help please 🙏 Brembo Upgrade

[RussShadowS550]

I found a pair of calipers from a PP 24 GT front and rear. 6/4.

I want to retrofit them onto my 18 S550 premium GT Vert.

If I want to retrofit them, I am not experienced with sourcing parts and swapping.

They come with some OEM pads (ill worry about upgrading pads at a later time if my budget doesn't allow).

What else would I need?

OEM 15” Rotors for Front PR3Z‑1125‑B X2

OEM 14” Rotors for Rear L1MZ‑2C026‑A
OR BRRF‑403 X2

Steeda Stainless Steel Brake Lines: (S550)
MPN: 555-6027

Will these work with the S650 calipers? Since I'm putting them on the S550 platform I didn't know if I'd need the 650 or 550 version. I'd love to use the S550 since it saves about 100$ by doing so.

OEM Dust Shield RF: FR3Z‑2K004‑H
OEM Dust Shield LF: FR3Z‑2K005‑H
OEM Dust Shield RR: FR3Z-2C028-C
OEM Dust Shield LR: FR3Z-2C028-D

Front Brembo Hardware Kit:
https://www.opmustang.com/store/p16...ormance_Pack__Front_Brake_Hardware_Kit.html#/

Will this hardware kit work since I'll be utilizing the 2024 6 piston brembos?

Also, the rear I'm kind of lost on hardware wise since 4 pistons are obviouslt a lot different than single piston sliding calipers.

This is where I feel like I'll “waste” a lot of my budget on hardware.

Could someone help me out figuring out what I'll need for the rear conversion with part numbers and or links?

Finally, am I missing anything??

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[kz]

I don't think there is a reasonable way to use rear S650 brakes.

 

[Sumjay]

Fronts are pretty simple. Get a set of copper brake line washers at Autozone. They're under $10, you'll need these for a good seal between the hose and caliper. As for the hose fitment, you can a) email Steeda and ask or b) go to LMR and look at the hose numbers for their Brembo swap kit and compare to OEM. For the rotors - double check that size. I'm pretty sure S550 rotors are 15" and S650 rotors are 15.4". For the shields, LMR has them for ~$40 for the pair.

The rears are the big question. You 100% will not be able to bolt them up without a few more parts. If you don't feel like going that deep scratch that and stick with just the fronts. The car will run fine with that setup.

That said, I've been researching the rear swap for a minute. It's going to be an in depth project, and if you want to attempt it you might be the first to do it. I'll share what I know but can't make any guarantees.

The S550 and S650 rear suspension, (assuming you're not equipped with magneride since you don't already have front Brembos) are essentially the same. Are the shocks and springs different? Possibly, but not in any major way that could affect this project. The toe link (2), strut assembly/mount and spring components (4-10), upper control/camber arm (11), and sway bar components (13-16) are all inter-compatible. My evidence is that Steeda and BMR's replacements are the same part for 15-26. I'm sure a lot of Ford part numbers will match, I just haven't made a list yet.

The variables here are 1 (knuckle), 3 (vertical link), and 12 (lower control arm).

The vertical link is easy - we need the GT500/S650 vertical link. You can find someone's OEM takeoffs or get an aftermarket upgrade.

The LCA and knuckle are the two big issues. Visually, I can't find any differences between the S550's and the S650's. As for part numbers, I'm getting conflicting results but they're either the same or off by a digit.

I can't say for sure without testing, but if every other component is the same across the generations, then the LCA being the same is more likely. If the LCA is also the same, then the knuckle has to be able to bolt up (given that you use the new vertical link). If the knuckle fits, then you can mount your caliper but we need to factor in rotor offset.

If the rotor sits too far out, I don't think the project will work. If it sits too far in, odds are it's just a few mm and a slip on spacer behind the rotor can bring it out. However I can't say for certain if it's safe to use a spacer like that. I will say, given our other factors there's a good chance the rotor fits, and when I put an S650 PP rotor on the back of my S550 the offset seemed the same.

So, if all goes to plan we can remove the original knuckle and vertical link, install the new knuckle and link, and mount up our caliper. Next step: brake lines. I don't know the fitting size or the length of either OEM hose. This info can probably be found online, I just haven't gotten there yet. The S650 hose might be a better option if it fits just because that caliper sits on the front of the hub as opposed to the rear so I'm guessing it's longer. If neither OEM options work, you can definitely order custom rear hoses. Not sure about the price but you can request specific fittings and length.

