Creating a 'Trackable' Daily Driver

[shogun32]

A larger master would be needed if you increased the volume significantly (which you aren't) ... So - not needed.

It seems Vorshlag is (only one?) advocating for it vocally. Steeda recommends it (they swapped on their EB race car), and Optimum doesn't see the need. So, I guess try it as-is and see if everything works for you. But it seems pad selection and ABS interaction could be part of the issue.

The ABS will detect and work around a brake friction level that is too high for the grip. This can cause the front brakes to be over loaded, 2 less tires to provide braking because the abs bleeds the pressure from the rear to the front after sensing the rear wheel speed is decelerating at a higher rate than the front. If it happens mid corner now the front tires are stopping and re-directing 4000 pounds.​

Sponsored

 

[Stuntman]

It seems Vorshlag is (only one?) advocating for it vocally. Steeda recommends it (they swapped on their EB race car), and Optimum doesn't see the need. So, I guess try it as-is and see if everything works for you. But it seems pad selection and ABS interaction could be part of the issue.

The ABS will detect and work around a brake friction level that is too high for the grip. This can cause the front brakes to be over loaded, 2 less tires to provide braking because the abs bleeds the pressure from the rear to the front after sensing the rear wheel speed is decelerating at a higher rate than the front. If it happens mid corner now the front tires are stopping and re-directing 4000 pounds.​

Ford doesn't recommend or sell the kit with a master cylinder. So I'd go with them over a tuner shop. Also, given the function of a master cylinder, it will not change the brake bias (which is the reasoning argued by those shops) it still does not make sense to change it.

 

[BmacIL]

Ford doesn't recommend or sell the kit with a master cylinder. So I'd go with them over a tuner shop. Also, given the function of a master cylinder, it will not change the brake bias (which is the reasoning argued by those shops) it still does not make sense to change it.

It can change bias if it is proportioned differently between the front and rear ports. That said, no one has provided any evidence that the internal proportioning is different. I am thinking about buying one of each, tearing them down to answer the question for once. Bore diameter alone does not affect brake bias in a bled system.

 

[shogun32]

all things equal (just swapping masters) a bigger bore at the MC means the pedal travels less for a unit of caliper piston travel, while the smaller bore can allow more "feel". The Shelby uses the smaller MC in common with the V6 and down-market Ecoboost.

You're right @BmacIL, when there is an active manager of brake pressure independent of the driver (ABS control unit) involved the concept of 'bias' becomes moot: it is up to the algorithm parameters and it's reaction to wheel deceleration rates.

I wonder if a case could be made for bolting a 100+lb weight to the wheel well to keep some weight on the rear of the car. I wasn't planning on changing out the simple V6 brakes in the back and wonder if that is going to cause undesired side-effects.

 

[NightmareMoon]

I would at least read Vorshlag’s blog about their experience with

Ford doesn't recommend or sell the kit with a master cylinder. So I'd go with them over a tuner shop. Also, given the function of a master cylinder, it will not change the brake bias (which is the reasoning argued by those shops) it still does not make sense to change it.

I trust the engineers who put a different master cylinder on the PP cars with the Brembos more than the Parts department sales people who sell whatever they can make money on.

I also trust analytical people who test parts and have first hand experience running the cars at the limits. I’d at least read Vorshlag’s blog about their brake swap experience before dismissing it.

 

[BmacIL]

I would at least read Vorshlag’s blog about their experience with


I trust the engineers who put a different master cylinder on the PP cars with the Brembos more than the Parts department sales people who sell whatever they can make money on.

I also trust analytical people who test parts and have first hand experience running the cars at the limits. I’d at least read Vorshlag’s blog about their brake swap experience before dismissing it.

That said, I've spoken personally with Billy Johnson about the topic and he also has done the calculations and, like me, found that the calipers alone hardly move the overall brake bias (accounting for the piston area changes and the rotor change (thus increased radius where the center of pad is). I am not yet convinced that the master cylinder swap isn't needed, but the math shows that it should not have happened, and that other circumstances were at play (way too aggressive a rear pad being one). I need to see the internals of each MC to verify if there is internal proportioning differences. But, as you've pointed out, Ford has a different part for the PP and they would not introduce that complexity and cost without a good reason. What many others have found, however, is that the swap is not necessary for track use and the only guy who has had a documented issue is Vorshlag. Are they probably faster than the average guy? Sure. But they are also known to be a bit of a pissed-off gorilla when it comes to driving the car hard.

 

[NightmareMoon]

Aside from Vorshlag, do we know anyone else who as done the swap and also run the car to the limits? Most of the guys I see who do the swap here are not driving hard at the track.

My main point is that Ford did put a different master cylinder on the PP cars with the bigger brakes. They don't do that without a reason. Something in the Ford engineer's calculations determined that a different MC part was a good idea, and they followed through.

Either way, I don't have a horse in this fight. My car came with the PP Brembos from the factory. I do find the Vorshlag blog information very interesting, because I have not read any other track reports from people who have converted to the 6-piston calipers.

 

[BmacIL]

Aside from Vorshlag, do we know anyone else who as done the swap and also run the car to the limits? Most of the guys I see who do the swap here are not driving hard at the track.

