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Topic: Another spring/lowering question  (Read 675 times) previous topic - next topic

Another spring/lowering question

I have read the 94/95 Mustang convertible springs will lower the birds/cougars about 1.5”. I’m curious what the difference are between Cobra convertible vs. regular convertible because I have access to both. Also if I go this direction do I use SN95 shocks/struts

I have rear shock adapters and will be getting C/C plates from MM

Thanks for any info

My Tbird is an 85 with 5.0
87 Tbird LX w/Factory floor shifter:D   3G upgrade. Tinted Windows...85 Mustang GT steering wheel(non-cruise) 17'' Saleen SC style wheels,Front/Rear TC sway bars/poly bushings & Mustang GT steering rack...'05 Mustang V6 springs...93 Cobra MC & booster, MM adjustable C/C plates,  Work  In  Progress.......  ( On The Shelf---HO computer, 19lb injectors, HO cam, BBK headers, Explorer Intake, Cold Air Intake ,Phantom Gauges, Stinger stainless exhaust pipes )
 S O L D

Re: Another spring/lowering question

Reply #1
Are you talking "base" V6 convertible, or V8 convertible?

On the GT and Cobra springs, there isn't a whole lot of difference. The Cobra spring rates are a slightly lower at first glance, but the progressive rate is different and get more aggressive as you compress the springs more. They might feel "softer". The load rating is about the same.
The V6 springs have a linear rate (on all 4 corners IIRC, but for sure on the rear). They also have a lower load rating. Not recommended.

Somewhere I have the specs for all of the standard 96-98 springs based on the 3-letter codes. It has been over 25 years since I was digging around in these. If I have a look, I might find the paper with the details.

In '99, Ford changed the way the values on the springs were listed on the tags.
Before that, you would have the 3-letter code and the spring and load ratings listed (Metric).  Such as "RRR" which was a '96-98 Cobra rear spring had "28.9/3470" which is the spring rate in N/mm and load rating in N. Converting that to lbs/in and lbs is 28.9x5.7 lbs/in and 3470/4.44 lbs. Or 165 lbs/in and 780lbs.
As an example, the stock rear springs in my old '84 XR 7 were "JAD" "33/4200" (185 lbs/in and 944 lbs)

In the end, the main difference in the springs is the load rating, as they changed what springs were in the cars based on options, etc. The V8 convertible springs were always the highest load rating, which is what I tended to use on the rear of my cars. (I have always tried to use Motorsport C-Kits on the front). You can see in the example above, the rear springs on our cars are kind of beefy.

Anyway, probably a lot more than you asked for, but it does remind me to try and find that info, for posterity sake.


Long live the 4-eyes!  - '83 Tbird Turbo - '85 Marquis LTS - '86 LTD Wagon

Re: Another spring/lowering question

Reply #2
Thanks Chuck for the info. I was referring to V8 springs , not the V6. What would be your suggestion on shocks/struts?
87 Tbird LX w/Factory floor shifter:D   3G upgrade. Tinted Windows...85 Mustang GT steering wheel(non-cruise) 17'' Saleen SC style wheels,Front/Rear TC sway bars/poly bushings & Mustang GT steering rack...'05 Mustang V6 springs...93 Cobra MC & booster, MM adjustable C/C plates,  Work  In  Progress.......  ( On The Shelf---HO computer, 19lb injectors, HO cam, BBK headers, Explorer Intake, Cold Air Intake ,Phantom Gauges, Stinger stainless exhaust pipes )
 S O L D

 

Re: Another spring/lowering question

Reply #3
I would use SN-95 struts, mainly due to the extended length.
I picked up a set of the Koni non-adjustable orange struts(STR.T) for the LTS, which is the same as your 85 TBird. Decent choice for a driver. I've used KYBs as well, but they don't last too long.

On the rear, you really have no choice, if you want something decent. All of the 79-04 Mustang shocks are too short to use as-is. Either make yourself a set of my old lower shock brackets (I have the old drawings linked here on the forum) or get a set from 23Parts.com, as they've put them into production and should have them on their website.
Long live the 4-eyes!  - '83 Tbird Turbo - '85 Marquis LTS - '86 LTD Wagon