretically start out on anything and still has long legs up top for better MPG. 12 is a big number to get to 60 MPH and I can see where that might get old fast but still, I intend to drive 8 hours total and then rest and I expect I will stay awhile at my destination sooooo, again conflict. I think the 4 speed is out for me and I hear of a 5 speed in newer coaches. How much better is that and what would be the ideal? 7 speed, 8 speed, 6 speed? Again with my gut is a 12 speed with an "Auto Shift" seems the ultimate with the only drawback being it is slow to 60. I am in no hurry and anything I don't time with a calender is maybe pretty quick for me. A very nice Nut told me that a 12 speed Auto Shift would become a 12 speed "Select Shift" if the trans was installed on a non electronic engine and that opened up the market of used parts.
OK, hit me...and each other. I need this info though, honest.
John
Enough is enough but too much is plenty.
John
The buses with 4 speeds have been getting around the rockies and the Appalachians, Blue Ridge, Cascades, Sierras, White, and every other mountain range in the US for going on a hundred years.
Yes, they have trouble starting out on a steep grade, but as long as you are on one of the main roads, (not the Spraddle Legged Indian trails), or the majority of County State and US highways, you'll have no problems.
Even with the high gearing in my 4103 and my itsy bitsy 6-71 I've had no trouble with main roads.
However, there have been a couple of campgrounds where I ran completely out of power before topping a hill.
Once was at Warriors Path State Park in NE Tennessee where you go around a corner and hit a really steep grade from almost a standstill and the other was at the campground where NC Bob lives in Franklin, NC. Again I had to hit it from a standing start when some idiot 4 wheeler decided to come down while I was going up. Uncle Ned and Jack Conrad were there for that one.
As for the multispeed transmissions like Road Rangers, you don't drive them by hitting every gear on the way up to the big hole and down to a stop. The proper way to drive them is to 'skip' shift to the proper gear for the load and the grade you are driving on. What the split gears do for you is to allow you to keep the engine in the sweet spot of it's RPM range under any condition.
Good luck on your quest, I hope you can find one that suits you.
Dallas
Finally a question I think I am qualified to answer. Maybe. Similiar situation. My '74 Crown 40' bus has the older Fuller RTO-910 10-speed Roadranger. Superb tranny. Very close gears with a 6.27 to 1.00 or sooss 1st gear, all the way up to an .82 to 1.00 tenth gear; a 22% overdrive. With the idle torque of the 855 inch Cummins 250 engine, the math indicates she will start up on an 18% grade. Never tried that; best I have done is a "certified" 12% gravel Forest Service road. No problem, she motored right up.
I find it hard to understand/believe/realize that your planned bus will not start up on a 6% grade. Yea, that is quite a slope and it is possible that for some unplanned reason you may have to do sooss, but you should be able to. Factory engineers try to design engine/drive trains that give at least a 12% startablity. Allisions are very cool and fun and easy to drive and are easy on your left leg. I choose the manual. Once I am up to speed, downshifts/upshifts are rarely needed. Your choice. :) :) :)
Hello John.
Never mind that talk about not being able to start on a grade. Someone has misrepresented something or got their wires crossed.
In the 2 stroke vintage MCI, in revenue service it was considered that a stick shift would get 1 mpg better than an automatic. So, 6mpg instead of 5 mpg was expected.
Somewhat misleading for our purposes, since we don't flog our equipment all over the place with a hired driver.
How you use it will dictate a lot on fuel economy, same as your car. Someone who uses a 4 speed auto with gentle throttle use on acceleration, anticipates lights, lets the bus coast down more than uses the brakes will get close, or maybe beat, the same as a guy who floors it on every shift with a stick shift and drives aggressively.
As for the unmeasurables.... my heart would be with a manual transmission, but as I grow older, and the choice is available, why do I want to be rowing gears and standing on clutch pedals anymore?
