2000, V10 Limited, 136K , Bone Stock + plus new Helwig

I wanted to thank WE3ZS for the advice from another tread.

So we got the trailer (36’ 7500 dry weight) last week, trailer wasn’t really planned when we bought the Excursion earlier this year. Decided that we were going to pull the trailer first and then start making upgrades.

First pull was pretty embarrassing hit 53 mph and trailer sway took me 5 foot on to the shoulder, amazing how much room everyone gave me on the interstate after that. Since then, replaced tires with 265 Michelin E load rating from over sized Falkin 285 D load rating, Helwig (highly recommend) rear sway bar and some front end parts.

With tinkering this weekend in tire air pressure, sway bar adjustment and another chain link up on the WD hitch, it’s pulling pretty good on a 60 mile test, I still haven’t taken it up the hill just west of Denver yet. I hit 65 max mph; it’s behaving reasonable well, huge improvement from childish behavior from the first time towing. I have taken fender measurements after different adjustments and they are all pretty close. I will be working on weights next.

However, when being passed by a semi, I’m getting some decent push and a little sway. Enough push that it's very concerning. In my readings of the Forum, going to the B spring conversion should solve that. Right? The appointment is made. The spring shop (Denver Spring) gave me an alternative of adding leafs rather than replacements, planning on going with replacements. I would love to hear others thoughts on adding a leaf just for conversation.

And the main question, what can I expect going from 3.73 to 4.30 gears? What changes will I see? Is the bang for the buck worth it? (I’m planning on having 4 Wheel Drive in Denver to do the conversion. If you have thoughts on others in Denver to do the work, please let me know.)

Right now on flat to slightly hilly it will go into overdrive, but when it drops out of overdrive it stays in 3rd, only way to get it back to over drive is to back out of the gas. If anyone has thoughts on what I can expect 3.73 -vs- 4.30 going up this hill just west of Denver or other areas/improvements I should be looking at, it would be appreciated.

 

Glad to hear you are getting it sorted out. Like I said previously, it's going to take many trips to get it dialed in. You are on the right track. As far as going to the 4.30...expect it to be able to go into OD even on a slight grade! I would also go so far as to say your mileage should increase by about .5 mpg, mine did. I did the swap just for how much easier the gearing is on the X. You will wonder why Ford even offered 3.73's in such a heavy vehicle. I would even go so far as to say that 4.56's aren't out of the question with stock size tires!

After you do the gearing invest in a tuner from 5Star. This again will make towing with the X an enjoyable experience. I have done many trips of 10-12+ hours and I don't feel tired or beat up at the end!

Good luck!

 

4.30 should have been the only hear Ford offered for the ex and super duty trucks in my opinion. 3.73 are HORRIBLE and 4.30 are just right for a stock tire. I have 4.30 with a 33" tire under my f350 with the 5.4 and it's ok now nothing like a v10/4.30 combo but it's night and day now. And a 4.56 gear isn't much higher in rpm on the highway and for me would have been the right choice the first time but I well

 

I don't think you will ever totally stop the impact of an 18 wheeler passing a long vehicle string. I know with my enclosed I have pulled it with a dually, motor home and Excursion and the big truck sucking in the rig is always there.

 

SO….. The 5 Star with Y pipe and cold air intake is on order. B Spring conversion and 4.30’s will happen the week of 7.6.15 I will also have the Y pipe installed next weekend, I will get the Cold Air and Tunes installed somewhere in there.



Pre Tuner, Y pipe, cold air and 4.30 and post installation what kind of just for fun data should I collect to compare the pre and post installs?

 

WOW! You are doing a lot work in a hurry there!
I keep MPG logs of every tank of gas run through my EX (and Metro!) and as most of my EX's miles are towing that's what I focus on. I went from 3.73 gears to 4.88 with 32" tires over the same route with the same load and saw a 1 to 1.5 MPG improvement while towing. Later mods included Banks headers, custom 5Star tunes and taller 35.28" tires (which effectively lowered the ratio to 4.39). Totally stock I was pulling a 9,500lb toyhauler and saw a low of 6.5 MPG and average of 7 to 7.25 MPG, with my current mods and a longer TT that weighs 11,000lbs we are seeing average towing tank averages of 8.5 to 9 MPG with a best yet of 9.25.
On the 5Star calibration request form did you enter in all of your mods including the gear swap? They will tailor the tunes to take advantage of each item.
The B code rear springs (where are you getting them from? New or used?) Should help keep the rear of the EX feeling a little more planted while towing with less tongue weight influenced rear steer or squishiness. But don't expect it to do away with the push and pull of passing big rigs, that's always going to be a part of towing a high profile trailer. A good towing setup will keep the push/pull under control though.

 

All that other stuff is fine and wonderful but how 'bout MPC?

Miles Per Cheesesteak? That's more pertinent.

 

Oh man! I'm way overdue, my last one was with you, so almost 2,000 MPC. I like seeing lower numbers there!

 

I hear you, I order a Chicken Philly (in these here parts) 'cuz they can't get the steak correct.