BBK recommendation for Forced Induction
 

I tried searching, but I couldn't find any threads about this. What BBK would you guys recommend for someone who is going FI? Nothing crazy, just a Vortech kit with maybe 240-260whp.

Before I decided to go FI, I was already set on getting the Essex Sprint AP Racing kit. Perfect for NA since it saves a lot of unsprung and rotating weight. But now that I will be going FI, I'm not sure if it will be adequate enough.

I am not a hardcore track guy, I track the car maybe once a month, sometimes even less. I would also like something that will be able to clear the stock 17" wheels, so I can still use them for drifting. Someone has already said that the Sprint kit will clear the stockers with a 10 spacer.

I'm willing to sacrifice the ability of running the stock 17" wheels if a bigger BBK is needed though. If so, what do you recommend? AP Racing Formula, Willwoods or Stoptechs? I would like something that will not alter the stock brake bias. Of course, price is a consideration. Thanks in advance!

The stock brakes, with a little upgrade, can manage forced induction (stage 1). These are after all WRX brakes, used on heavier car with more power (stock).
AP - http://www.ft86club.com/forums/showp...7&postcount=10

It all depends on how experienced YOU are. What's your past experience? What setups have you used and what were your results?

Price being a consideration and BBK don't usually go together lol. At best, you'll be over $3 grand for a front and rear bbk.

I would suggest something along the lines of Stop Techs sport upgrade (Stop Tech rotors, pads, and stainless lines) and some Motul 600. That's more than enough for stopping power and track day durability.

I cant push these quotes enough. Get some quality pads, and some quality fluid. You will see a substantual increase and more than likely see more than the gains you were looking for. I would rather spend the $$ on quality wheels & tires to shed the weight on a street car as wheels look "prettier" and can shed weight. That or fuel upgrades for E85 as I am an E85 whore. :) Or even some suspension upgrades.

Or hell some damned fuel! I would rather drive my car more than necessary than spend a few thousand on brakes. :D

Thanks for the input guys. I'm currently on the stock discs with Performance Friction pads, Performance Friction RH665 fluid and Goodridge SS lines. I only started going to the track when I got my 86 last year, so I don't have that much experience. With the brake mods I did, the brakes did improve but I fear that they might not be enough for the SC.

Regarding the wheels/suspension, I already have Volk Racing TE37SL Black Editions and KW V3 coilovers. I have also ordered a bunch of supporting mods for the Vortech - Koyo radiator, Perrin oil cooler, Cusco AOS can and DW 700cc injectors and 265lph pump. So the only thing left is the brakes, which I plan on getting later this year when more funds come in.

Unfortunately, E85 is very hard to come by in my area so we'll have to see about that :(

http://i374.photobucket.com/albums/o...ps8082bf84.jpg
http://i374.photobucket.com/albums/o...ps4f451eae.jpg

Did the SC arrive already Rob? Good luck on the build bro!

Thanks Tye! How are your brakes holding up to the added power of the SC? Mine isn't here yet, ETA is mid Feb

According to some discussions i've read regarding the worthiness of upgrading to a bbk vs. just upgrading to good pads, lines, fluid, mcb, rotors..the difference in stopping distance is NOT markedly cut shorter whether it is from a 200km/h FI run setup or a 200km/h N/A run setup. Bbk's are mainly for the cooling effect at the track, but that also depends on your braking tendencies. I know the bigger rotors will dissipate heat faster but im not sure if upgrading to just ProjectMu Club Racer rotors for example, will do a decent job as well in cooling as well.
Maybe @CSG Mike can shed more light for us :)

The heat capability of your brakes is dictated by how you drive, not how much hp you have. If you're braking incorrectly you can EASILY overheat an awesome set of brakes on stock power, while if you're braking correctly you could be fine on slightly upgraded stock brakes with FI power.

Upgraded pads and fluid are a must, I wouldn't touch the rotors until you find they're an issue. I also replaced my lines but those won't do anything for heat capacity or stopping distances, just pedal feel.

Big brakes don't necessarily make you stop quicker, they just allow you to stop more frequently. My car is still on stock brakes and I've done pulls up to over 150mph and they slow the car down fine......once. I'll be doing pads, rotors and fluid in the spring though. Don't forget you can only stop as much as your tires will allow.

