Skyjacker FR904S... why just deaver?

[RPG]

sent PM

 

[AlbertaRaptor]

thank you!

BTW an FYI here:

My front height is 39" and rear currently is 41.5"

I'm surprised the front is so much lower than everyone elses measurements

Jeff

 

[JP7]

Hey Alberta,
It's too damn cold out for me to measure mine right now, but I'll see if I can come up with one tomorrow.

I'm subscribing to this thread, as I have a modified lift in mind as well. I haven't had a lot of experience with Skyjackers, but friends have found them to be a bit stiffer on their full size lifts. And we're talking 12", not the mild 6".
I personally think the truck will look better with an extra 2-3" of lift, and I actually like the ass end to sit higher than the front. That's primarily for field of view while driving so I'm not guessing as much trying to look over the hood.
The pre-runner stance I can see being useful in the desert, but short of Drumheller and the Oilsands, I haven't found any deserts here...

Looking forward to reading what approach you take!

 

[BIRDMAN]

or as it's affectionately known as in the Jeep world: Sky Junker

 

[pirate air]

I didn't believe regular f150 springs were the right/same length to fit on the Raptor. That's why we can't use regular f 150 deaver springs that cost less but must use Raptor specific deaver springs that cost almost double....

 

[DocSpooK]

My post kind of sucked so I'm going to clarify the height aspect of what I said:

If you leave the rear alone and go top perch the truck will be sitting high in the front by about 1-2 inches or so compared to the stock rear as I understand. Yes?

So to "level" the truck as in rear being about an inch or so higher than now so it sits equal to the top perch I am looking as the Skyjacker springs.

If we use deaver springs and remove the lift block from the rear ( mostly for axle hop ) the deavers come in about an inch or so lower than stock as I understand, this is using the +2 deaver spring.

So if the skyjacker is in there and it would lift an advertised 6 inches over stock and we eliminate the BS advertising and realize it wil not be a true 6 inches most likely 4-5 inches. We remove the lift block and "net" a 1-2 inch height gain in the rear over stock.

If the front on top perch would be the same 1-2 inches higher than stock rear height and the skyjacker spring nets us the same 1-2 inches the truck should theoritically be the same height front and rear.

If that makes sense lol, as it does in my head.

Now the second statement concerns the quality comparison between skyjacker and deaver. Beyond any doubt I am sure the deaver is better....way better I bet.

The question stands then if the $550 cost for a pair or Skyjacker springs for those of us that don't jump the trucks daily would be an okay solution compared to $1350 Deaver springs?

I am not sure and that begs the original post beginnings.



Jeff

If you get the +1 deavers and put them on the block then you get the rear 1inch higher than stock, that's what I did. Subtle, but you can see it compared to stock

 

[AlbertaRaptor]

If you get the +1 deavers and put them on the block then you get the rear 1inch higher than stock, that's what I did. Subtle, but you can see it compared to stock

Do you stil get axle hop on the lift block?

Jeff

 

[MarkT]

SNIP The overall progression rate makes the ride night and day better over stock leafs. SNIP

I keep hearing about "progressive leaf springs" like Deavers and National Spring. I think the word "progressive" is being used by these manufacturers to somehow describe the "pyramid stacking" of the leafs, not a progressive spring rate that increases as the spring compresses.

I have not seen the National Springs, but the Deavers I've seen have all the leafs in full-length contact. This means that, barring the effects of friction between the leaves, the Deaver springs are linear rate not progressive rate.

In fact, Deaver's website says "the even, LINEAR RATE CURVE of our progressive system spring is the primary key to excellent ride quality"

In comparison, the stock Raptor spring is more of a progressive rate design than the Deaver springs... When the suspension compresses on a stock Raptor the spring rate changes when the "overload leaf" makes contact with the leaf above it.

Not saying Deavers or Nationals don't work better than stock... just saying they are not progressive rate springs if all the leaves are in full length contact.

 

[f16YODA]

I don't see how just because the leaves are all touching that makes them linear. Individual leaves can have completely different spring rates, right?

Here's a pics of my National Springs from RPG that are waiting for my truck.

 

[RPG]

I don't see how just because the leaves are all touching that makes them linear. Individual leaves can have completely different spring rates, right?

Here's a pics of my National Springs from RPG that are waiting for my truck.

You sir are correct. Individual leafs can have different spring rates. Leaf thickness, width, length and arch all come into play. All of these key factors have been addressed in the design of the National Springs.

The OE application has a primary and secondary rate. The primary rate utilizes the main leaf and one leaf below it. When you reach a certain amont of arch in the spring, your secondary spring now comes into effect. This leads to a very harsh change in spring rate.

Where as the National Springs are designed to have a NON LINEAR "aka progressive" spring rate as the spring travels upwards in compression. Leaf springs need to be viewed as one whole unit not a single leaf.


Cant wait to your new ride when it shows up.