If everything works up to here, we have a new knuckle, vertical link, rotor, caliper, and hose. The car should be drivable. People on this forum are usually concerned about brake bias when considering this swap; the closet we have is people pairing the S550 GTPP front Brembo 6 piston with the GT350 rear Brembo 4 piston. Two users on this forum have shared their experience; one states the rear end became unstable under a very hard brake, the other states that he felt ABS kicking in and that the car stopped safely. This is outside of my knowledge, but I'm thinking this can be corrected with pad choice, a proportioning valve, or some kind of software adjustment. For you specifically OP, no one knows how the car will respond to having both the front and rear from an S650. The front swap has barely been done, and as far as I can tell, the rear hasn't been done and posted publicly at all. No telling what to expect, so proceed with caution.

Now the hardest part: parking brake. Your options are to either delete it entirely or to go with an aftermarket option. Several states require a parking brake for inspection. This complicates the build as now we're force to used non OEM parts. If we were to somehow retain the S550's parking brake it would kill the whole point of thus swap as its standard and parking brake are one unit. Our generation only had an electronic parking brake on the GT500; it may be possible to use those parts and possibly mix some in from the S650, but that's going to get complicated fast.

There are two aftermarket parking brake styles: electronic and manual. Both will require some type of custom bracket to mount to the car. Electronic brakes are usually $500-1200; probably not worth it. For manual, the only rear option is a Wildwood parking caliper. Specifically the 120-15484/120-15485 (L/R). These are about $190 each. They fit the S650 rotor's width and diameter. The only issues are figuring out a mounting solution and figuring out how to connect the OE parking brake cable.

If you make it to here, you'll have swapped the knuckle, vertical link, rotor, caliper, hose, built a custom bracket, mounted a third party parking brake, and integrated the factory cable. You should have a functioning rear 4 piston caliper and parking brake. Keep in mind you may lose the line lock feature if you have it; I think I heard someone who did the 350 rear sway say that was their experience. It's probably going to be a little pricey and if you need something warrantied on the rear end you'd probably have to revert to stock. Also remember you may have unbalanced braking. And that if you go through with this you're not going to find many resources online to help because this reply is all the information I could find. I might've read that Steeda is looking into this but I could be wrong and they probably would've done it years ago by now.

That being said, I hope you do try it and it does work. While a lot of people are disappointed in how similar the S550 and S650 are, I'm personally happy that we have a potential source of new upgraded parts. We already have the front Brembos which are being released as kits. Some tuners are testing the Get 4 intake manifold on the Gen 3; Wengerd saw gains of ~40hp at the high end. We may get a kit or at least a build guide for that swap. Hopefully we can stay competitive with the S650s now that their tuning is unlocked.

For anyone else reading that would like to help with information instead of saying not to try this:

Can anyone find part numbers for the LCAs/confirm or deny that they are the same?

Does anyone have information on rear hose fittings?

Does anyone have both cars? Are you willing to do some wrenching to see if the knuckle and link fit?

Any guess as to how ABS will behave, and if line lock will be disabled?


TLDR: The rear caliper will only bolt up to the S650 knuckle. All of the connection points in the rear end suspension of the two generations are the same, except we can't confirm that for the LCA. If the LCA is the same, the knuckle should fit, and if the knuckle fits the caliper should mount. New hoses will probably be needed. The electronic parking brake from the GT500 and S650 is probably too expensive and complex to add, so Wilwood's MC4 120-15484/120-15485 are probably the best option for a mechanical caliper. They'll probably need a custom bracket to fit. Overall, I'd budget ~$1000 for this project if you use used parts and do the work yourself, which isn't bad considering the front kit is ~$1500?

OP or anyone else trying to figure this out, feel free to DM. Hopefully if one of us doesn't do it someone will come across this in 6 years and it helps.

 

[MAGS1]

For the fronts, you need the larger 15.4” rotors that are on the S650 if you plan to use S650 Brembos. They don’t work with the 15” rotors found on the S550 cars that came with Brembos. As mentioned above, there are kits available now for our cars.

Have not seen anyone here so the rears from the S650, my guess is the juice may not be worth the squeeze there?

The GT350/R kit is probably the better option if you want the 4 pots in the rear. It’s a bit pricey, but it comes with everything you need and it’s a proven option.

Good luck, will be interested to know if anyone attempts and is successful doing the S650 rear brake swap.

 

[RussShadowS550]

Sadly, you all have convinced me that for me the juice isn’t worth the squeeze. I’m going to do S550 PP fronts with upgraded pads and rotors and see what I want to do after that.

I also decided to use the money saved to invest in quite a few suspension modifications to mitigate rear end slop and add adjustability to my suspension without going super harsh

 

[MrMike]

Sadly, you all have convinced me that for me the juice isn’t worth the squeeze. I’m going to do S550 PP fronts with upgraded pads and rotors and see what I want to do after that.

