Agree completely. Had a project once where we tied into an existing 8" water line. Turned everything on and pressure was right where we expected. Continued with construction and after a couple of months we got to the point of doing tests on the complex. Pressure was great but after only a couple of minutes the pressure dropped big time. The line we tied into was at the end of a big loop and what we knew was an 8" line had only about a 1" passage through a bunch of sediment. Pressure but not the volume to back it up. Would be the same with calipers as bigger pistons will require more fluid. Would need to determine whether the system is able to provide sufficient volumes to maintain the clamping force created by the pressure. Hence the need for piston and incoming orifice information.

 

I am not raining on the parade. This is one good video of one problem to avoid.

 

I did say I was "crazy", not stupid. Although I do know I need no help looking stupid, as I can do that all by myself every day.

 

As soon as I heard him say he was in Gainesville and saw he had blue & orange colored sneakers on, I knew why he had the stupid look on his face at the beginning of the video, UF. Most people with common sense know that FSU is the better university just as in North Carolina its NC State.

 

ugh.....that kid has much to learn about brakes and NOT USING A TORQUE WRENCH TO LOOSEN LUG BOLTS!!!!!!!!!!!
I hate 6 piston kits, the caliper is going to flex more than a 4 piston. People like 6 piston because it "looks" cooler........

 

He saved so much money on the kit that he went out a bought a new torque wrench. Its in another of his vids . . . . .

 

that is the same as the gp2 caliper right? I had them on my 135i. The ceramic pistons will decompose/crumble on the track but fine for street I liked them

 

 

You learn to walk by falling first so either you are just really smart and know about the elsd thing or you have fried some eggs. Also, yes the Gen2 GP rotor appears to be the same thing as the 135i BMW rotor.

Some "thoughts", notice the quotes as I am by no means a brake expert, in no specific order.

1.) For some reason BMW decided to use 4x100 bolt spaced hubs on our Gen1 and Gen2 cars. There are not too many performance cars out there with such a set up unless you consider a Scion worthy of that term, I do not. Couple that with the 22mm rotor thickness and the options are not that great.
2.) As energy cannot be destroyed, the speed/force of a car is converted to heat when we want to slow down with our foot on the brake pedal. Therefore, less energy will need to be converted by using a larger rotor.
3.) With a larger rotor, a smaller clamping force would be required thereby requiring less piston force that also reduces the need for a larger brake cylinder.
4.) A larger pad with both surface area and volume is able to dissipate the created heat quicker. This also applies toward a rotor.

With these thoughts a brake system wish list might be; a.) Thicker rotor, 25 to 32 mm (1' to 1 1/4"), b.) Wider rotor, 316 to 330 mm (12 1/2" to 13") c.) A bigger brake pad, 8 square inches or larger, and d.) Total caliper piston areas not much larger than the R56/Gen1 JCW of approximately 3.5 square inches. Keeping Mr. UF in mind, need to make sure the wheel offset will work along with the inner rim dimension.

To accomplish the above, and considering the 4x100 issue, it appears that Wilwood has rotors and hats that will accommodate.

 

Are people driving these cars so hard on public roads that they find the brakes insufficient with performance pads, fluid, and brake lines? For track-work, sure, I understand the urge to move toward a BBK.

 

I've cooked street pads in the mountains, so yes..

 

And what were you running for a pad?

 

There are a few things that I found out after destroying many sets of rotors and pads trying to negotiate the "Toe" at Watkins (turn 7). This is an uphill, 180 deg, corkscrew of a turn that is about the worst turn for a MINI to negotiate. And Watkins Glen in general, where a lot of the braking zones are down hill in take a MINI S from 110-120 mph down to 60-70 mph.

The stock MINI brakes, with race pads (Carbotec XP10s), are a really good brake, until the caliper heat soaks and the brakes go soft on you.

The one thing that kills most brakes when running on the track is the wrong pads. For the track, no "street/track" pads. These are right up there with thinking that a performance All Season can be a really good 4 season tire. If brakes are not working for you, put in a better pad that is appropriate to what you are doing.

