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  1. #1

    Default The Ultimate Four Eyed 4 Lug Brake Upgrade Thread

    So you're staying old school, eh? Traditional 4 lug, traditional coil springs, shocks, and struts. You want it to look factory but drive much better than it did originally.

    I don't think I've seen anyone do that type of thread. Now that 5 lug swaps are getting more and more popular, fewer cars are rolling on 4-lug wheels and real resources and info that is current in 2018 is getting a bit more scarce. These factors, over time, are slowly making it harder to achieve reasonable 60-0 performance on our old foxes for the crowd that love their old-school 4 lug rims.

    I recently started looking into this very thing for my 1985 "Saleen-006" (for those that get the joke) and found it was much harder than it was "back in the day" --- PRE SN95 swap parts bin era.

    Lets settle on some goals and discuss good/better/best approaches to 4 lug setups that will produce a car that actually stops, and how well it stops, etc.

    For those who like to cruise around town or in the parking lot lets identify an ackerman correction capable 4-lug compatible spindle

    Also maybe pinpoint front disc setups that work well
    -- Under old-school metric TRX wheels
    -- Under 14" wheels
    -- Under 15" and larger wheels
    -- Under 16"+ wheels (doubt those will ever be a problem with 4 lug parts bin brakes but who knows)

    Rear drum of stock size - what works the best.

    What pads -- what work the best.

    Alternative rear drum setups that work well

    Rear disc conversion setups that work well

    General suspension changes that help transfer weight properly for better stopping - be it X2 balljoints up front or torque arms out back, etc.

    Not even opposed to talking about which springs yield what ride height with parts being played with, etc. The thought is no coilovers and no 5 lug. Four lug pride??
    Last edited by erratic50; 01-28-2018 at 09:25 PM.

  2. #2


    For those who haven't looked at this in detail before, warning- there will be a little bit of sticker shock in all of this vs SN95. You have to REALLY want your 4 lug and you have to REALLY want it to stop better.

    For 14" wheels to fit, your stuck with 79-86 4/6/8 cyl and/or 87-93 4 cyl spindles and rotors. AFAIK the stock brake is the largest that will fit inside of a 14" wheel. My Saleen clone roller had some 14's on it when I bought it and there's no way another 1" of brake would have fit without hitting. That's not to say you can't go with carbon-fiber pads in front and just do the upgraded rear brake pads and improved hoses. You for sure can. IMO you should.

    For 15" and above you may be able to run an 11" brake in front. 10 hole rims fit. Metric and reproduction TRX rims fit.

    [Calling it out now — SSP 15” steel rims DO NOT fit over 87-93V8 spindle/brake/caliper setups. You’ve been warned!]

    If all you want is stopping 15% better than the stock 87-93 (which is about 30% better than the 79-86) and you're running 15's then hit the bone yard or Ebay and source 87-93 spindles/rotors/bearings/calipers and get the MM brake upgrade kit.

    If Ackerman correction wanted/needed .... still hit the bone yard but the answer for what spindles you want is different.

    82-83 Continental / SVO spindles
    -- correct Ackerman
    -- support 11" front brakes
    -- support 87-93 bearings, rotors, calipers, pads
    -- require SN95 balljoints and spindle adapters (do keep that in mind)

    Usually the foundation of better brakes is switching to 100% disc brakes.

    Rear disc conversion for 4 lug is available as a complete kit in Mustang track-width from North Race Cars "Complete kits without axles" $599 + $41 Uses 87-88 turbo coupe parts

    Another kit available -

    If you really want slotted rotors in the rear also -- call North Race Cars and have them do up a kit minus rotors then get rear slotted rotors here $155.00.

    There is a stack of parts needed to make such a system come together and produce vastly improved 60-0 stops on a 4 lug car

    HB-263 HPS Hawk Brake Pads, 1987-93 5.0L Mustang V8, front $73.97

    • Compound: HPS (F)

    ================================================== ============

    Pads and rotors is always a discussion. There is a SSBC kit that comes with slotted rotors and pads for front for $231.61 each. Their description says the pad compound is "performance brake pads" that is all it says. What's the gamble worth with unknown compound?