Sent from, The Frozen North

I think the AP kit is probably the best on the market. The Stoptech kit doesn't look too far behind, and Wilwood a nice option too.

I have a Wilwood kit designed for a WRX bolted up to mine. It's great on the street (or autocross) and non-FI track use (or a smaller track). When I added the supercharger with the long straights at VIR I ate through my rotors as I was going from 135-140mph down to about 55mph. My kit only has 21mm rotors, I assume with 28-32mm you will have enough thermal capacity.

I've been running the Carbotech XP-10 pads all around and have been happy with them. Also running Motul RBF 650. Personally, I'd opt for something upgraded up front to get a bigger pad/better thermal capacity, get stainless lines, fluid, and pads and you should be good.

To answer the OP's specific questions...yes, our Sprint Kit will be adequate for your needs. We have cars running over 300hp+ to the wheels on that kit consistently at the track with no issues. It does not impact the factory brake bias, spares are cheap, pads are cheap, and the consumables will last far longer than the OEM parts. Long-term running costs will be low, your confidence on track will be high. Mission accomplished.:thumbsup:

There's a LOT of stuff going on in this thread though. Here are some thoughts to the OP...

First, have you read my brake upgrade guide? I'm guessing you may have, but figured I'd post it anyway. Some of the points addressed in that article are applicable here. What you're doing currently with your upgraded pads and fluid is correct. Don't waste your money on OEM-style replacement discs. They will gain you nothing. Also, don't waste your money on a rear big brake kit for your car. For what you're doing, it will gain you nothing. Focus on the front end. Good pads and lines in the back are perfect.

It sounds like a few things are going on in your situation:

• With forced induction you'll be going into corners faster. You terminal speed at the end of each straight is going to be higher. Stops from higher speeds transfer more energy from motion to heat (see my "Timmy" example below for more detail).
• You'll be adding a bit of weight to the nose of the car with the FI and associated parts
• Your driving skill is improving, which will likely increase your cornering speeds...which in turn will again increase your speed coming into each brake zone

Here's an example I posted when someone was asking about whether they should get our Essex Sprint kit or our Endurance Kit. It gives some insight into how braking needs can change along with the car and driver:

Heat Capacity/Energy Conversion

Ultimately, the Endurance system has greater heat capacity. That is literally the only thing you gain with the Endurance system over the Sprint system. It has larger discs, which can absorb more heat. It also has the built-in provision to attach a brake duct hose, which allows for cooling air and temperature reductions. The discs are floating in the Endurance system, meaning that when they do get hot, they can expand with less strain on the disc at the point where it attaches to the hat. Again, those are all related to heat. So, in a certain range of temperatures...from ice cold to fairly hot, performance between the Sprint and Endurance kits will be identical. Only when a massive amount of heat is introduced to the system will any differences between the two kits become evident.

So what happens when a massive amount of heat is introduced, and how would the two kits react differently? At some point, any brake system will run out of heat capacity. Brakes convert kinetic energy (a spinning disc) into thermal energy (the brake pads rub against the disc and generates friction). Energy is converted, not created. Depending on the disc size, pad volume, caliper design, cooling, etc., the conversion of energy happens at a certain rate, and the brake system has limitations on the rate at which it can convert energy. Here are the primary things that would push a brake system towards its limits of being able to adequately convert motion into heat.

• An increase in speed- Kinetic energy = mass x velocity (squared). As the car travels faster, the disc spins faster, and there is more energy that needs to be converted to heat. Since speed is squared in that equation, an increase in speed has the most dramatic impact on the amount of kinetic energy generated. In other words, if you add 200hp horsepower to your car, it will be have a far greater impact on your brake requirements than if you add a 200lb. passenger...and it will push your system towards its maximum heat capacity much more quickly.
• An increase in mass- Things in motion are harder to stop as their mass increases. The amount of leverage, torque, etc. to slow a heavy object is greater than what is required for light one. A freight train requires a very different brake system vs. a Lotus Elise.
• An increase in friction- The friction between the object in motion vs. what it is moving against makes a big difference as well. If you slide a book across a table, it slides easily. If you slide a book across a rubber mat, it won't go anywhere. The friction between the two objects is much greater. If you mash your brakes on race slicks, you have greater friction with the road vs. mashing the brakes on stock tires, which are far less sticky. With the race slicks and higher grip, you have a much greater capacity/ability to turn your motion into heat quickly.

