Not yet, but when I get my car back after a new ported/polished head + Schrick cam, I'll take some more pics and post them.

BTW, two things about this Wilwood-based kit need to be stressed --- 1) the car's caliper-mounting bracket does not need to be modified to accommodate the custom bracket in this kit. This is unlike some of the others on the market. 2) There appears to be no need for spacers because the hat dimensions, caliper thickness (6-piston, narrow rather than 6-piston standard), and rotor thickness of 27.9mm (1.1") are part of a package that was designed to work on the Mini with a wide range of wheel styles and offsets. Therefore, suspension geometry is not altered by the use of spacers. I'll try to get the distributor/designer to comment more specifically on this latter point.

Cheers,

 

I've been debating exactly how to post this but given a number of PMs of late as well as one asking me if I too would consider producing a BBK to match that of another supplier I feel it's time to state my postion on why I will NOT produce a kit to compete with some of the others.

A properly built and designed kit takes into account a number of things. These being; stock piston area, bias, rotor sizing, rotor weights, vehicle weight, fit and of course price. From a technical stand point the appearance is second to a properly functioning product.

As the posts by Bob are not that of a supporting vendor and second hand info I don't feel it inappropriate to comment on the proposed kit. It is not intended to offend him nor his opinoins, but rather educate everyone. Given I can of course produce the exact same product (and was asked if I would in a PM) I can speak with some authority on it and its shortcomings.

The MINI has about 2.8 square inches of piston area in the front and about a 70/30 bias split. I'm sorry to report but the use of the larger BSL6 caliper is simply, fully and completely incorrect for this application. The BSL6 (and 6n, I use them all elsewhere) support a 4.1sq" area. This caliper change represents a near 50% increase in piston area. This is a horribly sized caliper for the vehicle. As is supported by another well known builder; the use of such mis matched parts can have a negative effect on the overall performance of the car rather than one which helps.

By the numbers: The use of the BSL6 (and perhaps others on the market) places way too much emphasis on the front system and shifts bias to nearly 88% front! That's static bias and not dynamic bias where it will be even higher. The result will be a less effective package and not one properly 'balanced' to coin a phrase. In addition to this the volume displacement of this caliper is very large for the MINI's master cylinder. The small mc on the MINI results in very high pressure but minimal volume. This combo will produce a very long, soft and unpredictable pedal feel.

There are ways to counter this situation however and if done correctly it may prove to be a fine package. First the 'feel' can be altered by the fit of a larger (I'd suggest 1.00") master. This will at least make the pedal feel more linear. The horrible bias issue is one that will need some work though. The rear of the car will need some major enhancements. Beyond that of my own build. To properly balance the proposed BSL6 up front one would need both larger rotors and larger calipers to sway the bias numbers back into check. The fit of larger calipers will perhaps remove the parking brake also. There is talk of a new WW rear caliper with internal parking brakes but this alone will not cure the problem. Why? Because when you fit larger caliper piston area to the rear to aide the over biased front you'll also need more fluid to displace the package, thus the need for a larger mc to make it all work. Add to that the required changes to perhaps 12+" rotors out back and the reworking of the parking brakes....well, you are a bit beyond the bolt on kit.

So why not do all of this? Won't putting those X piston calipers on the car make it stop better? And if I do the rear too make it better still? Nope. The final issue comes back to proper bias and where the rubber meets the road. Larger or more piston area will not 'stop your car faster' nor will larger rotors. More pistons do not stop your car better either. Now supposing one was to put a BIG kit on the front and then counter with a BIG kit in the rear this would surely make it all better. Nope. You're right back where you started, simply using more fluid displacement for the same net result. Bais is bias. A large front kit up front and a large one in the rear is the same as a properly engineered kit from the get go.