    It might be desirable to switch to a larger bore master cylinder. A lot of this will come down to personal preference. I suspect the factory 7/8" will work. Its a good starting point. You can always go up to a 15/16" SN95-ish setup or a 1" Lincoln Continental M1858 master cyl. (1858 is what I run on my 86 with SN95 brakes -- it works GREAT with the stock booster. Only required one line adapter too)

    1973 Torino master cyl is a direct fit 1” bore option. Even better than the M1858

    personal preference is a big factor. 86 MarkVII and 88 Tbird used 1.112" according to McParts specs. SVO was 1.125.

    There is a myth floating around on the internet that you need to go to a Cobra brake booster when you go to rear disc brakes. RUBBISH. Look at the specs of the Cobra booster vs the stock foxbody booster. There is BARELY ANY difference.

    Inner wheel seals and inner/outer wheel bearings and some plane-jane 87-93 calipers are available from parts geek. $142.95
    -- LX/GT 60's instead of SVO/Lincoln 73's because the big ones are too large for use with TBird rear disc brakes
    -- National bearings and seals for 87-93 LX/GT 5.0
    -- Fully re-manufactured calipers with steel pistons Centric are inexpensive.

    If someone knows of a way to go SVO rear calipers without going 5 lug, more power to you-- post away. Along with what off the shelf 4 lug rotors to use. (do they bolt up to Turbo Coupe/Cobra adapter brackets out in back? Do the Turbo Coupe rotors fit??). (Yes those are rethorical questions)

    Let's keep this dicussion open to lots of ideas as long as you stay 4 lug. Back in the day there were many great kits that are now nostalgic kits that would have to be sourced used -- if you know, what are the part numbers so people know what to hunt for.

    At one time Baer and a few others did kits that whack off the caliper ears and go with a mounting system that's towards the center of the spindle and extends out with larger rotors and very nice calipers. 12-13", 4 piston calipers, etc. They are no longer made, but info helps knowing what to look for.

    Just trying to archive this stuff before we collectively forget about it. That and before more people go off the deep end and install SN95 stuff with wheels simply because they want their car to stop and turn. (feeling guilty about changing up my 86 I guess.... but the results are awesome)

    Last edited by erratic50; 04-22-2019 at 09:30 AM.

  3. #3


    Interesting - Baer is making a 4 lug 13" brake kit for front. $2000

    Minimum wheel is 17" which eliminates most factory 4 lug, except for the 93 Cobra

    In one aspect it would be about right on a 93 Cobra. The problem is a 3/4" spacer is needed due to the factory 93 Cobra wheel's unique offset. It would work fine with a well designed hub centric spacer setup and longer lugs...

    Or get imitation 93 Cobra directional rims with normal foxbody mustang offset.

    What they recommend for the back reportedly works with 15" wheels but is a 12" disc. $1395

    Would likely have to go to standard fox length axles and the same spacers mentioned above in back to make factory cobra wheels work. One advantage is improved disc ventilation.

    If I had a real 93 Cobra I think I would leave it stock!

    The fake 17" 93 cobra directional 4 lug wheels made for foxes would probably work better with those brakes.
    Last edited by erratic50; 01-22-2019 at 06:02 PM.

  4. #4
    Moderator wraithracing's Avatar
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    Jun 2010
    Grand Junction, CO/RR TX


    Just go 5 lug! You know you want to!

    Come to the Dark Side! Feel The Power! Feel the Force!

    Ok! Sorry I couldn't resist! Good Information So far!

    "I Don't build it hoping for your approval! I built it because it meets mine!"

    "I've spent most of my money on Mustangs, racing, and women... the rest I just wasted."

    Mustangs Past: Too many to remember!
    Current Mustangs:
    1969 Mach 1
    1979 Pace Car now 5.0/5 speed
    1982 GT Ongoing RestoModification
    1984 SVO Awaiting Restoration
    1986 GT Wrecked by PO, but still want to save!

    Current Capris:
    1981 Capri Roller
    1981 Capri Black Magic Roller Basket Case
    1982 Capri RS 5.0/4spd T-top Full Restoration Underway
    1984 Capri RS T-top Roller
    1983-84 Gloy Racing Trans Am/IMSA Body Parts

  5. #5


    We shall find out what a "bad ass" 4 lug kit that fits behind my mesh wheels will do.