Why upgraded pads and rotors?

Even fast people use OEM rotors or plain centric rotors on the track. PP pads are fine for a novice, swap to G-Locs once you get faster.

 

[RussShadowS550]

Want the brake dust control while maintaining performance. Plus, I put the kit together individually rather than buying a standard kit. Ended up being minimally more expensive to get G locs and upgraded rotors than a standard PP set the way I did it.

 

[Sumjay]

Sadly, you all have convinced me that for me the juice isn’t worth the squeeze. I’m going to do S550 PP fronts with upgraded pads and rotors and see what I want to do after that.

I also decided to use the money saved to invest in quite a few suspension modifications to mitigate rear end slop and add adjustability to my suspension without going super harsh

Fair enough. Keep in mind you can run just the S650 front brakes. The kit is sold on its own for the S550; might as well use it if you have it already and sell the rears.

 

[Free Spirit]

Fronts are pretty simple. Get a set of copper brake line washers at Autozone. They're under $10, you'll need these for a good seal between the hose and caliper. As for the hose fitment, you can a) email Steeda and ask or b) go to LMR and look at the hose numbers for their Brembo swap kit and compare to OEM. For the rotors - double check that size. I'm pretty sure S550 rotors are 15" and S650 rotors are 15.4". For the shields, LMR has them for ~$40 for the pair.

The rears are the big question. You 100% will not be able to bolt them up without a few more parts. If you don't feel like going that deep scratch that and stick with just the fronts. The car will run fine with that setup.

That said, I've been researching the rear swap for a minute. It's going to be an in depth project, and if you want to attempt it you might be the first to do it. I'll share what I know but can't make any guarantees.

The S550 and S650 rear suspension, (assuming you're not equipped with magneride since you don't already have front Brembos) are essentially the same. Are the shocks and springs different? Possibly, but not in any major way that could affect this project. The toe link (2), strut assembly/mount and spring components (4-10), upper control/camber arm (11), and sway bar components (13-16) are all inter-compatible. My evidence is that Steeda and BMR's replacements are the same part for 15-26. I'm sure a lot of Ford part numbers will match, I just haven't made a list yet.

The variables here are 1 (knuckle), 3 (vertical link), and 12 (lower control arm).

The vertical link is easy - we need the GT500/S650 vertical link. You can find someone's OEM takeoffs or get an aftermarket upgrade.

The LCA and knuckle are the two big issues. Visually, I can't find any differences between the S550's and the S650's. As for part numbers, I'm getting conflicting results but they're either the same or off by a digit.

I can't say for sure without testing, but if every other component is the same across the generations, then the LCA being the same is more likely. If the LCA is also the same, then the knuckle has to be able to bolt up (given that you use the new vertical link). If the knuckle fits, then you can mount your caliper but we need to factor in rotor offset.

If the rotor sits too far out, I don't think the project will work. If it sits too far in, odds are it's just a few mm and a slip on spacer behind the rotor can bring it out. However I can't say for certain if it's safe to use a spacer like that. I will say, given our other factors there's a good chance the rotor fits, and when I put an S650 PP rotor on the back of my S550 the offset seemed the same.

So, if all goes to plan we can remove the original knuckle and vertical link, install the new knuckle and link, and mount up our caliper. Next step: brake lines. I don't know the fitting size or the length of either OEM hose. This info can probably be found online, I just haven't gotten there yet. The S650 hose might be a better option if it fits just because that caliper sits on the front of the hub as opposed to the rear so I'm guessing it's longer. If neither OEM options work, you can definitely order custom rear hoses. Not sure about the price but you can request specific fittings and length.

If everything works up to here, we have a new knuckle, vertical link, rotor, caliper, and hose. The car should be drivable. People on this forum are usually concerned about brake bias when considering this swap; the closet we have is people pairing the S550 GTPP front Brembo 6 piston with the GT350 rear Brembo 4 piston. Two users on this forum have shared their experience; one states the rear end became unstable under a very hard brake, the other states that he felt ABS kicking in and that the car stopped safely. This is outside of my knowledge, but I'm thinking this can be corrected with pad choice, a proportioning valve, or some kind of software adjustment. For you specifically OP, no one knows how the car will respond to having both the front and rear from an S650. The front swap has barely been done, and as far as I can tell, the rear hasn't been done and posted publicly at all. No telling what to expect, so proceed with caution.

Now the hardest part: parking brake. Your options are to either delete it entirely or to go with an aftermarket option. Several states require a parking brake for inspection. This complicates the build as now we're force to used non OEM parts. If we were to somehow retain the S550's parking brake it would kill the whole point of thus swap as its standard and parking brake are one unit. Our generation only had an electronic parking brake on the GT500; it may be possible to use those parts and possibly mix some in from the S650, but that's going to get complicated fast.

