Lets talk brakes, specifically rears

[Redneckbmxer24]

It's getting close to time to do brakes on my car. I notice that the braking power in the rear doesn't keep up to the power of the fronts at all. I'm interested in doing the 13-14 conversion or the Baer setup (same thing basically) but a lot of people say that once thats done the rears will brake too hard for the factory fronts and that they should be changed to 13-14 6 pistons. I just don't see how that's so. Yes they will have the same diameter but that's where it ends, the fronts still have 3 more pistons, and way more surface area on the pads and rotors. I just don't see how the rears would brake too hard. Can anyone with a 11-12 that has done this comment?

I would probably go with Hawk ceramic pads front and rear and if I do the Baer kit I'd probably do Baer 2 piece rotors in the front as well just too match. I'll also do SS brake lines at the same time.

 

[Imatk]

My first question would be how did you observe that your rear brakes weren't doing the job?

Other than the fact that the rear rotor is tiny in the wheel and kind of looks bad the brakes were setup with a particular bias that works for your front brakes. In other words... they were engineered to work correctly together.

If you put the 13/14 brake on the rear it will affect your bias with the 4-piston brakes. How much I don't know. Will you notice the difference? Probably not too much unless you track the car. Would I do it? No.

But to each his own. The 13/14 rear is pretty inexpensive so I'd say give it a shot and see how you like it.

If you find it's too much brake in the rear and it's braking badly then you can either put the stock rears back on, or move to the 6-piston setup.

Just be aware the 6-piston will need 19" wheels to clear the caliper.

 

[barspen]

I have the '13/'14 rears and they are mostly for looks. I have had ample track time on them and I can tell you I feel no difference in way the car brakes or any feeling of a bias shift. They will dissipate a little more heat, but that's about it functionally. They do look much nicer IMHO.

How can you tell the rears brakes on our cars do very little to stop the car...drive about 40MPH down the road and slowly pull the e-brake. The place you do see heavy rear braking is when traction control engages.

Can't speak to the big brake kits, but I believe those will make a difference in stopping power and the bias. You a probably looking at spending bigs bucks to upgrade all 4 corners.

As far as pad, Hawk makes a solid product, but for the $$, AutoZone CMAX (Duralast Max) pad as a great bargain that provide good stopping power on the street, very little dust and no noise. I've tried a few different types and I'm going back to Duralast Max next time.

For track and autocross use, it's a whole different discussion...

 

[Robert M]

It's getting close to time to do brakes on my car. I notice that the braking power in the rear doesn't keep up to the power of the fronts at all. I'm interested in doing the 13-14 conversion or the Baer setup (same thing basically) but a lot of people say that once thats done the rears will brake too hard for the factory fronts and that they should be changed to 13-14 6 pistons. I just don't see how that's so. Yes they will have the same diameter but that's where it ends, the fronts still have 3 more pistons, and way more surface area on the pads and rotors. I just don't see how the rears would brake too hard. Can anyone with a 11-12 that has done this comment?

I would probably go with Hawk ceramic pads front and rear and if I do the Baer kit I'd probably do Baer 2 piece rotors in the front as well just too match. I'll also do SS brake lines at the same time.

I'm not sure which Baer rear brake set up you saw that is basically the same as the oem 2013/14 GT500, but below is the Baer 6S calipers, front and rear. The rear is standing on its side and the front is laying down.

I took this picture about a year ago for comparison purposes to show that the physical caliper housings are the same size and look very cool when viewed behind a wheel (front and rear), but the pistons are sized accordingly for their specific location, front or rear............

^^^Also note the progressive piston sizes in the front caliper. Unlike some other brake manufacturers that use the same size pistons in each of the four or six bores, Baer has found that piston size progression works best in their Extreme application.




R

 

[ShelbyGT5HUN]

On a previous track car I owned, I ran into a slightly similar problem. I changed a few things in brake department, and was getting rear wheel lock up (non abs car here), under extreme braking. Trail braking with this lockup would cause a spin. I could have added a proportioning valve, but found replacing the rear pads with stock ones, and the leaving the high friction ones up front, worked well and was a cheap and easy fix. You really don't want a ton of braking in the rear. Forward weight transfer, under braking, being the main reason.

