New brake kits

[LittleBeefy]

I really like those calipers too - and they're really popular for some of the newest Fox body conversions but I feel those calipers are all too small for the front of our heavy rigs. Perhaps @LittleBeefy may have other feelings but I think calipers with total piston areas in the low-mid 4" sq.in. range are too small.

Todd Z.

@duffymahoney I hate to rain on your parade, but @toddz69 is spot on. There is no way I would put those CTS-V calipers on a Bronco. The pistons are way too small. Even if you found a way to use a similar sized rotor as a CTS-V (14.57"!), the stopping power just isn't there. Compare the CTS-V Brembos to the GM front disk swap kit:

Brakes	Rotor Size	Piston Size	Piston Count	Piston SA	Distance of piston center from edge of rotor	Piston CoF Distance	Caliper PSI	Clamping Force	mu	Braking Force	Braking Torque (lb*ft)
1978 Chevrolet calipers	11.72​	2.953​	1​	6.85​	1.476​	4.38​	550​	3766​	0.4​	3013​	1101​
2009 CTS-V Brembos/14.5" rotors	14.57​	1.496, 1.339, 1.181	3 (6)	4.26​	0.669​	6.62​	550​	2344​	0.4​	1875​	1034​

So you get better braking with the GM calipers. Plus the cost of two piece custom rotors that fit the 5x5.5 hubs for the CTS-V calipers would be astronomical. I don't know if you've priced those before, but a cheap set is about $1k and you could realistically expect to pay twice that in a lot of cases.

Lastly, aluminum has a lower modulus of elasticity than steel or iron. Higher modulus of elasticity means less flex. Aluminum has a modulus of around 10 million Pascals, cast iron is around 14.5 million and steel is about 30 million.

If I were to use an off-the-shelf opposing piston caliper, I'd probably adapt the Toyota 4Runner or LandCruiser units. Big pistons and less flex.

https://www.rockauto.com/en/moreinfo.php?pk=9744404&cc=3307075&pt=1704&jsn=683
https://www.rockauto.com/en/moreinfo.php?pk=9744412&cc=3307198&pt=1704&jsn=783

I personally don't see a tremendous amount of value in using aluminum calipers in trucks and SUVs. I have no interest in reducing unsprung weight for a vehicle that I'm not trying to get great handling out of. I know people like the way they look (I do too), but I'm not going to sacrifice stopping power for aesthetics.

 

[duffymahoney]

The Brembo CTS-V 6 piston is
2x1.2
2x1.3
2x1.5
So roughly 8

Also the mustang is roughly 8 as well.

 

[toddz69]

The Brembo CTS-V 6 piston is
2x1.2
2x1.3
2x1.5
So roughly 8

Also the mustang is roughly 8 as well.

But you only count half the pistons when computing piston area for brake force calculations.

Todd Z.

 

[toddz69]

If I were to use an off-the-shelf opposing piston caliper, I'd probably adapt the Toyota 4Runner or LandCruiser units. Big pistons and less flex.

https://www.rockauto.com/en/moreinfo.php?pk=9744404&cc=3307075&pt=1704&jsn=683
https://www.rockauto.com/en/moreinfo.php?pk=9744412&cc=3307198&pt=1704&jsn=783

I messed around with the Toyota stuff years ago when I was still trying to fit calipers like that under 15" wheels. I realized that it's nearly impossible to mount tab mount (or whatever proper term is) rotors on 4WD knuckles and have enough space for everything under a smaller wheel. The stock EB drum knuckles are easier than the '76-newer disc knuckles but still not easy.

Todd Z.

 

[LittleBeefy]

I am positive that a hellfire is about to rain down on me for showing y'all this, but I'm a big believer in math, so I'm going to lay it all out for you in a clear numerical format. Here are many of the options for brakes that you can put on the front of a Bronco. I listed them from best to worst in terms of stopping performance. I will admit to having to take some liberties in estimating the exact center of the pistons relative to the axle centerline (I don't have access to the CAD schematics to make these exact). What pad you use will have an impact, but you can find varying coefficient of friction pads available for most of these, so I standardized at .4. There's also pad deformation, caliper flex, larger MOI for larger or thicker rotors, sliding caliper compression force requirements, etc that are wholly omitted from this calculation (I'm sure I'll be damned for eternity by some for making such a greivous mistake in the name of coming up with actual numbers). Regardless, this creates a very reasonable basis of comparison for every option.

If you disagree with these numbers, show me yours. In God we trust, but all others must bring data!

