Junkyard Dog said:

Can the OEM S650 4 piston rear brakes be retrofitted onto an S550?

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I dont know honestly. I also believe s650 hasn't the brake by wire tech?

The brakes are still hydraulic. They are electronically boosted.

The rears have an electronic parking brake, which the S550 has a mechanical.

But the brakes themselves should work. You just have to figure something out for the parking brake if you want to use one.

This guy started the swap, with photos. I don't know whether he ever finished.

flyhalf said:

update
Real good info on the REAR BRAKES
Some update and great info for many of us.
I'm researching the best option for optimizing heat management for rear brakes in the PP mustang.
Small summary.
As you know we have 1 single huge piston.

I'm looking for 4 piston caliper option to better heat managing the rear brakes ,pad life and consistency

Identified 3 options
1 AP racing. REAR KIT 4piston
2 WILWOOD 4piston 20mm rear kit
3. Gt350

So I talked to AP RACING. They absolutely advice to AVOID installing only their rear kit. Especially for the Mustangs.
According to them their kit is created to work in tandem with the front.
They said the ICE MODE we have is mainly due to the REAR single piston triggering the abs cause the very strong torque and low modulation.

I always thought the front is the issue. This was revelation if it is true.
For sure it is exactly what I'm experiencing. En fact, I reduced the Ice mode putting OEM
Rear compound rather than more aggressive pads.
(But they last 3 sessions at max pace)

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Modulation with the AP system is superb. Nick even says it is better than the Brembo system in the DHR but overall braking performance with the Bosch ABS system is better than OEM 350 or even the FP 350 setup he had in the white car. You don’t need to be fixated on the rotor diameter but AP does strongly advise using either their front set alone, or in tandem with the rear kit. Not rear only for sure. Secondly you may think the AP investment is expensive which it is, but amortization of consumable costs vs the OE based setup you are running will prove out in about 25 track days. The rotor rings last 1.5 times longer than Girodisc and 2X over OEM. The 25 mm thick endurance pads last 2X over the factory Brembo shape and cost just a few dollars more. And please try and get away from those Hawk pads. If you don’t like the Pagids, (don’t understand that but to each their own) try some things from Ferodo or Mu. You deserve to be running proper Motorsport pad compounds. Finally post some full brake g traces, would love to see what sustained deceleration rate looks like. All that aero is definitely paying off

Honestly I will probably do this swap some time further down the road

What Steveespo said over the hawk pads. I have seen new DTC30 pads AND discs ruined in one 10min qualy session. They did not like braking from 150mph in a heavy car. At all!

You are at the point that you are asking the ABS and brake components to work with things they weren't calibrated for. Suspension, aero, power, weight have all changed. You've spent on everything else, now its time to spend on the brakes. Trouble is S550's aren't as easy electronically to mix and match like S197s.

Quick answer is FP350s ABS and the AP Front and rear kit. But also remember suspension/shock/ride height can all play into brake performance as well.

@Mad Hatter hopefully they weren't being used on the Front axle, if so, that is on the driver choosing the wrong compound for the job.

Thanks

ajaquilante said:

You are at the point that you are asking the ABS and brake components to work with things they weren't calibrated for. Suspension, aero, power, weight have all changed. You've spent on everything else, now its time to spend on the brakes. Trouble is S550's aren't as easy electronically to mix and match like S197s.

Quick answer is FP350s ABS and the AP Front and rear kit. But also remember suspension/shock/ride height can all play into brake performance as well.

@Mad Hatter hopefully they weren't being used on the Front axle, if so, that is on the driver choosing the wrong compound for the job.

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ajaquilante said:

You are at the point that you are asking the ABS and brake components to work with things they weren't calibrated for. Suspension, aero, power, weight have all changed. You've spent on everything else, now its time to spend on the brakes. Trouble is S550's aren't as easy electronically to mix and match like S197s.

Quick answer is FP350s ABS and the AP Front and rear kit. But also remember suspension/shock/ride height can all play into brake performance as well.