Barspen,

Did you notice any improvement in the ability of the traction control system to reign in the wheel spin with the larger rotors? Anything more than half throttle, and this motor has the power to blow through the traction control system. I wish this car had a more advanced/useful trac system.

 

[barspen]

Barspen,

Did you notice any improvement in the ability of the traction control system to reign in the wheel spin with the larger rotors? Anything more than half throttle, and this motor has the power to blow through the traction control system. I wish this car had a more advanced/useful trac system.

With full TC on, the rear brakes engage like crazy and the throttle get cut when you do any trail braking. Never noticed any difference between stock 11.8" and upgraded 13.8" as far as wheel spin goes.

I've run in "Sport" mode on several track runs and it is much less evasive, but far from perfect. It does help me get a feeling for when I'm pushing the car too much on a course.

Robert, those Baer 6P calipers look incredible

 

[Imatk]

You guys should try the 07 GT500 TC... it never engages hehe.

I think it turned on a couple of times at a stop sign near my work because the stop is on a slight hill so when you leave the right wheel loses a bit of traction.

Other than that the TC just never comes on.

Yeah I mean I get it that the rear brakes don't really have much braking power, but like Shelby wrote you really don't want too much in the rear. You want most of your braking up front.

I suspect even if you went to a Baer setup in the rear you wouldn't find much difference in pulling the e-brake... if you did it would overpower the ABS anyway which you wouldn't want.

I remember having a car back in '05 and slapping a BBK on it. It was awesome until I overpowered the ABS and hit what they call "Decel Hole" nearly pooped my pants because the damn brakes just stopped working for a second because the ABS couldn't keep up.

 

[Robert M]

Robert, those Baer 6P calipers look incredible

Thanks, I grabbed them from eBay when Shelby Auctions had them listed. I chose the Red/Black lettered Baers for the front when my car went through the Mod Shop, they looked best with my Torch Red - Black striped '08, IMHO. Then a couple of years later the rears became available from Baer, so I saved and saved and saved until I was able to get matching rears in Red/Black letters. Then at some point I noticed Shelby offered Nickel plated Shelby calipers for a $300 upgrade, I wanted those, but I did not need the whole kit for the front and rear again, and Baer wanted $1200 per caliper?!?!?!?!?

Tom (Shelby Auctions) listed these Nickel Baers in two different auctions, they were missing some hardware but the calipers were there and that was all I needed. I cut an even better deal with him when I told him I didn't need the hardware, just the calipers (he needed the hardware for another set he was going to sell). By the time it was done, I think I have $1200 including shipping in those 4 Nickel 6S Extremes, the rears are new and the fronts need to be resealed.

^^^That was a steal!!

I am not sure what color I am going to do the letters on those Nickel calipers? All Black? Black "SHELBY" and "6S" with the Baer claw in Red? The paw Black and the claws Red? <<I'm not sure yet? Either way, they will look pretty cool!!



R

 

[Ohio Snake]

I have a '12 GT500. I pulled the factory Brembos and rear FOMOCO off and replaced with Shelby Wildwood front and back system (black w/ Red lettering Shelby).
The front was replaced with the 6 piston then tested with the original OEM rears. Huge difference in braking power for the front.
Replaced the rears with the 4 piston. All calipers match and not that much noticeable difference from OEM rears.
Frickin looks great with cross drilled two piece rotors and works great. This year is the third year with them on.


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Geoff M
2012 Shelby GT500
2015 BMW 528i xdrive
2015 Winnebago Vista 35F

 

[GT Premi]

I have larger rotors in the rear and notice that the rear end will wiggle a little bit if I hit the brakes too firmly at high speed.

 

[Robert M]

I have a '12 GT500. I pulled the factory Brembos and rear FOMOCO off and replaced with Shelby Wildwood front and back system (black w/ Red lettering Shelby).
The front was replaced with the 6 piston then tested with the original OEM rears. Huge difference in braking power for the front.
Replaced the rears with the 4 piston. All calipers match and not that much noticeable difference from OEM rears.
Frickin looks great with cross drilled two piece rotors and works great. This year is the third year with them on.