Brakes	Rotor Diameter (inches)	Piston Diameter (inches)	Piston Count	Piston SA (inches^2)	Distance of piston center from edge of rotor (inches)	Piston CoF Distance (inches)	Caliper PSI	Clamping Force (lbs)	mu	Braking Force (lbs)	Braking Torque (lb*ft)
Huge Brakes Upgraded Package	13.3​	2.205​	2​	7.64​	1.06​	5.56​	1200​	9162​	0.4​	7330​	3397​
2020 F150 (stock)	13.78​	2.125​	2​	7.09​	1.06​	5.83​	1200​	8512​	0.4​	6809​	3307​
Huge Brakes Base Package	13.25​	2.126​	2​	7.10​	1.06​	5.56​	1200​	8520​	0.4​	6816​	3159​
1976-79 F250/F350 (D60 with Dual Pistons)	12.56​	2.181​	2​	7.47​	1.09​	5.19​	1200​	8967​	0.4​	7174​	3102​
SSBC 66-75 Conversion	12.13​	3.150​	1​	7.79​	1.57​	4.49​	1200​	9349​	0.4​	7480​	2799​
1978 T-Bird calipers	11.72​	3.094​	1​	7.52​	1.55​	4.31​	1200​	9025​	0.4​	7220​	2595​
2022 Bronco (stock)	12.24​	2​	2​	6.28​	1.00​	5.12​	1200​	7540​	0.4​	6032​	2574​
1978 Chevrolet calipers	11.72​	2.953​	1​	6.85​	1.48​	4.38​	1200​	8217​	0.4​	6574​	2401​
Wilwood D8-4	12.19​	1.880​	2 (4)	5.56​	0.94​	5.16​	1200​	6672​	0.4​	5338​	2293​
1975-79 Ford F150/F100/Bronco calipers	11.72​	2.870​	1​	6.47​	1.55​	4.31​	1200​	7764​	0.4​	6211​	2232​
Wilwood Forged Narrow Superlite 6R	12.88​	1.75, 1.25x2	3 (6)	4.86​	0.71​	5.73​	1200​	5832​	0.4​	4666​	2228​
Wilwood Forged Dynapro 6	11.75​	1.62, 1.38x2	3 (6)	5.06​	0.86​	5.02​	1200​	6072​	0.4​	4858​	2032​
2003 F150 calipers/12"	12​	1.750​	2​	4.81​	0.88​	5.13​	1200​	5773​	0.4​	4618​	1972​
Baer 6P 11.9" Front Pro+	11.9​	1.625, 1.375, 1.1875	3 (6)	4.67​	0.70​	5.25​	1200​	5600​	0.4​	4480​	1961​

If you want to convert from drums to discs and still use 15" wheels, go with the SSBC kit (shameless plug: we sell them and they are a very affordable option)
If you have a 76 or 77 with stock discs, want better brakes and still use a 15" wheel, go with the T-bird calipers (you can get them just about anywhere and may or may not need to do some very minor clearancing to them to fit your brake hose on the caliper outlet)
If you want the best brakes and are okay with a 17" wheel or bigger, the Huge Brakes kits are unbeatable.
If you are dying for aluminum, opposing piston rotors, keep an eye out for the SSBC 6 piston kit that we will have available for sale very soon. Until then, the best option in aluminum is the Wilwood D8-4 kit.

 

[duffymahoney]

So basically I could go

@duffymahoney I hate to rain on your parade, but @toddz69 is spot on. There is no way I would put those CTS-V calipers on a Bronco. The pistons are way too small. Even if you found a way to use a similar sized rotor as a CTS-V (14.57"!), the stopping power just isn't there. Compare the CTS-V Brembos to the GM front disk swap kit:

Brakes	Rotor Size	Piston Size	Piston Count	Piston SA	Distance of piston center from edge of rotor	Piston CoF Distance	Caliper PSI	Clamping Force	mu	Braking Force	Braking Torque (lb*ft)
1978 Chevrolet calipers	11.72​	2.953​	1​	6.85​	1.476​	4.38​	550​	3766​	0.4​	3013​	1101​
2009 CTS-V Brembos/14.5" rotors	14.57​	1.496, 1.339, 1.181	3 (6)	4.26​	0.669​	6.62​	550​	2344​	0.4​	1875​	1034​

So you get better braking with the GM calipers. Plus the cost of two piece custom rotors that fit the 5x5.5 hubs for the CTS-V calipers would be astronomical. I don't know if you've priced those before, but a cheap set is about $1k and you could realistically expect to pay twice that in a lot of cases.

Lastly, aluminum has a lower modulus of elasticity than steel or iron. Higher modulus of elasticity means less flex. Aluminum has a modulus of around 10 million Pascals, cast iron is around 14.5 million and steel is about 30 million.

If I were to use an off-the-shelf opposing piston caliper, I'd probably adapt the Toyota 4Runner or LandCruiser units. Big pistons and less flex.

https://www.rockauto.com/en/moreinfo.php?pk=9744404&cc=3307075&pt=1704&jsn=683
https://www.rockauto.com/en/moreinfo.php?pk=9744412&cc=3307198&pt=1704&jsn=783

I personally don't see a tremendous amount of value in using aluminum calipers in trucks and SUVs. I have no interest in reducing unsprung weight for a vehicle that I'm not trying to get great handling out of. I know people like the way they look (I do too), but I'm not going to sacrifice stopping power for aesthetics.

Steel brake calipers just rust, zinc coating looks like crap after a year or two. Nice aluminum calipers, just are nice I found online that the 4 piston cts-v is 6.26. Front 2 pistons are 1.63 and back 2 are 1.5. I also love the how they top load the brake pads on some, just nice designs.