How many miles are you going to drive per year to make a difference worth measuring? Buses consume hundreds of dollars of fuel per outing, no matter what fuel mileage they get.
If you have plenty of miles under you, you know what's right for you.
If you don't have lots of miles with a non-syncro transmission, the shine may come off that apple right quick, when the novelty turns into frustration and PITA.
Yes, one of the automated transmissions without the clutch pedal would be quite nice in a bus conversion. Best of both worlds: no thinking and good fuel mileage potential.
happy coaching!
buswarrior
Just a question but on my ht740 in high gear is'nt it a lockup converter? if this is the case once the bus is rolling wouldnt the fuel miliage come out about the same? if so then the savings would only be in the city fighting traffic and lights. just curious as mine is still laid up in the "why did I tear all this out" stage so I never get to go anywhere yet.
steve
Yes, the Allaison 740 used in buses has a lockup torque converter so the fuel penalty is in city driving. After a couple of drives in heavy traffic with a stick shift, that penalty looks very attractive.
I bought my bus to be a pleasure to drive and so went with an auto. mucheasier to back in to those tight RV spots in a park too. Jerry
I'm a GMC guy so forgive me if I goof on comments pertainint to MCIs.
A nine or ten speed will work just great for any bus. Anything above 10 speeds is excess baggage. I think the 9 sp is lighter weight so it is better. The main difference in driving the two is that first on the 9-sp is used only once and not used again like on the second go around on the 10-sp.
You must have a T drive to install any of these.
I thought that some model MCIs had 5-sp trans? That would be ideal unless fifth is an OD, then you are still stuck with first being too high.
In the MC-9 era they came with both five and six speed sticks. Way back when (1950s), MCI came with a five speed synchromesh.
For myself, a manual transmission is best. I am an old fashioned straight red neck. I like the control that the stick shift gives me. Driving a straight cut keeps you on the ball and alert and aware of where you are at whith your machine. An automatic would be nice, but it is never 100% right and at times will shift up or down unnecessarily. (My manual shifting isn't perfect either, but there is only myself to blame).
All that being said, you have to consider that the wife might have to drive once in a while. And she should, so she can get behind the wheel in case something happens to you one day. Even just a flu or a broken leg, so you'r not stuck. That is why our next coach might be an automatic.
Quote from: JohnEd on November 08, 2007, 10:29:28 AM
I need this info though, honest.
John -Since you haven't taken the purchase plunge yet, here are my views, after 25+ years in the bus industry:
:) - Buy the NEWEST coach you can, even if it stretches the budget a little bit now.
;D - Buy the NEWEST coach you can,
with the powertrain in it that you want. You will NEVER recoup the cost of a powertrain swap, so buy what you want first. That, plus the fact that it just complicates your conversion project that much more. . . another headache you really don't need.
:o - Real world statistics, from my own log books (average of 80K miles/yr): MCI 8/9 with four speed stick = 5.5 - 6.5 mpg. MCI 8/9 with Allison HT-740 or HT-754 = 5.5 - 6.5 mpg. Didn't make any real difference whether it was an 8V71, an 8V71T, a 6V92TA or an 8V92TA, mileage was consistently in this range, running the 11 Western States based out of Fresno CA - and that means 6% grades any which way we went.
:o - Real world statistics, GMC: PD4106/4017/4108 = 8.5 - 10 mpg PD4903/4905 = 6.5 - 8.5 mpg. All the GMCs were OEM four-speed sticks, same basic travel patterns as the MCIs. They just weigh less. . .
::) - 99% of the time, the stock OEM four-speed stick shift will take you where you want to go. If you have to start on a 6% grade somewhere, you, as the driver, goofed. It's not the fault of the bus. Smoking the clutch on such a grade is very bad karma. . . You
will have to turn to the east and praise Buddah 36 times to overcome this.
