Yes I am a somewhat MINI newbie so the entire "web did this or that" meant nothing to me. Randy Webb, ok now I get it.
Back when I bought my first MINI I checked the forums out and what I found was; 1.) Do not use those red coil units, 2.) A 15% pulley is better and 3.) You do not go with a Shark tune thing. Now on the red coil and the shark tune, I did find folks that had written about major issues. At that time it did not dawn on me that relative to pulleys there was not allot of hard data that was out there, at least that I found. What I did find was the; its going to cause cavitation, its going to spin so fast the fuel limit range limiter is going to be triggered, its going to spin so fast the water pump is going to blow up or it does create more heat. Well of these, the heat thing is correct and is backed up by data.
So I focused on the heat thing and started thinking; 1.) Why is more heat created, 2.) What is the range where the heat creates issues, and 3.) Is there something that can be done to mitigate the heat? IMO when somebody asks a question about pulleys the statement that "the smaller pulley will make the supercharger spin too fast" should not be offered but rather that the smaller pulley will create more boost at lower engine speed but will start to lose efficiency when it reaches a certain point close to redline with more heat as the byproduct. The spreadsheets I created reflect the engine rpm range where the inefficient points are reached. These points range from approximately 6400 for the 19% to 6600 for the 15%. I also provided information based on gear ratios where these points would be encountered in somewhat normal street driving.
To mitigate these issues there are three basic choices; 1.) Do not make the change, 2.) Do not drive in a manner that your engine rpms exceed the inefficient points or 3.) Use MI to reduce the intake temperatures. For me and now with the understanding that even the JCW appears to spin beyond the 16,000 range that Eaton specifies (still have not found any data released by Eaton stating such) it was easy to decide to go with MI and to give me just a little more "power" with the 19% pulley.
Page 1 of 7
I took a bunch of measurements and it does appear it would work with no issues on my 17" wheels and depending on your type of rims perhaps with a 16". The caliper is about the same length as the JCW/r56 (just over 7") and is just a little bit wider based upon the approximate 1.75 inches from the outside edge of the rotor to the outside edge of the caliper. The Wilwoods are not as tall as the JCW/r56s and therefore the JCW/r56s have a bigger pad at approximately 8 square inches vs the Wilwood of 6.36 square inches.
We might get lucky and have a brake/auto engineer that could explain some of the finer details here as it appears we have over 36% more clamping power but the pad is about 25% smaller.
As I had to say over on the NAM, talking possibles and/or options here.
IMO finding a set of Gen2 JCW calipers for $400 is the exception and not the rule for once the word Brembo shows up in any ad the $$$$$$$ follows.
Next, regardless how big/good the brakes are, once the friction of the pad to rotor exceeds that of the tire to the road, it is all a mute point.
On clamping force and heat, in my feeble little mind clamping force does matter in the short run but as the energy from the motion of car is converted to heat during braking yes a bigger pad will have the ability to dissipate the heat quicker. On friction areas, the Brembo is around 14 sq inches of surface area whereas the R56 is around 7.8 and the Wilwood is 6.4. Would think the Wilwood with the smallest pad area and the largest piston area would have one helluva bite but then they would also be creating the most heat in the smallest area so they would fade the quickest under constant heavy braking.
So, if you are lucky enough to find a very good deal on used Brembos, buy them. If you cannot and do not want to spend anywhere from $750 to well over $1,000 for Wilwoods, then the "possible" idea I have floated with costs of around $300 plus the price of some steel to fab your bracket AND you are not tracking the car, might work quite well for you.
Found some interesting stuff on a Chevy Cobalt Brembo and have posted the below over on NAM. I also made a post on a Cobalt forum to see if they could help out with some dimensions that I have a hard time trying to find.
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.
No mountain runs yet but it they are working quite well.
With the money I saved on this Rube Goldberg set up, Goldberg was a very smart man, I am going to get a meth injection kit and put on a 17% pulley. Not going to "tune for meth" but rather use it to mitigate the extra heat from the 17.
