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TeeLew

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It seems that once a company decides they've got anti-lock on a car, they completely disregard mechanical brake bias. It's a pretty bizarre practice, but I've seen it on several occasions, and it's not necessarily one way or the other. I can understand a rear-bias, because that would tend to put more heat/wear to the rear in events which were under threshold, but lord help you if the electronics fail.

Most brake companies make sports car brakes which have a fairly high mu, aggressive bite front pad and a very benign rear pad with nice modulation characteristics to avoid locking or excessive ABS modulation. On the front, you can run something with a ton of bite and mu, but the rear is a different story. Some portion of the hydraulic split may be to accommodate this difference.

This is the Pagid pad options:

1600106993749.png


It's not uncommon to run any version of RST 1-5 on the front of a car with the RST D1 on the rear.

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As far as either 6-pot brake system in general, they seem unnecessarily large to me. The GT 4-piston caliper has plenty of disc, piston and pad area, as does the single pot rear sliding caliper. The biggest issue has got to be the absolute lack of cooling to the disc by putting the venting on the wheel side of the disc. That's just stupid on a performance car.

I think most people with anywhere near stock power levels could be perfectly happy on track with:
  • Racing pads (not HP street) from any good racing manufacturer. (PFC, Hawk, Pagid, Ferrodo, etc.)
  • Fresh racing brake fluid. (PFC, Motul, AP, Castrol, etc.)
  • 2 piece discs of stock size, but with the venting to the inside of the hat. I personally prefer PFC discs, but there are reasonable alternatives.
  • Some sort of real cooling to the brakes, like the FTBR kit or just a couple scoops and some 2" brake hose pointed to the inside of the disc & out the venting.
I just can't see 14" front and 12" rear brakes being insufficient for a ~3500# car with no aero, no slicks and anything close to stock power levels.
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racingandfishing

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Is that confirmed to be the only difference between the two? I was looking at part numbers on the levittown website and interestingly the GT PP master cylinder is only used on the GT PP. Both the regular GT and GT350 use the the other master cylinder. Which in the case of the regular GT has even more front hydraulic bias according to the piston areas mentioned at the beginning.

None of this adds up!! :cwl:
From an Optimum Peformance post:

"We have measured every caliper and piston on the S550. Going from the stock 4 piston calipers to the 6 piston Brembo caliper reduces the piston area by 4.7%. The master cylinder used with the 4 piston calipers is the same master cylinder used in the GT350. The GT350 total piston area is a 14% increase from the 4 piston calipers and a 19.4% increase from the 6 piston calipers."

https://www.mustang6g.com/forums/threads/brembo-brake-upgrade-master-cylinder.101907/page-2
 

racingandfishing

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Brian@BMVK

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TeeLew

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From an Optimum Peformance post:

"We have measured every caliper and piston on the S550. Going from the stock 4 piston calipers to the 6 piston Brembo caliper reduces the piston area by 4.7%. The master cylinder used with the 4 piston calipers is the same master cylinder used in the GT350. The GT350 total piston area is a 14% increase from the 4 piston calipers and a 19.4% increase from the 6 piston calipers."
Caliper piston area is adequate in any of these scenarios. The caliper itself needs to be sized to keep the pedal effort in a reasonable range and to hold a pad big enough to not run excessive surface temps. Large pads tend to have taper wear issues, which is why you see 6-piston and multi-pad calipers.

We can shift stopping power around by 20% with a pad change. These differences in piston area are not consequential to the operation of the system.
 

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TeeLew

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The Baer are also drilled, but have heard that is not always a good thing.
Drilled discs are good for companies selling pads and more drilled discs. They are not for performance.
 

Brian@BMVK

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Caliper piston area is adequate in any of these scenarios. The caliper itself needs to be sized to keep the pedal effort in a reasonable range and to hold a pad big enough to not run excessive surface temps. Large pads tend to have taper wear issues, which is why you see 6-piston and multi-pad calipers.

We can shift stopping power around by 20% with a pad change. These differences in piston area are not consequential to the operation of the system.
Yep, which is why swapping the 6 piston brembos onto a base car works just fine, it just has a little more pedal travel/pressure required due to the smaller MC bore.

The GT350 has staggered piston diameters to significantly improve pad taper on both the front and rear calipers. The biggest reason the braking performance and feel of the GT350 is so good is because of the very rigid caliper (integrated bridge), the piston stagger leading to even pad pressure, the less conservative ABS calibration, and lighter rotors. Of course the pad compounds are quite good, too.
 

Ewheels

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While on the brake topic, does anyone have experience with the Baer vs. Steeda or Giro 2 piece rotors? The Baer are also drilled, but have heard that is not always a good thing.

https://www.cjponyparts.com/baer-br...15-pair-performance-pack-gt-2015-2020/p/BR91/

https://www.steeda.com/steeda-performance-pack-front-brake-rotor-s550-555-6032

https://www.girodisc.com/Rotors_c_1334.html
It seems everyone and their mother uses Girodisc. I would think Steeda is very similar in performance to Girodisc.
I don't know anyone who competes or even regularly tracks their car who uses Baer rotors. I don't have any experience or knowledge with Baer rotors but I would guess track guys are not using them for a reason.

And to reiterate what's been said on the drilled rotors: it's not that they don't work but they will not last you very long. Drilled rotors are just for looks and manufacturers know that
 

TeeLew

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PFC discs are more expensive than any of these options, but for good reason. Now if someone would just design hats to use them...:idea:.
 

racingandfishing

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It seems everyone and their mother uses Girodisc. I would think Steeda is very similar in performance to Girodisc.
I don't know anyone who competes or even regularly tracks their car who uses Baer rotors. I don't have any experience or knowledge with Baer rotors but I would guess track guys are not using them for a reason.

And to reiterate what's been said on the drilled rotors: it's not that they don't work but they will not last you very long. Drilled rotors are just for looks and manufacturers know that
That was what I had heard about drilled being for the looks and that they have more issues with cracking. I'd also read somewhere that the engineers didn't want to put drilled discs on the GT350's but lost to the marketing folks. Seems like some truth to that since they stopped putting them on the 2019+ and they aren't on the new GT500.

I put one piece drilled and slotted from a name brand company on a couple of years ago, but no longer trust the brand after reading about some failures. So while I am at it replacing them, looking to go to a two piece. Could have saved some money doing it right the first time!
 
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Ewheels

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Could have saved some money doing it right the first time!
Hey, that's the best way to learn. Yes it's more expensive, but now you have great first-hand experience. I did the very same with pads and rotors. Bought cheap stuff to save money and learned first-hand that they are cheaper for a reason. Now spent extra to correct it
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