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Topic: Flashbob's regearing questions (Read 385 times) previous topic - next topic

Flashbob's regearing questions

Quote from: Tim Fiedler –
Price of diesel really not a factor I think, more important is stability of pricing and availability of fuel. 

I have seriously considered re gearing my rear axle to raise the mph the peak torque of my m11 occurs.

I understand the wind resistance issue but I bet I can get 9 mpg+ at 70 on flat ground that way.

The interstates are not a problem at 60mph but the secondary roads have the truckers on my tail fairly often

Bob
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Flashbob's regearing questions

Reply #1 –
Quote from: Dave M –
Bob,
Since your coach has the 3.91 gearing now, What magic ratio would you prefer for the M11@400hp for better fuel mpg ?
Loose weight, carry less fuel, water and pots & pans, anything to lighten the load, change all lubes to synthetics, do not exceed 65 mph, run tires at max psi and put a raw egg between your foot & throttle pedal and remove all awnings, add the resonator.
Dave m

Regeared 3176 marquis in 1991 to 3.21's if memory serves me.  Had only a four speed trans.

Probably 3.42 or similar numbers.  Not sure if the regearing pencils versus buy more fuel.

As the marquis were brand new then the gear  sets were swappable from the gear guy. 
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Flashbob's regearing questions

Reply #2 –
Quote from: Dave M –
Have you worked all the numbers for these gear sets?  Using the 6 speed Allison you may never get into high gear while not enjoying any acceptable acceleration.
I have played many gear games vs tire size, rev per mile, transmissions, engines, etc, not just on paper but leal life. 
My opinion, with the 3.91 with the 275/80X22.5 is a very fine overall setup. If there was a better ratio, I would have already changed. Also my turbo model change was a biggie.
Do what makes you smile, I do.

Our 95 U320 with the M11, Allison 6-speed and stock gearing (3.91:1, I believe) seems to be optimum. I can find absolutely no reason to change it.
David and Carolyn Osborn
1995 U320C SE 40' Build 4726 Feb 1995
FMCA 147762
Motorcade 17186

Re: Flashbob's regearing questions

Reply #3 –
Quote from: D.J. Osborn –
Our 95 U320 with the M11, Allison 6-speed and stock gearing (3.91:1, I believe) seems to be optimum. I can find absolutely no reason to change it.

Unless you want 1350 rpm at 65-70 not 60. 

I find if I can go 60 normally I can go slightly faster.

Monaco did it in the early 90's with a two speed rear axle.  No six speeds yet.

Allison held back the trans four years as they told me in 89 that the had just rebuilt the production line in Indianapolis as would not release the world class trans they were displaying until the line tooling wore out.

No competition was the reason I was told. 

I strongly asked for an earlier introduction in 1989 when I had the Allison guy on the phone.

Not sure how much difference in the mpg is at 1500 rpm versus 1350?  Ten percent more rpm equal ten percent less mpg?

Even 65 or 68 mph for my uses might  be better. 

More hp normally gave better not worse mpg.  Fun to turn up the m11 at the same time.

Shop mechanic mentioned Pittsburgh power for modded boxes.

We regeared and reprogrammed the marquis 3176 and got better performance and increased mpg.

Bob
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4
 

Re: Flashbob's regearing questions

Reply #4 –
Hmmm. 10,000 miles a year fuel is 25% of annual expense..... Save 10% on fuel, save 2.5% of annual expense.

I just hit the pedal and fill up when below half.....

Maybe I am lazy....
Tim Fiedler    2025 LTV Unity MBL on Order
2000 Chevy Tracker 2 Door Convertible 4WD Now lifted 4.5"
1985 Citroen 2CV6 Charleston
Murphy Rebel on wheels with 175HP Titan
Cessna P337
1980 48' Westport MY (!/4 Share)