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Brakes 5 Lug Conversion My Specific Application

  • Thread starter Thread starter 69shocktower
  • Start date Start date Jul 27, 2015

69shocktower

Active Member
Nov 5, 2003
173
21
39
Dakotas
Jul 27, 2015
#1
  • Jul 27, 2015
  • #1
89 Mustang GT

I want to do a 5 lug and 4 disc brakes conversion. Worrying about only the front for this question. If I were going to upgrade master cylinder to a 95-99 GT master cylinder and 80's Mustang SVO front disk calipers. Rotors off which 5 lug cars will work with the 80's SVO calipers? Or I guess if i could just order some SVO 5 lug rotors that would work too? And I should not have to change the spindles, hubs? Just the rotors?

Thanks,
 

coupestang2

Active Member
Sep 11, 2014
108
132
53
Cornelius NC
Jul 27, 2015
#2
  • Jul 27, 2015
  • #2
Just do the 5 lug swap, off of a 94-95, that's it!
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,226
17,911
224
Massachusetts
Jul 28, 2015
#3
  • Jul 28, 2015
  • #3
Either 84-86 SVO rotors, or 84-92 Mark 7 front rotors will work. Keep in mind your wheel selection may be limited due to the large hubs on those rotors.


However, your master cylinder choice is incorrect. The 94-98 GT MC is VERY large and will result in a very stiff pedal if used with rear drums and worse braking performance. Your stock setup is a 16.3/1 ratio in terms of front caliper to MC surface area. (ignoring the drums) Your setup you are proposing is 14.6/1. A lower ratio results in a stiffer pedal.

If you used a 1" 1993 Cobra Master cylinder, your ratio would be 16.5/1, so it would be very close to stock feel.


I go into detail about how this works in this post. I'm dividing front caliper piston surface area by the master cylinder surface area to come up with the ratios

Brakes - The Ultimate 4-lug/5-lug Brake Conversion/upgrade Thread | Mustang Forums at StangNet
 
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