I will be assembling my front end and rear axle late this Summer and would like to begin identifying what the plan will be for braking.

The car is currently on 17" front wheels and 18" rear wheels, I could go to 18" fronts if I have to, but I prefer not to.

The plan is primarily street driving, rare road course time, and more frequent autocross. The car is equipped with a 6spd and the occasional high-speed braking event will happen. The car is also configured for a manual master cylinder.

Naturally, I am also after larger brakes to fill up the open 5 spoke wheels. The current 11.75" front brakes are quickly swallowed up. I currently have late-model B-body spindles, from what I understand, they are too tall and put extreme angles on the upper ball joints. So I may need to budget for spindles as well.




I would like to spend no more than $1,750 for front and rear disc brake assemblies [brackets, hoses, mounts, rotors and calipers, hubs (if applicable)].


Options I have found within budget

Currently Dr. Diff seems to have product offerings within my budget, the Cobra 13" front kit and Cobra 11.7" rear kit.

• http://www.doctordiff.com/cobra-style-13-front-disc-brake-kit.html
• http://www.doctordiff.com/rear-disc-brake-kit-11.7-rotor.html

My Questions

• Does anyone have either of these Dr. Diff kits? What are your thoughts and do you have any installed pictures?
• What other comparable options are out there keeping a ~13" front and ~12" rear rotor?

I am not considering a "custom" brake setup as my time-frame to get the car on the road again is quite compressed, a bolt-on solution is much more appealing at this stage. Perhaps it will be something I entertain down the road, as I do have access to a laser cutter/mill/lathe, but I am just not chasing that project at this time.

I haven't used them but they seemed liked quality parts. I like Dr Diffs rear kit as it has the parking brake built into the caliper and just uses an aluminum adapter instead of welding a mount to the rear end. I believe the parts are commercial off the shelf from a Mustang GT. I have the front end kit. It also wasn't difficult to install. Using washers to shim and center the calipers got old and annoying. My only gripe about them is the redrilled Mercedes rotors. God forbid Dr Diff discontinues the rotors or goes out of business, someone who doesn't have access to a reliable machine shop may have trouble sourcing rotors. However, I believe Dr Diff can get you a set of 2 piece Baer rotors. The calipers are also ginormous.

In the pictures, the rear setups were with a 17" wheel I borrowed from a friend. The fronts were with 18" wheels. The calipers were barely rubbing on the 17" wheels.

Ah no, read the tech article,

http://www.bigblockdart.com/techpages/spindles.shtml

Don't you have aftermarket UCA's as well? Some of them re-angle the UBJ to "correct" this as well.

Let me find my broken record. Unless you are running national level competition, advantages of the largest rotors for improved "Modulation", are unnecessary, you likely have more flex modulation issues with the MC firewall mounting, but size also helps with extended braking, of course, and from a weight standpoint, the cheesiest brake duct set-up will easily match the next sized up un ducted rotor, besides all the cost and rotational weight issues of hauling around the extra heavy rotors. From what you have shared, in your application, IMO, anything over 13" front and 12 3/16" rear, with any ducting, is eye candy.

Thanks for the link, I have not come across that one before. It seems to make a case for the late B spindles, it's worth trying. They're paid for.

As for UCAs, I do plan on buying a set of Hotchkis uppers.


I based my earlier statement on this write-up:





http://www.moparaction.com/Tech/archive/disc-main.html

What about just sticking with the stock brakes for now until you want to take the time to build a cool setup from scratch? (It's not all that hard really having done it) Just as a thought to save the in between sort of step if you have a larger setup in the back of your mind as a plan still..

I run the Cobra style setup on my '70 Challenger. It is street driven and gets back to back road track laps on a course tough on brakes.

Fronts are originally from Baer upgraded with rotors and recommended pads from Dr Diff (EBC Yellow from Summit). Rears are the Dr Diff 11.7" setup. I changed the rears to discs after I thoroughly burned up the drums up on the track.

The EBC yellow pads are a bit soft cold and warm up and bite well with one good stop. I trust the setup with hard braking from ~130, ~90 and ~110 MPH inside 1 minute 30 seconds.

The Cobra setup is well balanced F/R. Piston area on the Cobra calipers is kinda small and it needs plenty of line pressure. A Dr Diff 15/16" master + 8" dual diaphragm booster gets it done for me.

Pic of the rear is attached. I do depend on the parking brake with a manual transmission and it works fine.

PS: The rear setup does space the axle flanges out a little. With tapered bearings, that means the axles need to be a little longer. I welded a hardened washer to the end of one of my axles and ground it down to set end play. I understand an alternative is to add adjusters to both sides of the axle.