My main point is that Ford did put a different master cylinder on the PP cars with the bigger brakes. They don't do that without a reason. Something in the Ford engineer's calculations determined that a different MC part was a good idea, and they followed through.

Either way, I don't have a horse in this fight. My car came with the PP Brembos from the factory. I do find the Vorshlag blog information very interesting, because I have not read any other track reports from people who have converted to the 6-piston calipers.

@SVO MkII has.

 

[Stuntman]

I would at least read Vorshlag’s blog about their experience with


I trust the engineers who put a different master cylinder on the PP cars with the Brembos more than the Parts department sales people who sell whatever they can make money on.

I also trust analytical people who test parts and have first hand experience running the cars at the limits. I’d at least read Vorshlag’s blog about their brake swap experience before dismissing it.

Common sense would tell you that master cylinder don't affect brake bias and that going to smaller caliper pistons would result in less travel than stock. Yes going to a larger master would reduce travel even further.

Vorshlag isn't known for their engineering abilities. They draw many inaccurate conclusions due to their terrible testing methods. For the caliper-master cylinder argument, they changed brake pads. Anyone who has ever tracked their mustang knows (or should know) to never put an aggressive brske pad on the rear. Although then again a lot still do out of ignorance and/or following the ignorance of Vorshlag.

 

[sonicc]

My main point is that Ford did put a different master cylinder on the PP cars with the bigger brakes. They don't do that without a reason. Something in the Ford engineer's calculations determined that a different MC part was a good idea, and they followed through.

IMO this right here is enough evidence to stop all argument about this topic. If they could justify the added expense of fitting PP cars with different MC, then there had to be enough difference. You can chose not to swap MC if you don't want to, but performance may be reduced.

In my experience when swapping brakes from higher end model of same brand (mostly VW and Honda) it is always recommended to swap in MC as well.

 

[mikeD4V]

Aside from Vorshlag, do we know anyone else who as done the swap and also run the car to the limits? Most of the guys I see who do the swap here are not driving hard at the track.

My main point is that Ford did put a different master cylinder on the PP cars with the bigger brakes. They don't do that without a reason. Something in the Ford engineer's calculations determined that a different MC part was a good idea, and they followed through.

Either way, I don't have a horse in this fight. My car came with the PP Brembos from the factory. I do find the Vorshlag blog information very interesting, because I have not read any other track reports from people who have converted to the 6-piston calipers.

16 track days and counting with brembos and a 300a system. I've gone through 3 sets of brake pads with them so far and have ~2 days left on the current pads. Not using race pads or hoosiers, 1 set of stock pads and on my 3rd set of power stop track day pads with my own brake ducts and square 305 NT01s.

A friend ran the brembos on his 16 GT automatic without the PP master swap either for 2 track seasons but has recently moved to a GT350 so no more data there.

May do the PP master swap to see if there is a difference since I have plenty of miles and laps on the current configuration. Attached pic shows I'm not easy on the brakes and the 300a system/brembos combination hasn't been a problem for me. Pic was taken last Thursday when I switched back to street wheels/tires.

OE rotors - 3.5 sets of pads by MikeD, on Flickr

 

[Stuntman]

Looks good. Did the brake pedal travel or effort change much when you went to the PP brakes?

How do those powerstop pads compare to stock?

 

[Thub]

I swapped the brembo calipers on as well. Havent been to a trackday yet, and I also did stainless lines at the same time, so while the pedal feel is different, it might be the lines. On the street, the brakes are a little more grabby, but not a major difference. I won't be doing the master cylinder. While the larger diameter cylinder would increase braking effort, which I'd like (imo ford over boost all their brake systems) , it is not worth the time or money to me to swap it.

 

[mikeD4V]

Looks good. Did the brake pedal travel or effort change much when you went to the PP brakes?

How do those powerstop pads compare to stock?

Sorry but I honestly can’t remember how the original pedal feel was. The PP brakes have been on for ~2yrs/20k+ miles now. I’ll try to find a PP equipped car to drive and compare.

The powerstops seem to have a little more initial bite and hold than the stock pads. Stock pads are smoother on the initial stop and then stopping increases linearly with more pedal pressure where the powerstops seem to start with more bite and stay there with less pedal modulation. For me the stockers are better all around pads and the powerstops more of a track pad that can be street driven but they make some noise. I have more confidence in the powerstops at the moment since the car is 75/25 track/fair weather driver now and they’re $200 for all 4 corners. They both dust but the powerstop dust sticks to black wheels if it’s not cleaned and turns brown. I'd really like to try the DS1.11 pads and/or G-Locs at some point since they're probably a better match to my tire but they're not recommended for street driving and I don't want to switch pads every few weeks.

 

[SVO MkII]

@SVO MkII has.

Yes I have. Brakes are wonderful after just swapping the calipers/rotors. As others have noted, Ford performance sells the caliper/rotor kit as a straight bolt on for the 4 piston cars. No worries. Side benefit; I was actually surprised at how well the stock GT PP pads held up as well. Waaaay better than the stock 4 piston pads. Those were worthless. I just bought some G-Loc R12/R10s. Road America here I come!

Sponsored