@Mad Hatter hopefully they weren't being used on the Front axle, if so, that is on the driver choosing the wrong compound for the job.

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Thanks AJ. IKnow I should do it but but I unfortunately dont have enough. I read a post here on Trackmustang saying the FP350S is a nightmare to install. I do have the M4 bosch option but it is unknown territory to how be in the car. Mmr makes a plug and play m5bosch for mustang but is 9 grand.
Fpr the suspension. I guess a softer springs might give more front grip? Would that be better? However I was thinking actually slightly stiffer cause the splitter hits a little too much the ground.
Please feel free to advice.

my last question for you is. If you have 10k only. Would u upgrade the hardware or the abs first?

About Bosch M5 being plug and play from MMR, I see nothing in MMR's ad that makes it actually as simple as they make it sound. Plus, I'd spend some money on fittings/ brake lines to move it from from the over-crowded area next to the master cylinder to the passenger foot well. Is M5 Clubsport ABS worth it at your level of car at this point, I'd say yes

One catch is that any aftermarket ABS install will have the same issues with the OEM electrical infrastructure. FP350 ABS should have the least since its from Ford. I've done some work to see what has to be done to keep other things happy but other projects have gotten in the way. I'm fairly certain I can get around most OEM things, you never know what you may run into when unplugging important pieces of the puzzle. They also all will need to have brake lines modified/lengthened shorted/re-flared, etc.

I'm assuming the M4 system is used, if so I'd pass. Those units are a minimum of 10 years old now.

Have you had anyone else drive the car to give feedback? Giving suspension advice over the internet is nearly impossible when you consider the variables of different stuff people have done and different tracks. I've hopped in a few cars that I was told by the owner that the car felt great to them only for me to run 5 laps or 10 laps and come back with a list of things to work on. Also what kind of data collection are you using?

Is there any data on the front pad? How is your wear? We ran DTC-60s on the front with the 6-piston PP caliper with good success, but with a lot less horsepower, and only OEM body work.

10k to spend? Skip a few events, wait till the budget is bigger, so you can take one big step to my answer in my first reply instead of tiny steps.

ajaquilante said:

About Bosch M5 being plug and play from MMR, I see nothing in MMR's ad that makes it actually as simple as they make it sound. Plus, I'd spend some money on fittings/ brake lines to move it from from the over-crowded area next to the master cylinder to the passenger foot well. Is M5 Clubsport ABS worth it at your level of car at this point, I'd say yes

One catch is that any aftermarket ABS install will have the same issues with the OEM electrical infrastructure. FP350 ABS should have the least since its from Ford. I've done some work to see what has to be done to keep other things happy but other projects have gotten in the way. I'm fairly certain I can get around most OEM things, you never know what you may run into when unplugging important pieces of the puzzle. They also all will need to have brake lines modified/lengthened shorted/re-flared, etc.

I'm assuming the M4 system is used, if so I'd pass. Those units are a minimum of 10 years old now.

Have you had anyone else drive the car to give feedback? Giving suspension advice over the internet is nearly impossible when you consider the variables of different stuff people have done and different tracks. I've hopped in a few cars that I was told by the owner that the car felt great to them only for me to run 5 laps or 10 laps and come back with a list of things to work on. Also what kind of data collection are you using?

Is there any data on the front pad? How is your wear? We ran DTC-60s on the front with the 6-piston PP caliper with good success, but with a lot less horsepower, and only OEM body work.

10k to spend? Skip a few events, wait till the budget is bigger, so you can take one big step to my answer in my first reply instead of tiny steps.

