7.3 "Godzilla" V8 - Page 2

DavidEM · 03-13-2021, 08:35 PM

Quote:

Originally Posted by Chance

The only exception is the new V8 with “Economy” tune which is rated lower than previous V10, but I have yet to see a single RV manufacturer select that “Economy” option.

Not the Thor Axis 24.1 based on the E350 chassis? I thought it has the "Economy" engine with a numerically smaller rear end ratio.

David

Pete'sMH · 03-13-2021, 08:37 PM

Quote:

Originally Posted by RVGUY45

I have a V10 in a 30 ft class C towing a Honda Civic on a dolly and it never screams, just purrs happily along the highways of Canada

Me too. It only screams if you let it.

IDguy · 03-13-2021, 09:14 PM

My V10, on F53 Georgetown 30x3, doesn’t scream or moan but frequently likes to operate around 4,500 rpm. You can’t go anywhere in Idaho without mountain passes. I just installed the drain hose fix to try quiet it some, though. Will test Monday.

Chance · 03-13-2021, 09:24 PM

Quote:

Originally Posted by DavidEM

Not the Thor Axis 24.1 based on the E350 chassis? I thought it has the "Economy" engine with a numerically smaller rear end ratio.

David

Thor specs show standard “Premium” engine, not the optional “Economy” version. It’s actually a lower-cost option that I recall saving around $350. It has 300 HP and 425 lb-ft.

Final gear ratios are 4.10 or 4.56 for E-350 and 4.56 for all E-450.

Since Axis has lower “frontal area” than many Class C built on E-350, I hope Thor chooses 4.10 gearing for greater fuel economy.
.

Bob Denman · 03-13-2021, 09:27 PM

Those taller gears would really kill it in the mountains...

Chance · 03-13-2021, 10:08 PM

Quote:

Originally Posted by Bob Denman

Those taller gears would really kill it in the mountains...

OK, I’ll play along. Why?

Bob Denman · 03-13-2021, 10:14 PM

Real simple physics: the taller gearing will have less multiplication affect, and there'll be less power for climbing.

dstringer · 03-13-2021, 11:58 PM

I have a 28.5’ 2021 Thor Chateau , 14,000 pounds. It’s a bullet, lot’s of power. I love it!

Chance · 03-14-2021, 01:05 AM

Quote:

Originally Posted by Bob Denman

Real simple physics: the taller gearing will have less multiplication affect, and there'll be less power for climbing.

Simple physics or are you making issue TOO simple?

Let’s test Ford Engineering wisdom versus yours. What do you think is faster,

an E-450 at 14,500 pounds with 4.56 gears,
or
an E-350 at 12,500 pounds with 4.10 gears?

And to be clear, do you think your Sprinter Wayfarer is faster in mountains than an E-350 Axis at 12,500 pounds with 4.10 gears? Why be negative on a motorhome that is much faster than your rig?

After this, we can move ahead to why transmissions have multiple gears.

Bob Denman · 03-14-2021, 01:26 AM

You're actually trying to compare different vehicles: when I was only comparing the effects of different rear end ratios.
Given the same power characteristics: a vehicle with lower gearing will always out-pull one that is geared taller.
Throw in less power: it gets even worse.

Chance · 03-14-2021, 01:46 PM

I’m not TRYING to compare different vehicles, I AM comparing different vehicles. That was made clear.

There is no need to scare or worry people with baseless nonsense by stating that an E-350 with 4.10 gears is somehow going to struggle in the mountains. That’s just not the case, and will be no worse than all the E-450s that do have 4.56 final gears.

Taller E-350 gearing will deliver 90% of torque to rear wheels.

4.10/4.56 = 90.00%

However, E-350 has lower GVWR and GCWR than E-450.

GVWR = 12,500/14,500 = 86.2%

GCWR = 18,500/22,000 = 84.1%

Simple math confirms the sky is not falling.

Main difference is engine will run 10% slower and improve fuel economy a bit.

Bob Denman · 03-14-2021, 02:53 PM

(See your post #24...)No: you were discussing putting taller gears into the economy tuned Godzilla... for better fuel economy. I was just pointing out the tradeoff being made.

Chance · 03-14-2021, 04:20 PM

Two different subjects in one post must be too difficult to keep straight.

Economy tune option and final gearing option are not one and the same, and my post did not state that.

Example here of Economy engine tune with 4.56. NOT that it should matter anyway, because as I stated, Thor specs show they order chassis Premium engine tune.
.

Bob Denman · 03-14-2021, 04:46 PM

Final gearing will always affect fuel economy...

sportcoupe · 03-14-2021, 04:46 PM

There are no such thing as tall gears.

There are low gear ratios (numerically higher) and high gear ratios (numerically lower). That is all. Have a great day.

Bob Denman · 03-14-2021, 04:51 PM

"High, low, short, tall": that's just semantics.

Pete'sMH · 03-14-2021, 05:38 PM

Quote:

Originally Posted by Chance

I’m not TRYING to compare different vehicles, I AM comparing different vehicles. That was made clear.

