Attention PSD X owners and engineer types. Need some help

[rtm038]

Hello all,
I need some help on how to improve the ride and handling of my 2002 X Limited Ult. PSD 4x4. It's on order, but I know how they handle (I've driven one before) and I'd like to have all the parts here & ready to go when the new X arrives in January 2002. I know this topic has been discussed in the past in detail and I have read other posts (like "Help Major Handling Problems!!!"), but many times things get real complicated and I become a little lost. So please, lets keep everything in simple terms.. [img]images/icons/smile.gif[/img] .
First the shock and rear sway bar debate. From what I've read thus far, I plan on instlling Bilsteins and the rear Hellwig sway bar. This will help the X's overall straight-line performance.
Now on to the spring debate. I understand that the rear springs on the X are rated around 5200 pounds. Now should I install the X spings (6200lb (?) rating) up front or the V code springs (5200lb rating)? I ask about the V code springs because I think someone in another post has suggessted using front and rear spring rates that were relatively close, in order to help produce a better "balance" between the front & rear axles. However, I assume (could be wrong, though) that the front of an PSD X weighs more than the rear. If this true, I would think that you'd want to use the X springs to help compensate for the weight difference between the front and rear, which in turn would promote a better "balance". (Note: Would improving the balance, improve the handling of this beast in corners and during evasive manuevers?) What do you think?
I know I've just grazed the tip of the iceberg on this topic, but I'd like to hear comments from anyone who may know how to go about improving the X's overall handling and ride during ALL driving conditions and situations. But please remember to keep the "lingo" simple... [img]images/icons/wink.gif[/img] [img]images/icons/laugh.gif[/img] .

Thanks,
Ryan

[Chris Brandt]

Will go first and tell you what I would do if starting from scratch and spending my own $$$

Rear Bar
Bilstiens
Timbren load booster up front. (Revised front bump stops)
Remove or change rear blocks (optional)

In that order

Note that this does not include a front spring replacement. Why this combination... My Ex won't go in my garage with my current height. I have a rear bar, a custom front add-a-leaf and thats it. Still running factory shocks more out of lazyness than anything else. I sit a bit tail low but that will be corrected soon. The front sits abot 3" over stock height.

The optional removal of the rear block would level the Ex at a lower nominal height. For my day to day use this would be better than the 2-3" lift that I have.

2nd Choice

Rear sway bar
A front add-a-leaf
Level the back (block, add-a-leaf, air bag depending on use and cash to spend)
Bilsteins
Steering stabilizer

3rd choice

Remove leaves from front and rear spring packs.
Custom anti-wrap bars front and rear.
Panhard bar rear.
Custom front and rear air bags with on board compressor and in-cab control
Adjustable remote resivoir Bilsteins.

The set-up I am SERIOUSLY looking at. Have started the engineering and componet selection for the rear. Want to be nominal at 1" below factory height (based on the rear ride height) with an adjustment range of -2 to +4 inches. Need a bag with a 7" working range (9010 Firestones have 9"'s) I don't expect a streetable ride at the fully dropped or fully raised positions. It would be a glorified air helper spring system, with the factory leaves still handling axle location duties but lightned up enough to droop to the bump stops without the help of the bags. Lightned up this much they will need some help in the anti-wrap department. The rear panhard bar may not be necessary but its worth considering at the onset.

Other people will of course have other opinions based on their operating parameters. We will all agree stock sucks !

[rtm038]

Thanks for the reponse and info Chris.

Ryan
(RTM038)

[rtm038]

I also want to add that I'd like to use the X springs, but I'm afraid it'll bring the front up too much. Does anyone have pics of a PSD 4x4 with X springs installed? If so, please post or email to me (rtm038@aol.com). Also, if I was to use the X springs, what can I use to bring up the rear a little. Would anyone recommend using an add-a-leaf. Maybe adding some extra "stiffness" (common side effect of add-a-leafs) to the rear leaf packs would be a good thing. What do you think? I'm not a huge fan of the "levelled" look. I'd just like to add a little extra height to the rear.

Thanks all,
Ryan

[Chris Brandt]

Your above comments are exactly the reason why I wouldn't start with front springs unless you want to lift both ends of the truck. Try it with the bar and the Bilstiens and you have lost nothing of you need more up front. The Timbren load boosters might be enough for you. If thats not enough I recomend the front add-a-leaf over the X spring because its much easier to install than the full spring pack. Also note that for 2 springs with a given spring rate the spring with more leaves will ride better and flex better than the one with fewer leaves.

[rtm038]

Thanks again Chris. I think I will go a 1" add-a-leaf all the way around, in addition to the rear bar and Bilsteins. That may be the best set-up for me. You're right. It's much easier to add the leaf, then swap out the packs.

Thanks again
Ryan

[ptemplin]

Here's what I did, followed by what I think I should have done.

I did this:

X springs
(long pause)
Rancho RS9000 shocks x4 corners, plus Hellwig rear bar

I should have done:
W springs, Rancho shocks, Hellwig front & rear
New tires

The X springs make the front sit too high. Not by much, but enough that I find myself driving around parking lots until I find someplace to park that is "downhill", so the truck has a chance of looking level. My wife's Excursion originally sat slightly higher in the front than mine with stock suspension (the difference was only really noticable by staring at the mirrors). Now, the front lift is drastic enough that you can that the front is lifted by looking at the rear bumpers.

I don't really want to get air bags, but I think it's going to come to that, or try to find someone with a slightly different application who has W springs but wants X springs. I may also go the route of putting on a "Texas" bumper, which might offer enough "counterweight" to bring the front end back down.

I didn't order the front Hellwig bar, but wish that I did. The vehicle does stay much more "right side up" in corners, but I can tell that it could probably do better with a new front bar. There have been plenty of discussions about the merits of doing both together, but I felt "oh, you can always order the front later" at the time I ordered, which I now think was stupid.

If you plan on getting replacement tires, do not get them until you have done all of your suspension work. My truck had so much body roll that I seem to have "polished" the right rear tire. It is very easy to spin now, under a wide variety of conditions. On my old Jeep, I had managed to do the same thing, and would spin a lot until I put fresh Michelins on it. The Jeep started spinning the RR at 30k on the original Goodyears, but didn't spin at all with 40k+ on the Michelins (perhaps because I had an expensive Saturday: tires x4, shocks x4, brakes x4, and alignment x1).

[coldair]

You can correct that high front end by adding a winch or air bags to the rear.

[rtm038]

Which springs are the "W" springs? My F-350 has the "V" springs, but I've never heard of the "W" springs.
I think that I will either go 1 of 2 ways (but things can change when presented with more info.. [img]images/icons/laugh.gif[/img] ).
I'll either go with a 1" add-a-leaf front & rear with Bilstein 5100s and front & rear Hellwigs or the "W" springs with the Bilsteins and Hellwigs.

Thanks for the reponses/info and please keep it coming.. [img]images/icons/wink.gif[/img] .

Ryan

[djellenz]

Does anyone have an opinion on which shock provides a softer overall ride (Bilstein vs. Rancho RS9000). What price range do these shocks run for a set of 4? My main concern is in town driving, highway driving doesn't seem to be a problem.