My own JK 'Big Brake' research:

Majik said:
I've been doing alot of digging lately, trying to reassure myself that my caliper selection is valid. I found a nice piece of info: Wilwood makes a 'big brake upgrade' for the JKs now. It's cheaper than the $4400 Brembo upgrade...but it still costs about $2000 just for the front caliper and rotor. Nothing else. Still 'ouch' in my opinion. But here's the reassuring part: they just so happened to select a 4 piston caliper, using 44mm pistons, and a 14" rotor!!! The caliper I'm working with uses the exact same piston sizes, and the rotor is the same size, too! They also advertise that their system, because of the caliper selection they use, does not require a master cylinder upgrade! (Which is the same thing my calculations indicated for a 4-piston, fixed caliper with 44mm pistons.) This is EXTREMELY reassuring info. Now the only thing to determine is whether or not their upgrade's braking improvement is strictly due to the larger rotor, or if the fixed 4-piston caliper design actually adds power vs our stock floating piston design. On paper, the effective piston surface area is not any larger with their fancy, fixed design. But, as I've discussed before, the question is whether the more rigid, efficient caliper, combined with the much more even application of pad force due to the multiple piston design actually adds braking power. My suspicion is that yes, it does, and that it may be more noticeable than a simple comparison of caliper piston sizes might show. If it didn't add performance, why would auto manufacturers use them on their 'performance' models, like the SRT8 packages from Mopar, or the GT500 package from Ford, when they are in the business of making money? If a cheap floating caliper with one or two pistons with EQUAL piston surface area to a 4-piston caliper fixed caliper provided the same performance, and give them the same 60 to 0 times to post, I highly doubt they would fork out 3-4 times the price for a fixed caliper.

Guess it's time we prove that idea :) The pressure film I mentioned last week is being shipped and should be here any day. Then maybe we will have some comparisons of stock vs new caliper pressure distributions to view! All in all, I am going to continue with the 4-piston fixed caliper build, after coming across applications like the one from Wilwood that I mentioned above. I think we are on solid ground.
Click to expand...

Sounds pretty cool :brows: looking forward to 14" brakes without robbing a bank :bleh:
Thanks for all you efforts :beer:
 
I subscribed to this forum for this thread. :clap2:

Looking forward to the progress. Subscribed!


No sig yet - I'll get on that. Standard stuff: 37's, LS V8, etc. :beer:
 
Majik said:
I've been doing alot of digging lately, trying to reassure myself that my caliper selection is valid. I found a nice piece of info: Wilwood makes a 'big brake upgrade' for the JKs now. It's cheaper than the $4400 Brembo upgrade...but it still costs about $2000 just for the front caliper and rotor. Nothing else. Still 'ouch' in my opinion. But here's the reassuring part: they just so happened to select a 4 piston caliper, using 44mm pistons, and a 14" rotor!!! The caliper I'm working with uses the exact same piston sizes, and the rotor is the same size, too! They also advertise that their system, because of the caliper selection they use, does not require a master cylinder upgrade! (Which is the same thing my calculations indicated for a 4-piston, fixed caliper with 44mm pistons.) This is EXTREMELY reassuring info. Now the only thing to determine is whether or not their upgrade's braking improvement is strictly due to the larger rotor, or if the fixed 4-piston caliper design actually adds power vs our stock floating piston design. On paper, the effective piston surface area is not any larger with their fancy, fixed design. But, as I've discussed before, the question is whether the more rigid, efficient caliper, combined with the much more even application of pad force due to the multiple piston design actually adds braking power. My suspicion is that yes, it does, and that it may be more noticeable than a simple comparison of caliper piston sizes might show. If it didn't add performance, why would auto manufacturers use them on their 'performance' models, like the SRT8 packages from Mopar, or the GT500 package from Ford, when they are in the business of making money? If a cheap floating caliper with one or two pistons with EQUAL piston surface area to a 4-piston caliper fixed caliper provided the same performance, and give them the same 60 to 0 times to post, I highly doubt they would fork out 3-4 times the price for a fixed caliper.

Guess it's time we prove that idea :) The pressure film I mentioned last week is being shipped and should be here any day. Then maybe we will have some comparisons of stock vs new caliper pressure distributions to view! All in all, I am going to continue with the 4-piston fixed caliper build, after coming across applications like the one from Wilwood that I mentioned above. I think we are on solid ground.
Click to expand...

So the monobloc brake calipers on my old bike were worlds better than standard Brembos. It was like putting braided lines in place of stock lines all over again but without the somewhat wooden feel the braided mod did. I think you are definitely on to something.
 
That is one helluva slab of steel there!!! I'm in lust!

Although I do have to wonder if there will be any issues with heat dissipation with there being so little clearance in there... Still, good job!

EDIT: Ok, after spending a bit more time drooling over the photos I guess I was just being paranoid. It looks like there's still plenty of room for the ventilated disks to breathe. :D
 
Last edited:
P33J_JK said:
Beefy caliper = heat dissipation
Click to expand...

That's what I've been told! And this caliper is huge compared to stock :) Huge rotor, too.

One thing though that I've tried to keep in mind during my work on this: Heat dissipation is likely to be a minor issue for us with Jeeps. We are unlikely going to be doing back to back to back hard braking like a sports car that is carving corners. That application has to really think hard about heat dissipation. Our rigs need raw brake torque for low speed crawling, and for panic braking on the road (which should typically only occur once in a while with cold brakes anyway). Think about it... Have you ever had to worry about brake fade due to a repeated set of panic braking scenarios back to back to back? Probably not. We want super strong brakes that can be modulated easily while crawling down a hill, and brakes that will stop on a dime even with 120+ pound, 37"+ rim and tire combos, when someone runs a red light while you are on the way to your favorite trail. Now...... I will recognize the need for fade-resistance when driving our rigs down a very long grade, when towing, or in the mountains heading downhill, but in those scenarios, we all should be using some engine/tranny braking anyway :)

Raw brake torque comes from sticky pads that are sticky even when cold, big rotors, and strong calipers. Thus my focus with this project :) We obviously are going to gain huge amounts of fade resistance compared with stock anyway...
 
You must log in or register to reply here.
Top Bottom