The Gen II JCW sport brakes and the Wilwood track kit with DynaPro (SS pistons and no dust boots) Calipers both have a smaller total piston area than the stock S caliper. I was told that this is to improve pedal feel and reduce pedal travel. These smaller pistons are what screw up the DTC (with the eLSD), hence needing the recoding. If you don't have DTC with the eLSD, the recoding should not be an issue. So, I would think that if you go with a larger area piston setup you may wind up not having enough pedal travel to make the brakes work and you will have no margin if brakes go soft on you.

You are correct about the Gen II GP brakes. They are the 135 brakes, but MINI also recodes those to the DTC on the car. There are a number of posts on NAM about the installation of those on non-GPs.

However, for outright stopping ability TCE has his own kit with a 13" rotor and a huge pad (0.80" thick and a large area) which is bigger than any stock option. Check out his TCE 13" kit on his web site:
http://www.tceperformanceproducts.co...01-06/kits-16/
These will fit a lot of 17" wheels for MINIs. I have seen these in use on the track on a friend's MINI and they do fine without being more than 0.81" thick. I have been told that "good brakes" have a lot to do with metal mass. These have metal mass.

It is almost impossible to to get duct hose to the Gen II MINI brakes. there is no clearance to get around the engine and transmission. This is what kills most Gen II MINI brakes; not being able to get cooling to them. Most ducting shown for MINIs is for the Gen I. This might help:
https://www.northamericanmotoring.co...or-r56lci.html

The Gen II MINI brake ducts offer little help. The dust shields block the air from getting to the rotor. But, without the dust shields the air being blown in over-cools the inside of the rotor without cooling the outside and in a very short while the rotor will crack (again, experience). I have battled hot brakes vs cooling since I bought the car.

The wheels available for the Gen I and Gen II MINIs are basically driven by the demand created by the Miata crowd. That leaves little for us. The 4 bolt pattern may be a leftover from the Omni influence. But there are several wheels out there that are BBK friendly. My Kosi and Enkei wheels are 2 that I have personal experience with.

The BMW E30 and E36 race crowd runs a "vendor grown" race brake that uses Wilwood calipers, a "manufactured" bracket, 11.75" x 0.81" rotors (various suppliers out there besides Wilwood; Hawk and Coleman Racing to name 2) and a custom hat. You could look into some of their setup for ideas for yours.

Hope this helps. This is probably more than you wanted, but I put it out there for consideration.

 

I had ebc reds on that day, I use hawk HP+ on the street now, or wilwood bp-30 depends on which car I take

 

edit, I tried carbotech/g-loc pads, xp12 did not last long for me, one weekend and half gone, and it was a rain event at VIR (easy on brakes even dry) if I try them again it would be the 20 or 24 pads, I am a late & trail brake driver that's where I catch the high HP cars, corner entry/exit speed... I run st43 pads on my track car now, I reallly like these pads and they are only 100 $

I gave up on ducting on my r53, there's no way to get behind the axle and have any measurable airflow it's a long run with many bends, now I dump the air right in the front pointing at the rotor, it cut my pad wear to 1/3 what it was with the actual ducts installed on the hubs, drastic wear difference, inside/outside pad wear is the same, wilwood will taper pads so I flip them over between events.

Rotors are gonna crack if you do trackdays, the crazing eventually connects the dots and runs to the edge, I have had cracking on inside half and outside half, no pattern to it.

I'm not going with more rotor mass, my little wilwood 11.75 .81 rotors come up to temp quick and have never caused pad or fluid failure on the track, more mass might make them hold more heat but proper ducting is far more important on the track it's just physics if you do not remove the heat you will have a problem eventually. 24 hour race cars use ducts big ducts, go check out a champcar or AER event and see what they are doing, regular guy cars that run non stop events.

 

Last couple of posts are great, thanks to both Mr. Blah and Eddie07S.

