Colin_S

iTrader: (2)

Please don't shoot me down if I am wrong but if all else remains the same but both front and rear rotors are increased in size in proportion would the car not stop in a shorter distance?

There are a number of kits for other cars that do this albeit they may be from 'lesser' companies.

Todd TCE

iTrader: (1)

Nope. Assuming you added 1" of rotor to each and no other changes you'd have the exact same bias and the same stopping. The only changes you'd experience is that you'd need a tad less effort to stop the car with pressure and you'd have a greater thermal capacity for improve efficiency.

Think of removing both a front and rear lug nut. If I gave you an 8" ratchet and a 10" ratchet. The lug nut is still torqued to 90lbs. You'd just not work as hard to undo it with the longer ratchet.

When you work with the bias calculators also consider max tq values. Say for example that 50,000 is lock up or skid. Whatever other values you use to get there won't matter, the 50k remains the max deceleration the car will hold for the given tires. You can use 16" rotor or 2" pistons, whatever, it all nets the final tq value of lock up.

Colin_S

iTrader: (2)

Ah I think I get it, you would just need less presure on the disks but would lock up at the exact same point so would not stop any quicker.

So when getting more power out of your car i.e. Twin turbo and require 'better brakes' what does that mean? Are you just trying to reduce the effect of fade or playing about with the bias to make it stop quicker (or worse if you don't get it right)?

Edit: when I say you I am not talking about anyone in particular.

Todd TCE

iTrader: (1)

"Better brakes" to one person means one thing, to another something else.

The best I can describe it (as I feel correctly so) is that the system will function with a lower duty cycle and higher level of efficiency. Meaning the feedback or feel is improved, the parts larger and thus less taxed, the thermal capacity greater and durability greatly improved.

But to someone else it might only mean they look better. So be it.

Jeff92se

iTrader: (4)

The thing is most here have upgraded tires and wheels so a rotor dia upgrade could very well result in shorter brake dist.

bbs350z

iTrader: (85)

i love my stoptech's. on a roadcourse, my stockers didnt stand a chance.

fallenromeo

iTrader: (11)

Am I reading this right? So why would anyone pay for a Wilwood BBK? What am I missing?

redlude97

iTrader: (11)

Its not all about stopping distance, BBK's are really for increased heat capacity for track use. Purchasing a BBK expecting a decrease in stopping distance is kind of foolish.

Colin_S

iTrader: (2)

That sounds like a good explanation to me. When i said 'better brakes' i was referring to function rather than looks esp when you are running large power increases.

ResIpsa

Did you have the 4 wheel kit? That is the holy grail of brake balance. I know it is asking a lot, but could you post the piston diameters of the front and rear kit?

The stoptech kit could be used as the bench mark for all us guys with other kits.

Todd TCE

iTrader: (1)

Yes and no. I won't say you are wrong, but I get nearly zero connection between big brakes and HP.

I get this all the time and I still don't totally get it. I'd put my money on a good driver with stock motor and good brakes on the track over the mondo-motor and stock brakes any day. Yes clearly a track car with more HP can use more brake. But so too can the low HP car.

All I'm really getting at is that HP is nice but it doesn't have any bearing on the value of a BBK. To say that the lower HP car cannot benefit from them is simply wrong. Maybe not to the same extent for the most hard core use, but let's be honest those folks are more the 1%ers of the bunch.

Colin_S

iTrader: (2)

I was basically refering to a number of posts and discussions i've had over the years when when your talk about big hp gains you always seem to get someone or some people who say make sure you get 'better brakes', or slate people who have big gains and don't have 'better brakes'.

chrisj2k

So what if it dilutes the market. Demand creates it's own supply. And in an oligopolistic market place, sellers are going to set their price to cover 1.) Fixed Costs. 2.) Variable Costs, 3.) Reasonable rate of return on capital investment. So, if Demand increases, supply will follow, and contribution margins skyrocket. Suppliers will lower prices (of your BBK) to prevent new market entrants. Sellers will benefit from this lower price.

Also increasing industry demand generally spurs R&D expenditures in consolidated industries. This results in BETTER brakes. Ta-da WIN-WIN situation for everyone.