    My prediction is greatly in favor of the 5 lug. my 1986 with Baer 11" rotors and 99GT calipers on SN95 spindles with X2's and great pads in front plus a proportioning valve and my stock 95 8.8 with great pads in back on my 86 is a combo that will be hard to beat- especially with the 4 lug parts I've ordered. It's not going to happen.... I suspect my best 60-0 in my Saleen when it's done will be longer by at least 12 feet.

    Yet 5 lug works for the cases we are talking about only if someone makes a narrow 5 lug setup that works with a 5-->4 adapters so original wheels work
    10 hole

    Mods to the wheels are possible for some, impossible for others. Unlikely the entire time.

    Afaik the test mule SN95 cars initially rolled on 5 lug 10 hole 15" wheels. Those of course were not released and are made of unobtanium.
    Last edited by erratic50; 01-30-2018 at 05:03 AM.

  6. #6
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Dunedin 9011, New Zealand, South Pacific


    Brakes: 1" thick 13.00" front rotors, 11.45" rear rotors with combination AP/Girling 4 pot callipers

    Ferrari 108 mm on four stud knock-on for Centrelock Momo 10 x 15” magnesium wheels...

    Guess what?

    Proof of the Ferrari 4 on 108 mm stud knock ons. Same as the factory Pinto/Mustang II/Fox 4 stud spacing.

    And look at the non standard front to back axle stagger....some serious alterations were going on underneath, with probably the "Baby Atlas" narrowed 53" rear axle on this speciman with later wider SVO IFS suspension width. It has clear, and very noticable stagger.

    Quote Originally Posted by xctasy View Post

    Rudof Frieds wounderful Group A racing photos from Czechoslovakia's Brno circuit racing Mustang GT shows he final take on the heavily swaged compomotive / ronal magnesium turbo, this time with different sizes and hole arrangements, and Momo style hex nut, which used the Ferrari/MG 108 mm pitch center studs


    Notice that even in the 1984 Group A racing Mustangs, they had converted to fully customised MacPherson sturt, adjustable spring hanger uprights with those 1" thick AP Racing hubs

    and the later 9 " Differential with Disk rear brakes

  7. #7


    That's awesome info! Check out those parts! Swaybar, a-arms, spindles, tierod, calipers, etc. very cool and unique. No joke parts there for sure!

  8. #8


    If your going to bend and flare your own brake lines for the rear differential and your using turbo coupe / 93 cobra soft outer lines. there are 2 different size tube nuts. The inner soft line is 3/8” x 24 and the outer soft lines are 7/16” x 24 thread both are standard double inverted flares.. If you use sn95 soft lines they use a different thread which I believe is 8mm with a bubble flare.
    84 LX Vert. 5.0 5speed canyon red on white
    99 cobra, electric green on medium parchment, vortech s-trim

  9. #9


    Editing to respond to the rear line modifications mentioned directly above. What we did on my 85 build is source a line kit from LMR. It’s a direct bolt-on

    FYI - caliper sleeves listed above I'm told are a significant upgrade over stock all by themselves.

    It was suggested to me that with the turbo coupe / 93 Cobra disc brakes and front 60mm calipers and a stock foxbody booster that the 94-95 Cobra master cyl is considered by many to be ideal. That is 15/16 - right between the stock 7/8" and the M1858 or 93 Cobra 1".

    A low buck version of that setup might consist of:
    Stock 60mm front calipers rebuilt
    SSBC or Northern 4lug rear brake conversion (turbocoupe/93cobra)
    94-95 Cobra master cylinder and installation kit
    Manual prop valve
    Stock prop valve plug
    Hawk HPS pads all around

    Forgo the slotted rotors, upgraded hoses, Ackerman correction, and improved balljoints.
    Last edited by erratic50; 03-24-2019 at 11:00 AM.

  10. #10


    Ok - so who's adding a sticky to this thread. 4 before 5 .....

  11. #11


    Bumping this thread.

  12. #12


    For many a 5 lug rim that looks correct to the car sorta negates the purpose in staying 4 lug.

    5 lug pony wheels
    5 lug 10 holes

    5 lug mesh would be great too. Saleen made some but they are extremely expensive and the lugs show on those.

