Suspension What Makes That "new Car Ride"?

Discussion in 'SN95 4.6L Mustang Tech' started by DrScientist, Jun 1, 2013.


  1. DrScientist

    DrScientist Member

    Joined:
    Apr 19, 2011
    Messages:
    84
    Likes Received:
    0
    Trophy Points:
    6
    We've all felt it, that new car ride. I don't necessarily mean something like you might feel in a 4-door Mercedes or a Lexus or the like. In fact, I can feel it in my wife's 2010 Toyota car and my buddy's 2012 F-150. Somehow cars that still have that "new" ride feel, feel both firm and soft at the same time. That's the only way I know to explain it. You can just tell from riding in the vehicle, that its well... new.

    Then you have older vehicles. Those cars that aren't quite worn out, but just don't have that good ride anymore. My other friend's 2005 F-150 feels this way. My 1994 Mustang GT feels this way. My sister's Nissan, and my well maintained, 1 owner 87 silverado feel this way. When you go over bumps, you get that "Ugh" feeling. Or perhaps the "Oomph!" feeling. You can also hear the bumps more. When you go over something rough, you may hear more of a... sound then when you do it in a newer car. They're just not what they used to be. And I'm talking about largely stock vehicles. No suspension mods that would contribute to the loss of the new car ride feel. Just normal wear and tear.

    The purpose of this thread, and what I'm trying to identify here, is the exact part (or parts) that are responsible for this phenomenon. My '94 GT Will make a good example. I have replaced the springs with 1" lowering springs from LMRS. The SVE ones. So they are new,. So we know its not the springs. I've replaced the shocks with new ones from Bilstien. Again, no change. So we know its not that. Had to replace the rack and pinion and both tie rod ends, not that I had suspicions that they were the culprit. So that's not it either. What could be the cause?

    We've only got a few parts left that it could possibly be. Ball joints, and various bushings. You've got those big bushings in the front and rear control arms, and ball joints. And that's pretty much it. So if a person could replace all the bushings under their car along with all the ball joints, could they then get back that nice, new car ride? Is such a thing even possible? Or is it that once its gone, its gone forever and its not coming back?
    #1
  2. bhuff30

    bhuff30 Founding Member

    Joined:
    Dec 11, 2001
    Messages:
    6,013
    Showcase:
    4
    Albums:
    1
    Likes Received:
    28
    Trophy Points:
    89
    Location:
    Olathe KS
    New (factory replacement) shocks and struts will make a big difference and ride nicely. New tires also feel better than old worn out ones. I know my tires are getting worn and the ride isn't as pleasant. In your case, I see that you have lowering springs and performance shocks/struts. The lower springs will have a higher spring rate because you just lost 1" of suspension bump, so they are going to be more harsh. While I have heard good things about Bilstiens giving a nice ride for a performance strut/shock, they are still a performance unit and will increase harshness. If you want a stock, factory like ride, get it back to stock.

    However, there is another factor at play here too. The 79-04 mustang uses a modified McPherson strut front suspension. You'll notice the spring is tucked into the lower control arm. This puts pressure on the ball joint to hold the vehicle up as well as the control arm bushing (where you don't want it). The pressure on the bushing creates bind, and additional harshness, and a stiffer than stock spring makes the problem even worse. Ideally, the spring should be further out, such as a coil over, where the coil is integrated in with the strut assembly. If you look at an 05+ mustang and nearly any fwd sedan, the coil will be integral with the strut. This provides a better ride quality while also providing better handling (since the spring is acting directly where needed instead of also pushing on the bushings). So just by design, when your mustang was factory stock, it wouldn't ride as well as a newer car, and even many cars build at the same time. And of course the 4-link solid rear axle assembly does not contribute to the ride either. That is a huge amount of sprung weight, supported by a suspension that is designed to bind. The 79-04 mustang kept this type of suspension because it kept the cost of the car down and for packaging reasons.

    So you might also want to consider switching to coil overs all around for a better ride quality... but be conservative with the spring rate. Many of the coil over setups are designed for racing and will provide a much stiffer wheel rate (thus harsher ride). I would guess a front spring around 150-200 would be good for you.
    #2
  3. DrScientist

    DrScientist Member

    Joined:
    Apr 19, 2011
    Messages:
    84
    Likes Received:
    0
    Trophy Points:
    6
    Nice! Thanks for the reply. Yeah the SVE springs that I'm running right now are at about 350. Which I was told, isn't any different from stock, in that they are static springs. Now, at times, they are just like stock but other times they are stiffer, as the stock springs were not static. I actually noticed an increase in ride quality when I switched to the Bilsteins, but that's probably just an indicator that my stock stuff was worn out. Thanks for the info on the coil over setup though. I never knew that the stock stuff put the bushing in a bind and made for a worse all around suspension. I'll certainly look into coil overs, but I was also looking at bags as well. Some say bags can still handle well even though they do give a softer ride.
    #3
  4. Rusty67

    Rusty67 Well-Known Member

    Joined:
    Dec 3, 2002
    Messages:
    3,612
    Likes Received:
    13
    Trophy Points:
    59
    Location:
    SB, CA
    As for the rear suspension, it is all about bushings. Bushings, bushings and more bushings. New upper rear control arms or replacing the bushings in the upper rear control arms is a good thing as well as the bushings in the axle itself. I have never replaced the bushings in the axle with rubber but replacing them with poly was hard enough. I would pay a mechanic to do those specific bushings. The lower control arm bushings are a problem and I would replace them with an aftermarket set of arms. Even though the poly bushings are more harsh, it is worth it because the stock arms just have too much play in them even for a stock GT. The quad shocks are a band aid solution for a problematic 4 link and no one ever replaces them. If you have aftermarket lower control arms, you may not even need the quad shocks....
    #4

Share This Page