Convertible Sub Frame Connectors?

I recently acquired an ultra low mileage all stock 2004 convertible. The car is beautiful, and I love everything about it...except all of the rattles, squeaks, and cowl shaking it does while driving...especially while driving over road imperfections and railroad tracks.

Even though the car is all original with no modifications, I’m seriously considering having sub frame connectors installed....if that will result in more stability, better handling, and less rattling and squeaking.

Based on the research I’ve done, I think I’d go with the Stifflers Fit System. In addition to stiffening the unibody chassis, they claim zero loss of ground clearance with their system, and I’ve also heard and read that they’re a good jacking point to lift the sides of the car.

Has anyone installed the Stifflers Fit System on their vert?

How much of difference did it make in ride, handling, and rattles and creaks from having no sub frame connectors?

In addition to the Stifflers Fit System, are there any others I should consider?

Thanks!

As a convertible owner, yes you will benefit from a set of full length sub frame connectors. The flimsy ones the car comes with are inefficient.

I really need to install a set on my car. The entire body twists and flexes over drive way entrances and exits, as well as down my driveway. I drove a friends convertible with sub frame connectors, jacking rails, and front and rear strut tower braces; the car was solid. There was no flex, no noise, and the car was extremely responsive.

I don't think anyone makes an X brace to mount behind the rear seats on the New Edge cars, but I may fabricate one when I am able.

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I have these:

MM Full Length Subframe Connectors, 1979-04, powdercoated

And this:

2003-04 Mustang Cobra Strut Tower Brace

I can jack either side near the front and get 3 tires off the ground.

I have the MM on mine. It is by far the best Mod on my vert - it makes a world of difference to these cars.

I have the Stifflers Full Fit System, it made it huge difference, I have no squeaks or some rattle except on railroad tracks only, Also excellent for jacking up the car, I use a low profile jack with some wood on them.

Thank you RI-SVT. Did you also add their spider brace and lower chassis brace, or just their full Fit System?

i run the full FIT system, spider brace, lower chassis brace and a MM strut tower brace on my 10th vert. car is very solid now and very responsive. there are still some creaks and rattles but that is every new edge and fox chassis car. id do it all over again if i had to.
you should have a factory bolt in subframe connector and a factory brace that connects the k-member to the front frame rails. i removed both of these for the stifflers and MM parts.
i guess you can consider them mods but i cant see them taking away from the car

Thanks 94slow...

If you had a shop do the install, do you recall approximately how many hours It took them to install everything?

Did it all myself, sorry. Everything was pretty straight forward except the spider braces took a little time to get set up correctly

Good for you! I have no welding experience, so I’ll have to rely on a shop for the install.

Just make sure whoever does the work has the weight of the car on the wheels (suspension loaded). Other than that it's not complicated

I have Stifflers FLFC. I did not get the whole fit system. Made quite a difference. I still have some cowl shake on certain types of bumps Anyone know if any of the strut tower braces will fit with VMP blower and JLT RAI?


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I have the MM strut tower brace that is meant for aftermarket blowers. It fits over my 2.3 vmp with gt500 t/b. I also have the jlt rai and it clears that too

FWIW I have the Stifflers FIT system on my coupe and I noticed a difference. I can only imagine what it would do for a vert.

I originally installed the MM full length sub frames on my 04 vert, they made a world of difference, I then bought the jacking rails, web brace, k member brace and spider brace from Stifflers. Made a massive difference in the feel of the car, I highly recommend it. As someone else mentioned make sure all parts are installed with the weight of the car fully loaded, a 4 post lift is best for this.

Thanks OldYeller.

If I take the plunge, I’ll go with the same setup as yours. However, I’m having seconds thoughts about it now. My car is 100% original with just 1100 miles on it. I’m concerned that the suspension upgrade, although it will vastly improve the cars’s handling, will detract from the car’s originality and value.

FL.-Frank said:

... I’m concerned that the suspension upgrade...will detract from the car’s originality and value.

Click to expand...

It absolutely will.

There's no getting around that. Those are suspension mods. Plain and simple. But, those mods will also be desired by many, so it actually can be a plus. Just depends on the future buyer if you choose to sell it. Assuming you haven't added other mods. When I owned my '03 Cobra, I was more interested in the enjoyment factor, so modding (nothing crazy) wasn't a big deal. Personally, the overall enjoyment factor was much higher when the car drove to my satisfaction vs. all stock. JMO.

Here's a wild example to consider when talking about a car's orginality. Let's say you have a horrendous creak in your radio. You take it to the dealer and their fix is to modify the radio bracket, but they don't make the bracket any longer so they fabricate a bracket that looks great and solves the creaking issue. Guess what? Your car technically is no longer original. That's an extreme example, but you get what I'm saying.

Well stated Bob.

I willingly paid a premium for the car a few months ago because of its ultra low mileage, pristine condition, and no modifications. Although I’d like to keep it in its current like new condition, that means keeping it tucked away in the garage the majority of the time and only driving it occasionally. The tradeoff is missing out on the enjoyment of regularly driving the car.

However, in its current factory original state, I don’t find the driving experience as enjoyable as it could/should be. IMO, the handling is just ok, and the amount of flex, rattles, creaks, and squeaks really diminishes the overall driving experience.

Based on the responses I’ve received here, if I decide to improve the suspension I’ll probably go with Stiffler’s
Fit System, along with their Spider Brace and K Member Brace.

So, it looks like I’ll be doing a lot of soul searching to decide if I want to keep the car bone stock and just learn to live with its shortcomings the few times I’d drive it, or, upgrade the suspension and enjoy driving it more frequently.