I think I had around 100 deg F heat rise. Its been a long time ago when I logged it so I cant really remember. I believe @Dave.0 said the Meth brings him back to ambient. He has a 17% now maybe he can tell you what it is with meth.
That picture cant be Dave, I know because his middle finger would be a little higher then the rest.
The heat come from the M45 EATON a.k.a ‘Heat-On” spinning way out of its running range. It is a old design and is not very efficient at all. That’s why JAN and other have been trying for years to come up with a bolt on replacement for the old tech “HEAT-ON” M45.
HARROP is Australia has a complete kit available now to replace the old school OEM M45 SC and upgrade to the new Eaton TVS 900 SC.
JAN sell the kit in the USA
HARROP TVS900 DIRECT BOLT ON KIT $3,325.00
She is one special lady . . . . .
Now you are getting it.
The faster you spin the SC the faster it will die over time. I am on my second one now with a 17% and my first one almost lasted 100 K with a 15%.
I don’t really care about this SC as when it dies or before it dies I will be going with the new generation TVS by Eaton.
TVS900 Supercharger Kit utilizes the latest Eaton TVS supercharger technology and provides superior performance when compared to the smaller, 5th generation M45 supercharger factory fitted to the R53 Mini. A significant benefit of TVS technology is the transition to four lobe rotors providing a 160 degree helix, as well as revised inlet and outlet port geometry to achieve greater thermal and volumetric efficiency. Being a larger displacement than the M45 unit, the TVS900 also provides higher performance potential for modified engine packages.
Not sure how I got through this "brake" thread, but for what it's worth. Having transitioned to TVS900 makes all of these calculations exhausting. The TVS is singificantly more efficient (cooler, reliable), you can run a smaller pulley (I'm currently on 60mm but think you can run down to 50mm) and boost levels of 19+ are easily achievable. I can tell you the kick at WOT is very noticeable compared to an M45. Then I went to LinkG4+ and Wideband and it was more interesting. I would keep the 15% and save $$ for TVS and be done with it. I'm never going back to M45. Sooner than later that won't be a option anyway. And as a bonus you can burn that stupid plastic intake tube and green gasket. Such a POS design.
To clarify, the "track wannabe" does not track. I fully understand the big brake kits when you are shedding triple digit speeds entering a corner but for most purposes of street driving IMO they are more bling than anything else.
Just my two cents . . . . .
I started this thread over on NAM and have linked them to MA. Now going to link MA to NAM. Have some good thoughts between the two sites.
But of course why would there not be good thoughts when you get the two best MINI sites together?
Bigger pads and larger rotors also give better heat dispersion. If you're going to drive it hard this is an important factor to consider.
It's not all about clamping force. The 4 pot calipers allow for larger pads and better distribution of the force to the pad.
I did this as there are those out there that have a MINI, want to do some mods but don't detail cars on the weekend, yes had to get Dave.0 into this, and are looking for budget mods. This appears to fit.
Actually in discussions know with Jan over at RMW about a revolutionary new modification that will produce some good torque values You have to visit the ex Big Bad Boogeyman site to read about. Posts #63 and #65.
I am already thinking about all the ways I am going to spend the money . . . . . .
- Like x 1
- Funny x 1
I agree with Jan, "I can get stock brakes with mods to work as good as Wilwoods........not sure what all the extra wasted brain power is all about here"!
Your stock brakes with good pads will work as good as or better than the Wilwoods setup you are suggesting.
I still don't understand all the need for bigger brakes on street driven cars. I've done plenty of track days in my previous 2003 JCW and in my current 09 Cooper S and I've never had brake fade problems - as long as I had good clean fresh brake fluid. What are you guys doing that you're getting brake fade on the street?
I have not been able to find too much technical stuff on Brembo. Nothing that will cross reference a MINI or a Chevy part number to their system. Everything I found was basically forum based. Would think the Suburu stuff might work but they may be 1.25" rotors and on CL when you see anything with WRX the prices go way up. Nissan has the Sentra SE-R Spec V but have not done research on them.
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 tried to order remanufactured units but every place I found them, they were out of stock.
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.
Page 1 of 7