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Mach 1 vs GT350R brake master cylinder and prop valve

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I am building a bit of a hybrid that Ford wouldn't build - a 2021 Mach 1 converted with a number of GT350R parts. After spending the weekend driving the M1 and my friend's R back to back at Summit Point, it's clear the brakes on the 350R are significantly better and have a much higher thermal capacity. However, they won't fit the M1 wheels (of which I have 3 sets of). So to blend the lines a bit, I purchased the AP Racing Radi-cal brake kit for the 350R. I have purchased all of the components to convert the hard parts to 350R spec based on the Ford Performance Parts GT350R brake upgrade kit - axles, knuckles, parking brakes, rear knuckles. I also pieced together the front end from part numbers for the front knuckles, control arms. I picked up hubs from OP Mustang for all four corners.

Can anyone confirm if the master cylinder and prop valve already in the car are the same as the GT350/GT350R spec? I believe they are, but have yet to be able to confirm that 100%
 
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I am building a bit of a hybrid that Ford wouldn't build - a 2021 Mach 1 converted with a number of GT350R parts. After spending the weekend driving the M1 and my friend's R back to back at Summit Point, it's clear the brakes on the 350R are significantly better and have a much higher thermal capacity. However, they won't fit the M1 wheels (of which I have 3 sets of). So to blend the lines a bit, I purchased the AP Racing Radi-cal brake kit for the 350R. I have purchased all of the components to convert the hard parts to 350R spec based on the Ford Performance Parts GT350R brake upgrade kit - axles, knuckles, parking brakes, rear knuckles. I also pieced together the front end from part numbers for the front knuckles, control arms. I picked up hubs from OP Mustang for all four corners.

Can anyone confirm if the master cylinder and prop valve already in the car are the same as the GT350/GT350R spec? I believe they are, but have yet to be able to confirm that 100%
I can't offer any guidance on the master cylinder/booster but as far as I know, the ABS module handles proportioning in our cars. Ford Performance has said in the past that SVT and FP cars (Shelby's and the GT) are programmed with different front-rear bias depending on the chassis mode - Comfort, Track or Sport. It's hard to know if that's true at all - it could be marketing nonsense - and it's even harder to know where Ford (non-FP cars) stands on the matter.

The easiest check is to look at the piston sizes in the new brakes and compare them with the factory brakes. If the number of square millimeters of piston area is the same as OEM, then the braking will be close. If it's different by more than about 20%, expect some issues - long pedal or hard pedal perhaps.
 
I can't offer any guidance on the master cylinder/booster but as far as I know, the ABS module handles proportioning in our cars. Ford Performance has said in the past that SVT and FP cars (Shelby's and the GT) are programmed with different front-rear bias depending on the chassis mode - Comfort, Track or Sport. It's hard to know if that's true at all - it could be marketing nonsense - and it's even harder to know where Ford (non-FP cars) stands on the matter.

The easiest check is to look at the piston sizes in the new brakes and compare them with the factory brakes. If the number of square millimeters of piston area is the same as OEM, then the braking will be close. If it's different by more than about 20%, expect some issues - long pedal or hard pedal perhaps.

Thanks. The thing I'm banking on is the fact that Ford sells the GT350R brake upgrade kit for the standard GT cars. I'm hoping that means it's at lest compatible.
 
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Try a Pagid RST-3 on the front and an RSL29 on the rear of the Mach 1 before you swap hardware. Also Add brake cooling ducts - Vorshlag and others sell them. I’m referring to the deflector type plates and not hoses.

The RSL29 is an endurance pad. It doesn’t have a huge amount of bite or overall friction level. It does last and take heat.
 
I already have the new hardware on the way. I was planning on switching to the AP setup anyway. I run them on all of my cars.

even though these are an endurance pad, the car are through them due to the heat, I think. Sure, there are further changes I could make, but I know the AP kit will solve it.
 
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I am building a bit of a hybrid that Ford wouldn't build - a 2021 Mach 1 converted with a number of GT350R parts. After spending the weekend driving the M1 and my friend's R back to back at Summit Point, it's clear the brakes on the 350R are significantly better and have a much higher thermal capacity. However, they won't fit the M1 wheels (of which I have 3 sets of). So to blend the lines a bit, I purchased the AP Racing Radi-cal brake kit for the 350R. I have purchased all of the components to convert the hard parts to 350R spec based on the Ford Performance Parts GT350R brake upgrade kit - axles, knuckles, parking brakes, rear knuckles. I also pieced together the front end from part numbers for the front knuckles, control arms. I picked up hubs from OP Mustang for all four corners.

Can anyone confirm if the master cylinder and prop valve already in the car are the same as the GT350/GT350R spec? I believe they are, but have yet to be able to confirm that 100%

This is a little off topic, so feel free to PM me if you prefer, but what benefit do the GT350R knuckles have over the Mach 1 knuckles?

