Lets have a discussion about brakes.

The first thing I'm considering doing to the Mustang is a brake upgrade. I have a dislike for brake fade or failure. The G35 had Brembos on it. They worked very well. 

There are a ton of options for the Mustang. In the front big brake kit world, Willwoods are $2200, Brembos are $2900, and odd man out, the PowerStop kit is $800. 

All of these sets have 14" rotors, and 4 piston calipers. The Willwoods have 2 piece rotors, the others have 1 piece rotors. 

Assume the car will see 50-50 track and autocross.

Any advantages or disadvantages between the 3 sets? Are 2 piece rotors an advantage or disadvantage? Is Brembo $700 better than everyone else or is it just the name? Will the $800 PowerStop kit do as good a job for less than half the price? 

Lastly, why is is so hard to find brakes that aren't cross-drilled? Do performance rotors not crack at the holes like every other rotor? 

First question: Is there not an OE upgrade over what you have? Say GT brakes over a V6 etc? Those, IMO, are always going to be a better long term option. What happens when the manufacturer that sold the kit goes out of business? Where do you get replacements? How much are they? etc etc etc.

The 2-piece rotors last longer and can take more abuse, the ability for the disc to expand relative to the hat greatly reduces cracking and eliminates coning effects. Unfortunately the 2-piece rotors also cost a lot more, so it's not clear whether they'll save you any money...

I highly doubt that the Brembos are $700 better than the Wilwoods and I'd bet that the PowerStop kit is the best value for money by a wide margin strictly in stopping power. Do look at weight and consumables costs as well though.

Why is is so hard to find brakes that aren't cross-drilled? Probably because they're both 2 Fast and 2 Furious. The disadvantages of cross-drilled rotors greatly outweigh the advantages with modern brake pads...the disadvantages in higher-quality rotors aren't as pronounced, especially with a 2-piece rotor, but they're still there.

bobzilla said:

First question: Is there not an OE upgrade over what you have? Say GT brakes over a V6 etc? Those, IMO, are always going to be a better long term option. What happens when the manufacturer that sold the kit goes out of business? Where do you get replacements? How much are they? etc etc etc.

This was my thought too - first consider whether you really need bigger discs and upgraded calipers at all, most vehicles don't. If you can reliably lock up (or trigger ABS on) the brakes when they're cool then you don't have a braking power problem, you may just have brake heat capacity problems or braking feel problems (such as needing to use more pedal pressure than you'd prefer). Most cars just need brake vents + high-temp pads + high-temp fluid.

In reply to bobzilla :

Hmm, that's interesting. The GT and the V6 share the same caliper. The only difference is the caliper bracket and the rotor. That would be a fairly cheap step up from a 11.8" rotor to a 12.4" rotor. 

The 11-14 GT were also factory available with a 14" Brembo option. They're readily available as take-offs from people upgrading to the 15" brakes, or as reman... It's a much cheaper option to DIY than the kits originally noted.

Also consider how the path you take here affects your wheel, and by extension tire, size options.

One more thought, consider that good track brakes can be bad autocross brakes. Example, my AE92 has EBC Yellowstuffs that are invincible on track but cause braking power to ramp up sharply over the course of an autocross run, which is extra bad for a car without ABS. If they were even more serious brakes that didn't like low temps the problem could be even worse.

First of all, its breaks...

The Brembo's in the PowerStop kit are probably the 07+ GT500 calipers just rebuilt/repainted. They used to be cheaper than $800. 

You can find them on ebay in the $450-600 range with calipers, lines and rotors. They bolt right onto the hub. 

I ran them and loved them on my 2005 GT. Pad selection is huge. Rotors are heavy as hell though so the 2 piece rotor would be the big weight loss.

In reply to Toyman! :

Thats been my go-to for years. The larger rotor gives you a bigger heat sink and a little more mechanical advantage over the wheel. Plus being the same caliper it won't mess with the master cylinder volume issues

I personally can not justify the huge costs for 2-piece rotors when I can buy 1 piece blanks from China (rockauto) for 30 bucks each and replace them every year whether they need it or not. I would research which BBK can utilize an OE size/offset rotor that you can buy on rockauto for 30-50 bucks and start with that option 1st. 

dang, there's really nothing for me to add.  Bob and Gameboy hit all the main points.  But Gameboy is falling into the Keith Tanner school of saying "pedal pressure" when he really means "pedal force."  Cut that E36 M3 out!