So what does that all mean? It means that every car can find the limits of a certain brake system if it is made faster or heavier, or it is given more grip. Let's look at an example:

Little Timmy got his FR-S for Christmas. His paper route isn't earning him much chedda, so he has to leave his car stock. He goes to the track. It turns out Timmy is the next Kimi. He is super talented and fast. He is hitting high top speeds into the brake zones, and changing a lot of kinetic energy into heat. Since his stock pads aren't really designed for that, they melt (they're made to be quiet and work well cold). As they are melting, they smear all over his discs, giving him vibration and judder every time he hits the brakes. His discs are in the same boat...they don't move much air through them, and they are overwhelmed by the heat. They are cycling between extremely hot and cool, and they develop huge cracks. Since the pads and discs are not efficient at handling heat (they weren't made for that specifically), they are heat soaked. All of that heat has to go somewhere.

1. It radiates into the air around the brakes, sits in the wheels, etc.
2. It conducts- it transmit through the actual hard parts and metal. The wheel bearings get hotter, etc.
3. It soaks into the brake fluid through the caliper via convection

All of that pad and disc heat wears on the other parts around the brakes, and it soaks into the brake fluid making it boil. When it boils, air bubbles are produced. Since air bubbles can compress...the brake pedal is no longer rock hard as it should be.

So Timmy has some problems. His pads are melted, he has judder since they smeared all over his discs, his discs are cracking, and his brake pedal is soft because his fluid boiled. Timmy needs some help. He needs some brake components designed to handle high temperatures.

Timmy buys a Sprint Kit and a pyrometer to take disc temperatures, because he wants to learn more about vehicle dynamics, and he wants to get faster. He leaves everything else on the car stock, and goes out to Willow Springs raceway (a relatively easy braking track). The day goes great and he has a blast as he starts to realize that track driving is addictive. His discs were hitting 950F consistently, but he had no brake problems. The pads didn't fade, and his pedal remained firm all day. Timmy wants to go faster though, because all of the Corvettes were passing him all day. He goes out and buys some race slicks before his next event at Buttonwillow.

Timmy heads out to Buttonwillow. The race slicks allow him to get through the corners much more quickly, exit turns faster, and hit a higher speed at the end of the straights. He now has to go from a higher speed down to reach his corner entry speed, which transfers a lot more energy into heat. His driving skill is also steadily improving as he gets more experience. He's getting through the turns faster, and getting closer to his tires' ideal slip angle. He still can't catch the Z06 vettes, but he passed a couple of M3's and 911's. His brakes worked great all day, but when he was checking temps, he noticed that he was hitting 1200F consistently on his discs. He also saw a few spider cracks develop on the discs. By the last session of the day on Sunday, a lot of people had already gone home. He was out there with very little traffic in his run group, and he actually did 40 minutes straight instead of the usual 20 mins. At the very end of that last session, he started to feel a little softness in his brake pedal. When he went home and bled his brakes he noticed that a couple of air bubbles came out.

At this point, Timmy goes a little apesh*t. He decides that he is going to make the Z06's feel silly when they're passed by a lowly FT86. He installs a turbo kit that adds 150 whp. He goes back to Big Willow for his next event. Something similar to the last event happens, and they get the chance to run for an hour straight at the end of the day. He runs the car a full hour flat out, but doesn't have any brake troubles at all...no soft pedal, nothing. He doesn't see any air bubbles when he bleeds the brakes. He sets the fastest time of the day, passing a Gallardo down the front straight.

Back to Buttonwillow next time. Because he is so fast, Timmy runs in the fastest group. He goes out and tears it up in the first session. By the end of 20 mins. though, he's having some brake issues. At first he notices that even though his pedal is hard when he brakes, the car isn't slowing down like it's supposed to (brake pad fade). Uh oh. A few laps later, his pedal starts to get lower and lower going into brake zones...double uh oh. Timmy pulls into the hot pits and his friend zaps the front disc with the pyrometer. 1350F...ouch! Timmy wisely decides to go back out for a couple of cool down laps before the session ends, to get some air flowing through the brakes.