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Geoff M
2012 Shelby GT500
2015 BMW 528i xdrive
2015 Winnebago Vista 35F

^^^Yes to that^^^. There are so many cars out there in todays world, hi-performance and even lesser performance that have nice looking caliper options front and rear. The matching look does not add so much to braking performance, but it does add to visual performance..........<<Is that a performance? visual?


You all know what I mean......




R

 

[Ohio Snake]

^^^Yes to that^^^. There are so many cars out there, hi-performance and even lesser performance that have nice looking caliper options front and rear. The matching look does not add so much to braking performance, but it does add to visual performance..........<<Is that a performance? visual?


You all know what I mean......




R

Both actually. Mostly performance.


Sent from my iPhone using Tapatalk
Geoff M
2012 Shelby GT500
2015 BMW 528i xdrive
2015 Winnebago Vista 35F

 

[Imatk]

I saw a GT350 yesterday when I had to take my car in for the aribag thing... those rear Brembos look sexy as hell

 

[Steve@TF]

My first question would be how did you observe that your rear brakes weren't doing the job?

Other than the fact that the rear rotor is tiny in the wheel and kind of looks bad the brakes were setup with a particular bias that works for your front brakes. In other words... they were engineered to work correctly together.

If you put the 13/14 brake on the rear it will affect your bias with the 4-piston brakes. How much I don't know. Will you notice the difference? Probably not too much unless you track the car. Would I do it? No.

But to each his own. The 13/14 rear is pretty inexpensive so I'd say give it a shot and see how you like it.

If you find it's too much brake in the rear and it's braking badly then you can either put the stock rears back on, or move to the 6-piston setup.

Just be aware the 6-piston will need 19" wheels to clear the caliper.

this.

the stock brakes are certainly sufficient if you change the pads. certainly for street. for track, change the pads, fluid and add SS lines.

i upgraded to 13 stock brakes front and rear. ss lines, ATE brake fluid and hawk pads. ive tracked the heck out of it never had an issue with fade. i never tracked on the stock brakes but i know van has said many times that the stock stuff is sufficient if you make the minor changes, that you should make anyways. and that's for the track. for the street? you really dont need any of that. maybe just the pads. otherwise its all for looks.

you have to be careful of some of the big brake kits that slap big brakes on the front and rear. they could possibly be throwing the brake bias off. most of the time its for looks, and its an expensive look.

before the 13s came out, it was quite common for guys to upgrade the rear brakes to 14s with Baers eradispeed(?) kit. probably not noticeable on the street (bias wise).

keep in mind, the more crazy you go with brakes, like race spec, the more often you need to maintain it. the faster you will consume pads and rotors and stuff. oem stuff is designed to last a long time. but also depends on how much you drive the car and how of course. high performance brake fluid does need to be changed at least once a year though iirc. and definitely overkill for a street car. and if you do track it, youre supposed to bleed it between track days.

I'm not sure which Baer rear brake set up you saw that is basically the same as the oem 2013/14 GT500,

he may possibly be referring to the Baer kit which allows you to run a 14" rear rotor. so the rears are the same as 13/14s, but fronts are not.

i think they have an adapter kit now from ford racing? but i got an early set of oem 13/14 rear brakes and we had to pull the axles to install them. quite a bit of work for that.

 

[Mainn]

this.

the stock brakes are certainly sufficient if you change the pads. certainly for street. for track, change the pads, fluid and add SS lines.

i upgraded to 13 stock brakes front and rear. ss lines, ATE brake fluid and hawk pads. ive tracked the heck out of it never had an issue with fade. i never tracked on the stock brakes but i know van has said many times that the stock stuff is sufficient if you make the minor changes, that you should make anyways. and that's for the track. for the street? you really dont need any of that. maybe just the pads. otherwise its all for looks.

you have to be careful of some of the big brake kits that slap big brakes on the front and rear. they could possibly be throwing the brake bias off. most of the time its for looks, and its an expensive look.

before the 13s came out, it was quite common for guys to upgrade the rear brakes to 14s with Baers eradispeed(?) kit. probably not noticeable on the street (bias wise).

keep in mind, the more crazy you go with brakes, like race spec, the more often you need to maintain it. the faster you will consume pads and rotors and stuff. oem stuff is designed to last a long time. but also depends on how much you drive the car and how of course. high performance brake fluid does need to be changed at least once a year though iirc. and definitely overkill for a street car. and if you do track it, youre supposed to bleed it between track days.

