Too much guessing (and exaggerating..........) and not enough research and facts equals bad info and questionable advice.
OK now I have my notebook and here are the FACTS from my Excursion with 4.88 gears. All of my speeds were from my GPS to avoid any speedo variations from the nonstock tire sizes. I made these notes while going to and from the tire shop when I upgraded from my old Continental 275/70 (or 75 can't remember) R18E 32" tires to my new Nitto Dura Grappler 305/70R18E 35.2" tires.
50 MPH 32" = 1930 RPMs 35" = 1720 RPMs
55 MPH 32" = 2075 RPMs 35" = 1900 RPMs
60 MPH 32" = 2280 RPMs 35" = 2055 RPMs
65 MPH. 32" = 2430 RPMs 35" = 2230 RPMs
So yeah, you would be doing around 100 at 3800 RPMs.
The V-10 is making very good torque numbers at these slightly higher revs and it pulls so much better with a lot less dropping out of OD and that helps with the towing mileage. 4.88s will not have your V-10 screaming rolling down the highway. And driving around town is much more fun!

 

The whole point I was making (including the exaggerated RPM estimate) was to get a specific & deeper look into speed/rpm relationship.

A couple of you here coulda/shoulda been a little nicer to me in responding.. but at least I inspired some real informative research for the OP.

I stand by what I said before: various tire sizes and transmission options coupled with $1,000 of aftermarket gears could be disastrous without proper research.

You're welcome.

 

Sorry that you feel I'm less than nice .
In the OP's first and second posts he pretty much outlined his typical use and the size tires he is running and what he would like to move up to in the future, so he was starting out his investigation into a gear swap with tire sizes and trans ratio as known values.
In my first post (the one immediately before your first post) I suggested using an online calculator. Then when the OP does use the calculator and gets correct data you say that you are skeptical and claim that very steep OD ratios and oversized tires would be needed to achieve his results.
To your credit you also did say that if you're wrong, then you're wrong, and you were so I suppose I should overlook all of the guessing, exaggerating and bad info and go happily on my way. But I think online forums (and I think this is one of the best) are awesome sources of great info, and I tend to point out bad info when I see it and provide good info when I can. I'm not very good at sugar coating things, sorry about that.

 

Very well put. I actually believed him when he said 3800 rpm... Research is the best tool lol

Anyways, I decided to do a bit of real world testing. I turned off my OD and slowed down til I was taching 2300 rpms, just to see what the engine/exhaust sounded like. It was quite a noticeable increase but nothing unbearable. It doesn't sound like it was going to blow up, so that was my main concern lol.

I may go all out and actually drive to work a few times with the OD off and taching 2300 rpm. I am still doing something like 55-60 so I can keep up with traffic. This way I can tell what my fuel mileage is going to do. It wont be a 100% exact test since I will still be accelerating with 3.73 gears but it will give me an idea of highway mileage. I may just go til a half tank to keep the test accurate, as Im sureI will forget to turn the OD off at some point otherwise...

Ill keep this thread updated!

 

Even though the 3800rpm was an exaggeration, I still don't have a problem running this power plant at those engine speeds. In fact, I do it all the time in the summer months around here hauling my 4000# camper with 2500# trailer behind up and down the high mountain passes near me. 4000rpm for 5-10 miles is nothing to worry about at all. Not in my experience anyway. And I regularly run the same load on the freeway with OD locked out at 65mph and 2400rpm for hundreds of miles.

 

El Camino Man, your plan of simulating the new gears by driving with OD off and running 2,365rpm is a great start. (I suggested the exact same plan in another post recently). It'll give you a great "feeling" of noise, vibration, throttle position, engine braking, etc.
I believe the most valuable thing you'll feel is the point I was trying to make: that a 415 cubic inch, 10cyl engine with a 100lb crankshaft is great in many ways- - but, extended operation at two and a half thousand RPM is touching the brink of 'mechanical immorality.' (But, as I said before "maybe we have different desires/values". I'm not judging people). I bet we all agree that we wouldn't want to run 3,000rpm in overdrive on the highway (even for 5 straight miles of your work commute). I guess it's just a situation of where each person "draws the line."