Im currently building a setup for my Dart using new C7 Corvette Brembo calipers...I got a complete set of front & rear new takeoffs on ebay for a steal of a deal. Way cheaper than the Viper brembos I see on there and always lots available. Some Wilwood hubs and brake hats, stainless hoses and MC from Dr. Diff, and custom rotors from Coleman Racing. Fabbing the custom mounts myself and into the setup for under 2K. Just my $0.02

Ehrenberg was spitballing when he wrote not to use the taller spindle.

The link I posted has actual numbers and testing done.

as much as i respect e-burger, i have always challenged that spindle deal for the simple fact that the "perfect" factory setup, due to the "exceptionally educated and trained engineers" is just a COMPROMISE in ride and handling for the uneducated masses who really don't give a big fig about how their car handles. else why is there such a huge deal made about eliminating the dreaded bump steer inherent in the "perfectly designed" factory setup ? plus the fact i have personally installed almost 40 sets of the "wrong" spindles over my lifetime and have had NOT ONE ball joint failure nor ANY alignment issues. these have racked up thousands of miles and some applications have been beat on like the proverbial "rented mule". in fact almost one of the first discussions i got into when joining up here was this very issue. i just asked "WHY NOT" ? at that time i had many of these spindles installed and running for years with no issues. why, you would have thought the end of the world and man's being was near ! a lively discussion it was indeed. the topic was still a hot issue every time it was brought up until the testing with numbers article was written, then it calmed down somewhat with e-burger still claiming the end is neigh. until just the last decade or so, the ONLY vehicles that truly had handling FACTORY ENGINEERED were the sporty types. all else was just a compromise for the masses because they hardly ever drove to the limits and they could just care less anyhow, as long as the ride was cushy and the car went in the direction it was pointed. and no, i don't have "SAE" after my name so don't hold that against me, please.

For an $89 fee you too can have SAE after your name. It's nothing more than a club, essentially. You do not need to be an engineer or even competent to join, just $89.

http://www.sae.org/membership/join/

Can I put SAE before my name for the same amount of money?
I personally don't dwell on any title anyway. Seems to me in our discussions, its just a threshold for one to stop thinking, and begin blind faith.

I used (as did Feets as well) Mercedes AMG Brembos.. 8 piston front and 4 rear. If you keep an eye out they come up for decent prices used as well.

With quite a few newer cars using the big calipers (and rotors) going with take off stuff and just doing some fab work you can end up with a pretty good package for a decent price.

I need to find some take off 14" rotors with around 1.5" offset. I hate being neutered on wheel choices with what I have now.

I looked at many options to source an off the shelf rotor and there is nothing with the proper bolt pattern and offset I needed.

The Wilwood brake hats I used were bout $130/pc and now I can just order the rotors from Coleman Racing or wherever with the hat bolt pattern and diameter/thickness of my choosing at any time, and no worries about rotors being discontinued or needing a bolt pattern machined into them.

Don't limit yourself to the original bolt pattern on the rotor...there are a ton of different things out there if you just have the rotor redrilled for bolt pattern. If you do some looking you should be able to find the rotor height you need I'd think.

Mercedes AMG 360mm (converts to around 14 1/4" from memory) rotors redrilled on my car. (The AMG rotors are slightly thicker then a lot of the other 14" ones out there from memory so make sure your caliper will suit it, these are the original 8 piston ones so fit is perfect.)

I had to watch rotor height too, to clear the rims I am using, these worked out well.

Thanks for the input all. I've decided to go with a Wilwood rear disc kit and put on what i have already for the front [11 3/4"]. I'll dig into the car after it's together to upgrade the front brakes to what I want later on.

Priority #1 is to get it on the road again! I'd rather hold off and do what I want over a weekend rather than delay the drive date.

Im sure you might be able to find something with the right offset or correct bolt pattern...but finding both together wasn't possible for my setup. Plus, I just didnt want the hassles of having to machine my bolt pattern in all my new rotors everytime I need to replace them!

I don't have a cheap source for machining, so for the cost of machining and cost of off the shelf rotors is way more than my rotors from Coleman. Also the aluminum rotor hats I used help knock off some weight too!

Yeah, I think my SRT rotors are pushing 30 lbs each.

is there a site that has a "calculator" type of set up that allows one to type in rotor size, hat offset, hub diameter, etc. and come up with a close match on a one piece factory type rotors ? if not, and i can imagine that would take an incredible amount of info to even come close to being workable, what or where is the best place for this info to be sourced ?