I'd find out if GT brakes are bigger than V6 and go from there, and i'd prioritize the mods in this way:

1. cooling
2. pads
3. fluid

which is exactly the order Gameboy said.

I pretty much stop taking any brake upgrade seriously if it comes with drilled rotors, because that means it's aesthetically driven. I prefer function over form in my brake kits.

Rotors need mass to absorb heat, but it's mostly in the outer ring. A two piece rotor allows for a lightweight center to be paired with a massive (literally) ring for a lower overall weight. It can also allow for the use of inexpensive/generic consumables - the circle track 11.75" rings on my Vanagon brake setup are something like $40, which is less than a stock non-vented rotor. That's on top of the benefits that Gameboy mentioned.

You really need to ask just what you're trying to do. Brake fade? Pay attention to ducting, and make sure you've got pads for your intended use as well as appropriate (and fresh) fluid. Then you can start considering making them bigger if you need more heat capability. Single stop distance? That's going to be proportioning above most other things, and just jamming a set of big brakes on the front can actually increase your stopping distance because the fronts will want to lock before the rears get a chance to do anything.

If you're going to be doing street, track and autox with this car, look at how easy it is to change pads. Because a good autox/street pad doesn't overlap with a good track pad, especially on a car with some horsepowers. That's part of what Gameboy is getting at in his last post, a pad that is happy at high temps is not going to be happy or consistent on the range of temps experienced in an autox run.

AngryCorvair (Forum Supporter) said:

dang, there's really nothing for me to add.  Bob and Gameboy hit all the main points.  But Gameboy is falling into the Keith Tanner school of saying "pedal pressure" when he really means "pedal force."  Cut that E36 M3 out!

Fair point. I'll try to stick to "pedal force" or "leg pressure" from now on

In reply to Toyman! :

Ignorance on my part. But are the factory Brembo's iron or Aluminum?  Do not track race with Iron calipers. 
  How readily available are different pads,  track racing calls for different pads than autocross.  Especially long fast tracks with sharp corners at the end of straight.  
  Finally how hard is it to bleed the brakes?  
      Brake boosters sometimes makes gravity bleeding  impossible.  
  A good set up is the master cylinder is significantly higher than the caliper.  Then you pull the wheels. Open the bleeder,   put a pan underneath to catch the old fluid.    Do your post session checks. Fill the master cylinder when solid fluid comes out, tighten the bleeders, brakes are done.  
      Granted some tracks aren't as brutal on brakes as Elkhart Lake.  But there I had to bleed after every session.  

I've always had good luck with better parts on a stock setup.

I will say a c5 conversion (12.6") on a 4th gen which would be similar size and weight to your mustang with similar size rotors to the GT upgrade works VERY well with good pads.

I agree with others that it goes cooling, pads, fluid

For Appleseed and Gameboy:

In reply to GameboyRMH :

I ran EBC Yellow on the G35. They worked pretty well for autocross and track on it. I will probably run the same pad on the Mustang. Street use isn't really a concern. This will not be a daily. 

Fade during a 20-minute track session is my biggest concern. CMP is known to be extremely hard on brakes. It consists of several fairly long runs down to sharp turns. The Brembos on the G35 were decent but even they would start to go away over 20 minutes. I would run 2 warm up laps, 3 hot laps, 2 cool down laps, and park the car. The brakes were pretty much done by that point. Pad transfer was a real issue if you weren't very careful. 1, 8, 11, and 14 were guaranteed to heat things up. While failure wasn't an issue, turning rotors blue was almost guaranteed if you kept pounding on it. 

The Lemons Civic would be running close to 100 mph coming into 1. It would be over 100 into 8 and 11 and for 11 you would have to haul it down to 40-50. There isn't much cool down time between the turns. Add 15+ mph and 2000 pounds for the G35 and Mustang. 