So what happened during Timmy's journey? He found the limits of his stock system quickly, as they were simply not designed for what he intended to do to them. Then he increased his car's ability to generate brake heat by adding better tires. He also improved his driving ability, allowing him to increase his speeds at the end of straights and pour even more heat into the system as he slowed from higher speeds. To offset those things, he installed a brake system specifically designed to handle the heat of heavy track use.
Ultimately though, he threw a bunch of HP at the car with his turbo, and radically changed the amount of energy being transferred from motion to heat. When he did so, he found the limits of the upgraded brakes.

Timmy sold his Sprint kit to his friend who didn't have any plans for forced induction. He ordered and installed an Endurance kit. Now he had larger heat sinks in the form of bigger discs. They could absorb more heat before transmitting it to other components. He also hooked up some brake ducting to the caliper brackets, allowing for more cooling air to get into the center of the disc, and pump air through them. Since the discs could now swallow and dissipate more heat, and his cooling ducts were bringing in a nice stream of cool air, his pads never got as hot...nor did his calipers...nor did his brake fluid. He went out to Buttonwillow and didn't have any problems at all.

A couple of points to note:

1. Every driver and track are different. What works well one place, may not be enough somewhere else, or with someone different driving.
2. Any brake system can find its limit with enough speed. It's just a matter of finding where that point is.

Choosing between the Sprint and Endurance kits is simply a matter of determining where you lie on Timmy's journey. At the time I write this, I have yet to hear of a single report of anyone running into any pad or fluid fade, premature disc cracking, etc. with the Sprint kit. That includes several forced induction cars, and loads of very fast drivers on tracks that are tough on brakes. Nobody has yet run into Timmy's problem with the Sprint Kit. It has been enough. That said, eventually, someone is going to take it too far due to too much power, too much speed, too much skill, too tough a braking track...you get the picture

There's another major point that people are overlooking in this thread...long-term running costs. If you plan to keep your car 2-3 years and track it regularly, buying our Sprint Kit will actually save you money! Before continuing to throw money at replacement pads and discs in the OEM size/shape, you need to read this. I firmly believe that if you track your car, our Sprint Kit is one of the best bang-for-the-buck investments you can make.

Below is an article I wrote for our blog in October 2012:

Big Brake System Benefits you may not have Considered

As we've been preparing for the launch of our Competition Brake Systems for the FR-S / BRZ, I've seen a lot of chatter on the forums about whether or not the FT86 platform needs an aftermarket brake system. While it's true that there have been quite a few FT86's tracked without major brake issues using just a pad and fluid change, that simple solution may not be the most economical or logical conclusion long-term. Before writing off a brake kit as "unnecessary," I would urge you to take a closer look at the realities of the situation.

Below I've compiled a list of some of the benefits of aftermarket brakes that aren't widely recognized or acknowledged. For the FT86 platform, these benefits are even more relevant and important due to the nature of the car.

Weight & Rotating Mass
The Competition Brake Systems we're putting together using AP Racing components are 5 to 10 lbs. less unsprung weight per front corner vs. the OEM equipment. Our smaller Sprint system knocks 20 lbs. off the nose of the car, which meaningfully improves overall F/R weight distribution. At this time, I don't believe unsprung weight reduction of that magnitude is possible via aftermarket wheels/tires or suspension on this car.
A sizeable body of work has been written on the merits of low rotating mass. The focus of most of this work has been related to lightweight wheels. It's been proven repeatedly that heavy wheels and tires essentially sap power from a car, impeding both acceleration and braking. Road & Track recently explored this topic when modifying an FR-S with aftermarket wheels.

The same principles are true with brakes. As with wheels and tires, brake discs are part of the rotating assembly. A heavy brake disc is more difficult to accelerate, just as a heavier wheel is. On a low powered car such as the FR-S or BRZ, lower mass is even more critical.