Can the rear really be improved upon to make this wild idea work? Only too a point. The fit of a big kit to the rear will offer better thermal management and a wider choice of pads. That's all good stuff. The down side is that dynamic braking on the car is such that exploiting the benefits of this are quite limited. The wheelbase of the car is so short that getting the rears to work much more is modest at best. You can't use much more brake if you can't keep the contact patch on the ground.

All this being said I'm sure there will be those who will disagree with me. That's ok, I didn't write the math for this, I only work with it. There are plenty of opportunity for fitting inproperly sized parts to a car (think tires, wheels, brakes, pulleys, springs, the list is endless I'm sure) for those who don't do proper research. And there are vendors more than willing to sell you products not engineered for the car. This has gone on for year and won't stop with my comments here either. But when it comes to shopping for stopping do your homework please. A pretty box does not make for a proper product.

Shop wisely.

******Edit: Worked the bais % again on the program. Assuming a basic .40 Cf pad the stock MINI is about 70/30, I'm at 74/26 front only, 69/31 front AND rear kit, the BSL6 front only is at 83/17 on a 12.9 rotor.

Given many choose a 'performance pad' of say .48 (middle of the road) the stock MINI comes in at 73/27 when changing ONLY the front pads. Changing both to the same pad keep bias the same. My choice of the Q pad is one which ramps up as temps go up, usually related to useage levels.

As a rule of thumb: Increase rotor diameter, decrease piston area, tune with the pad.

 

ToddTCE,

Great write up about six pistons. You are absolutely right. I looked into six piston calipers and you would have to use very small psitons to match the surface area of the of the stock piston or you totally screw up the bias. For those who want to also better understand this, when swtiching from a single psiton floater (stock) to non floater 4 (or 6) piston caliper you only use the total piston surface area on one side of the 4 (or 6) piston caliper when comparing to the stock piston. I have looked at some other kits on the market and they don't always do a very good job in matching piston area even though they claim the bias is not altered. Glad to see that TCE has done the proper home work. A properly set up braking system will not cause the car to get looser or tighter when braking late into a turn.

 

Caveat Emptor!
A couple of other things you may want to consider:
FMVSS - no BBK out there has to verify that it can pass all of the FMVSS (Federal Motor Vehicle Safety Standards) tests that your OE brakes have to.
NVH - your OE brakes have been engineered to perform with a minimum of Noise, Vibration, and Harshness...any joe shmoe with a CNC machine can build and sell brakes that will fit your car, how they perform is a totally different story.
There are also tons of full-turn, jounce-and-rebound studies that are done to make sure there aren't interference issues with any number of nearby components.
Thanks to Todd for giving us the Aftermarket engineeering point of view.

 

Lots of excellent discussion - bravo guys!

 

Todd's overview for how to approach brake stage 2 upgrades for the MINI makes alot of good sense.

We do assume that the commercial big brake kits are appropriate and fit the MINI since they are marketed for it but the truth is that although they might fit, there are many other considerations about how the total brake system will function with these kits.

At TCE they really are looking at the entire brake system when trying to offer MINI owners solutions for their braking needs. Often more functional solutions with lower cost in mind. Of course, appearance add ons such as caliper finish, drilled or slotted rotors and plating are available but not essential.

For quite a reasonable cost you can do quite a bit with a full four brake upgrade at the same cost of many of the name brand big brake kits.

The other plus about Todd and TCE is his willingness to go the extra mile to help us NAM members understand the basics and fine points of upgrading brakes. There IS quite a bit to consider and TCE is not going to try to compromise performance for looks without telling you that you're headed in that direction. Afterall everything is a compromise.

Props to Todd and TCE.

 

Todd,

I found your comments to be very helpful, and I certainly do not take any offense from your comments. Since I did not design the kit I described, it would be inappropriate at this time for me to address the technical issues that you raised. However, I can tell you that the kit on my car does not "produce a very long, soft and unpredictable pedal feel". When I get my car back after the previously-referenced engine mods, I'll certainly do some very aggressive driving/braking to either confirm or refute your/my contentions. I'll also have some of our better and very critical drivers put my car through its paces. Stay posted :smile: .