Can you share the part numbers for both the front and rear GT350R knuckles?

Are they the 2020 GT350R knuckles? They have changed from the earlier GT350/GT350R.

You can see a good video on the differences here:

upload_2020-5-5_8-10-37.png
 
I purchased FR3Z-3K185-AB and FR3Z-3K186-AB, which were supposes to be for a 2020 GT350R. I will have to check the castings when I get home.

regarding benefits
- weight savings as these are aluminum vs cast iron
- radial mounting for the calipers (I was originally going with gt350R brakes as well)
- I believe they are supposed to have better bump steer geometry as well
 

steveespo

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I purchased FR3Z-3K185-AB and FR3Z-3K186-AB, which were supposes to be for a 2020 GT350R. I will have to check the castings when I get home.

regarding benefits
- weight savings as these are aluminum vs cast iron
- radial mounting for the calipers (I was originally going with gt350R brakes as well)
- I believe they are supposed to have better bump steer geometry as well
I assume you are going with AP Racing brakes when you change to the GT350 aluminum hub carriers.
 
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Just checked my new knuckles and they are indeed the older design.

So you're saying you have the 2019 and below GT350/GT350R knuckles?

When switching to the GT350 knuckles, you have to use the Essex/AP Racing kit used specifically for the GT350?
 
So you're saying you have the 2019 and below GT350/GT350R knuckles?

When switching to the GT350 knuckles, you have to use the Essex/AP Racing kit used specifically for the GT350?

yes, they appear to be the knuckle design on the far left in the opening shots of that video, and on the left in the pic you posted.

you could also use the factory gt350 brakes. I have the Rs here brand new, just didn’t want to replace all of my wheels, which won’t fit the front brakes on the R. So I decided to get the AP instead, which I prefer to service track side anyway.
 
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yes, they appear to be the knuckle design on the far left in the opening shots of that video, and on the left in the pic you posted.

you could also use the factory gt350 brakes. I have the Rs here brand new, just didn’t want to replace all of my wheels, which won’t fit the front brakes on the R. So I decided to get the AP instead, which I prefer to service track side anyway.
Got it.

Thanks Quick.
 
...I have purchased all of the components to convert the hard parts to 350R spec based on the Ford Performance Parts GT350R brake upgrade kit - axles, knuckles, parking brakes, rear knuckles...Can anyone confirm if the master cylinder and prop valve already in the car are the same as the GT350/GT350R spec? I believe they are, but have yet to be able to confirm that 100%
I don't think the master cylinders are going to be the same for the GT350 and Mach 1 but I can hopefully tell you the external piston size of a GT350 master cylinder in a week or so. I am working on a similar plan on my 2015 Performance Package GT myself. My plan is to keep the front 15" GT Brembo brakes and add the rear 15" GT350 brakes. I am going to use GT350 rear control arms, knuckles, parking brake, hubs, calipers, cables, bracket, ect. I also have a GT350 master cylinder coming too. Based on my research and calculations the 6-piston Performance Pack GT, Bullitt, and Mach 1 front calipers and 6-piston GT350 front calipers have almost the same piston surface area; 3054 sq mm based on 34mm/36mm/38mm pistons in the GT350 caliper compared to 3052 sq mm based on 36mm/36mm/36mm pistons in the Performance Pack GT, Bullitt, and Mach 1 caliper. I have seen conflicting sizes listed for the GT350 4-piston rear calipers; 30mm/32mm pistons and 30mm/30mm pistons. Either way that is a huge increase in the piston surface are for the rear brakes at either 3019 sq mm or 2826 sq mm compared to 1554 sq mm for 44.5mm piston in the GT, Performance Pack GT, and Mach 1. I have seen threads where multiple people have upgraded their Performance Pack GTs using the M-2300-Y kit you referenced. They all appeared to keep their factory Performance Pack GT master cylinders and said they could feel an increase in braking performance. It appears a base GT has an external master cylinder piston size of 27mm and a Performance Pack GT/Bullitt, Mach 1 is 28.5mm. I haven't seen anything mentioned about a staggered inner bore but I think that may be the case. That would be one way Ford handles front to rear brake bias. The base GT and Performance Pack EcoBoost cars both use the same 4-piston front calipers that actually have a much larger piston surface area at 6500 sq mm for the 45.5mm/45.5mm pistons and use the smaller 27mm master cylinder. Maybe I can get a look at the inside of the GT350 master cylinder by throwing it in our x-ray machine.
 

captdistraction

GrumpyRacer
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Master cylinders are different. GT350 and GT share the same diameter, and the GTPP/Mach1 uses a slightly larger cylinder diameter (IIRC 1-1/16 and 1-1/8" or something to that effect). The end result is a slightly shorter and firmer pedal in your case - assuming a front only swap, I haven't done any of the math for the rears.
 

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