Adding horsepower is the common route to an improved power-to-weight ratio and increased acceleration. Reducing weight achieves the same thing, but with additional benefits. Shedding lbs. improves your power-to-weight ratio, but also makes the car handle better, easier on brakes, decreases wear and tear on tires, and allows for greater fuel efficiency.
Most enthusiasts don't bat an eyelash at spending $2,000 on a header and exhaust system that sheds some pounds and adds some horsepower. On the FT86, our brake systems are effectively accomplishing the same thing. As an added bonus, you get a wide range of additional benefits.

Spares/Long-term running costs
While there is a higher initial cost of a big brake kit vs. simply upgrading the pads and discs, the long-terming running costs of an aftermarket brake system are sometimes actually cheaper.

From what we've seen so far, track compounds in the pad shape we use in our brake systems are less expensive than the same compound in the OEM FR-S/BRZ shape. The pads in our system also have a 50% thicker friction puck. Since the discs in our system are far superior, the pads will also be running cooler. All of that adds up to far superior wear rates per pad set. Let's say the pads for our system are $175, while the same compound in the OEM shape is $225. If you would normally go through 4 sets of OEM-shaped pads in a season, that would be $900 in pads. If you only go through 3 sets of pads with our system, that's $525, a savings of $375. Over three seasons, that's $1,125 in pad savings alone. That is already half of the initial investment in a kit, and that doesn't factor in any of the other benefits.

Disc replacements for BBK's are obviously more expensive, but it's a similar situation. The discs in our system are going to last far longer than an OEM or OEM-style replacement disc. AP Racing discs have an array of features specifically designed to deal with track temperatures, including specialized crack resistant metallurgy. For every few sets of OEM style discs you go through, you'll use one set of the AP discs. I just had a customer on the corvette forum post that he got two full seasons out of one pair of our discs. He went on to say he had 3 dozen cracked OEM discs in his garage!

Because overall system temperatures will remain lower with a big brake kit, you will be putting a lot less heat into your brake fluid, and will likely have to bleed your brakes a lot less. Racing brake fluid isn't cheap, and constantly feeding it through your system can get expensive.

Wear and Tear
If you've ever tracked a car much, you know that there is a lot of associated wear and tear on parts surrounding the brakes. A huge amount of heat is built up in the area of the bearings, ball joints, etc. Running a big brake system keeps overall temperatures lower. Additionally, the aluminum hats on the 2-piece discs in a brake system are better at keeping heat out of the bearing area.

Convenience, Enjoyment, and Track Time
This is one huge factor that always seems to be overlooked...if you've ever been lying under the car in the pits bleeding your brakes while your friends are zooming by, it just plain sucks. If you've ever driven half a session, and then had your brakes start to fade, right when you were getting in the groove and setting your best lap times...it sucks. If you were playing cat and mouse with a friend and you have to let up because your brakes are flaking out...it sucks. Track time is expensive. You want to use it having fun and driving hard, not babying your brakes and tiptoeing around. A sorted, track optimized brake system allows you to forget about the brakes and just drive. You'll also spend less time bleeding, and you probably won't feel the need to tote as many spares around.

Resale value of car and brake system
If you try to sell your car in five years, and your OEM calipers are a burnt mess, that's likely going to cause some concern for the buyer. That's why most of the Porsche guys with PCCB's still run aftermarket iron disc systems at the track. They put the OEM ceramics in a box, and put them back on the car when they sell it.

Additionally, a brake system from a top-tier manufacturer holds its value well on the used market. I've seen some of our AP kits sell for 60-70% of their original price on the used market. That means you pay $2000-$2500, gain all the benefits of the system for the years you own it, then get $1200-$1700 back on them when you sell. Between the resale value and the consumable savings, you're basically covered on the total cost of the system.

Feel/Confidence
Along the same lines as some of what I wrote above, having confidence in your brakes is an awesome feeling on track. It allows you to focus on everything else going on out there. Having confidence allows you to push harder and improve your driving. If you're in a competitive situation (Time attack or wheel-to-wheel), this can make a huge difference in the outcome.

Initial Cash Outlay
If you plan to buy front and rear race pads, SS lines, good fluid, and a duct kit, you're probably looking at what, $750? Throw in some slotted discs, and you're over a grand. What will you have to show for it? Some pieces of iron that you'll throw away, and some black fluid. Even SS brake lines are wear and tear items that will need to be replaced.