For those of us who read this forum, would you let us know what the total surface area of your kit will be? Also, would you kindly share the same info from your observations of the other major big brake kits (e.g., Brembo, StopTech, Alta, AP, TarOx, etc.)? I'm sure such information will be helpful to the many Mini owners thinking about brake upgrades. Many thanks in advance for your help and consideration.

 

I can't speak for the others in their choice of piston area and the reasons they choose to do as they do. Sadly I think it's often 'what fits' or 'what sells' rather than what's right. And some manufactures have been known to supply or suggest MC changes as well or install proportioning valves etc. There clearly are some variables. And in fairness; no one set up will be 'perfectly biased' all the time. Ride height, Cg, tires, dampers, springs etc all play a roll in dynamic bias. Simply having four people in the car can make a change.

Pad choices alone for a specific builder can have a huge impact on the final numbers. Personally I feel a kit should come within a few % of stock for the most part. This at least keeps the system in check. On the far end of the scale one which over favors the rear can be a real problem. Certainly it's safer to over bias the front and get away with it than the rear!

The info on the BSL6 was one readily available on the Wilwood site for anyone. If manufactures wish to post specifics of their kits with everyone I'd be surprised. I think you'd find few want to share their engineering data with the other builders. One comon thing you'll find on well thought out kits is that piston area is smaller than stock for the most part.

See the edit above and the 'rule of thumb' there.

 

What size pistons are you running? While todd is right that larger pistons increases the front bias, the extra volume required at the front can allow the rear to lock up prematurely. The stock braking system (master cylinder and calipers)was designed to work together, however most manufactures tend to use the largest system that will fit in a stock wheel which in the case of the Mini is a 15" wheel. Real improvements are very possible for those with larger wheels, but it is critical to stay with close to the stock piston surface area unless you are prepared to change the master cylinder, proportioning valve and ALL of the calipers. If you stay close to the stock piston surface area having six or four pistons doesn't really make matter. The only real improvement might be the radical looks and bragging rights of six or more pistons. The main advantage of a BBK is the extra leverage and heat management. To increase clamping force you need larger pistons and then we are right back to the bias problem.

 

Could part of his pedal "feel" be the rears still working properly?

 

A good point. And for those not following as we go from too much front now to too much rear; the issue here is volume. In the tandem mc the volume of the larger calipers may well tax the capacity of the mc to the point of either 1. over pressuring the rears by way of compressing the rear volume more than need be, or 2. In fact cutting off the enitre rear circuit by way of the piston travel being greater than need be and the rear piston now covering up the feed line to it calipers. I don't recall which way the MINI is plumbed so you'll have to decide this one on your own.

Suffice it to say I think most of us who follow this stuff regularly can agree; nothing good ever comes of adding front piston area in a BBK. All out race cars with larger rears etc not included. We're talking basics here.


Cloak and dagger aside, I'll put up the facts. The FSLs in use are Four pot 1.25" models. Net area 2.45". In supporting my own postion above this is a reduction in area on a larger rotor. I now challenge the others to post the same. (I know this is being circulated by some to other shops, builders, etc. I'm not stupid, so put your numbers on the table....)

That being said, what makes this package 'better' than others? First I don't say it's better, but on par with many of them. There are pros and cons to them all.

1. Multi rotor width options. No street driver really needs 1.10 rotors on this car. With the .81 rotor you still gain mass over the stock parts. Effective mass. With that comes better fit options. More wheels to choose from. Stock ones in fact.

2. Proper piston area. As stated in great length, the right amount of piston nets you the proper feel, bias, and function. "But they are not booted like brand X" True, but unless you plan on year round, no maintenance, salt belt infested use this is really a moot point. Many of the 'boots' of other brands become vapor the first track day. Few run them in as dusty a condition as I do.

