There are a few threads on ratios and speeds. I decided to take a few passes with the old girl
I am not sure if my speedo is accurate but my average over 3 passes is 42.1 seconds
1968 MC5
3.71 rear end
8V71 with 65 injectors
Not sure if timing is advanced.
Full fuel tanks but not sure on overall weight
Top speed is about 75mph
Lets here what you've got Ed :)
I guess in the spirit of the Olympic games I can get some
"speed times" on the old bus.... I may need to use a calander instead of a stop watch though..... ;)
GMC 4104....ZOOM...ZOOM
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My best time tru the traps was august.
Randy, i have never thought to check my 0-60 time! :) I am usually pretty light on the throttle when taking off, and let off on the throttle way before coming to a stop, in the interest of better fuel mileage. ;D We won't be leaving Yuma until the 1st of April this year unless the boss calls me for work before that. Usually we stay till the 1st of May or so, but since it looks like i will be working on the other side of the mountains again this summer we will be starting work earlier. I will try to remember to take a few readings on our trip up. ;D Ed
Cody, isn't that the week that the snow is off of the roads up there? ;D
I haven't timed it yet, but found it is amazingly fast heading down an 8% grade. I think acceleration approached 32ft/sec/sec.
;D
POOR MANS DYNO - 77 MPH top speed --
I have always recorded the times 0-60 on a flat road for every RV vechicle I've owned - helps to let you know if your engine getting weak a few years down the line
works for me
the 0-60 in 27 seconds (.pdf file) was our Classic 1976 GMC 455 cu-in Olds Toronado front wheel drive 26'
From the top of the hill (7% grade), to the bottom, from a standing start, with a good tail wind, I was able to do it in under a minute.
I love soap box racers.
From a dead stop, my Onan will do 0 - 60 (Hz) in a little over two seconds.
Pete, was the 277 an input or an output from the program? I was doing some reading, and for my nominal 280 hp 8V-71 I would expect to take away 15% for driveline losses and about 30 - 40 hp for the squirrel fans and the alternator and other drive items. so I would have about 200 drive tire hp. I was reading this: http://www.holtrv.com/pdf/understanding.pdf (http://www.holtrv.com/pdf/understanding.pdf) and reading about hp requirements for grades and speeds and such. It seems to use rear wheel hp.
Brian
I believe that's 277 hp (at the flywheel) - I have a California EPA 6V92TA engine with a catalytic converter - / low smoke / low emiisions /
still penty peppy for me - does real great on the hills (I pass trucks) - and If i cruise at 62-65 - I can get 9-10 MPG
0-60??? My top speed is about 63 MPH !! I'll go for a spin this weekend and get a measure.
Quote from: RTS/Daytona on February 26, 2010, 08:36:25 AM
I believe that's 277 hp (at the flywheel) - I have a California EPA 6V92TA engine with a catalytic converter - / low smoke / low emiisions /
still penty peppy for me - does real great on the hills (I pass trucks) - and If i cruise at 62-65 - I can get 9-10 MPG
I have the 277 HP Californicated 6V92TAC DDEC II in my bus, with the same 4.1 rear end and probably about the same weight (your 35' is converted, my 40' is a tin tent and weighs about 25,500), and I'm guessing your bus may be a smidgeon more aerodynamic than mine. At a steady 60 MPH (just under 1900 indicated RPM), using 12R22.5 Michelins, I'm not getting 9 to 10 MPG. What's your secret? If I had my injectors replaced, would that help my fuel mileage by any noticable amount? Just curious (and slightly envious).