There are two aftermarket parking brake styles: electronic and manual. Both will require some type of custom bracket to mount to the car. Electronic brakes are usually $500-1200; probably not worth it. For manual, the only rear option is a Wildwood parking caliper. Specifically the 120-15484/120-15485 (L/R). These are about $190 each. They fit the S650 rotor's width and diameter. The only issues are figuring out a mounting solution and figuring out how to connect the OE parking brake cable.

If you make it to here, you'll have swapped the knuckle, vertical link, rotor, caliper, hose, built a custom bracket, mounted a third party parking brake, and integrated the factory cable. You should have a functioning rear 4 piston caliper and parking brake. Keep in mind you may lose the line lock feature if you have it; I think I heard someone who did the 350 rear sway say that was their experience. It's probably going to be a little pricey and if you need something warrantied on the rear end you'd probably have to revert to stock. Also remember you may have unbalanced braking. And that if you go through with this you're not going to find many resources online to help because this reply is all the information I could find. I might've read that Steeda is looking into this but I could be wrong and they probably would've done it years ago by now.

That being said, I hope you do try it and it does work. While a lot of people are disappointed in how similar the S550 and S650 are, I'm personally happy that we have a potential source of new upgraded parts. We already have the front Brembos which are being released as kits. Some tuners are testing the Get 4 intake manifold on the Gen 3; Wengerd saw gains of ~40hp at the high end. We may get a kit or at least a build guide for that swap. Hopefully we can stay competitive with the S650s now that their tuning is unlocked.

For anyone else reading that would like to help with information instead of saying not to try this:

Can anyone find part numbers for the LCAs/confirm or deny that they are the same?

Does anyone have information on rear hose fittings?

Does anyone have both cars? Are you willing to do some wrenching to see if the knuckle and link fit?

Any guess as to how ABS will behave, and if line lock will be disabled?


TLDR: The rear caliper will only bolt up to the S650 knuckle. All of the connection points in the rear end suspension of the two generations are the same, except we can't confirm that for the LCA. If the LCA is the same, the knuckle should fit, and if the knuckle fits the caliper should mount. New hoses will probably be needed. The electronic parking brake from the GT500 and S650 is probably too expensive and complex to add, so Wilwood's MC4 120-15484/120-15485 are probably the best option for a mechanical caliper. They'll probably need a custom bracket to fit. Overall, I'd budget ~$1000 for this project if you use used parts and do the work yourself, which isn't bad considering the front kit is ~$1500?

OP or anyone else trying to figure this out, feel free to DM. Hopefully if one of us doesn't do it someone will come across this in 6 years and it helps.

Only read the first few words but I recommend avoiding all AutoZone washers. 1, they are NOT the same thickness as OEM. Oem uses some weird size I think it's 1.2 and AutoZone or any hardware store is 1mm or 1.5 neither of which are good. Too thin and it won't crush good, too thick and it won't crush fully or seal. You need 2 per bolt but you can also reuse the olds ones worst case. But the biggest thing is the washers guy get from AutoZone or even Amazon are junk. They are not annealed properly so they are too hard and won't crush. Oem are soft and crush perfectly (I'm a welder and work with metals for a living). There's also 0 reason to not use oem since oem ones are dirt cheap and every dealership that has a repair center or service center will have the washers ON HAND for pickup same day or next day. No shipping no anything needed and you get own quality. Most parts are on hand at dealerships for pickup if you need them ASAP

 

[SVO MkII]

Other than aesthetics, it's hard to make a functional argument for the PP brakes on a street driven car. The main advantage to the larger 6 piston brakes is their ability to absorb greater amounts of heat before experiencing fade. If you are braking so hard and so frequently, while driving on the street, to cause brake fade in the standard 4 piston brakes, you are probably flirting with jail time, or death. Yes, the 6 pistons and larger rotors can provide significant improvement in braking for HPDE, but that is VERY different than street use.

 

[RussShadowS550]

Jail time. Every day all the time. Death never. I'm a vert so sadly, restrictions prevent me from being where I'd like to be (HPDE) and so I just have to make due with early morning weekday fun on rarely traveled backroads. Still got a kid at home non-driving age so can't cage the car or use roll bars to get on track for a few more years. I definitely need the brake upgrade for my own safety as well as for the safety of others in the rare cases where they are needed.

Literally the only excitement I get in my life and not willing to not drive 7-8/10ths rather just do it safely with compliant suspension and adequate stopping power.

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