4-lug brake options (??)

1991notchbackLX

Active Member
Dec 25, 2007
1,483
44
48
New York
My car is a 1991 LX with a completely stock braking system and completely NOT stock horsepower and torque levels. The car stops "okay" now seeing as the pads and drums are new all around. However, I think my opinion on a high horsepower car that stops well might be a little bit skewed because my first car was a 1972 Cutlass that weighed about 4000 pounds and had manual brakes as well as drums on all four corners. :rlaugh:

My question is this... do any companies (Baer, SSBC, etc.) make 4-lug brake upgrade kits, and if not, what are my options? What did guys do for better braking before the sn95 and up 5-lug cars existed? Were the 87-93 GTs equipped with better brakes than the LXs? School me on this, please...

Thanks,
Chris :nice:
 
  • Sponsors (?)


I know there are slotted/drilled rotors out there but i don't know how much bigger they are in diameter. If all you're doing is drag racing, you don't really need huge diameter brakes because you're only slowing down one time and not for a huge distance, whereas if you were road racing you would have to worry about fade and rotor heat. Think about it...the Strange racing brake kits aren't any bigger than 11 inches...and i'm pretty sure that's about the size of the '87+ GT rotors.
 
SSBC makes a nice, complete rear disc conversion kit. Had it on my '92 hatch and was very happy with it. Improved braking performance and feel.

I know there are some kits to improve the front set up as well (pads, pins, and braided lines). There might even be some big brake kits for the front but honestly, it might not be worth upgrading the fronts that way - the spindles (from what I have read) are the weak link in the 4-lug set-up.

I plan on getting the SSBC rear disc for my convertible as soon as I can afford it.
 
I know there are slotted/drilled rotors out there but i don't know how much bigger they are in diameter. If all you're doing is drag racing, you don't really need huge diameter brakes because you're only slowing down one time and not for a huge distance, whereas if you were road racing you would have to worry about fade and rotor heat. Think about it...the Strange racing brake kits aren't any bigger than 11 inches...and i'm pretty sure that's about the size of the '87+ GT rotors.


Correct. They are 11 or so inches, but the calipers are HUGE. They are drag brakes and really only good for 1 stop however before they fade to hell.



If you want to stop better, you need 2 things. 1.) larger, more powerful calipers, or 2.) larger diameter and massive rotors.....or a combination of the both.

There are ways to bandaid the stock setup and gain maybe 10-15 more feet, but take a ride in a 5.0 with a 13" brake setup and you'll see it's night and day.
 
put a turbo coupe disk rear setup in the back my buddy has this on his 88 GT thats still 4 lug. with stock booster and it stops damn good. better then the 01 GT i was driving for a few months. id advise a cobra MC though if you go thus route. prettu cheap to do as well. my plan is to just convert to rear disk and call it a day for brakes.
 
Been there and done that! With success! :nice:

Do the 87-88 T-Bird Turbo Coupe rear end swap!

Auto trans 87-88 Tbird Turbo Coupes come with 3.73 gears and manual Turbo Coupes come with 3.55 gears.
Cost is $125-$300 for the rear axle. Add another $100-$200 or so to complete the brake upgrade.

I choose 3.55 since I do more highway driving. Both ratios have 10 5/16" disk brakes with vented rotors as standard equipment.

It takes 2 guys the first day to get the old rear end out and the new one bolted in place.
It takes 1 guy another whole day to do the brakes.

You will need a several sets of fittings, I recommend that you get them from Matt90GT's website,
87-93 Mustang 5.0 Brake upgrade pages. Improve your 60-0 times!.
Read Matt's instructions thoroughly, everything you need to know about the brakes is all there. You need to be patient
and follow all the internal links, and there are many of them.
You will need 2 fittings in the rear to adapt your old brake
tubing to the TC disk brakes. The fittings go between the steel tube and the caliper brake hose. You will need another
set of fittings to make a 2 port to 3 port adapter. To make life simpler, just buy the kits from Matt.
You could piece them together, but it's not worth the time unless you work at an auto parts store with
all the fittings ever made.

You will need to drill the quad shock mounting holes 2” below the holes drilled for the Turbo Coupe
mounting points. The bolts are metric, so don’t loose them or the nuts. A 15/32” drill should be
about the right size unless you have access to metric sized drill bits. Going without quad shocks is
not an option unless you have aftermarket parts to soak up the wheel hop.

You will need a proportioning valve, Summit has one for $42 + shipping. Wilwood 260-8419
You will need a kit (FMS makes the part) to gut the stock proportioning valve, Summit also
has that, about $18. Ford Racing M-2450-A


You will need a new master cylinder, see Matt's site and make you choice. I used a 94-95 Mustang
master cylinder. Note that rebuilt 94-95 Mustang master cylinders do not come with a reservoir.
That means a trip to the junkyard and some more money spent.

Your brake pedal may be very hard and almost impossible to lock up the brakes. I had to replace
the front calipers with 73 mm calipers from a 91 Lincoln Mark 7 to get the braking performance up to par.

You can use the stock 5.0 booster if it is in good working condition. No need to replace the booster.

Bleeding the brakes will require 2 people and some coordinated effort. I don’t recommend using your
wife or girlfriend to pump the pedal – they get offended when you yell at them. I used a homemade
power brake bleeder constructed from a garden sprayer and some fittings from Home Depot. It cost
about $25 and was worth every penny. See how hard is it to bleed brakes? - Mustang Forums at StangNet
for details and pictures.

See Mustang Central.net FMS M2300K Brake Install for help with the emergency brake. The red words
link to some very useful photos on how to modify the handle. The stock setup tends to lock up and not release properly.
All in all I have been very pleased with the results.

Identifying a Turbo Coupe rear axle:
1.) Measure the rotors - a TC disk brake uses 10 5/16" vented rotors.
2.) Measure the length of the quad shock mount arm and compare it to the mount on your existing stock axle.
The TC quad shock mount arm is about 8" long if I remember correctly.
3.) Measure the distance between the axle flanges and compare it to stock. The TC rear axle assembly is
3/4" wider per side, or 1 1/2" wider for both sides.
 
waste of money? :shrug: SSBC Front Big Brake Disc Brake Kit for 87-93 Mustang V8

so basically my options are converting to turbocope rear discs? or drilled/slotted rotors for the front or a brake kit like above?

I would definitely do the rear disc conversion - either from a turbo coupe or the SSBC. I preferred the SSBC kit because it was a COMPLETE kit (master cylinder as well) and all new pieces. I'd rather use that than have to piece together other parts - but some have had great success piecing things together and saving some money.

As far as the front: that kit (listed in your post) doesn't really seem worth it UNLESS you need to replace your calipers as well. If everything is working fine up front, simply go with a quality rotor/pad set, get some stainless braided lines, and some bronze (I think) bushings/guide pins. I don't think you can REALLY improve the fronts beyond that without going to a larger rotor/caliper set up.