I have been digging into Chevy Cobalt Brembos that I mentioned earlier. They appear to be very similar to the Gen2 JCW units. Both have four 1.5" pistons that work out to the same approximate value of the Gen1 JCW/R56s. The Gen2 has a pad of approximately 14.24 square inches (121 x 76 x 14 mm) whereas the Cobalt is just a little smaller at 13.73 (125 x 71 x 15 mm). Both are mated to 316 mm rotors but whereas the JCW is 22 mm thick the Cobalt is 26 mm. What is really interesting on the Cobalts is that you can get remanufactured for around $120 that includes a core charge. You can get autopart type ceramic pads for less than $40.00. I need to verify the fluid inlet thread but I am thinking the MINI hoses might work. You would need to get the pins that hold the pads in.

For me the biggest question is whether the Cobalt would work with the 22mm MINI rotor. I do not know what the total piston extension is but would think that 2 mm is not going to kill the deal. I have not been able to find information on the hub connection spacing as well.

 

I need to drop in more often to this site! Entertaining read!

Plenty of 'opinions' I'm seeing here. My only regard is knowing their ability to STOP the car, especially when doing all day runs on US129.

 

I created an account at the Cobalt SS Network that is another IB owned forum hoping that some of their members can help more on the Brembo calipers their Turbo SS models use, GM 172-2484/2485. I have not been able to find any type of drawings so still do not know the bolt spacing or the offset information. I have found their hub assembly (GM 22701520) but same thing, cannot find any dimensions.

Can buy plain 316x22 Centric type rotors for $50 a piece. The remanufactured Cobalt Brembo is $100 each, ceramic type pads start around $40 (saw some Hawks for around $80) and the pad screw/shim kits are $18 each. Only part I have not been able to find is the fluid transfer lines that the Brembos require. A very interesting and in-expensive big brake idea.

Anybody know anybody that works in some autopart warehouses might be able to get us some info.

 

There are roads leading off the Blue Ridge Parkway with some good vertical drops. Outside Asheville is 151 that has some nice tight turns and the brakes can get very hot just averaging 35 mph.

 

I ordered a kit for the Cobalt calipers. I did a photo overlay so I knew they were very close in size and then I found a Saturn Sky forum post where the guy made some drawings up. The attachment center to center is 4 15/16" whereas the MINI is 4 3/4". There are other posts here about having to rework the hole by 2 mm, perhaps for the GP2/135i calipers, so I have a little filing to do. Will make the hole oblong by less than an 1/8" so there will there be no sideways movement and as the hole extension will be upwards/downwards, the caliper will not be able to slide up or down. Will mate them up to the Gen2 JCW sized 316 mm rotors.

I will take pictures through the process and post them. If everything goes as planned will then sell my JCW/R56 calipers that have EBC Yellows and Stop Tech slotted rotors. The pads and rotors have less than 5,000 miles on them.

 

What pads are you going to run?

 

The kit has some type of ceramic. I can be way off, but thinking as the pad is so much larger, the pad friction would not have to be as high. I don't track and don't drive as "spirited" as some others do.

Thinking just plain ole rotors with no fancy slots or holes as well, so this could be a $500 big brake kit. If you can find remanufactured units can cut $100 off. I found a used set of Cobalts but could not see paying what the guy wanted for used and when the ad said he had only one rotor along with that the car was in an accident, would make me really wonder about the side that got hit. The Chevy HHR also uses the same caliper as long as there is the 2.0 turbo engine. The Cobalt is similar in weight to our MINIs so it is logical to me that the big brake system would be similar. It also makes sense to me that Brembo has a standard "frame" design for cars of a certain weight and then puts on different "skins and wheels" for the different brand manufacturers. I need to dig into the Nissan Sentra SE-R Spec V as I am thinking they have a Brembo type system option.

 

torque is changed by moving the caliper further out from the axle, which you are doing or by higher/lower Mu pads, I do not think the pad size/shape affects much, but changing the sweep does

for the track, temp range is the first thing to consider, track pads suck on the street, they make noise, wear out rotors faster and do not have as much friction until hot

 

Whine not WalnutsWhine, to install Cobalt SS Brembo calipers on MINI you would need
to manufacture some utterly fanciful brackets. These calipers are nowhere near bolt-on fit with MINI 316x22 discs. If you "rework the hole by 2 mm" as you are planning the calipers will be installed on the much bigger radius than it is required to use with 316 mm discs.

 

The Cobalt uses the same size rotor, 316, Not thinking any bracket is required.