Many of the things I noted above are outside of, or in addition to, what most people typically associate with a big brake system. Do you absolutely NEED a big brake kit. No, particularly if you only drive on the street. The OEM brakes will stop the car. If you look carefully at the situation however, a BBK becomes a more logical purchase than you originally thought. People tend to dwell on the upfront investment of $2k, but you have to look deeper than that to understand what you're really getting long-term. In my opinion, if you plan to track your car regularly and keep it for 3 years or longer, a quality BBK is almost a no-brainer.

An Essex Sprint Kit on the scales next to the OEM front brakes.
http://www.essexpartsblog.com/media//OESystemweight.jpghttp://www.essexpartsblog.com/media/...tkitweight.jpg

- See more at: http://www.essexpartsblog.com/news/b....xKFT7S1E.dpuf

That's a setup that is suitable for beginners only. Stoptech pads are street pads.

A BBK is cheaper to operate in the long run, compared to stock brakes, if you're have a moderate amount of experience at the track. Pad and rotor replacement intervals get a lot longer, saving you money in consumable cost.

The biggest question I don't think anyone has asked is: What kind and what size tires do you run?

- Andy

Absolutely no need for a rear BBK unless weight savings is your goal. This assumes a properly engineered front system of course. If you change the brake bias enough then it might make sense, but that's pointless on these cars IMO.

For me, the Essex Sprint kit, or the the Endurance kit if you are concerned that the Sprint kit isn't enough, are still my preferred systems for these cars.

Unless you decide to see how much abuse the Sprint kit can take.. then you might crack a rotor with stock power, sticky tires and 1300+ degree rotors ;)

Wow thanks for the info guys. Especially Jeff from Essex. I'm leaning towards getting the Essex AP Racing kit, now I need to decide if I need the Sprint or Endurance. I really want to upgrade because as CSG Mike told me in his PM, it's better to have more braking capacity then not have it when you need it. I have overshot the backstraight at the track twice already, so I guess i was kind of traumatized with that. This was with stock pads though. Luckily the runoff was big enough and there was no damage.

Right now I'm running 255/35/18 Bridgestone Potenzas. I've already worn out the rears so I will be switching them out for Pilot Super Sports. No R compound for me right now because I'd like to sharpen my skills (or lack thereof :) ) with street tires first.

Does Sprint kit fit under any 17x8 wheels?

Yeah, I run RPF1 and Kosei K4R's in 17x8 with them. There's a fitment thread, stickied I think that lists some other wheels.

As long as you don't have so much that the brakes cool down TOO much :) unlikely though given the car and the reasonable size of the Endurance kit.

I'll probably end up with the Endurance kit for my M3. DDs need that right? ;)

Stock rotors with dixcel ES pads do well for about 5-6 laps. After that, the pads fade. The SC adds at least 20-30kph to the top speed of the car. I now reach 200kph on the straight at CIS. Slowing the car down takes much more than NA. I needed to adjust my braking points to compensate. I brake a lot earlier now. Hopefully adding a bbk would bring me back to my previous braking points.

No problem...that's why we're here.:thumbsup: We've gone through this same situation 1000 times with other customers. As for future-proofing, the Endurance kit is exactly that. I have evo's, STI's, Z06's, and asphalt late models with 500-600 hp running the same 325x32mm discs that are included in that system. There is no way you'll ever exceed the limits of that system. Here are a few examples of customer cars on those discs, including some on-track video from races:
463 rwhp C5 Z06
C5 Z06
More C5 Z06's
497 hp Lancer Evo
E46 M3's (I went for a ride in one of the M3's which was putting out over 500hp...it was nuts when the turbo spooled! :O )

That said, the Sprint Kit is no slouch either. These cars were actually using the CP3862 discs from the Sprint Kit!
Some late model race wins

Yes, both the Sprint and Endurance Kits fit tons of wheels. Below is a list of some of the ones we've confirmed, but there are many others out there:

Sprint Kit fits without spacer
Name size offset
Enkei RPF1 17x8 45
Enkei RPF1 (very tight fit, but works) 17x9 35
Enkei Fujin 17x7.5 40
Kosei K4R 17x8 36
Mach V Motorsports "Awesome" wheel 17x9 42
Rays CE28N 18x7.5 47
Sparco (designed by OZ) Assetto Gara 17x7.5 48
Subaru OEM STI Wheels (2004) 17x7.5 53
Team Dynamic 1.2 17x7 38
Volk Racing TE37RT 17x9.5 +40
Wedsport TC105n 17x9 35
Work Ultimates 18x8.5 47


Endurance Kit fits without spacer
Name size offset
BBS CH-R 18x8 38
Enkei Fujin 17x7.5 40
Enkei RPF1 17x8 45
Mach V Awesome 17x9
Rays CE28N 18x7.5 47

We offer wheel fitment templates for each kit if a customer wants to check clearance:
Sprint Kit wheel fitment template

Endurance Kit wheel fitment template

We used ours under 17x8 +45 RPF1 for a long time :)

A BBK won't shorter stopping distances in most cases, so unless you've adjusted your braking points to try to keep the pads cooler it won't have much effect there. Unless your current brakes can't engage ABS, adding more stopping power won't shorten braking distances.

Braking earlier (and longer) also adds more heat to the brakes than braking later does in some cases (depends how hard you're on the brakes in both cases).

Thanks @wparsons! Good to hear that. Now I'm really confused! Haha!

My car on stock brakes with Dunlop ZII's couldn't engage ABS anymore when the tires were warm and I could overheat the pads badly in a hurry, switching to better fluid (ATE Super Blue) and pads (Ferodo DS2500) and haven't overheated the pads since, and can easily engage ABS.

It all depends on your individual needs.

100% agreed! I know that if I were to hand my car over to Mike he'd overheat the pads no problem :D

Just another addition to what I said above, if you compare 100% stock brakes to a typical BBK on sticky tires you will see a decrease in stopping distance, BUT that's because the BBK comes with better pads. If you were to simply put better pads in the stock calipers you'd see the same results.

A BBK with thicker rotors will help dissipate heat so the brakes don't hold as much heat, but that only helps prevent fade, not reduce stopping distance.

You can add the 17x8 +42 TC105N - I measured using your Sprint kit template when I was fitting the AP Formula kit.

Hmmm that's supposed to be on the list... we test fit that wheel!

My favorite BBK is your face - so ugly it could tear the asphalt apart!

To add to this, if you're not on the verge of hitting ABS, then you can brake harder than you currently are. The primary purpose of higher temperature pads and/or a big brake kit is to allow you to sustain this level of braking for longer periods without brake performance degradation.

I have your Sprint kit. You can add OZ Ultraleggeras to your list (no spacers needed).

- I run the RPF1 17x8 +45 on the track, without issues.
- I run the OZ Ultraleggera 17x8 +48 on the street, without issues (lots of clearance).

Done that too many times in other cars. It is something that's good to learn and take care of early to help minimize the "oh shit" moments ;)

Thanks for the info in this thread everyone. Helps for other people besides OP I'm sure.


Sent from my iPhone using Tapatalk

Confused why? You're going a LOT faster, so obviously you must get on the brakes much sooner in order to decelerate to your corner entry speed, which hasn't changed!

I'm confused because some people recommend getting a bbk, and some are against it and say just get better pads and fluid. Hope that clears things up.

Depends on an individuals needs. Some drivers are extremely efficient with their brake usage and can get by just fine with OEM gear with upgraded pads/fluid. Some drivers run 10-15 minute sessions and can use the OEM gear with upgraded pads/fluid. Some drivers do 60 minute sessions and delaminate the OEM rotors after 45 minutes.. oops! ;)

There are other BBK benefits (weight savings, consumables [wear rate and cost in some areas], feel/modulation, etc) also that aren't directly related to their primary purpose (additional thermal capacity and increased/more efficient heat removal - although consumables wear rate is affected by that also).

As an example of what these brakes can do, I faded the hell out of XP10s, ATE Super blue (both glazed the pads and boiled fluid) at sebring with the OEM gear. With the AP sprint kit (and AP 600 fluid/CL RC6E pads) I tried to destroy them braking at the absolute last possible spot for a 30 minute session and only cracked a rotor. And that was because I didn't let it cool down, I parked it with smoking rotors and jumped in the race car and went back out. If I let them cool down they would have been fine.