It looks like I can do the GT rotor upgrade for a couple of hundred dollars. I may try that and see how it works. 

In reply to Toyman! :

Are you running any ducting right now? Bigger rotors will help with the rotor temps, but getting more air into the rotors could help more.

Toyman! said:

In reply to GameboyRMH :

I ran EBC Yellow on the G35. They worked pretty well for autocross and track on it. I will probably run the same pad on the Mustang. Street use isn't really a concern. This will not be a daily. 

Fade during a 20-minute track session is my biggest concern. CMP is known to be extremely hard on brakes. It consists of several fairly long runs down to sharp turns. The Brembos on the G35 were decent but even they would start to go away over 20 minutes. I would run 2 warm up laps, 3 hot laps, 2 cool down laps, and park the car. The brakes were pretty much done by that point. Pad transfer was a real issue if you weren't very careful. 1, 8, 11, and 14 were guaranteed to heat things up. While failure wasn't an issue, turning rotors blue was almost guaranteed if you kept pounding on it. 

 

The Lemons Civic would be running close to 100 mph coming into 1. It would be over 100 into 8 and 11 and for 11 you would have to haul it down to 40-50. There isn't much cool down time between the turns. Add 15+ mph and 2000 pounds for the G35 and Mustang. 

It looks like I can do the GT rotor upgrade for a couple of hundred dollars. I may try that and see how it works. 

 

Don't forget your ducting and pads. It's really hard to get a temperature graph of EBC pads, but it sounds like the yellow can't handle the heat you're pumping into it. So either you go to a different pad or you decrease the heat by making it go away (ducting) or giving it somewhere else to go temporarily (rotor mass)

frenchyd said:

In reply to Toyman! :

Ignorance on my part. But are the factory Brembo's iron or Aluminum?  Do not track race with Iron calipers. 
  How readily available are different pads,  track racing calls for different pads than autocross.  Especially long fast tracks with sharp corners at the end of straight.  
  Finally how hard is it to bleed the brakes?  
      Brake boosters sometimes makes gravity bleeding  impossible.  
  A good set up is the master cylinder is significantly higher than the caliper.  Then you pull the wheels. Open the bleeder,   put a pan underneath to catch the old fluid.    Do your post session checks. Fill the master cylinder when solid fluid comes out, tighten the bleeders, brakes are done.  
      Granted some tracks aren't as brutal on brakes as Elkhart Lake.  But there I had to bleed after every session.  

Boosters have no effect on bleeding, they're not plumbed into the hydraulic system on any car I've come across. They're usually a pneumatic force multiplier on the master cylinder pushrod. 

If you're having to bleed the brakes after every session, you need better brake fluid and more ducting.

In reply to GameboyRMH :

There was some on the G35, but not as much as I would have liked. There was limited space to run them through the radiator support without hacking up the entire front of the car. 

I'll have to study the front of the Mustang but at a guess, I can probably get more ducting through it since the car is also designed for a V8. 

I will certainly start with ducting because I have that stuff on the shelf. I also have some time before the first track event. 

Keith Tanner said:

frenchyd said:

Brake boosters sometimes makes gravity bleeding  impossible.  
 

Boosters have no effect on bleeding, they're not plumbed into the hydraulic system on any car I've come across. They're usually a pneumatic force multiplier on the master cylinder pushrod. 

If you're having to bleed the brakes after every session, you need better brake fluid and more ducting.

prepare for lecture from Frenchy about 1950's british systems which had an upstream and a downstream master with some crazy-ass servo between, with masters below the floor.  totally irrelevant today except to Frenchy and the 3 other people on the planet who care about such nonsense.  i worked on one of these system once, and by "worked on" i mean "removed and threw in the berkeleying trash".  it was on a kit Cobra that was built in 1980.

You can also check with the track guys and see what kind of luck the V8 guys are having with the stock setup on the track.

In reply to AngryCorvair (Forum Supporter) :

You just described the brake system in the Bentley.  And it's a 1991.