Lets have a discussion about brakes.

AngryCorvair (Forum Supporter) said:

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.

That's why I said "usually" :) I'm aware of remote boosters but have never come into contact with one personally. I associate them with small production British cars with packaging challenges - which describes an AC Ace with a big motor pretty well. Or a Bentley.

But if you're having to bleed the brakes because you boiled your fluid AGAIN, it's probably just going to be in the downstream circuit anyhow.

Forgive me if I've missed it.

Have you tracked the car with proper pads and fluids and ran into a problem?

In reply to Keith Tanner :

The only time I've ever had an issue boiling fluid is in the mountains on vehicles that were long past their change fluid date. 

I have never suffered significant brake failure on track but I've never hit the track without a recent fluid change. I've seen enough cars go off from brake failures to know that's a bad idea that is frequently avoidable. Hence this discussion. 

In reply to z31maniac :

No. But I know how difficult it was to keep brakes on my wife's 03 GT to want to do some research on alternatives. I'm assuming a base Mustang will have similar or worse problems. The brakes on her car were pretty terrible and undersized. I don't want to fight that. I hate working on cars at the track. 

So I'm going to guess probably not, but does this mustang happen to share parts with the P71s? I know they stopped making them before this mustang came out, but it might be worth looking at. 

I ran "severe duty" pads and rotors and just swapped them every few months because the hardware was like $50 for all 4 corners.

In reply to Toyman! :

Ducting isn't just to prevent boiling brake fluid, it's also there to keep pad temps down. Basically, braking is turning kinetic energy into heat. That heat goes into the rotor and the pad, and also the caliper and fluid because they're more or less in contact with the pad. The rotor is pumping air through internal cooling passages to transfer the heat to the air - or just radiating it. Ducting helps the rotor shed heat. Thus all the comments about ducting instead of whether Brembo is worth a premium over Wilwood or whatever PowerStop is peddling. So if you're having trouble with the brakes fading, you have an overheating pad problem. If you're having trouble with the pedal going soft, you have an overheating fluid problem. 

What IS PowerStop selling? Given the price delta, is it just a pad and rotor replacement? The rotor is fundamentally just a big chunk of cast iron, about the only thing that matters is if it's machined properly and it hasn't had a bunch of crack-starting holes drilled in it. It's the least important part to worry about upgrading. In which case all PowerStop would really be providing is a set of brake pads.

From what I was able to find on the friction graphs of EBC compounds, I buy Hawk or Carbotech. Haven't had a chance to usw the Carbotechs but the Hawk pads (HP+ and I have reasoning) modulate very well over their intended heat range. I anticipated higher temps than they can handle next time I take the mustang out, so I bought a set from Carbotech when DTC pads were out of stock due to the 'rona. 

I am of the opinion that you have a heat problem so I agree with Keith, better pads and better cooling. 

In reply to Keith Tanner :

Thanks. 

Ducting only works to a point. Even with ducting it is possible to overheat the pads and they become less effective. The G35 is a case in point. After 3 hot laps, the brakes were starting to go away even with ducting. With the amount of ducting I could get to the rotors, it still wasn't enough. The brakes would generate more heat than the ducts could remove. I don't want to deal with that issue. From there you need larger rotors and pads to help with heat control. Larger rotors and pads are able to absorb more heat without degraded performance. The larger rotor and pad will also dissipate more heat due to the larger surface area. 

The point of this discussion isn't to debate whether the car needs better brake hardware or why. I don't know that yet as I haven't driven it in anger. The point of this thread is to discuss the relative effectiveness of 3 brake kits and why one might be better than the other in terms of performance, cost, availability, and the ability to deal with track use on a heavy car. Then I can make an informed decision as to which direction I go if I decide it is needed. 

I am hoping that people with familiarity with the three manufacturers in question will share their insights as to which they prefer and why. 

My experience, albeit it limited, has been that OEM stuff works well if you get cooling air to the brakes. I'd see if there was some OEM bolt on stuff; if not I'd research the Powerstop kit.

With that said paying for brakes that can be hammered lap after lap is worth every penny. 

As an aside; can we please stop saying as long as you can lock a wheel the brakes are adequate. We've all driven cars with undersize brakes that do almost nothing at 50lbs of pedal pressure then finally lock the brakes at 100lbs of pedal pressure. Using this logic there is not need for disc brakes on mountain bikes because the old cantilever brakes can lock a wheel.  

Toyman! said:

In reply to z31maniac :

No. But I know how difficult it was to keep brakes on my wife's 03 GT to want to do some research on alternatives. I'm assuming a base Mustang will have similar or worse problems. The brakes on her car were pretty terrible and undersized. I don't want to fight that. I hate working on cars at the track. 

 

Not trying to be a jerk, but were you using appropriately rated pads and fluids for that vehicle? There are plenty of race cars using the stock brakes, ducted, with pads and fluid rated for the appropriate temps. With slicks and aero as well. 

Keep in mind I say this as someone who is considering buying a BBK for his non-tracked BRZ just because it will look awesome behind those big ADVANs I put on the car. 