My V10 E350 runs that rpm (about 2400) at about 80mph with stock tires and drivetrain. Wind noise/MPG/speed limits/safety/engine wear are definitely contributing factors to me staying under 80mph for sure... But my point (spelled out in the paragraph above) is one that I believe people don't know until they've experienced it. That's the whole reason I piped in. If you disagree with me after living with it in the real world (like I have with my E350 and my friend's Excursion) then, so be it. I'd love to hear your opinion.

Anyway my last point is that your simulation is great for everything except fuel economy. The simulation has you running lower speeds; i.e. lower wind resistance and lower rolling resistance from the drivetrain and tires. Also, does your tranny have a lockup torque converter? If so, will it lock when you have the OD off? Too many variables for any accuracy in testing fuel economy.


WE3ZS:

- - - No you're not- you continue your unfriendly tone in this very post.

"In the OP's first and second posts he pretty much outlined his typical use and the size tires he is running and what he would like to move up to in the future, so he was starting out his investigation into a gear swap with tire sizes and trans ratio as known values. "

- - - Nice job sugar-coating the bad info here. We didn't know his transmission ratio nor his actual highway speeds until I came along and inspired the actual reaseach via my questions and purposeful RPM exaggeration.

"In my first post (the one immediately before your first post) I suggested using an online calculator."

- - - More sugar-coating here (see? you are good at it!). What you DID was used the online calculator for a PARTIAL answer. So much for being the Bad Info Police on this forum... All you did was the hypothetical tire size increase. And even that was bad info. A tire size change does not change the ratio. Even a Monster Truck tire would still turn exactly one time for every 4.88 turns of the driveshaft. Something must be missing from your equation here.

"Then when the OP does use the calculator and gets correct data you say that you are skeptical and claim that very steep OD ratios and oversized tires would be needed to achieve his results."

- - - He too was skeptical of the online calculators. You didn't give him a hard time about it.

"To your credit you also did say that if you're wrong, then you're wrong, and you were so I suppose I should overlook all of the guessing, exaggerating and bad info and go happily on my way."

- - - Sassy like a woman. I humbly offered up my possible defeat in advance, and you chose to rub it in my face. Not classy nor even respectable. Be a man.
Besides that; I was correct about everything I said except the intentional RPM exaggeration and my thought about results from the rpm calculator (which, AGAIN, the OP shared my suspicion about online ratio calculators).

"But I think online forums (and I think this is one of the best) are awesome sources of great info,"

- - - I agree. Also a great source of anonymity for people to be disrespectful with others. People that make posts like yours are bad for any forum community.

"and I tend to point out bad info when I see it and provide good info when I can."

- - - As do the rest of us. But we are expected to be adults about it.

"I'm not very good at sugar coating things, sorry about that. "

- - - ^ Already covered this one.

And regarding the 3,800 rpm: I never actually thought that would be the actual result. I figured 3,000 could be realistic, based on worst case scenario (as I said days ago), and based on my real world experience with my friend's Excursion (which I mentioned days ago, and no one responded.) In his ORIGINAL post he noted that he didn't want to be "screaming down the interstate." I agreed and affirmed this from my personal experience with interstate driving of two V10 vehicles.

With all that said; I like all of your notes and research. Especially the fact that you used the GPS for watching speeds during calculations.

 

I think part of the difference in opinion stems from 1, being in a van where you're almost sitting on the motor, and 2 Florida, never been there but I'm thinking flat land.

I was in the same boat contemplating a regear, fearful of overdoing it, as a lad I recall driving the freeway with my big block and 4.11s and she was wound pretty tight.

