99 Cobra wheels...

blksn8k

Registered User
Ok, guys, winter is almost over even though it's being a minor pain sort of like the Republican Guard. :D Anyway, it's almost time to drag the SC out of mothballs. I have two birds (pun intended) that I'd like to kill with one fell swoop. The car needs tires and the front brake rotors aren't worth a crap. I also have a '99 Cobra that I replaced the wheels and tires on last year so the originals are just taking up space in the garage and they have about 4000 mi on them. My SC is an '89. I know a little about the pre-'93 spindle thing but not enough to make a decision. Keep in mind this is not a race car and as long as I own this car it never will be. That's why I bought the 'Stang. The Cobra wheels are stock '99s - 17x8 with BFG 245/45s. What do I need to do to use the Mustang wheels as well as fix the front brake rotor issue? What are my options? If the cost gets out of hand I will just replace the rotors and buy a set of tires for the stock wheels. I do not use the SC enough to warrant a huge investment but I do want it to be a safe and reliable road car. Thanks.
 
Read the article from the TCCOA here:
http://members.tccoa.com/dlf/Article.html

The starting point for all upgrades is new front spindles. For the front then you need to get Mustang hubs. They should bolt right on the spindles. Then you can bolt up any Mustang brake kit as well. Anything with a rotor size greater than 11.6" will require 17" wheels.

The rear is kind of a bolt on solution. It uses new mustang Cobra hubs and bolts right up. But the brakes are a different question. From the article I can't tell if you can use the stock SC caliper with a stock mustang rotor on the rear and just change the hub out. Maybe someone else can answer that.

In either case you always have the option of having the hub re-drilled for the mustang bolt pattern as a cheap alternative.
 
Also, if you just want to change the bolt pattern, and not spend a bunch of money on big brakes, you could use 94 - up Mustang front bearing hubs and 94 - up V6 or GT Mustang rotors, on your old front spindles, with the original SC calipers. Then on the rear, re-drill your hubs and rotors for Mustang bolt pattern. Putting the Cobra hubs on the rear with stock SC rotors requires a spacer ring to take up the difference in hub-hole diameter of the Mustang and Bird rotors.

So depending on whether or not you have access to machine shop facilities at a reasonable price, the bolt pattern swap alone can be done fairly cheaply without doing a big brake upgrade, and having to swap spindles on the front.

As an added note, the 245-45-17 tires will look a bit small in diameter on the SC if the car isn't lowered ... they are approx. 1" shorter height than the stock 225-60-16 tires. If you don't plan on lowering the car, you may want to consider selling the tires if you can get a decent buck for them, and going for a set of 245-50-17 tires, which will be almost identical to stock diameter.

cheers
Ed Nicholson
SCCoO
 
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Thanks for the info, guys! One more question...what is required to correct any speedometer error resulting from tire and/or gear ratio changes? Is it possible to change a plastic gear on the speedo cable or will it require reprogramming the computer? Again, my car is an '89. I'd crawl under there and do some investigating on my own but the car is in storage about 160 mi away. :D
 
Yes, speedometer driven gears are available in various tooth counts to compensate for changes in gear ratio, or tire size.



cheers
Ed N.
 
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