Brakes The Ultimate 4-lug/5-lug Brake Conversion/upgrade Thread

I am not opposed to doing hydroboost setup. I also thought about manual brakes, but wasn't sure how difficult it will be to press pedal in when braking. I plan on running rear 15x10 wheel 21.5mm offset with 6.25" back spacing. I think the axles I purchased are stock length, just in 5 lug form. Front wheels are 15x3.5 with -28.7mm offset and 1.2" back spacing. I'm willing to swap out whatever I need to to make it right. This will be mostly street driven. Not sure if 94/95 spindles or 96-up would be better in this case either.
 
  • Sponsors (?)


. Front wheels are 15x3.5 with -28.7mm offset and 1.2" back spacing. I'm willing to swap out whatever I need to to make it right. This will be mostly street driven. Not sure if 94/95 spindles or 96-up would be better in this case either.
Running skinnies up front on the street is a very bad idea. Over 85% of the braking power is in the front brakes. Skinnies will lock up and burn all the rubber off when you do a panic stop at anything over 50 MPH. Don't believe me? Look at all the high performance cars; they all run the big brakes up front and smaller brakes in the rear. That is because when you use the brakes, the vehicle weight bias shifts towards the front of the car.

Bottom line; skinnies are OK on the drag strip because no one is going to jump out in front of you on the race track., But you are just asking for trouble driving them on the street where almost anything can happen.
 
  • Like
Reactions: 1 users
I didn't notice in this thread, but I'm tossing around the idea of doing the conversion on my 90.

There are junkyard methods and there are higher end methods. The thing I've noticed in both cases is that the spindles seem to always be used or refurbished one way or another. Seems unfinished ones on eBay list for around ~$180. Cleaned up and painted ones are more like ~$250 on eBay. LMR has "refurbished" ones for $500. The pricing is pretty much all over the place.

Anyone have a recommendation or advice as to where to source a good set of spindles?
 
Wherever you can get the best deal. The ones lrs carries are most likely 96-04 vs the 94/95 based on shear production numbers, so depending on your wants/needs either is a viable option, and the lrs ones likely have new bearings (hubs actually)
 
The only manufacturer of spindles is/was Ford, so your options pretty much are junkyard, or buy then from a vendor who has refurbed them.

And yes, based on sheer number, you will find there are a lot more 96-04 spindles out there than 94-95 spindles. Expect to pay a little more for 94-95 and assume any kits come with 1996+ spindles
 
@Mustang5L5 So I was gearing up to run regular 99-04 pbr gt calipers and 94-95 rear calipers. Instead i got a killer deal from nick on his 97 cobra stuff front and rear coming off his new project. My question is will the 93 cobra booster master still work for this setup? Or do i need to swap to say a 94-95 15/16 bore master?
 
@Mustang5L5 So I was gearing up to run regular 99-04 pbr gt calipers and 94-95 rear calipers. Instead i got a killer deal from nick on his 97 cobra stuff front and rear coming off his new project. My question is will the 93 cobra booster master still work for this setup? Or do i need to swap to say a 94-95 15/16 bore master?


So, the correctly spec'ed MC for that setup is the 15/16" bore MC.....


However, years ago I was fortunately enough to have a convo with the Ford engineer who did the braking system on the 1994 Cobra. He told me that originally the spec'ed MC for the setup was a 1" bore MC. (same as 1993 Cobra) and the car stopped fine with it. The issue however was that when the brake pads were cold, testers were finding the first stop lacked power, and could not even come close to locking the brakes up. As the system got heat into the pads, they were fine.

Since this was Ford flagship braking system at the time, they couldn't send it out the door like that and stepped down to the 15/16" bore MC just to overcome that cold pad lack of power.


So, you can run the 1" bore MC that you have no, but keep this in mind.
 
So, the correctly spec'ed MC for that setup is the 15/16" bore MC.....


However, years ago I was fortunately enough to have a convo with the Ford engineer who did the braking system on the 1994 Cobra. He told me that originally the spec'ed MC for the setup was a 1" bore MC. (same as 1993 Cobra) and the car stopped fine with it. The issue however was that when the brake pads were cold, testers were finding the first stop lacked power, and could not even come close to locking the brakes up. As the system got heat into the pads, they were fine.

Since this was Ford flagship braking system at the time, they couldn't send it out the door like that and stepped down to the 15/16" bore MC just to overcome that cold pad lack of power.


So, you can run the 1" bore MC that you have no, but keep this in mind.
Being I just literally ordered the master from LMR I'll bet I can swap it for the correct 15/16 . If that's the correct way to go . Still running the 93 cobra booster is all good as well correct ?


Sent from my iPhone using my fingers while my auto correct makes me seem illiterate
 
Yup. The 93 Cobra and SN95 booster is virtually the same other than thread pitch and pattern.


keep in mind you run the 15/16" MC requires a differenr 3-2 conversion than the 1993 Cobra style.

But yes, with the 94-98 38mm Cobra calipers (and Sn95 rears), I'd stick with the 15/16" bore MC.

With the 99-04 40mm cobra calipers, I'd run the 1" bore MC. This is my personal setup.
 
Yup. The 93 Cobra and SN95 booster is virtually the same other than thread pitch and pattern.


keep in mind you run the 15/16" MC requires a differenr 3-2 conversion than the 1993 Cobra style.

But yes, with the 94-98 38mm Cobra calipers (and Sn95 rears), I'd stick with the 15/16" bore MC.

With the 99-04 40mm cobra calipers, I'd run the 1" bore MC. This is my personal setup.
That's the plan then thanks for all the help . I haven't bought the 3-2 for it yet - would you happen to have the mm part number for it ?


Sent from my iPhone using my fingers while my auto correct makes me seem illiterate
 
I have a built to rearend with fox length axels I flipped the brackets now I need to know what adapter fitting I could use for tc soft line
 

Attachments

  • image.jpeg
    image.jpeg
    158.4 KB · Views: 403
  • image.jpeg
    image.jpeg
    80.9 KB · Views: 320
I am about to get 97 Mustang spindles and brakes for my 88. How do 96-04 spindles affect a lowered mustang? shouldn't a lowered mustang correct this geometry issue by just being lowered?

Shouldn't a lowered car and the 96-up spindles be a good thing geometry wise?
 
I am about to get 97 Mustang spindles and brakes for my 88. How do 96-04 spindles affect a lowered mustang? shouldn't a lowered mustang correct this geometry issue by just being lowered?

Shouldn't a lowered car and the 96-up spindles be a good thing geometry wise?
The arm ( outter tie rod hole ) on the newer spindle is higher than the factory spindle. When you lower a mustang it lowers the pivot point at the control arm and k member making bump steer worse......even worse with newer spindles.

However, with offset rack bushings and a bump steer kit it shouldn't be a problem. I ran my 89 for years like that and it handled well.

You want the tie rod to be at just about the same angle as the lower control arm at normal driving height. As the tie rod angle goes up or down it wants to pull the front of the wheel in.....ie. Bump steer. ( it swings in an arc ).
 
The arm ( outter tie rod hole ) on the newer spindle is higher than the factory spindle. When you lower a mustang it lowers the pivot point at the control arm and k member making bump steer worse......even worse with newer spindles.

However, with offset rack bushings and a bump steer kit it shouldn't be a problem. I ran my 89 for years like that and it handled well.

You want the tie rod to be at just about the same angle as the lower control arm at normal driving height. As the tie rod angle goes up or down it wants to pull the front of the wheel in.....ie. Bump steer. ( it swings in an arc ).

Thanks, this makes much more sense now.