Performance upgrade options for V10

[Fish_mojo]

I have a 2006 Kodiak 22' B+ with the 6.8L V10. It really feels like a dog climbing mountain passes, continually downshifting and jumping RPM's to keep up. 6% grades really affect it.

Are there any reasonable power upgrades that can be considered? Banks, tuning options? Anything? Looking for a balance of power vs fuel economy. Don't want to make changes that will drop fuel mileage.

[j-d]

14050 makes it a pre-2008 E450. Or a late 1990's "E-Super-Duty", same chassis.

[time2roll]

No idea on chassis but GVWR was 14,050

[pnichols]

smkettner wrote:
Recently drove a loaded 2007 v10 uhaul cross country and it seemed geared about the same and IMO did not have enough gear for 60-65 mph travel. We cruised at 70-75 so a little more rpm but at the bottom of any sweet spot so fairly easy to need downshift when encountering an incline. Still going to run 3500 and 4200 when pushed hard to the max. However I believe with ~15% more gear there was plenty of downshifts to avoid.

What chassis was under that U-Haul? Perhaps it was only the E350?

My E450 Class C turns ~2200RPM at ~60MPH when cruising in OD ... and this is with non-stock taller tires all around. I can maintain 60MPH up freeway-spec grades carrying the loaded RV's average total weight of about 11,800 pounds if I rev it to higher horsepower levels. With the less-tall stock tires it would pull even better due to the slightly higher RPM, however as I understand it the V10's torque curve is designed to be somewhat flat across the middle portion of it's RPM range ... which is what you want in a truck engine.

(My speedometer actually reads 58.5MPH at 2200 RPM due to the taller tires, but the GPS navigator indicates a true speed of ~60MPH.)

[time2roll]

Fish mojo wrote:

smkettner wrote:
If it seems to downshift too easy consider new differential gears.

What RPM are you turning in OD? What speed?

If I recall, 2100 rpm at 65 in OD. Going up hill downshift hits 3500 rpm to 3rd, if it really lags, hits around 4200 rpm when it kicks down to 2nd.

Recently drove a loaded 2007 v10 uhaul cross country and it seemed geared about the same and IMO did not have enough gear for 60-65 mph travel. We cruised at 70-75 so a little more rpm but at the bottom of any sweet spot so fairly easy to need downshift when encountering an incline. Still going to run 3500 and 4200 when pushed hard to the max. However I believe with ~15% more gear there was plenty of downshifts to avoid.

[pnichols]

Jopops wrote:
The 6.8L V10 is meant to rev. It behaves more like a Honda than a typical burbling V8.

Let it do its thing. On a little 22' that engine is overkill; let it spin.

We just today completed an RV trip in our 24 footer that including going over the High Sierras and several mountain passes in Nevada, Utah, and Wyoming. We like to cruise at 58-60 MPH and we did all the time - with the V10 purring away many times, and for many minutes - at 3000-3500 RPM or at 4500-4800 RPM. On long uphill pulls we kept up with, or passed, all diesel pusher Class A's, and of course passed all big rigs.

Something is wrong if the OP can't do this in their small Class C with the two-valve V10 in it. :h

P.S. There may be some chassis difference between the OP's setup and ours accounting for this. Our small Class C is on the E450 chassis - which may have more pulling power than an E350 due to differences in their rear differential ratios.

[Oldme]

Our 2000 is on the E450 chassis.
It came stock with the Ford V10 and Rear Gear Ratio = 4.63:1.

I turn off OD and allow the motor to rev as needed.
This is on a 24 ft RV.

These are medium duty truck chassis and not sports cars.
They need gears and torque to pull weight.

[Vulcan_Rider]

smkettner wrote:
There are plenty of gasser trucks towing heavy that seem to think better gearing can actually increase mileage vs. the OEM gear lugging the motor. Or if mileage drops it does seem to be minor.

Your situation might be different but after 3 fairly long trips in my 28' Winnie with the E450, it seems to me that it has PLENTY of torque and power for the task.....PLENTY.

I have seen absolutely NO evidence of lugging, not even when I purposely try to "encourage" it to stay in high gear going up moderate hills.

Now I haven't done any mountains yet but see no reason to believe that it won't pull them just fine if I let the transmission do it's thing.

[carringb]

Lower gears improved my towing fuel economy, at the expense of my non-towing fuel economy. In the end, it came out to be a wash, and the 4.56 gears are WAY better for towing heavy.

That said... A rig that light should do just fine with stock 4.10 gears. Try Tow/Haul mode. That's what its for. If that doesn't improve the shift patterns enough, then try 5-star tuning. The V10 shouldn't need more help if you stay within stock ratings, but a tuner can definitely improve drivability.

[time2roll]

Vulcan Rider wrote:

smkettner wrote:
The benefit will be when it does not need to downshift or just to 3rd instead of second.

Maybe not on it's own.
Not knowing exactly what the inputs to the electronic transmission control ARE....it's hard to say what would happen and when.

The downside probably would be worse gas mileage......and it's bad enough already.

There are plenty of gasser trucks towing heavy that seem to think better gearing can actually increase mileage vs. the OEM gear lugging the motor. Or if mileage drops it does seem to be minor.

IMO the ratio is often chosen for mileage over drivability. Drivability should increase more than economy is lost and this addresses the original complaint.

[klutchdust]

coolmom42 wrote:

klutchdust wrote:

coolmom42 wrote:
Turn off your cruise control and shift down manually. Put it in whatever gear it needs--possibly 3rd on a 6% grade-- and leave it there to climb the grade. Nothing will trash your transmission faster than the constant shifting up and down.

I've never driven a vehicle that wouldn't shift down on a 6% grade, regardless of engine size and/or load.

^^:B

Can you explain why this is so funny?

The post below mine says essentially the same thing.

Actually I posted in support of what was said, maybe the icon I used isn't up to your liking,I changed it ,geezzz....

[coolmom42]

klutchdust wrote:

coolmom42 wrote:
Turn off your cruise control and shift down manually. Put it in whatever gear it needs--possibly 3rd on a 6% grade-- and leave it there to climb the grade. Nothing will trash your transmission faster than the constant shifting up and down.

I've never driven a vehicle that wouldn't shift down on a 6% grade, regardless of engine size and/or load.

^^:B

Can you explain why this is so funny?

The post below mine says essentially the same thing.

[j-d]

In looking at downshift issues under light load, we really need to separate

Ford TorqShift (Tow/Haul helps and a re-tune helps further)

Ford 4R100 (really ate up with this problem, driving in OD-Off/3rd gear or without cruise, little to no feedback on re-tune and results)

All Others (how many non-Ford complaints about the downshift issue?)

[Vulcan_Rider]

jamesk1 wrote:
I have found that mine will hold a gear a lot better (less downshifting) when I use the tow-haul button.

Well it certainly holds the lower gears longer but I haven't tried it on the highway yet. Certainly worth a shot before investing in a "chip".

[Vulcan_Rider]

j-d wrote:
That 65-Front and 80-Rear is nothing but the pressures to be used if a pre-2008 E-Series

Well I HAVE a pre-2008 that is 28/29 feet long and judging from the tread contact and sidewall profile I don't think I would want to run much less than 65.