Checking out the possibility of upgrading my rear brakes to the GT500 Rotors. Supposed to be a very easy swap but does require the rear axle to be pulled. Going to have my differential serviced anyway so though this might be the time to pull the trigger. Wanted to verify that I have everything I need. If so I can get the parts for under $400 shipped.

Are these the only parts needed to upgrade the rear GT brakes to the GT500 brakes on the 2013/2014 models? I realize I probably don't need the bolts, but may start with new.

 

If you want to Vorshlag sells a kit with everything you will need for around $300. There is also a guy who sells a bracket so that you don't have to pull the axles in order to put the new brakes on.

Here you go

http://www.svtperformance.com/forums...brackets/page2

 

Read from this page forward...

https://themustangsource.com/forums/...0006/index194/

 

Thanks I will check these out.

Edit:
The Vorshlag package is what I was trying to build and you even get the ceramic pads too. Great info on both posts.

 

In case anyone else is interested in this upgrade here is the Vorshlag product mentioned above. Nice write up on why you want to do this.

http://www.vorshlag.com/product_info...roducts_id=606

 

Since I always over analyze things I decided to talk to one of the shop mechanics at my favorite local Ford dealer about the rear brake rotor swap. I want to know what I am getting into before I proceed in making the change, any change to my car.

Love the idea of more stopping power, cooler brakes, and a better looking back rotor through the wheel spokes. Does seem like a lot of open air in the rear wheel. Rear rotor just looks very puny compared to the front.

The mechanic seems to be very knowledgeable on Mustangs and modifications. He had heard of the GT500 rear rotor swap, but had not done one. He had concerns the increase diameter of the rotor and moving the brake calipers further out from center would cause uneven braking. His concern is that this change would shift the majority of the braking to the rear wheels. He thought that by doing the swap the rear brakes would become more sensitive than the front, more likely to lockup or trigger anti-lock braking. He had concerns of car control issues when braking.

Is there really a concern here?

What have those that have made the move experienced? Does the hydraulics of the braking system compensate for the change? Or is there some kind of an adjustment required?

 

I did this swap. Larger diameter rotor only improves braking because the larger surface dissipates heat better. Just do it.

 

Yes it does increase braking torque on the rear wheels as you suggest. This does shift the brake bias toward the rear wheels a little.

But it is not a problem. The front brakes still do most of the braking. ABS still works fine; as far as I can tell. I'm pretty sure the ABS front and rear circuits are separate.

I have run mine on road course, high speed and very hard braking right on the edge of ABS with no problems. There might be some situations where it would matter, like maybe threshold braking in snow or ice but I think it is fine in most situations.

EDIT/NOTE: I have the Brembo front brakes and I assume the others who have commented have those also. Your signature says you have the track package so I believe that means you have the Brembos up front, so you should be all set. I would not do the rear brake upgrade with the standard non-Brembo brakes on the front.

 

What he said! The brake bias does shift a tiny bit, but not enough to the point where you are upsetting the balance of the car under braking. There is a few long threads over on TMO about this and no one has had any adverse effects from doing this.

 

+1. The only situation I can think of where this would make a difference is in trail braking. Tail might start coming around more with less brake pedal apply mid corner. But that's the same effect as having more aggressive pads on the rear, and ABS won't care since it does closed-loop control on wheel slip. But some people like more rotation mid corner with trail braking, so it depends on how you look at it.

 

I did this with my 2011 GT, with 3-4 track days per year. Excellent upgrade, very good price, and you get to re-use your stock calipers. Great stopping power on the track, without cooking the rear brakes. Brake bias change in minimal if you have front Brembos. Here's my TMS thread on this:
https://themustangsource.com/forums/...pgrade-537228/
Also, you may need to file down your calipers for rotor clearance, like a couple millimeters, at most. Good luck!

 

Great info from all of you. Thank you to all for the input. Glad to hear this really is a non-issue.

PRJMGMT... Great thread, thanks for the link. I now remember reading that thread. I think that is were the bug was planted... Thanks for pointing me in that direction. Great info in there. Nice to read the positives and glad to find no negatives on this Mod.

 

The Vorschlag kit looks like you have to pull the axle to install the new brackets. The other brackets from the other links above just bolt right on. Not sure what you are thinking but just wanted to mention that again.

 

Yeah, just do it already!

 

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It is my pleasure, good luck, and post up results.

 

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So what I learned a couple years ago when I did this is that there are two approaches to the brackets:
1) REMOVE the OEM GT/Boss caliper mounting brackets, and install OEM GT500 brackets. Need to pull the rear axles out on each side to do this.
or
2) KEEP the OEM GT/Boss caliper mounting brackets, and install adapter plates/brackets that mount to the original bracket...an extender...if you will. These are not made by Ford, but others on TMS have used them with no issues reported. Benefit here is it is much quicker and easier, without the need to pull the rear axles out.

I went the OEM route, just to be a little safer, knowing that this is the setup used for the GT500. See others' posts to get more info on the adapter method, if desired.

 

I have the extenders, and my pics are in one of the threads linked earlier in this thread.

I was a little concerned about adding the extender to the original bracket which was not designed for that additional load/bending moment . . . but I know others have used those on the track and I hope there is enough safety factor built in to the design of the original brackets to handle the extra stress.

But yeah if you want the safest approach, OEM is the way to go.

 

Thanks everyone. Great info!

 

How much more stopping power does this mod really give you. Yes it looks much better but does it make a world of difference? How many feet can you shave off your stopping distance from say 60 mph?

 

It would be more for cooling and keeping the brakes working during long track days as opposed to raw stopping power.