Just trying to figure out which set to order for my '03. My rig is going to see long highway miles and long dirt miles to go with it, and I won't be towing heavy very often. This chart shows them both with a 3000 lb rating, but the B codes appear to have more arch and less pack thickness? How does that translate into real world behavior? Will the B codes give a slightly softer ride and more flex vs the F codes? Where will the B codes leave me in terms of lift? I don't mind a little, but I'm not trying to reach the sky either...

https://www.sdtrucksprings.com/ford-...h-f250-springs

 

Do you know what your current code is? The rear spring options are very similar to one another but small things will be different such as ride height and small differences in weight capacity. IMHO I can't really tell much of a ride difference between some of the rear spring codes because they are so so close. The F code is pretty expensive. If you don't know your code I would suggesting going with either a B code or C code. Both are still a factory replacement option but the B code will be right around 300 lbs lighter per side (not much in terms of ride stiffness) and it will have a slightly lower arch. Many many customers of ours go with the C code because they are basically the same price as the B code and work a little better in my opinion. Do you know what front spring you have? That may help determine the best option for you so you can match the ride height a little better and not sit super high in the rear.

We will price match any spring from SD and our shipping rates are much better because we are actually charging you what UPS is charging us and not making money on people.

-Junior

 

Cool, thanks for the input. I'm fairly certain that the current springs are whatever came stock on the Excursion, I don't think there was any difference between years or packages? I know the B code and F code Superduty springs are common swaps to lift the truck and improve towing a little, but I hadn't heard of the C codes. I'll look into those too. The front springs are also stock, I have a Superduty leveling leaf that should stick a little arch back in there and get them off the bumpstops, so my goal for the rear is to (roughly) match that lift and give me a little more travel and flex to play with in the rear when I'm on the trails.

Happy to throw a little business your way once I make up my mind, I like a vendor who's active on forums!

 

None of the F250 dual rate rear springs are well suited to your uses, we used to use them out of the junk yard because that was all that was available but now there are the correct single rate rear springs available for about 1/2 the cost of the dual rate springs that come with the additional benefits of getting rid of the rear block which means you do not need to use or add the traction bar, and most people find they do not need to add a rear sway bar with a single rate the way they do with the dual rate B,C, F whatever code f250 rear springs.

your factory rear G code is a single rate rear spring with a 410 pound per inch spring rate.
the B code dual rate spring has a main spring rate 320 pounds per inch and a secondary rate of 670 pounds per Inch.

When you use the dual rate spring in your Excursion the additional curb weight over the F250 compresses the main spring so it almost sits on the secondary or overload spring at ride height. This means you are riding around on a spring rate of 1000 pound per inch..... way way way to much ..as in it is ridiculous setup that we used to use because it was free out of a junk yard.

this is what a B or C f250 spring looks like when installed on a Excursion ...
notice the lack of gap between the main spring pack ( top 4 leafs ) and the very bottom overload spring.
on a f250 this gap is over 4 inches

 

This is how a dual rate spring is designed to work on the F250,

notice the gap gap between the main spring pack and the overload spring.

 

You say you do not want a “lift” but you do not say what your current ride height is.

measure from the center of the hub straight up to the bottom of your fender arch at all 4 corners and post up those measurements.

stock was about 23” front and 24” rear.

because the excursion was “lowered” 2” from the factory it has limited suspension travel and benefits greatly by adding a few inches of additional suspension travel which will increase your ride height accordingly.

springs are available to set the ride height at 25” front 26” rear however the best handling and ride comfort is at the sweet spot of 27”

fwiw a single rate spring with has a more suitable spring rate runs $100 each with everything you need runs about $1000,
We have a list with links to all the parts available from 2 vendors.

 

I learn something every day.

 

Here we go again haha.

The Super Duty swaps are a great alternative to factory Excursion setups and guys not wanting to go with lift springs.

There is no one right way to go about these swaps, there are many ways. Comes down to personal preference, budget and what your trying to get out of the setup. Saying there is just one way or your way of doing it isn’t correct and misleading.

Look around this forum and you’ll see a lot of great reviews from our kits with people very pleased with ride height, ride quality and price.