3. Simple, effective rear package to compliment the front. Larger rotor, more mass, slight bias shift, stock caliper. No fuss, no muss, simple and afffordable.

4. Hands down the number ONE choice for brake pad options. **yes the FSL has a slightly different pad plate than the older SL caliper but anyone with a hand file can turn a Hawk HB101 into a FSL pad. More manufactures will catch up soon on this plate change. (it doesn't have the cotter pin hole)

5. Better pads. Most of your choices offer calipers with pads of .490 and .630" thick. All TCE kits are using only .800 thick pads. That means less heat transfer to the caliper. Some kits with .490 pads may burn through a set in a day...What's keeping the heat out of your caliper?

6. Cost effective parts replacement. Rotors from $89 to $125ea. Pads from $65 and new calipers if needed for $139. You'll spend more on tires than brakes.

7. Options, options, options. Sure some companies let you order on line. Send me 1 number 349057wx, but what if you don't want suffix w? TCE builds each of them to YOUR order or need. Not a box of parts with a part number on it.

8. The BLING factor. Sure, we can do that. You want holes? Yup. You want zinc? (for the love of brakes I just don't get zinc, it all rubs off in short order, except for around the hat) But, can do. You want slots? No problem. Your want red? You'll have to paint them yourself. I've quit doing colors in house. It's simply not cost effective. Eastwood makes a nice kit for this and honestly; I wouldn't pay $200 more for it. And I'm the WW dealer!

9. How complete is the kit? From hoses to pads and everything in between. Yes, the MINI has some fit issues to deal with and some minor grinding of the knuckle to fit the FSL, but this isn't going to take you more than a few minutes a side. I can grind a lot for $600+.

10. Value. Folks all the banter on numbers, sizes etc won't mean a thing if the value is not what you want. For those who have money to spend and simply need the 'best' buy what you like. For those who realize they may not be getting any more than a pretty part in a shiny box...well, let's go tear it up on the track where counts. You won't find more value for the $.

I've done my best to help the NAM community to understand what the options are and why I'm here. I don't wish to cause any other vendor or supplier harm in their business by way of extended comparrisons. I stand firm on the finished product and am certain you'll feel the same as a satisfied customer.

 

I agree that there's plenty to improve on the Mini's brake system for the track. I'm not sure that "the big brake" is THE answer. Vented rotors and better pads along with improved fluids and braided lines will go a long, long way in improving braking performance as well as better tires.

However, no matter how big a brake you have, if you miss your braking point, you will NEVER have enough brake.

Late braking is usually reserved for passing manuever, not for minimum lap time. During those manuevers, you'll notice that the late braker usually overshoots his apex and then has to pray that the opponant does not have enough power to give you the Touche' by taking back the lead on the inside. There's not much reason to late brake if there's no one in front of you. You're better off to brake at the proper distance that your "brakes" are capable of aborbing without screwing up your "proper" line and aligning for a faster exit speed.

 

Most of my experience is setting up my sons race car for oval track racing. Being able to out brake a competitor is how the pass happens most of the time. In spec racing all the cars are very evenly matched and if you can't pass you don't win.

 

True...but Ryan wasn't racing anyone. He was doing tune up laps... as much as I'm aware of. From his description of the event to me, I believe he was trying for the fastest solo laps.

BTW...I'm no track expert...but I stayed at the Holiday Inn

 

he was racing his mom.

 

That's who he was tryn so hard to pass

 

That's why he must have better brakes! If he tries to dive under mom and late break her, he risks wrecking himself and mom if his brakes aren't up to the task.

 

My MOM is tough to pass because she takes up so much of the track - I need all the help I can get, and shorter stopping distances will certainly help. :smile:

 

Being that this is my first post on the board, let me say hello to everyone and introduce myself as well. Im Sherwin, the co-owner of Brake Zone and designer of the "other" Wilwood kit on Bob's car.