There is no need to scare or worry people with baseless nonsense by stating that an E-350 with 4.10 gears is somehow going to struggle in the mountains. That’s just not the case, and will be no worse than all the E-450s that do have 4.56 final gears.

Taller E-350 gearing will deliver 90% of torque to rear wheels.

4.10/4.56 = 90.00%

However, E-350 has lower GVWR and GCWR than E-450.

GVWR = 12,500/14,500 = 86.2%

GCWR = 18,500/22,000 = 84.1%

Simple math confirms the sky is not falling.

Main difference is engine will run 10% slower and improve fuel economy a bit.

Exactly, let’s not overthink this. None of our machines are ever going to tear up the street but ALL of them will do the job. Some folks are all excited that the new engine is more powerful than the old but it’s only by about 9%. It may well be more sophisticated and pleasing in use but it’s not going to blow the doors off an older coach of the same size. Just sayin.

mgunnin · 04-06-2021, 12:01 AM

Well after all the talk high-low, tall-short.
It seems everyone might like to say the V-10 is a pile of _ _ _ _ or something like that.
I have owned a Class B 21' with the V-10 in 2000. Then a Class A 32' with a V-10 in 2001. Both were ok and I took the class A from GA to the West Coast through the mountains. I can only remember one time that she got down low and slow.
Now I have a 2018 Class A Vegas 27.1 with the V-10 and the six speed transmission.
The new V-8 would have to take we off the line with no engine noise beat me in the first 60' by 30' shift in to six gear and never talk back and get 25% better mileage than my V-10.
The 2018 is the best of the three. Quite off the line, can't hardly tell when it changes gears. It it smooth and very nice to drive.
So I am saying Ford changed for $ reasons not for our pleasure.
I am completely satisfied with my V-10. Glad I did not wait for the year of the V-8.
Ya'll come back you hear!

Chance · 04-06-2021, 09:21 PM

Quote:

Originally Posted by mgunnin

Well after all the talk high-low, tall-short.
It seems everyone might like to say the V-10 is a pile of _ _ _ _ or something like that.
I have owned a Class B 21' with the V-10 in 2000. Then a Class A 32' with a V-10 in 2001. Both were ok and I took the class A from GA to the West Coast through the mountains. I can only remember one time that she got down low and slow.
Now I have a 2018 Class A Vegas 27.1 with the V-10 and the six speed transmission.
The new V-8 would have to take we off the line with no engine noise beat me in the first 60' by 30' shift in to six gear and never talk back and get 25% better mileage than my V-10.
The 2018 is the best of the three. Quite off the line, can't hardly tell when it changes gears. It it smooth and very nice to drive.
So I am saying Ford changed for $ reasons not for our pleasure.
I am completely satisfied with my V-10. Glad I did not wait for the year of the V-8.
Ya'll come back you hear!

Since V10 is no longer available, and all F-53 and E-Series are presently getting the new V8, I’m not sure it really matters much what any of our opinions are.

Having said that, I’m wondering what you are comparing against if none of the three are V8?

Your reference to hardly noticing gear changes has more to do with your 2018 having a modern 6-speed transmission (6R140), while the 2000 and 2001 motorhomes probably had a 4-speed (4R100). Perhaps a 5-speed (5R110) but I think they came later.

No doubt 7.3L V8 may cost less to manufacture than V10, but that’s not necessarily a bad thing if it’s because V8 is simpler and has fewer parts, etc. What’s important to most is that it has more power and torque, is smaller, lighter, quieter, smoother, and probably slightly more fuel efficient; if for no other reason than for its higher compression ratio, and maybe lower friction also.

My V10 has been great, but I look forward to small motorhomes with the V8.

mgunnin · 04-06-2021, 09:45 PM

Quote:

Originally Posted by Chance

Since V10 is no longer available, and all F-53 and E-Series are presently getting the new V8, I’m not sure it really matters much what any of our opinions are.

Having said that, I’m wondering what you are comparing against if none of the three are V8?

Your reference to hardly noticing gear changes has more to do with your 2018 having a modern 6-speed transmission (6R140), while the 2000 and 2001 motorhomes probably had a 4-speed (4R100). Perhaps a 5-speed (5R110) but I think they came later.

No doubt 7.3L V8 may cost less to manufacture than V10, but that’s not necessarily a bad thing if it’s because V8 is simpler and has fewer parts, etc. What’s important to most is that it has more power and torque, is smaller, lighter, quieter, smoother, and probably slightly more fuel efficient; if for no other reason than for its higher compression ratio, and maybe lower friction also.

My V10 has been great, but I look forward to small motorhomes with the V8.

I was not comparing. I just made a statement that I am exceedingly happy with my V-10.
If I were shopping for a MH I certainly would not run from the engine and transmission set up, just to find the V-8. It will not be the greatest thing that ever happened to the RV Industry and the RV's world.

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