John
his charts said he was 19K lbs, that would make a difference from 25.5K. Also he said a 3.60 final drive ratio, also a big difference from a 4.10
The RTS is one of most Aerodynamic transit bus made
It has a drag Drag Coefficient of 0.55 and a Rolling Resistance Coefficient 0.011 see-> http://www.perthelectricvehicle.com.au/linksbus.php (http://www.perthelectricvehicle.com.au/linksbus.php)
Thats somewhere between an Original VW Bug at .48 and Hummer H2 at .57 (lower egual less drag) see-> http://en.wikipedia.org/wiki/Automobile_drag_coefficient (http://en.wikipedia.org/wiki/Automobile_drag_coefficient)
Most trucks +.6 -
My last M/H (1976 Classic GMC 26' MotorHome) .31 (same as a current Z06 Corvette)
and
Less than 10' height
single axel rear wheels
2250 RPM equals 76 MPH - (4.10 differential - .88 to 1 finial gear geraing V731 tranny) = effective 3.60 final drive in 3rd (final gear - 3 speed tranny)
I have 24.5 tires (although that sounds a lot taller - they are not that much taller)
John -
Pete snuck in with an answer before I could post mine, but here's the KISS version:
Couple of differences between your Crown and Pete's RTS easily account for the difference in fuel mileage.
First, even tho you both have 4.10 rear axles, Pete's V-730 has a 0.87 bevel gear ratio, which gives an overall final drive ratio of 3.567:1 (He's got a V-drive powertrain, compared to your T-drive.)
Second, Pete's RTS is aerodynamically "cleaner" than your Crown. Had you an original "twinkie" body style, chances are good that your mileage would equal what Pete's getting. The price of progress, eh?
FWIW & HTH. . .
;)
Ed, the snow leaves at different times each year, last year summer came early, it was on a tuesday. lol
Thanks for those explanations. Unless I can find a 3.7 pumpkin for my axle (yeah, dream on!), I'll just have to live with my 7 to 8 MPG. I don't and won't drive much, so it's probably not worth spending much to change ratios.
That also explains why folk with twinkie Crowns that have the overdrive Road Rangers are getting up to 12 MPG and/or up to 80 MPH! However, a mid-engine wouldn't work for me - I need the underfloor space.
John
With a 6V71 in a MCI5C with a three speed slush box it took a few minutes, even downhill. But I did get 12 mpg!! JIm
12 mpg... nice - I think that is the best I have heard of.
Well after 4 runs my average 0-60 time is 70 seconds ......
I tried to pick the most level road conditions. This was at 2am on my way home from a gig. I figured it best not get caught in daily traffic.
What is your setup?
Quote from: viento1 on March 03, 2010, 08:55:19 PM
What is your setup?
1960 4104
GVW - 23,420lbs fully loaded with fuel and gear (driver only)
Engine - 6-71, 4valve head, #65 injectors, duel 3" exhaust
Transmission - 4 speed spicer
Top speed per gear: (MPH determined using Magellan GPS)
1st - 16mph
2nd - 26mph
3rd - 42mph
4th - 63mph
Right now with gigs being slow (2-3 gigs a week) I drive about 225 - 275 miles every week. I go two weeks between fuel fill-ups. Fill-ups are averaging about 60-80 gallons diesel and 15-25 gallons generator gas.
I average 6-8mpg. With only about 50-60% of my mileage being highway I'm fairly satisfied...
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I'm saddened by the discriminatory objective and tone of this post.
As a 4104 owner (671) I feel that in the spirit of equal opportunity, there should be a 0-55 MPH category.
;D ;D ;D
I'll post as soon as we make it to 60 First we have to start the toad. Maybe it'll help if it pushes...Cable
0-60 in fifteen minutes :) now 0-30 i can hit like a rocket but after my 731 makes 3rd....it's a REALLY long haul!
6v92ta mechanical
Allison 731
Quote from: Flyboy on March 04, 2010, 07:23:35 AM
I'm saddened by the discriminatory objective and tone of this post.
As a 4104 owner (671) I feel that in the spirit of equal opportunity, there should be a 0-55 MPH category.
;D ;D ;D
So what you're saying, is that your 0-60 time is
NEVER..... ;D
There really isn't that much difference between 55mph and 60mph. You could see how much time it took to get from 50 to 55 and then add that time to your 0-55 time. Or just take the 0-55 time and post it with an * next to it.....
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Hey Zimtok,
'bout the only place for me to go over 60 would be the downhill side of Montgomery Pass BTW Nev and Cal! :o
60's overated anyways...just extra wind noise!! ;D Come to think of it though, more wind noise might not be such a bad thing. I'd have an excuse not to listen to the missus and youngins!! 6V92 TA here I come!!!! ;D