  13. #13


    Name:  CB8A9568-BA4F-4887-8589-15830F844A3F.jpg
Views: 2240
Size:  142.9 KBWorth mentioning that when messing around with a 7.5 or an 8.8 these parts often break and give fits. Crosspin and crosspin bolt for the spider gears

    When this happens if you drill at just the right spot you can take your scratch awl or a small punch and gently push the broken off end out to where you can get on to it with a pliers and pull it out. Trey posted up some info on that in my 85 build thread as the 8.8 I re purposed from my 86GT had this problem.
    Last edited by erratic50; 04-22-2019 at 10:54 AM.

  14. #14



  15. #15
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    SE Michigan


    Mods are fine.
    Best combos from multi years or aftermarket keep the cars fun.
    A nightmare if ever have to take to a shop for repair.
    Not having a garage to DIY.

    Car has factory 9.3" rotors. Need replacing.
    Guess early 79 2.3T cars before 12/78 had 9.3". Same as n/a.
    Going up to 79 10" V8 rotors and matching semi-metallic pads.
    Some came with V8 calipers, some not.
    Mine came with V8 calipers, semi metallic pads.
    Boosters, m/c, all the same in 79. Am good to go there.
    Keeping 4 lug, 15" turbines with new tires.
    No ceramic pads. No organic pads. No Hawks or green, yellow, orange.

    New rotors, hoses, calipers, bearings, seals. Off the shelf all the way. Ballpark 150.00 of quality parts.
    From what i see, simple swap, 79-82 factory config. Easy to get parts. Low cost.
    No change to rear brakes.
    Too much work and money to further mod this daily driver that, frankly, stops fine now.
    Rears lock up first. Need more front rotor for the panic stops.
    10" like it should have had all along from the factory, which corrected this later on.

  16. #16


    bumping this thread.

  17. #17


    I have an '85.

    4 years ago I replaced the 7.5 with an 8.8. New 3.55's and bearings etc.

    Rear end got the turbo coupe/93 cobra rear brakes. Learn to flare lines. Makes life much easier than trying to use adapters. I used regular pads. All parts were brand new.

    Front end got the aero 10" brakes. EBC green pads. Drilled rotors (found them cheap unused, by EBC).

    I used the Lincoln town car master cylinder, gutted proportioning valve and ford racing adjustable proportioning valve.

    North car race e-brake cables

    Jalapeno car so had to go with red calipers - can hardly see them due to pony rims.

    Rotors all painted with high heat silver paint to keep them looking good.

    Deleted all the splash guards. It's a fair weather car. Probably better for the cooling anyway.

    Car stops straight, fronts lock up. haven't had the rears lock up. Stopping is better. I had quality pads/brake parts all around before anyway so I can't say performance is night and day.

    Did some comparisons with stopping distances between my daily driver (Forester at the time) and mustang. About the same stopping distance.

  18. #18
    FEP Senior Member Patrick Olsen's Avatar
    Join Date
    Mar 2013
    Where the Navy sends me...


    Quote Originally Posted by erratic50 View Post
    Ok - so who's adding a sticky to this thread. 4 before 5 .....
    Quote Originally Posted by erratic50 View Post
    Bumping this thread.
    Quote Originally Posted by erratic50 View Post
    Quote Originally Posted by erratic50 View Post
    bumping this thread.
    I sense a trend here.

  19. #19


    Last edited by erratic50; 03-24-2019 at 11:04 AM.

  20. #20
    FEP Member
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    Jul 2010
    Winnipeg Manitoba Canada


    I got an email says LMR has the 4 bolt rear disc upgrade back in stock.
    Anyone for a group buy?

    I'm doing an 8.8 swap and am a bit concerned about the parking brake cable length as the car is a Fairmont wagon.
    Last edited by Monty78; 05-11-2018 at 10:12 AM.

  21. #21


    That is the wrong master cyl for that combination and the kit is over priced to boot.

    Contact North Race Car and get their conversion kit instead.

    A stock 7/8” bore master cyl will work.
    15/16” like what is found in the SN95 is popular.
    M1858 1” bore (designed for lincoln) is what I would run with stock calipers in front.
    Revision: 1973 Torino master cyl is also 1" bore and a direct bolt-on, no line adapter or reflaring needed.
    1 1/8” is simply way too big. It causes too little pedal modulation during braking.

    LMR plug and adjustable proportioning valve suggested but not required
    Last edited by erratic50; 04-22-2019 at 10:59 AM.