:'( - Being stuck in traffic anywhere, be it Portland, Seattle, San Francisco or Los Angeles, is NOT FUN with a stick-shift anything, be it a bus, car, truck, tank, Piper Cub, whatever. Not too bad when you're 18, different story when you're left knee's knobby 'n wobbly at 58.
:-\ - A 10-speed RoadRanger is a great transmission - if you don't mind shifting six times to get to 35 mph. Unless, of course, you're really boonie bouncin' on a backwoods Forest Service road - in which case you should be in a skoolie, not a charter/tour coach conversion. Skip-shifting doesn't count - you still have to shift three times to get to 35 mph. . . BTDT.
:-\ - A 10-speed RoadRanger in a pusher bus will have a backwards shift pattern, UNLESS you do some fancy imagineering to turn the pattern around. Translation: Additional complexity added to the already complex conversion project.
:) - Unless you're a professional driver, learning to drive a coach is much easier and far less stressful if it's equipped with an automatic. Just stab and steer. If you're already a professional driver jockeying 18-wheelers around, it's still easier with the automatic. Most truckers find the stock coach four/five speed infuriating.
8) - Shifting the auto manually plus having a jake brake kills the "not as much control as a stick shift" argument significantly.
;D - Re-read Buswarrior's excellent comments - he, like me, is a professional bus driver trainer (altho I've retired). We've BTDT in all kinds of revenue-service coach equipment, so our perspective on these issues comes from real world experience. (Like that really makes any difference. . . LOL!!)
Thoroughly corn-fuzzled yet? ??? ???
FWIW & HTH. . .
;)
Russ, You and everyone are great. I will download all the posts and keep them but the message seems clear....Allison. I can't imagine wifey ever taking the wheel but I know it would only be possible with the auto. She would have to be snake bit and really hungry to boot for that to happen.
Thank you all....really,
John
If you have a 4 spd, you have other choices if you want to have more gears. You could go to a 5, 6 or 7 spd Fuller that is not synchromeshed like the 4 spd. If you have a 8V-71N with out turbo and with a maximum of 70 injectors, you could go with the Fuller FSO-8406 fully synchoe'd 6 spd over drive that can take up to 860lb/ft torque. The advantage to all these transmissions is that they are single shift transmissions without air operated splitters. Then there are the 8, 9, 10, 11, 13, 15 and 18 spds with splitters and range selectors (on the 11, 13, 15, 18's). For me, and this after driving over the road with nothing but 13 spd transmissions and 1.3 million miles worth, give me an Allison everyday of the week! Easy starting on the hills, and on my V730, I can get lockup as low as 20 mph and at 1100 rpm with easy throttle. With the ease and performance of the Allison, to me fuel mileage is secondary. Besides, just how many miles a year are you doing- 2,000, maybe as much as 5,000 miles? I don't think 1 mpg is going to make that big of a difference compared to the convenience, ease and relaxing mode when driving an Allison auto. Good luck, TomC
Without anything to compare to to, I can't comment too much on fuel mileage as an advantage to having a 5 speed manual, but it absolutely was a factor in our buying decision. Even though an Allison automatic locks into direct at some point, there must be some energy lost in the form of heat, as with any hydraulic system. So far, we are getting around 7 mpg, so I am not disappointed.
QuoteMost truckers find the stock coach four/five speed infuriating.
As far as ease of driving, I don't have a big problem with it, but Russ's comment comes pretty close to my first reactions, except that I would have to replace "infuriating" with frustrating. It just seems to take forever to get from one gear to the next, waiting out the big split. Truck experience or not, unless you like the challenge of learning to shift it cleanly, an automatic is well worth considering.
My other reason for preferring the standard is maintenance. Unless they are badly abused, standards seem to last forever, are simpler and cost less to fix. But my reasons would not matter to many others who have offered lots of excellent reasons to consider an automatic.
One other thing just came to mind. With the standard, I'm not fighting Lynn for the driver's seat. :) But she'll learn, in case I break a leg or something.
Don