-Junior

 

You are correct, There is no “right way” but there are some that are much better then others and there are many generally accepted principals engineers use and while I certainly appreciate you have many happy customers I have to wonder if they are comparing their new suspension from you to their old clapped out one or are they comparing it to many different setups on the market because I can use a couple of blocks of wood and make a Excursion owner happy compared to a clapped out stock suspension so it is difficult and not worth trying to quantify a person with limited experience in suspensions subjective experience.

so let’s take a objective look at the B code with no lift or modifications objectively and compare it to a stock Excursion setup.

these test graphs are taken directly off of Ford’s leaf spring blue prints.

the stock Excursion is a single rate spring with a rate of 410 pounds per inch
total suspension travel is 7”
up travel at curb weight is 2.5”

 

No let’s look at The graph from Ford’s leaf spring test as shown on the blue prints.

as you can see the B code has 7” of total travel and we know the main spring pack has a rate of 330 pounds per inch and the auxiliary or overload leaf has a spring rate of 670 pounds per inch.

as you can see in the picture I post in a previous post the weight of the Excursion compresses the main pack down onto the overload spring at curb weight, This give you a 1000 pound spring rate and as you can see in the graph that leave some you with only 2” of up travel

 

“I can use a couple of blocks of wood and make a Excursion owner happy compared to a clapped out stock suspension”

This is what I’m taking about. No you can’t. I understand you have all the graphs and information about spring rates but at the end of the day we are installing these and supplying customer throughout the country and making life a lot easier for Excursion owners.

I don’t mean to take over this thread and have a disagreement with you but I feel it’s my due diligence to not just sell on this forum but to make sure Excursion owners understand their factory suspension woes. I understand you have knowledge in this field and have given some good info to people in need but to say this is a junkyard fix is again just misleading and not helpful to people on this forum and those who share the same enthusiast passion for the Ford Excursion.

Sorry, end rant. I’m taking my fly rod and going fishing haha.

-Junior

 

In summary.

using the B code takes the Excursions already limited up travel of 2.5” and reduces it to 2” while at the same time takes an already high spring rate of 410 pounds per inch and increases it to 1000 pounds per inch.

The generally accepted engineering design principal is a suspension is to set the ride height at 1/2 of the suspensions travel and the more travel you have means the lower spring rate you can use. Using the lowest rate possible to support your payload is the goal since it requires the least amount of shock valving for the best ride and handling.

however with the B code you increase total travel but increase the rate by almost 3 times and rather then increasing up travel by 1” you decrease up travel by 1/2”

Since ride quality is subjective we can not really submit “facts” But I am curious, are you having somebody built you custom shocks to control the 1000 pound spring rate ? The Bilstein 5100 is tuned to a 400 pound spring rate so I know you can’t be using those.

 

that is exactly what’s it is, a junk yard fix because when it was originally done that is where the parts were sourced.
no Shame in that, it is what it is. Like I said, it worked back in the day when that was the only option available.

you go right ahead and keep selling the same setup we were digging out of the junk yard 15 years ago, I will keep informing people of a much better and oh by the way considerably less expensive method of making their Excursions better then stock and certainly better then the junk yard suspension setups of yesteryear.

 

if you do not want any lift then honestly the best solution is stock springs, replacing any of yours that are sagging.
and get a new set of shocks, The KYB mono max is a great highway ride with just enough compression and rebound for dirt roading with a stock height Excursions on stock-ish tires. They run about $50 each.

the stock excursion ride height as measured from the center of the hub straight up to the bottom of the fender arch was 23” front and 24” rear.


I have built many Excursions of my own with everything from junk yard springs to exotic linked suspensions with coilover shocks and helped either design or setup many many more for others and from my experience the “sweet spot” for ride height is 27” But 25” front and 26” rear is also doable using single rate springs of the correct....or let’s say more ideal spring rate. If you want one of those setups I would be happy to post the links to the parts needed from 2 vendors ( of which I am not affiliated with ) price comes out to $1100 complete with everything you need.

 

Lots to read here, I'll come back to this tonight when I have more time to digest. And I don't mind you guys arguing in my thread, as long as the knives don't come out , sounds like you both have valuable insight to share.

I spend a lot of time off road in places full size trucks aren't generally supposed to go, and this thing is long and low at stock height. A lift of just a couple inches sounds ideal for increasing ground clearance without raising the CoG too high. I dunno that $1100 is in the budget but I'd be happy to look at your links if you wouldn't mind posting them!