Cummins 5.9 with AT545 85mph?

[Thunder]

I am not the most knowledgeable with drive trains and stuff. So please tell me if I am dumb. But I am currently looking at a 2000 Bluebird TC2000 8 Window.

The guy says that it is governed at 85mph and was driving it at 85-90 across the country. From my understanding a governor limits to that exact speed. But also would a year 2000 TC2000 Cummins 5.9 with an AT545 and 4.44 gearing even get to these speeds? The speed he listed was also in MPH not KMH.

Also it is supposed to consistently get 15 Miles Per Gallon. (Which I know is Plausible.)

Any thoughts and suggestions are always helpful!

[turf]

without pulling out a calculator, i';d say he is full of it.


ok, ok
now i found a calulator and he is full of it.

2700 rpm
4.44 rear
1:1 4th gear
41" tire height (11x22.5)

gets you 74 mph. pretty fast in the bus world. no chance of pulling 15 mpg that fast. maybe 7 or 8mpg

Gear Ratio Calculator

i dont think you'll even find a dodge truck that will go over 85

[Rusty]

90mph in a bus would convert to a pucker factor of 9. These weren't really built for top-end speed.

It's not the " going", it's the stopping.

Tell him to hop on the freeway and snap a pic of the spedo at 90 mph.

[Thunder]

Originally Posted by turf

without pulling out a calculator, i';d say he is full of it.


ok, ok
now i found a calulator and he is full of it.

2700 rpm
4.44 rear
1:1 4th gear
41" tire height (11x22.5)

gets you 74 mph. pretty fast in the bus world. no chance of pulling 15 mpg that fast. maybe 7 or 8mpg

Gear Ratio Calculator

i dont think you'll even find a dodge truck that will go over 85

Thank you a ton Turf for your help and response! Really appreciate it!

[Thunder]

Originally Posted by Rusty

90mph in a bus would convert to a pucker factor of 9. These weren't really built for top-end speed.

It's not the " going", it's the stopping.

Tell him to hop on the freeway and snap a pic of the spedo at 90 mph.

I will definitely do this and post back if a photo surfaces!

[Charlies.Contingency]

Originally Posted by Thunder

I will definitely do this and post back if a photo surfaces!

If he does, I would contest that the speedo was calibrated to something around 3.70 to make it the tach show the speed. Though the bus would be chugging in the 60's in real life. [emoji12]

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[cadillackid]

technically with my bus i could go 117 MPH with my gearing.. however even in a shorty once I hit 70 im finished.. in fact finished enough that I went into the computer and programmed the top speed of 70.. and I drive it at like 65-68 most times..
80 in a school bus sounds like a crazy man at the wheel... after all if something happens bad in traffic you have to stop that 80 MPH bus quickly...
-Christopher

[togetherwayward]

Originally Posted by Rusty

90mph in a bus would convert to a pucker factor of 9. These weren't really built for top-end speed.

It's not the " going", it's the stopping.

Tell him to hop on the freeway and snap a pic of the spedo at 90 mph.

OMG this made me cackle laugh out loud!! A pucker factor of 9 took me by surprise hahaha....aww thank you, a brief but much needed moment of diversion from all this research and information overload lol

[EastCoastCB]

Originally Posted by cadillackid

technically with my bus i could go 117 MPH with my gearing.. however even in a shorty once I hit 70 im finished.. in fact finished enough that I went into the computer and programmed the top speed of 70.. and I drive it at like 65-68 most times..
80 in a school bus sounds like a crazy man at the wheel... after all if something happens bad in traffic you have to stop that 80 MPH bus quickly...
-Christopher

MY shorty does 75 with a LONG straight road. I'd love to get a bit more just for bragging rights, but honestly 65 is plenty fast in these things.

[Charlies.Contingency]

Originally Posted by EastCoastCB

MY shorty does 75 with a LONG straight road. I'd love to get a bit more just for bragging rights, but honestly 65 is plenty fast in these things.

What are your RPMS at that speed? I would hate for you to throw a rod man.


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[EastCoastCB]

Not even the max. 2550- maybe 2600.
Don't worry, its all good. Rarely do I have any chance to go that fast.
Sucker was built for it though. 4.10 rear, 10r's and air ride!

[Charlies.Contingency]

Originally Posted by EastCoastCB

Not even the max. 2550- maybe 2600.
Don't worry, its all good. Rarely do I have any chance to go that fast.
Sucker was built for it though. 4.10 rear, 10r's and air ride!

Crap that is a nice set up. I was hoping to eventually get a Daily Driver bus, gear down to 4.56 or something. 4.10 would be great for highway.


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[Alan N]

3208 Cat. 2800 rpm redline.
RTO 610 transmission. .78 overdrive.
5.29 rear end gears.
11r24.5 tires.
You do the math.

[brundige]

I drove my 40 ft tc 2000 today and had no problem going 70 on the flats at 2k rpm. I averaged 11mpg

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[jctrembly]

After I redid my rear end, my bus goes 80mph+. Prior to taking the seats out we did a 1600 mile church trip and had to keep reminding by relief driver (a retired school bus driver) that 80 was a bit fast. Lol. It's a rear engine bus, it was so quite it kept sneaking up on him, and the governor is currently rpm limited, not speed limited.

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[cadillackid]

I ran mine up to 75 before I changed the speed limiter.. i think it was at like 1850 - 1900 RPM.. on any incline it drops down to 5th gear and runs up the RPM a couple hundred at that speed..
-Christopher

[EastCoastCB]

Originally Posted by cadillackid

I ran mine up to 75 before I changed the speed limiter.. i think it was at like 1850 - 1900 RPM.. on any incline it drops down to 5th gear and runs up the RPM a couple hundred at that speed..
-Christopher

You're definitely the coolest kid in town, Chris!

[cadillackid]

LOL not the coolest.. some of these conversions im seeing on here are QUITE FANTASMICAL!!! ... I just treat my bus more like one of my old hotrod projects concentrating on mechanicals / electricals / driveability.
-Christopher

[mmoore6856]

got to 85 on the flats with my 98 still had more but ill never find out. mine did like 65 it seemed as it was easy to hold ill have to find a cruise control to add to it as being mechanical it didnt come with one however on the good side in the event of a electrical failure mine will stay running as you only need juice to shut it off

[Versatile]

No trouble for me to get 78 mph on freeways @2800 rpm