Big Brake Kit on a Budget, has been pondered in parts on these previous threads...
- Front rotor upsize
- Rear options
- Rear e38
** What is BBKoB? **
- Your original front calipers, euro CSi excluded.
- A larger front rotor borrowed from the e60. Representative examples...
Brembo on a plain Zimmerman...
..or ATE-60/30, on a slotted & drilled Centric.
- A bracket pair that repositions your existing caliper to fit the larger rotor.
Two versions depending on caliper, and also left & right side.
- Optionally, a swap out of the rear stock caliper for something more substantial.
Here the E90-44/22, on a slotted Centric.
** Status **
For a half year now a couple of friendly e31's have been running around with this BBKoB stuff installed.
Back in the shop, a small lot of mounting brackets have been produced to the final specification.
In parallel, an inventory of other deliverables has been built up including rotors, calipers, pads, etc.
** What now? **
I am now looking for another install, maybe two, to happen some time between September 16 and September 30.
This will involve me driving to you with a box full of BBKoB stuff and either Brembo or ATE up front, demo'ing the result, then installing on to yours.
For this immediate project, the deliverable options will limited to the following...
- Rotors will be Centric brand, basic style, not slotted or drilled
- New pads, supplied by me, with an option of either Jurid or Centric PQ's.
- Your choice of rebuilt rear caliper from: e31-40/12 (no not your old ones), e38-40/20, e53-42/12, e53-42/20 and e90-44/22.
- Beck/Arnley brand rubber hoses, not stainless braided
- ATE brand parking shoes if needed
- Pentosin brand Dot4LV fluid
Interested candidates should contact me at hyper@hyperworld.com.
Please satisfy these criteria...
- You are an adventurous soul, especially when it comes to cars.
- You live within a radius of the San Francisco Bay area.
- You own the e31 getting the brake update.
- You like my deliverables as-is.
- You have 18" wheels all around including the spare.
- Your e31 is roadworthy and you intend to drive and report on the swap.
- You have access to a level work space that you can call your own. Sorry apartment dwellers.
- You have "a little bit" of money that you don't mind wasting on your car.
Beyond this round of installs, 2018 could see the shipping of a DIY kit that includes the front brackets, rear calipers and a tool set.
Last edited by Hyper; 08-23-2017 at 05:28 PM. Reason: More criteria
* Yep, eighteen inches separates the men from the boys.
During development the front mod failed my 17" style 42's, and in the rear I surprisingly got the e38-40/20 mod to fail a particular 17" aftermarket.
* I wouldn't know what people are looking to spend. Perhaps something less than a Brembo GT BBK plus rears. Btw, my near-term installs are loaded with my services and R&D amortization.
This looks like a well executed idea. I am interested but on the wrong coast, when you get further along the line I may buy a set. How much pad surface is gained with the rear swap?
*In the short term, I see more installs by me, then local pro shops, then distant pro shops, then maybe someday owner diy's.
*At the rears the nominal pad size is not changing, but rather the pressure is altered by the selection of a different piston size.
(Nominal: I've found some brands that have a beveled pad material vs straight sides on others, thus altering the surface area).
To decode the caliper nomenclature...
- e31-40/12 and e38-40/20 have the stock 40mm diameter piston size.
- e53-42/12 and e53-42/20 are at 42mm. Alex is using this and is the standard pairing for the upsized front.
- I've been using the e90-44/22 at 44mm to eval the limit of front-rear balance.
To a first order approximation the pressure should increase in proportion to the area.
After that you are into a half-dozen non-linearities in the pads, the braking system and the operator.
- - - Updated - - -
Any chance of 4 Pots for the rear? Or Brackets to mount them, Very interested in going that route and thanks for sharing your work, Awesome skills!
Probably no chance.
Im not opposed to 4-pot technology but, "Budget" applies to R&D time also and I'm trying to get back on to engine & ecu development.
*********
As you could see in the rear link post #1 that, given data about rotor diameters and offsets for each of the bmw models, it was relatively quick to come up with alternate calipers that are easily rebuilt and require minimal machining (e53-42/20 & e90-44/22) or are bolt-on with no machining (e38-40/20, e53-42/12, e52-46/20).
If there WAS out there a common dirt-cheap 4-pot that could be adapted, it would have to compete against the list of known solutions.
There are cheap alternatives, I was just checking to compare.
Are the single pot calipers lighter than the brembo ones?
Loaded with pads, and prob some fluid...
Per a counter top scale, Brembo: 9.6lbs, aka 4.4kg
Per a bathroom scale, ATE: 14.6lbs, aka 6.6kg
ATE iron is heavier than Brembo alum by 5lbs, aka 2.2kg.
Can we order just the brackets for the Brembo calipers?
No.
I can't devote any time to that business matter, and the brackets won't go out without a kit surrounding it.
The kit involves tools and instructions. The tools are not built yet, the instructions need work.
Stepping back for a bigger picture, the installation procedures need verification on a larger sample set than 2 and the plan was/is for me to do the work on several more victims to check out the steps.
Also the early kitting is to include rear calipers to follow the method that has been proven to work so far, in terms of satisfaction over the end result.
The only way to proceed currently is for a local victim to sign up with work done by me at my place.
However, I'm about to lose my garage bay to another job that has me under pressure.
I don’t understand. What if someone doesn’t want all that? If all it’s doing is shifting the position of the caliper to utilize an e60 rotor why not just sell the bracket and allow people to get their own pads and rotors and what not. Doesn’t it just bolt on?
Sure, I'll take another try.
My goal is to guarantee an end result concerning your vehicle braking performance, not to just sell a part.
You Working on a turbo kit?
No. But if I was, that kit would also require tools and instructions, which don't exist either.
And it would require a beta cycle of testing and review, along with a managed roll out.
So don't bother asking for a turbo mounting part.
*** The real story ***
The piston & rod is real.
Its a tear-down, update & rebuild of my Ford Vulcan 3.0 V6 push-rod, currently developing 125 hp according to my G-Tech.
A later crank and pistons lower NVH and drag for an asphalt-ripping 145 hp. So...
A turbo is hanging around for back-burner space-planning what-if R&D, and to make my posts look better than other people's.
There are some issues that can come up that make the install go from level 3 install (scale of 1-10) to a level 9 real quick. From backyard wrenching to specialty tool that some mechanic shops don’t even carry. This is due to the our aging cars and all backup parts and tools should be available in hand when the install takes place or the car willl be on lift while specialty tool gets in.
Note, my car is pretty mint too and there were obstacles that came up that was definitely out of my level of expertise.
Alex
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