I don't know how their e-brake works, I can't seem to find that info. I asked my buddy that designed the cts-v kit for the 240z.

 

[LittleBeefy]

So basically I could go

Steel brake calipers just rust, zinc coating looks like crap after a year or two. Nice aluminum calipers, just are nice I found online that the 4 piston cts-v is 6.26. Front 2 pistons are 1.63 and back 2 are 1.5. I also love the how they top load the brake pads on some, just nice designs.

I don't know how their e-brake works, I can't seem to find that info. I asked my buddy that designed the cts-v kit for the 240z.

I'm not sure how you get a SA of 6.26 using those piston measurements. I get 4.33. You only use one side for SA because the formula for braking force accounts for the other side.

I agree that aluminum calipers look great. I think that's one of the reasons people pay so much for them and use them on the $250K+ Bronco builds. I get my iron calipers powdercoated so they don't rust, but they still don't look as good as aluminum calipers.

 

[duffymahoney]

I'm not sure how you get a SA of 6.26 using those piston measurements. I get 4.33. You only use one side for SA because the formula for braking force accounts for the other side.

I agree that aluminum calipers look great. I think that's one of the reasons people pay so much for them and use them on the $250K+ Bronco builds. I get my iron calipers powdercoated so they don't rust, but they still don't look as good as aluminum calipers.

See I didn't know that

 

[LittleBeefy]

@gunnibronco How about an update on that brake swap. Did you get it done? If so, how were the results?

 

[gunnibronco]

@gunnibronco How about an update on that brake swap. Did you get it done? If so, how were the results?

Unfortunately I haven't done anything. I didn't want to tear into it before Super Cel in NV. This week I had other priorities. Now I'm leaving town for 2 weeks for work. So it's going to be a little while still. I'll be sure to report back. All the parts are sitting on the shelf, just waiting.

 

[gunnibronco]

I tried, but was quickly stopped in my tracks. The Eldo caliper uses a 7/16" banjo bolt, the JB/JD6 calipers use a 10mm so my brake hoses won't fit. I'm running custom hoses from Crown Performance so it will take a couple weeks to get new ones made.

I did post a couple questions about the Eldo calipers on another thread if anyone knows the answers please, and thank you.
https://classicbroncos.com/forums/threads/eldo-calipers-without-e-brake.322019/

 

[56f100bbw]

I’ve been looking at brakes set up for my 65 Fastback street or track brand are really nice but quite expensive

 

[toddz69]

I’ve been looking at brakes set up for my 65 Fastback street or track brand are really nice but quite expensive

I love Shaun's stuff at Street or Track. Most of his brake kits appear to be using Wilwood calipers or some clones thereof. I do like his vintage K-H Trans Am setup too. Mike Maier also has some nice setups from Wilwood that are less $$, I think.

Todd Z.

 

[gunnibronco]

Here is a comparison of your current brakes vs the large Eldo brakes (assuming you are using the very common FF pads):

Brakes

Rotor Size

Piston Size

Piston Count

Piston SA

Piston CoF Distance

Caliper PSI

Clamping Force

mu

Braking Force

Braking Torque (lb*ft)

Bias Rear

Bias Front

Fronts (FF pads)

12.95​

2.2​

2​

7.60​

5.3765​

550​

4181​

0.4​

3345​

1499​

Current rears (FF pads)

12.50​

2.935​

1​

6.77​

4.7825​

550​

3721​

0.4​

2977​

1186​

44.2%​

55.8%​

Eldo rears (FF pads)

12.50​

2.5​

1​

4.91​

5​

550​

2700​

0.4​

2160​

900​

37.5%​

62.5%​

So I pulled my JD6 calipers off and test fit the Eldo calipers last night so I can measure/order brake lines.

My current rear pads are GH rated. So my bias is even worse than your calcs. I don't know what my fronts are, I can't see the rating and haven't pulled the calipers to check, but my guess is they are FF.

 

[nvrstuk]

OK, glad I got hooked up here
Great thread.

 

[bronco italiano]

I have a custom kit setup for my 240z. It's not cobbled together, it's engineered with stop tech for perfect bias, pedal feel and stopping. It's amazing.

Is it the Z car garage kit?

 

[duffymahoney]

Is it the Z car garage kit?

Yes it is. It's a miata kit that they adapted

 

[bronco italiano]

From memory BMC69 told he that he used a dual piston caliper for a 70's model F250-350 once on one of his builds.
I thought it was interesting but never pursued it myself and I don't think I have ever seen anyone do that before?

That caliper is a Monster

 

[Yeller]

I wish the friction numbers were listed when you are shopping for pads. I would really like to try some FG pads on the front of my bronco but since they aren't listed all my local parts store has is FE for friction material and I'm sure what are on it, can no longer tell, and I'm sure contributing to my bias issues, the rear are FF. Anyone have any tips? calipers are from an85 chevy K30.

 

[bronco italiano]

Yes it is. It's a miata kit that they adapted

I paid over 4k for that Baby big brake kit. Stop tech brakes are incredible. My son is a professional driver and he really likes the balance/brake force on his Z.