1984 International Air Force Bus

[M1031A1]

Originally Posted by Famousinternetjesus

I appreciate your concern for safety etc, however, I have no reason to believe that with proper gearing I couldnt cruise at 80. I've got six new tires, The engine runs like a top and my alignment/steering are impeccable. If I could drop my rpms by 500 or so maybe a little more I could hit 75-80. I looking f

Even new truck tires, unless you shuck out BIG $$$$, are not intended to drive over rough roads at 80 mph. High quality semi tires (like Michelin, Goodyear, et. al.) are intended for Interstate Highways for high speeds. Even then those roads are not always in the best of condition. Some states and local municipalities have the big $$$ to keep up their roads. However, those places are few and far between in this economy. I'm concerned driving over 75 with my pick-up truck. We've recently had to rent a car for almost two weeks and I'm TERRIFIED with that P.O.S. doing 70.

As I said earlier, drive for your brakes, your engine, and now include driving for the road and its condition. I'd think loooooong and hard before trying to do 80 in a converted school bus. Better to get there alive than not at all.

Just my opinion.

M1031

[Tango]

One more item to check/verify regarding tires...

The "V Rating"

(V = Velocity...Speed) The last character in the tires ID sequence.

All tires have a V rating which should never be exceeded. It can vary from tractor tires to formula racing tires (I used to race formula motorcycles and after some mods had to upgrade my tires to today's equivalent of a Z rating).

Many school bus tires are only rated to 62 or 68 mph. That is precisely the reason most techs will not re-program Allison 5 speeds to pick up 6th gear on a Skoolie. The vehicle would then exceed the factory tire rating.

See the current ratings here...

Tire Speed Ratings | Tire Speed Rating Chart | Discount Tire

[Famousinternetjesus]

I understand all that and what you're saying is legitimate. I knew I was gonna catch a lot of negative responses with this because it's kid of crazy. Once I get videos up showing how pristine this bus is, zero rust, and mechanically perfect. I used to hit 75 in it with the old G159 tires on it but i think my new tires are a hair smaller making it hard to get up there. The bus is smooth and vibration free, purring at 65. I know lots of guys are thinking I'm an idiot. But just imagine being able to pop you at545 into "overdrive mode" and cruise at 75 at 2700-2800 rpm. Anyone that's driven cross country in three days like I have repeatedly knows this sound like heaven. I guess I'm just looking for that next gear haha

[Famousinternetjesus]

Oh yeah and my tires are RV tires designed for high speed use ad they are brand new, they cost exactly one arm and one and a half legs

[Tango]

Not me. I'm just always surprised at how few people are even aware their tires HAVE a speed rating.

[Famousinternetjesus]

Yeah the wrong tire is veeeeery dangerous. That's why I bit the bullet and replaced mine, the G159 was only rated to 65 and was known to have a history of critical tread separations/failure yikes!! Not something I wanna deal with in a 13000 pound vehicle hence the pursed to tires rated to 85

[Famousinternetjesus]

*upgrade not pursed haha damn auto correct

[Famousinternetjesus]

So does anyone in fact manufacture an overdrive unit for the Allison at545?

[Booyah45828]

No, none that I'm aware of. The problem with going faster in any HD vehicle is the aeration of the gear oil and subsequently burning them up. They weren't designed to go that fast. Another thing you have to look at is the critical speed of the driveshaft, and make sure you don't exceed that. OD is essentially made to shift into at highway speed and just cruise at, not as an alternative to make the bus go faster. Change your rear gear if you want a higher top speed.

[nat_ster]

Originally Posted by Famousinternetjesus

Will the MD3060 mate up with the 6.9

Originally Posted by Famousinternetjesus

So does anyone in fact manufacture an overdrive unit for the Allison at545?

IMO

Famousinternetjesus
Don't take this the wrong way, but read and under stand the next few sentences.

You need to lean how to press the "search" button, and press the "post" button less.

Search MDT trucks of the same year range as your bus.

Most of the searching you you need to do now, should have been done before you bought a bus.

That 6.9 is one of the worst engines you could have picked.

Nat

[Famousinternetjesus]

Well I appreciate everyone's time. I clearly haven't been clear enough about what I want. Natster, thanks man but I'm very happy with my bus.
6.9 diesel 43000 miles...
No rust
Tall ceiling (Air Force )
Medium length + excellent ground clearances
And it does everything I want it to.
I'm just trying to eek another ten mph out of the old girl without redlining and blowing the engine. That being said it is the perfect bus for me and I paid almost nothing for it, less than I spent on the tires, the transmission fluid is pristine and red and beautiful and the oil wasn't all fouled and burnt before I changed it and the filters just because. So it's actually an awesome bus... Oh well I was really hoping to hear from people that had positive things to say about how that little extra boost could be accomplished. I'm sorry if I somehow offended anyone

[nat_ster]

We need pics to start the happy energy.

Nat

[opus]

Just be content with your speed and power and you'll be golden. Trying to increase both will make you nothing but broke and frustrated.

You must be young...young people always want to go fast. LOL!

[charles_m]

Swapping in a new trans with either more gears like a 3060 or a lockup converter like a mt643 would drop your rpms and is probably the cheapest way to do what you want. But dude, you have it soooo good. 70 is a dream for most of us. We,'re talking a few thousand bucks to make this happen unless you get real lucky. Or just put in some 3.70 gears in the rear and see where that gets ya.

[The-Breeze]

Really.....our BB runs down the road pretty well. As I wasn't driving I have no clue how fast we were going. Needless to say whatever it was I was perfectly content. She most definitely will never win a speed contest, but who cares. Wasn't the main idea around getting a skoolie to see the sites?

As for hills & mountains....the poor thing would rather cringe on the side of the road in tears than go up anything. We made it up Burnt mountain in Georgia on our way to Tennessee. She made it but I swear I could have walked up it quicker if I was healthy & 40 years younger. We knew that was going to be when we got her. She thinks she's a scenic cruiser, a senior citizen scenic cruiser but a cruiser nonetheless.

At least we don't have cruise control so we don't have to worry about Alzeimers kicking in.

We don't know what the elevation & grade was up the mountain...I'll let you know when I can find out.

[crazycal]

At least take a video of when the bus blows up.

[Famousinternetjesus]

Seems like you have a lot of negative things to say crazy cal. For those of you who are interested, there are actually several divorced unit auxiliary transmission made to handle bus sized loads. One is made by gearvend

[Famousinternetjesus]

Gearvendors, yes they do make it, it is rated to 25000lbs towload significantly stronger than my 13000 pound bus. Another is the spicer5831 which also gives you a 30% under drive, there is also the us hear dual range which is out of manufacture but still exists, then of course there are the many versions of brownie boxes out there... Hope everyone is having fun out there

[Famousinternetjesus]

And I'm well aware of the costs, if id wanted to buy something I didn't have to put a bunch of money into, I would have bought a Winnebago haha.

[Famousinternetjesus]

Originally Posted by crazycal

At least take a video of when the bus blows up.

I'll be sure to pm you a video showing just how much I hate cruising at 75 with low rpms, it's gonna be so awful