My own JK 'Big Brake' research:

I think that between the information you have already released and some recent pics you posted, the savvy readers :blush: will be able to guess where the rotors came from.

I must applaud you on your effort thus far :clap2: It is nice to know that there still are those who think outside the box
"Neccesity is the mother of invention, it is true -- but it's father is creativity, and knowledge is the midwife."- Jonathan Schattke
 
Markymark420 said:
I think that between the information you have already released and some recent pics you posted, the savvy readers :blush: will be able to guess where the rotors came from.

I must applaud you on your effort thus far :clap2: It is nice to know that there still are those who think outside the box
"Neccesity is the mother of invention, it is true -- but it's father is creativity, and knowledge is the midwife."- Jonathan Schattke
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First, thanks :)

Second, I agree. There's nothing secret here. Like I said...I'm trying to do as much as possible with off the shelf parts. For the 'less-than'saavy' crowd, or the more impulsive-types out there, I just didn't want to anger them if they suddenly ran out to start buying parts and then I found the need to head a different direction. There are several posters on this thread with less than 10 posts (not that I have many myself LOL) that may just be here looking for a quick answer to this issue. I just wanted to keep inpulsivity down a bit until I had definitive results. ;)
 
Oh, and you should see the spreadsheet I just built to analyze ratios of master cylinder bore to total caliper piston areas for different possibilities... Very geeky, yet very, very useful!!
 
Md_rubi said:
Wondering if your brackets will fit the rockjock?
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I would need 3 measurements to tell you:

1. center to center distance between caliper mount holes on the knuckle
2. distance from front face of those holes to front of hub flange
3. distance from centerline of hub/axle to one of those caliper mount holes (this measurement is difficult to get unless you have the axles out

If you happen to get these to me I'm happy to check!
 
Awsome work here! just read through it all and cant wait to see the final product:thumb:
 
Don't assume fewer posts means less savy. ;)

Very interested in this project and I want to say THANK YOU for sharing this with us along the way. You could have waited until you were completely done and then done a write-up, but letting us share your trials and tribulations as you progress through this project keeps us all on the edge of our seat like a good novel. Well done so far. I can't wait for the next chapter!


Sent from my iPhone using WAYALIFE mobile app
 
dgriz said:
Don't assume fewer posts means less savy. ;)

Very interested in this project and I want to say THANK YOU for sharing this with us along the way. You could have waited until you were completely done and then done a write-up, but letting us share your trials and tribulations as you progress through this project keeps us all on the edge of our seat like a good novel. Well done so far. I can't wait for the next chapter!

Sent from my iPhone using WAYALIFE mobile app
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Thank you very much!! And of course you are right...fewer posts just means new here, like me...not less saavy. :)
I'm really glad there is so much interest in this. I've had a lot of vehicle projects in the past and one thing I've found people sometimes put off in an effort to get to the big tires and other fun stuff is the boring stuff...like brakes to stop those huge wheels. So I hope that if I can make this all affordable, more people will be inspired to do it right and keep themselves safe!
 
So my little Excel spreadsheet that I constructed to analyze master cylinder and caliper piston size combinations has revealed a few interesting points.

1. I think that using front and rear calipers off of a pickup truck is NOT going to be a good idea. An interesting pattern arises when you compare MC:caliper piston area ratios (pardon the technical ramble here, but I find it is interesting and pertinent to doing this right the first time) - pickup truck brake systems have a disproportionately large difference in the MC:caliper piston area ratio between the front and rear brakes. My theory is that this actually reduces the hydraulic advantage (and thus pressures) at the rear brakes in an effort to avoid rear wheel lockups in a truck caused by the very front-heavy weight distribution of a pickup. Now I understand that a proportioning valve can also serve this purpose, but after I compared a bunch of braking systems out there, I think the OEMs do this in part to rely less on a proportioning valve in controlling rear wheel skid on hard braking.

Why does this matter?? Well, because our JKs are NOT a truck. The weight balance is much more even. If I tried to use front and rear truck brakes, we would actually lose potential braking power in the rear. Its all about the caliper piston surface area compared with MC piston area, and the ratio of caliper size front to rear.

Like I said... just trying to be thorough and get us the best bang for our buck!
 
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so the flux capacitor with solid state caps is out and the jigawatt matrix isolator will reduce the efficiency of using buckminsterfullerene for the rears?

just having fun...thanks for the updates!
 
jeeeep said:
so the flux capacitor with solid state caps is out and the jigawatt matrix isolator will reduce the efficiency of using buckminsterfullerene for the rears?

just having fun...thanks for the updates!
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:cheesy: :cheesy:

Just watch out if you hit 88mph!!
 
I have to say I've seen this post on the "today's posts" for a while and have kept over looking it until today. This is by far one of the best threads I've come across if not for the potential awesome brakes then simply for the determination you've shown in your research. It's also very impressive how you could potentially make a lot of money off of this research but are willing to give it to us for free. Thanks and I will be following along!
 
So this may be stupid, but what if you used the 2 sets of front brakes off or a ram, with a different master cylinder?
Not super familiar with dodge trucks, but all the fords I have had have rear drum brakes, would this account for the difference?
 
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Lane87 said:
I have to say I've seen this post on the "today's posts" for a while and have kept over looking it until today. This is by far one of the best threads I've come across if not for the potential awesome brakes then simply for the determination you've shown in your research. It's also very impressive how you could potentially make a lot of money off of this research but are willing to give it to us for free. Thanks and I will be following along!
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Well now you guys are giving me alot to live up to! I sure as hell hope I don't fail! LOL! :thumb:

It's been quite fun and a great learning experience so far, so I don't see why I won't carry this through to the end. Putting together the Excel spreadsheet to do all of the calculations of piston area vs master cylinder bore, etc, was the best thing I could have done. It allows you to see visually what combination of front and rear calipers will give us a certain type of pedal feel. I think I'm gonna have to just buy the caliper tomorrow.... then I can move on to taking measurements for the caliper bracket/adapter. I noticed some online fab shops selling such adapters out of aluminum, and while good for heat dissipation, I feel more comfortable using thick plate steel. 120+lbs of spinning wheel/tire is a huge rotating mass, and I feel better with a big chunk of steel holding my caliper to my knuckle. My machinist is just itching to do the first one!!

BTW, as a question to the crowd: If you were going to be able to order the calipers painted, what color would you pick if they were all to be ordered in the same color? Assuming standard colors (silver, red, black, blue...) - not body-matched colors.

Thanks for following this fun project everyone!!! Even my boys are excited to see your questions and help with the research!!
 
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