  22. #22
    FEP Senior Member 854vragtop's Avatar
    Join Date
    Dec 2006
    Greensboro, NC


    I have the 73mm front, Turbo Coupe 45mm rears, and SVO M/C with stock '85 booster, gutted stock prop valve and adjustable prop valve for the rear at the R/H hood hinge. I've been driving this combo for the last 6-7 years. Pedal seems fine, but I really haven't had to do a panic stop in awhile. Daily driving seems fine, but after recently doing a big brake conversion on the front of our 2007 Honda Odyssey (installed 2010 13" Honda Pilot rotors, calipers, and pads), I'm loving the fantastic braking power. Toying with the idea of putting the 1.0" '85 Lincoln Town Car M/C in my '85 GT convertible to see what kind of a change it will make. I've considered the SN95 conversion, but really don't want to mess with shoehorning in the SN95 booster. It's hard to get my head around going back to 60mm calipers from the current 73mm fronts. You mention that you've kept the stock '86 booster with your setup. Describe the pedal feel and any reservations you have about not changing out the booster. Is it too easy to lock up your wheels with your SN95 setup?
    Last edited by 854vragtop; 05-18-2018 at 07:55 PM.
    '85 Mustang convertible GT, 5 speed, 4V
    Stock bottom end, Comp Cams XE264HR-14, GT-40P heads w/ Alex's springs, Weiand 8124 Street Warrior
    8.8 Turbo Coupe rear end w/ 3.55 gears, '94/'95 Cobra brakes, '85 Town Car M/C, '93 Cobra booster, MM Panhard bar.

    '68 Mercury Cougar, w/ '88 5.0L, 4V
    My photo website:

  23. #23


    I kept my cars with a stock booster because changing boosters is unnecessary and is a pain in the neck.

    I have the modulation and pedal effort vs stopping power application that I want with the 1" bore (M185 and Stock booster.

    Ill let Jack do the honors and detail why 73mm calipers are bad in combination with anything other than the 1 1/8” bore SVO master cyl and SVO rear brakes.

    edit: M1858 is fine if you want to adapt or replace or reflare one line. the 73 Torino master cyl is a direct fit with 1” bore. A better option
    Last edited by erratic50; 04-22-2019 at 11:00 AM.

  24. #24


    Thanks for all this useful information, I was searching for WEEKS on what to do for a brake combination and still keep 4 lug

  25. #25
    FEP Supporter burntorange84's Avatar
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    Dec 2006
    GT (georgetown), TX

    Default some options

    Glad you started the thread.

    I've been using the 93 cobra set up (minus the cobra booster and ft rotors) for about 5 years; adjustable prop. valve too. I run the 1973 LTD/Torino MC which is a direct bolt up for the lines; thanks to MAD MIKE. I've been staged to swap back to the stock size MC b/c the pedal throw is very short, and I can't heel and tow down shift anymore . With the 73mm front calipers, the pedal might go further down? But I've been warned to either go with the SVO set-up or Cobra for the balance; not to mix caliper sizes.

    I have toyed with in the last couple of years, the upgrade to 5 lug and slap the 17" 98 GT dual spoke five stars on there to have more tire choices. The other factor is that the 60 series 15"ers are not good for a track day. My tires are approaching 12 years now, so track days aren't happening.

    Lastly, quality pads are a large portion to stopping well. Years ago, I did a track day on my stock brakes and I was very surprised to not incur brake fade. I wasn't pushing 911 GT3 speeds, and the car wasn't lowered yet and clumsy in the turns with the stock suspension and ten holes. But I was braking hard and a lot.

    Quote Originally Posted by erratic50 View Post
    A low buck version of that setup might consist of:
    Stock 60mm front calipers rebuilt
    SSBC or Northern 4lug rear brake conversion (turbocoupe/93cobra)
    94-95 Cobra master cylinder and installation
    1973 LTD/Torino master cylinder, direct bolt on (1" bore)
    Manual prop valve
    Stock prop valve plug
    Hawk HPS pads all around

    Forgo the slotted rotors, upgraded hoses, Ackerman correction, and improved balljoints.

    Question: why does the town car/SVO spindle help correct the Ackerman steering. Is it in the strut angle or a longer steering pivot arm?

    Last edited by burntorange84; 05-29-2018 at 01:07 PM.
    1984.5 Mustang GT: org. 5.0, 5spd, 3.27's;
    GT-40's w/93 exhaust; t-bird TC brakes....

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