For that reason i chose to go 4.30s, rather than err on the high side and never be able to drive over 65 on the freeway ( or so I thought ), after doing that, pulling the camper (cant seem to go 30 miles any direction without some kind of grade ) I've come to this conclusion:

3.73s if you dont mind going into 2nd, a lot. (tuner helps, if you don't mind flashing it to tow mode every time you pull the camper, but what it changes are the shift points to a higher rpm)

4.30 seems to be a decent mix if you dont always tow, mpg doesn't seem to suffer as the motor stays in its power band more often. (tuner might be helping in that regard, mine tends to keep rpms near 2k) don't want to go oversized tires for fear of losing the gains I've made.

4.56 or higher will allow you to use OD more in towing situations and will allow for oversize tires. May be a bit high for unloaded daily freeway driving with stock tires.

You can search v10 rpm range, or something similar to find many others that would agree with my finding that 2.5k rpm isn't much to worry about, and that 4.5k is common with RVs (with the same motor) when climbing any kind of grade. Personally, 4.5 is the high end of where I like to run mine, but sometimes its necessary.

I agree the "usable rpm range" is far different than your normal big block motor (i've had my share, and then some) , and it does take some getting used to but that seems to be how it works.

This is all just one guys opinion, and i do appreciate the others that take time to share theirs.

 

One point that has my attention is transmission differences. My van has a 5 speed automatic. Is this the same transmission that's in all the full size Ford trucks? If so, what model years? And which transmissions have (or dont have) lockup torque converters? I tend to think ALL automatic transmission vehicles for the last couple decades have it, but I wonder.
Wait, actually I just remembered that the 2003 E250 I owned was not a 5 speed... So anyway; are there many transmission options in the recent 15 years? Seems important to know in a conversation about upgraded gears.

 

I'm not sure what year your van is but in '05 the vans kept the 2 valve V-10 while the trucks went to the 3 valve motors, the Excursions also kept the 2 valve motor in '05. I don't know how long the vans stayed with the 2 valve engines but in '05 they also got the excellent torqshift 5 speeds while the soon to be extinct Exs kept the 4 speed auto. Both trans have lockup converters and should lock up in Drive as well as OD (maybe even lower gears, I'm not sure.) The SuperDuty trucks were 2 valve 4R100 (4 speed) up till '05 then they went 3 valve 5R110 (5 speed) along with coil sprung fronts on 4X4 models.

 

My research shows 3 valve engines never offered in the vans.
So only two transmission options in recent decade?

And yes this 5 speed is great: it really adds to the driving fun. And probably fuel efficiency.

 

Yes only the two trans choices, neither the vans or Excursions ever came with manuals to my knowledge, I really wish the EX would have gotten the 5 speed when the vans did in '05 but Ford knew the Ex was fading away so it didn't get any drivetrain updates in '05.

 

Thank you.
Hopefully we have now gotten all of the "sassyness" out of our systems and can get back to talking about gears and V-10s! And how 4.88s aren't so bad thanks to OD!

 

Iv got the 4 speed (4R100). I can definitely feel the torque converter lock-up also, even without OD. And the 5R110 and 4R100 both have identical gearing on the last 3 gears, including an overdrive ratio of .71.

I believe my test should give me pretty similar results to actually having the gears. With my OD off at 2300 rpms puts me at 58 mph. With 4.88s at 2300 rpms would be 65 mph so the wind resistance should also be similar. The only difference between now and the future should be when I actually get my bigger tires.

According to the lie-o-meter, Im actually getting near identical mileage. Im not gonna lie, Im getting pretty pumped for this swap

And SEE! We CAN get along! Lol. Im glad, now lets talk some gears lol

 

If I knew how to make two smiley faces tap beer glasses I would do it also!
I definitely appreciate where you are coming from now, and I'm glad to have it smoothed over. I'm sorry for adding heat to the fire.
See you all another post!

 

Its in the smiley section!