Toyman! said:

In reply to Keith Tanner :

Thanks. 

Ducting only works to a point. Even with ducting it is possible to overheat the pads and they become less effective. The G35 is a case in point. After 3 hot laps, the brakes were starting to go away even with ducting. With the amount of ducting I could get to the rotors, it still wasn't enough. The brakes would generate more heat than the ducts could remove. I don't want to deal with that issue. From there you need larger rotors and pads to help with heat control. Larger rotors and pads are able to absorb more heat without degraded performance. The larger rotor and pad will also dissipate more heat due to the larger surface area. 

The point of this discussion isn't to debate whether the car needs better brake hardware or why. I don't know that yet as I haven't driven it in anger. The point of this thread is to discuss the relative effectiveness of 3 brake kits and why one might be better than the other in terms of performance, cost, availability, and the ability to deal with track use on a heavy car. Then I can make an informed decision as to which direction I go if I decide it is needed. 

I am hoping that people with familiarity with the three manufacturers in question will share their insights as to which they prefer and why. 

 

 

I'd still be taking a hard look at brake compounds. If you're overheating your pads, maybe they're not the right pads. We are taking the EBC Yellow as a given, but why?

Can you post a link to the actual products in question? That will make for better conversation than generalizations about "I like Wilwood". We don't know what's in the PowerStop kit, for example. Does it actually increase pad and rotor size?

Keith Tanner said:

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

Or a better cool-down lap.  My turbo Miata's brakes were fine on track, but it would heat soak everything and if I didn't do a really good cool-down lap the fluid would boil when parked in the paddock.

z31maniac said:

Toyman! said:

In reply to z31maniac :

No. But I know how difficult it was to keep brakes on my wife's 03 GT to want to do some research on alternatives. I'm assuming a base Mustang will have similar or worse problems. The brakes on her car were pretty terrible and undersized. I don't want to fight that. I hate working on cars at the track. 

 

Not trying to be a jerk, but were you using appropriately rated pads and fluids for that vehicle? There are plenty of race cars using the stock brakes, ducted, with pads and fluid rated for the appropriate temps. With slicks and aero as well. 

Keep in mind I say this as someone who is considering buying a BBK for his non-tracked BRZ just because it will look awesome behind those big ADVANs I put on the car. 

 

I have never driven the car in anger. I have driven the car 4 miles on a test drive and the brakes were great. I've never had it on track. I've never autocrossed it. I've never had the abs engage. I do not know if the best pads are Super Carbon Fantastics by Unobtanium or Autozone Dirt. It may turn out that the stock brakes work perfectly and this is only a waste of words. I don't know. 

I'm just trying to discover the difference between a $2900 set of Brembos, a $2200 set of Wilwoods, and an $800 set of Powerstops. 

In reply to Keith Tanner :

The Wilwood Kit. 

The Brembo Kit. 

The PowerStop kit. 

In reply to Toyman! :

links to the kits you're pondering on?

In reply to Toyman! :

LOL timestamps

In my humble opinion:

The existence of the OEM 4-piston Brembo's on 14 inch rotors makes the expensive aftermarket 4-piston Brembo's on 14 inch rotors entirely redundant and massively overpriced. This option makes zero sense to me.

The existence of the OEM 4-piston Brembo's on 14 inch rotors makes the less expensive aftermarket 6-piston Wilwood's on 14 inch 2-piece rotors largely redundant and largely overpriced, yet a decent value for what is included. This option still makes little sense to me for a 'budget' V6 build.

The existence of the OEM 4-piston Brembo's on 14 inch rotors makes the inexpensive aftermarket reselling of the OEM 4-piston Brembo's on 14 inch rotors with some lipstick added to the calipers in a convenient one-stop-shop package somewhat redundant and somewhat overpriced. This option does make some sense to me, namely for street users who are not willing and/or able to take the time to figure it out for themselves nor looking for specific things like track pads... Assuming that in addition to rebranding the calipers with their name, they haven't also modified anything to prevent the standard fitment pads from other brands from being used.

If you want fixed calipers on 14 inch rotors, rather than standard GT rotors/brackets, I see little reason to look any farther than the factory setup. If that's still not enough, you can use factory parts to DIY an S550 6-piston Brembo's on 13-14 S197 GT500 15 inch rotor package.

Toyman! said:

In reply to Keith Tanner :

The Wilwood Kit. 

The Brembo Kit. 

The PowerStop kit. 

The 2-piece nature of the Wilwood kit has been discussed -- that's a significant extra cost for certain benefits (lighter and, if it's implemented properly, the ability for the rotor to move a little bit laterally)

Other than that, on paper the kits look similar but a brake system's performance depends heavily on aspects of the components that aren't listed.  The metallurgy of the rotors makes a huge difference in how they handle heat, but from the outside iron just looks like iron.  Similarly, a stiffer caliper will produce a much better pedal feel and will wear the pads more evenly, but you can't tell which one is stiff just by looking at them.