First off, I d like commend Todd on the work he has done here and for the community. Its obvious that he has spent many hours tooling around and designing application specific components for the Mini. I myself started in the same fashion doing custom applications for the Honda S2000.

I just wanted to clarify a few things before everyone is led astray. The calculations you have presented regarding this kit are indeed correct. The 6 piston set up obviously has too large a total piston surface area to be perfectly balanced with the stock rear set up. Thats because it was not intended to be.

Bob called me a few months ago requesting a custom kit to be built for his mini. We went over his requirements and I told him what we could do. He also told me that he wanted a full rear kit to go along with the front kit. Knowing that Wilwood is soon to release a rear caliper that has a mechanical e brake attatched, I designed the front kit to work with the rear kit that we will build once the caliper is released.

I know the diameters of the pistons of the rear caliper and I know that this ratio works. It does this while keeping a postive pedal feel as well. It is a aggressive approach given the bore size of the master, but as I said before, it does work. This will not be the first time I have used this set up nor the second

The advantages of using this caliper body are plenty, but it definitely comes at a cost. As Todd has pointed out, these are not cheap calipers. The main reason I went with this caliper is because of its radial mount bracket design. I too originally wanted to use the Superlites but realized that modification of the OEM spindle was needed. I just didnt feel comfortable with customers having to modify the spindle in order to mount my kit. I wanted a direct bolt on affair. No modification needed.

Another key feature of this caliper is its narrow body. The shape of the caliper allows for more clearance and choice on rim selection. The Mini has very tight clearances as is and trying to house a 1.1" rotor with larger calipers is not an easy task. This caliper is by probably the narrowest of all big bodied calipers.

Probably the greatest feature of all though, is the availabilty of different piston diameters. Even though the other versions are of a 4 piston version, the external bodies are identical. They are the exact same size and shape as the 6 piston. The 4 pot comes in the 1.25" and 1.38" piston sizes as well. These are what we would use if a customer only wanted a front kit. As I said before, I knew going in that Bob was looking for a front and rear kit which is why we went the route we did.

Here is a pic and some detailed info of the 4 piston version of the same caliper which also has dust boots for those that care.
http://http://www.wilwood.com/001_TJ...4r14/index.asp


I hope that you dont find my post as any crossing of territory. Before I met Bob I had never heard of TCE. Since then I am happy to say, that I have heard many wonderful things about them from Wilwood. The Mini community is lucky to have a vendor that truly cares about the functionality of the products they produce. My only intent of this post was to clarify the issue regarding the reasoning behind the choice of calipers in my design.

 

I understand your position Sherwin, and I appreciate you taking the time to share the details of the situation. You expressed yourself very eloquently. And, welcome to NAM!

 

Sherwin, thank-you for the clarification of the Bob's requirements.

 

I'm confused...I thought that the only Wilwood caliper that was booted was the Dynapro

Bruce

 

Until the more recent release of the larger calipers for 14" rotors this was in fact true. There are now two of them. However this particular one I too considered but passed on as its intended fit is for 1.25" rotors if I remember correctly. I really don't think any MINI needs 1.25 rotors....lol

 

I double checked Bruce, yes there is a 1.10 version of this caliper as well.

If you'd be interested in exploring this possibility I'd be happy to help. Be ware it's not in the common $1100 price range however and will bump you into $1700-1800 range pretty quick. Also if you have road racing plans its not to my liking for such use given its thin pads and limited pad choices.

 

I would think that a serious road racer would want to stay away from a rubber booted caliper as they will usually just burn off. I have run willwoods on a couple of cars and never had a problem with with bootless calipers. Anodized bores and stainless pistons provide very good protection. For many years Willwood never offered booted calipers and they worked just fine on the road just as Wilwood claimed they would. I also know that competitors would knock Willwood for this. When I saw that they started to offer rubber boots, my first impression was that they where just trying to ensure that wouldn't loose sales to competitors that would beat them up on this.