And from a social standpoint, so what if more people have them on their cars!?!?!?! Safety and increased resell value (to some point), right?

Todd TCE

iTrader: (1)

I've had many, many comments later along the lines of "I wish I'd bought the brakes long before I bought the ______, every time I step on the pedal I know right were my money went. Not true of every purchase I've made to date."

35Z

This thread needs to mention that the 350Z have ABS and a brake actuator which aid in controlling the amount of brake bias front/rear. Also, the front brake piping brake hose differs from the non-brembo vs brembo calipers (See 350Z service manual for details/part list). Additionally, I suggest changing the brake fluid spec per the temp rating of the BBKs, that the vacuum lines be checked for leaks, and that the check valve is working properly and spec for the BBK. Of course, the new BBKs will need to have the disc rotor run-outs to be in spec as well as the wheel bearings are in spec (see service manual).

Thus, it is more than just r & r the stock brake calipers/rotors with BBK calipers/rotors.

Chad68

iTrader: (1)

As long as we are talking about BBK and heat dissapation...

I always wondered if the ugly looking stock calipers (non Brembo) actually vent out more heat than the pretty looking aftermarket calipers due to the factorys open caliper design which exposes part of the brake pad backing.

Most niffty looking aftermarket brake calipers enclose the whole brake pad and seems like that would retain heat more??

I know you get some cooling benefit with the drilled and or slotted rotors on the BBK's but having an enclosed caliper seems like that might cancel out some of the benifit gained by the larger and vented rotors?

Todd TCE

iTrader: (1)

A couple of reasons you see differences here.

Iron oem calipers are cheap to produce as most are iron with some being cast aluminum. Nearly all are single or twin pot 'floaters' which use reverse leverage to pull the outer pad into contact with the rotor. This requires a very thick and heavy anvil- the part bridging the caliper and securing the outer plate. When iron they also get hot and stay hot which is why they tend to boil fluid quicker.

Almost all aftermarket calipers are aluminum. Either forged billets, conventional billet, castings, most two piece and some one piece 'mono-block' design. The key here is that the alum is a better conductor of heat. Better said; it sheds heat quicker. And of course it's lighter. But due to deign and material it's often not as 'stiff' as the iron caliper. So, to make up for lack of rigidity the body is built with more bridge area or various concepts of stiffening design, bolts and pad retention. All simply there to limit the amount of spreading the caliper is subject to. In general; the beefier the caliper the stiffer and the more responsive the feel. For a DD that's not all so important but for track use it can add up to quite a bit of feel and responsiveness in time when excessive pedal travel due to flex is time.

Here's the example I use for some of my custom work for the track gurus. On the left is the W6a and on the right is the BSL6r found in factory Wilwood kits. Both do the same work but obviously one is much beefier than the other. So why are not all BBK calipers so large? Is the smaller one bad? It comes down largely to packaging. Bigger parts require more room. Smaller parts are not bad, they just have some limitations and should be balanced with use.

wheatz

iTrader: (4)

Wow, this is hilarious!!! Stoptech used as a benchmark... I think F1, WRC, Nascar, JGTC, IRL, etc would all disagree with that statement.

will350z

+1000 AP Racing FTMFW!

ResIpsa

Just to clarify, by benchmark I meant the % of bias between the front and rear brakes.

The point of my original post was to provide analytical proof that any BBK could obtain a single panic stopping distance equal to stoptech.

But I do understand your point. In my effort to establish some legitimacy for other brands of BBK's, I may have given too much credence to stoptech.

It seems, there is an almost religious attitude on these forums to Stoptech (when most members probably don’t even have a BBK) from the wildly publicized zeckhausen test. If you actually read the whole article, you learn that they never actually completed the test, and that half of the test was on a different day with a different car and tires.

Benchmark, maybe not...

Many of us (myself included) forget that zeckhausen makes a pretty penny selling these kits.

Honestly, pick up a copy of the latest Car & Driver, you can see that they had major issues with the brakes on their project 350Z (which was sponsored by stoptech).