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Thanks AJ, I answered you in PM

Not sure if he's still active - but @Black Boss put an FP350S ABS unit in a 350R a while back

honeybadger said:

Not sure if he's still active - but @Black Boss put an FP350S ABS unit in a 350R a while back

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Yes he did and it was originally a nightmare with the available AP kit that was supposedly designed for it. Working with Essex Nick got it dialed in but it is an incremental improvement over the GT350 programming and involved changing alot of hydraulics and the module to the Boss 302S/R version basically. I agree with AJ, at Alessandro's level of performance, going to the Bosch system is the smart answer. There is plenty of information and parts availability from Ford to make a very capable GT4 level braking system. Expensive? Yes. Plug and Play? Well none of this is plug and play but the work to install a 10 year old system from a factory car that never really raced at a Pro level also won't be plug and play. The answer is Bosch/Brembo in my opinion. $30,000 transmission deserves $20,000 in brakes. Getting close to just buying a GT4 car at this point.

flyhalf said:

They said the ice mode is actually due to a roo strong rear brake. So their kit moves forward the bias even more. This Matches what I feel actually. I have less ICE MODE WITH REAR OEM PADS. In other words because the the rear is worse from a
Clamping force it doesnt trigger that much the ABS.

Which sucks cause it reduces the overall braking capacity.

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The OEM ABS on this things is made for Street cars if the rear sees more than 1.2G of braking it triggers the ABS Ice mode. What cure it for me was going back to OEM rear pads. But in your case RSL 29 should be very close in mU to rear pads but much more durable for that 40 minutes session. I don't know why you are missing the Bear Brakes Rear Kit but Kenny Brown actually offers a great rear kit for S550s 15-inch REAR Extreme Plus Brake System hope this helps.

steveespo said:

Yes he did and it was originally a nightmare with the available AP kit that was supposedly designed for it. Working with Essex Nick got it dialed in but it is an incremental improvement over the GT350 programming and involved changing alot of hydraulics and the module to the Boss 302S/R version basically. I agree with AJ, at Alessandro's level of performance, going to the Bosch system is the smart answer. There is plenty of information and parts availability from Ford to make a very capable GT4 level braking system. Expensive? Yes. Plug and Play? Well none of this is plug and play but the work to install a 10 year old system from a factory car that never really raced at a Pro level also won't be plug and play. The answer is Bosch/Brembo in my opinion. $30,000 transmission deserves $20,000 in brakes. Getting close to just buying a GT4 car at this point.

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I think @Fair used a Factory Boss302R ABS in his car but he runs custom ECU no reason why the FP350 unit (M-2323-D)
will not work but you will still need a custom ECU to make it work properly at least the ABS was reasonably priced at around $1200 and should be easier to apply than anything else. I didn't know the AP kit could work with the OEM rear so that's a good way forward.

bnight said:

The OEM ABS on this things is made for Street cars if the rear sees more than 1.2G of braking it triggers the ABS Ice mode. What cure it for me was going back to OEM rear pads. But in your case RSL 29 should be very close in mU to rear pads but much more durable for that 40 minutes session. I don't know why you are missing the Bear Brakes Rear Kit but Kenny Brown actually offers a great rear kit for S550s 15-inch REAR Extreme Plus Brake System hope this helps.

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RSL29 is a good rear pad. RSL 1 or RST5 up front.

ajaquilante said:

@Mad Hatter hopefully they weren't being used on the Front axle, if so, that is on the driver choosing the wrong compound for the job.

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Point taken, was a friends car and they were up front. Told him not to do it!! Got to say, I told you so...

Keep in mind that in order to program the Bosch M5, you need a 1500$ cable.

Have you looked into Delta ABS? Half price of the M5 and much easier to setup

The other thing is maybe ditching the ABS completely. How does a properly setup with dual master and a balance bar compare to an OEM ABS system?

I spoke with delta. Lots of. I dont know. Maybe u need to research.

MMR has an m5 I dont want to say plug and play but very close to it.
And they pre program the abs base on their s550 (i run with them so very similar level on power and aero)
I also might have a gt4 m4 bosh.

But again. Would u install this before better hardware?

Lastly, no abs is slower IMO @Fabman might say if he would love the abs in his

flyhalf said:

But again. Would u install this before better hardware?

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If you don't want to have ABS Ice Mode yes. Because you can't have better hardware without the Ice Mode gone.

Found the article about stock style abs I had read. Short version, it assumes you are on ice until it determines otherwise everytime you hit abs. So upgrading the abs system first then allows what you have to work better straight away. Then you can address wear rates etc.