VERY good post.

I'd also like to add that I would be very reluctant to install larger brakes on the rear and leave the fronts stock. The last thing you want is the bias moving further rearwards, and having the rears lock up (or close to) first. It can actually reduce braking efficiency. I would only do this if I had a way of easily adjusting the bias.

With the race car, I replace the brake pads after every round. Same with a brake fluid bleed. You don't want track pads/rotors/fluid if you're not driving it on a track, trust me.

 

[Robert M]

VERY good post.

I'd also like to add that I would be very reluctant to install larger brakes on the rear and leave the fronts stock. The last thing you want is the bias moving further rearwards, and having the rears lock up (or close to) first. It can actually reduce braking efficiency. I would only do this if I had a way of easily adjusting the bias.

^^^^That is Very True. The big brake aftermarket kits have had some brake bias engineering behind them to work together front and rear for the specific application.

Changing one end without the other, or mis-matching for "a look", can degrade the performance of the brakes quickly.





R

 

[Robert M]

I had to dig back through some pictures to find this comparo...........

^^^^^^^^^Shown above are my oem 2008 rear rotor (top), the Baer Eradispeed rear rotor upgrade (left) that Shelby installed on my car when it was at the Mod Shop, and the Baer 6S Extreme rotor that was part of the Extreme rear brake upgrade including the 6 piston calipers. Notice the pad contact surface (heat dissipation and wider pad contact/friction area) between the two Baers.

Me personally, did I "need" the big brakes for performance? No. They are for looks on my car but they will do anything I want to do on the street. Shelby installed the large (nice looking) big brakes on the front and the Eradispeeds rotors on the rear, but this set up retained the oem single piston black caliper...........<<This look terrible in my opinion when viewed from the side of the car, especially through large 20" Alcoa's!

My 2008 is heavier than a 2013/14, if the SVT engineers (SVE) felt that this 100lb lighter nosed GT500 needed some additional braking from the factory with it's 662hp capabilities, I at least want to have my heavier nosed 2008 725 at a similar level if I press the car.

I also compare what other lighter hi-performance cars have for braking, let's say the multiple variations of Corvette, they have some monster brakes for their weight and hp levels. <<This tells me that a larger (well designed/engineered) system is not going to hurt the performance of a heavy GT500 Shelby, but the emphasis is "well designed/engineered".

............but do I "need it"..............No.....


I do also agree that the brake system needs to be well maintained, fluid regularly flushed etc. Many owners change pads and push that nasty contaminated (rusty) fluid back into the master cylinder when they compress the caliper pistons for the pad install. <<<This would be a Great time to open the bleeder(s), push the pistons back in and flush the system completely starting at the right rear.......




R

 

[whiplash920]

I have a similar situation for rear brakes, not trying to thread jack, but this is along the same lines.

Just upgraded my rear 8.8 to a strange s track and 35 spline axles c clip eliminator. Was told my stock brake setup would work, but when putting rotor and caliper mounting bridge on it became obvious the ends they put on my rear were for the larger 13' rotor.

So my plan is to order the larger 13.7" rear rotors and plug n play. My car has about 700 whp and does see the drag strip about 10 times a year. Should I be concerned about anything? Some on here have said there may be issues while others have said they did this and had none. Well?

 

[barspen]

Should I be concerned about anything? Some on here have said there may be issues while others have said they did this and had none. Well?

You have nothing to worry about. I've run larger rears on the street, several HPDE days and occasionally on the strip for almost 18 months. Increasing the rotor size creates no noticeable difference. They simply look better and dissipate heat a little more efficiently. Your pad choice has more impact if you uses different compounds on the front and rear, but that typically only applies for road course work.

 

[Robert M]

One other thing to mention as it relates to rear brake upgrades.........

I was on a mission to further upgrade my current 14" Extreme rear rotors to 15", that is a $995 optional set up from Baer and I had already done this on the front. A member on another forum actually did this upgrade using the solid Baer Extreme rotors instead of drilled/slotted. I noticed he mentioned that the car was now "grabby" when the brakes were applied. <<That saved me $995. I will stay with my 15" front and 14" rear, no need to introduce braking issues by trying to go bigger and bigger.........




R