We just got home from a trip through the mountains of Northern New England pulling our 35'/12,000 pound 5th wheel. There were some days when a nice, big, low rpm, high torque diesel engine would have been a welcome addition to that engine bay - but that ain't gonna happen!!

Gas economy was better then expected with about 8.8- 9mpg towing, 12mpg bob tailed and touring. BUT - those long hills and 40mph at 4000+ screaming rpm in Tow/Haul ........ phew! OK, had done a review here before and fancy exhaust systems and cold air boxes seem to be not much more then braggin' points and really don't add to the performance of a 3v V10. Love to have a Flowmaster 70 series - but the wife hems and haws about the Flowmaster's on my street rod with a mild 5.0. So, unless I've missed something, it appears that a tuner is the way to go. I know the 5 Star is highly thought of - but are there other decent options to consider? Or do I just give 5 Star a call, order the X3 and forget any one elses product?

 

What gears do you have? If you have the 373s I would definitely recommend a change to at least 430s depending upon tire size. I changed my '99 2WD from 373s to 430s (stock tires) and it became a different truck. It doesn't kick down near as often when towing and the RPMs stay in the V10 Sweet Spot most of the time. It was a night and day difference and the best money I ever spent on my truck!

 

It has 4:10's which are the 'standard' gear for an '06 Lariat version. Had I ordered it, I would have spec'd the 4:30s At the cost of doing both front and rear on a 4x4, even with me as the mechanic - my pension fund wont handle that cost

 

Just call Mike at 5Star and be done with it. Have never heard a bad word about Mike or the SCT tuners he sells. I know I am happy with mine.

 

I cant help but think the only hope is to hold i higher gear with the tuner, otherwise 4k still=40mph. Gears? Maybe, but my fear is then 4k=35 unless it'd hold a higher gear. I,'ll be calling Mike soon too

 

Whats wrong with 4k rpm at 40 MPH?

Its a gasser and you could have easily added 500 more RPM and not hurt anything.

I'm going to be changing my 3.73 to 4:30 or 4:56. 3.73 gears are simply not properly matched for the V10 with the 4r100 transmission while towing.

Thanks!

 

It might look funny, but the next time you need tires, go to a smaller diameter. That'll change the effective gearing just as much as regearing would, depending on the size.

Going from a 33" tire to a 32" tire is just slightly over a 3% increase in gearing. Going from 4.10 to 4.30 gears is about 4.8% difference. Not as much, but it's something worth thinking about.

 

With the Lariat's 18" wheels, there are a some limitations with 'E' rated tires as far as size availability - 33.2 to 33.7. I did that exercise when I bought the current tires

It looks like the 5 Star with 3 tunes will be my way to go - heck, might even add some gas mileage with some transmission reprogramming ----

 

I put on a 5 Star just before our trip to Wyoming. I was pleased. The downshifting was my biggest complaint. The 87 octane tow tune made a lot of difference, it often downshifted once and stayed there. Sometimes if I was under a big load and going slow the downshift was a little harsh. Small price to pay for the pluses. I have 4.30's and the tune made it a lot faster when I wasn't pulling.

 

I think about things like this a lot! Some of the grades out here go on for freaking forever!

First off, is it really a lack of power, or just that you don't like the RPM?
IE, are you floored or nearly floored at 40 mph and 4k+, or is there some power in reserve but if you let it shift up one gear there is not enough to hold speed at the new (much) lower RPM?

One possibility is to re-gear so that it is turning 3800 rpm at 40 mph in one gear higher. I believe the torque at 3800 is getting pretty close to the maximum, which is the goal. Get the engine spinning perfectly in the meaty part of power band when you need it most. Some math would figure out what that would take.

On the Flowmasters, a BB50 (or even the smaller 70) exiting in the stock location wil be NOTHING close to as annoying as whatever you have in the 5.0.... I found it to be barely louder in the cab than the stock muffler. Install it so that it would be easy to put back to stock (so the wife will let you experiment!) and give it a try. I do personally suggest the BB50 (and ONLY the Big Block version of the 50!!!!!!) over the 70. In FM's it seems the bigger the case, the less resonant and tinny they sound. Making it easy to remove later will also come in handy for those of you in rust belt. FM will not last anything close to as long as the stocker.

And we haven't yet discovered any other tuner worth considering other than Mike... He just understands these V10's, and he will make you happy if you let him.

 

 

My 06 has 4:10 gears and road my 12000 lbs race trailer with ease. It has a stock performance Ford tune.

 

OK - about ready to call 5 Star and place my order for the SCTx3. One question has come up about the PCM. For those that have done it on an '05 and up, does that module actually need to be removed to access that required number? There doesn't seem to be any number on the three plugs or face - and oh boy, what a rat's nest of wiring, hoses, tubes and odd and unidentifiable parts in front of that spot.

 

Talk to Mike. I think he can send you the tuner and you can use it to get the info he needs from the computer. Then with that info he can email the tunes that you can load to the tuner. I'm not very computer savvy and have had no problem doing this. Just followed the online detections, but I knew if I had trouble Mike would get me through it.

I highly recommend "Mike's Miracle Tow Tune" option. This will not let the tranny shift into OD until a preset speed when in Tow Haul. Makes the driving experience so much better. Without this I don't think I would still have the V10.

 

Calling Mike will be my next step - just hoping that I hadn't missed something with all that claptrap hanging off the cowl and don't like making an azzz of myself when I talk to someone - my modern car and truck smarts ends at carburetors an MSD ignition and a C-4 like my AVATAR '31 has .

When you say the 'miracle' tow/haul mod, I assume you mean the 5th gear lock out