Branding is also a part of the price difference.  AFAIK, Powerstop really isn't known for making racing parts, it's a brand I associate with mild street upgrades.  Wilwood is known for NASCAR and dirt/circle track racing parts, whereas Brembo makes brakes for F1 cars.  You will pay for that branding.

That said, I have been very pleased with every non-financial aspect of the Brembos that I have on my M3.  Great feel, easy serviceability, pads last a long time, no weird behaviours, zero brake fade -- they do exactly what I want a race car's brakes to do and I have zero complaints.  They are not cheap though.

codrus (Forum Supporter) said:

Keith Tanner said:

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

Or a better cool-down lap.  My turbo Miata's brakes were fine on track, but it would heat soak everything and if I didn't do a really good cool-down lap the fluid would boil when parked in the paddock.

Elkhart Lake has 3 loonngg!  straights followed by tight corners.  Total of 14 corners in 4 miles of race track. Coast through the cool off lap and still the fluid is way off color. 
       Oh, there are ways to get through a few laps without cooking the fluid. But it will cost you time.   

In reply to Driven5 :

That's good info. Thank You. 

Looks like piecing the OEM  Brembo 4 pot setup together would be about $660 plus pads of choice without buying junkyard parts. 

The Powerstop kit is $670 but comes with crap rotors and pads. 

One thing to remember is that big rotors are heavier.  That's both unsprung weight and rotating weight.  So they make the car slower, they make the ride worse, and they can hurt grip slightly on rough surfaces. 

Fixed calipers are better than sliding calipers any day, but I'd go to pads and ducting for heat tolerance before bigger rotors because of the weight related downsides.  Basically, don't run bigger rotors than you actually need. 

Lots of good reading here.  I'd be looking to do the upgrade to the performance pack brake setup.  Perfectly setup for the car and on the cheap if you look.  Lots of rotor choices out there so do whatever grabs you.  I love the multi-piece idea but have never been able to justify the expense.  On any of these nice setups you are thinking of - pad changes are literally minutes.  Just pull wheel, remove pin, swing the spring up and slide in the new pads.  This allows you to run a hot race pad for track and something lower temp for Autox if it is really an issue.  I'd do stainless lines while you are in there as the pedal feel improvement is massive.  The OEM Performance pack may already have them.

Toyman! said:

In reply to Keith Tanner :

Thanks. 

Ducting only works to a point. Even with ducting it is possible to overheat the pads and they become less effective. The G35 is a case in point. After 3 hot laps, the brakes were starting to go away even with ducting. With the amount of ducting I could get to the rotors, it still wasn't enough. The brakes would generate more heat than the ducts could remove. I don't want to deal with that issue. From there you need larger rotors and pads to help with heat control. Larger rotors and pads are able to absorb more heat without degraded performance. The larger rotor and pad will also dissipate more heat due to the larger surface area. 

The point of this discussion isn't to debate whether the car needs better brake hardware or why. I don't know that yet as I haven't driven it in anger. The point of this thread is to discuss the relative effectiveness of 3 brake kits and why one might be better than the other in terms of performance, cost, availability, and the ability to deal with track use on a heavy car. Then I can make an informed decision as to which direction I go if I decide it is needed. 

I am hoping that people with familiarity with the three manufacturers in question will share their insights as to which they prefer and why. 

 

 

This is why they make pads for track use. I've done the "performance street pad on track" and have gone and bought proper pads for track use. There is NO comparison. I'd do the easy GT swap and use a real pad that's track oriented, flush the fluid and go have fun. EBC Yellows are not the right option for that. Street driving and autox? Sure, but oe pads work in those cases. The track is another ball game.

We ran Porterfield R4 pads last year for one lap and I ran them all season with GL and some other groups. Coming into 1 at CMP no biggie. wait for the last brake marker stand on the brakes, release through the corner and back on gas. No mess, no muss, no fuss. Trust me, get some good pads for the job and it will work much better.

frenchyd said:

codrus (Forum Supporter) said:

Keith Tanner said:

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

Or a better cool-down lap.  My turbo Miata's brakes were fine on track, but it would heat soak everything and if I didn't do a really good cool-down lap the fluid would boil when parked in the paddock.

Elkhart Lake has 3 loonngg!  straights followed by tight corners.  Total of 14 corners in 4 miles of race track. Coast through the cool off lap and still the fluid is way off color. 
       Oh, there are ways to get through a few laps without cooking the fluid. But it will cost you time.   

I ran street pads for 20 minute sessions there without any fade or issue in 2021. I think you're doing it wrong.

bobzilla said:

This is why they make pads for track use. I've done the "performance street pad on track" and have gone and bought proper pads for track use. There is NO comparison. I'd do the easy GT swap and use a real pad that's track oriented, flush the fluid and go have fun. EBC Yellows are not the right option for that. Street driving and autox? Sure, but oe pads work in those cases. The track is another ball game.

Also depends on how heavy and powerful your car is. On lighter and lower-powered cars EBC Yellows can be plenty enough for track use. I've heard they even work well for track use on a Lotus Esprit.