Original wisdom seems to be that a front BBK with "stock" rear brakes is sufficient unless doing some heavy duty racing. But with the front Stoptech BBK putting more bias toward the rear, on a car already more rear biased than most, I can't see how the rear brakes can hold up. Even the 350Z test that STOPTECH conducted (BBK front/stock rear) produced rear brake temps 100 degrees higher than the stock Brembo setup. My point is, I don't want to spend 2K upgrading my brakes only to see my rears on fire back in the pits. Of course you can upgrade the rear rotors/pads but that won't do much for energy absorbtion. I just wonder if I'd be better off to take my 2K and get an upgraded Z Brembo or G35 05/06 setup (I have an 03.5 sedan) at all 4 corners? Also, anybody hear of a brake cooling duct system for the G?

 

Isn't the question: what is the rear pad friction coefficient at the peak temperature you encounter. That tells you what you must do.

100F hotter than stock doesn't mean much if stock is not hot ~~600F.

Rotor temp rise is a function of rotor weight and the heat flow from rotor to wheels...........increasing wheel tire mass while not adddressing the rotor wheel conductivity at junction [dirty corroded hats and inside wheels] the cast iron to aluminum alloy heat transfer characteristic.

Selecting wheels in a wind tunnel to optimize air flow in to rotor surface.

 

I'm considering one of many wilwood kits. Much more affordable.

I was a little concerned at first, thinking there may be some tradeoff between price and performance when compared to other BBK manufacturers. But I have conferred with a few local guys that actually do some real racing, and the general concensus is that the various wilwood are legit.

 

Q45Tech - so your saying we should clean the hat/wheel junction to allow the wheel to be a better heat sink?? That's a new one on me but I like it (in theory anyway). Maybe the F1 guys should devise a combination tire warmer/wheel cooler. May be worthwhile to machine smooth the contact area of the wheel?
Here's the link to the test I mentioned. http://www.zeckhausen.com/Testing_Brakes.htm
The rear brake temps seemed sufficiently high. I'm interested in keeping the rears fade free and reliable with a front (only) BBK. While you can optimize the pad composition for a high temp scenario but that would exacerbate the heat absorption "issue" (working even harder).
The Wilwood kits from AZ Z car seem to good to be true - hopefully someone can prove me wrong.

 

Our Sales Manager ran a front only 332 kit on his 350z with stock rear non-Brembo brakes. He ran plenty of track days and never had the rear brakes on fire. He ran the Hawk HPS or Axxis Ultimates in the rear. The rear brakes don't even get hot enough to even require track pads.

 

geeitup, I don't think it's fair to compare the rear temperatures of the stoptech front only kit to the factory brembo front/rear setup. The OEM brembo rear rotors are obviously much larger than the stock rear rotors, thus able to dissapate more heat quickly. If you're pushing you're car that hard on the track where rear temperatures are of a concern then you should be stepping it up to a 4 wheel BBK anyways. Or at the least get the rear bbk from RacingBrake that utilizes the stock caliper.

 

There would be significant differences between G due to wheel base weight, while the 350z is close why not make actual measurements to see the base variation then extrapolate if you must.

 

Odd. When you upgrade your front brake's performance w/ a bbk, you DECREASE the rear bias. Well more accurately, the more braking force you engineer in the front, the more braking bias is moved to the front. If anything, with a front bbk only, the rear brakes do less work.

 

I'm just a little paranoid about the rears - when I first got my car with stock pads, I was going through rear (stock) pads 2-3 times faster than the fronts, when track lapping. I chalked it up to the rear bias (relative to other cars) even factory guys acknowledged in interviews when the G35 first came out. If memory serves, they said it was better for performance (anti-dive?), kind of how they said they 50/50 weight distribution wasn't as good as the G's slight front bias - go figure. Maybe the original brake pad composition was softer in the rear too.
Q45 - you lost me
Jeff- you would think, but check out Stoptech's website - their kits are engineered to shift bias toward the rear, so the rear does more work. A BBK on the front is capable of much more work than stock brakes, but the engineers can manipulate the amount of work the front will actually do by sizing pistons, etc.

 

Unless StopTech is actually modifiying the rear brakes in some way, they can't shift bias rearward unless:

They decrease the amount of force being applied by the fronts. Not sure why they would do this.

Modifiying the master cylinder. If that's still where Nissan does the porportioning.

 

In many cases our front torque output will be less than a stock caliper in order to shift bias rearward. We never induce enough rear bias to cause an unstable or unsafe situation...only to get the bias to an area where the maximum tracitive capacity of all 4 tires achieved. Some cars cannot be improved upon balance wise and we offer the same torque output with our kits, but in many cases they come front biased from the factory and can safely handle more rear bias for improved performance and reduced stopping distances. It does sound counter intuitive, but it has been proven with our many performance test wins that our philosphy and technology works.

 

How do you reduce the front bias when it looks like you don't touch the rear system? It looks like you reduce the front force to move the bias rearward.

I'll assume that evening the balance out is what is reponsible for better braking stop distances. ie.. less front end lockup

 

Exactly. Most factory systems are able to lock up the front tires so adding more front torque is not going to improve anything. By sizing the front calipers smaller than stock we can make the rear brakes more effective which relates to reduced stopping distances and a car that stays flatter under braking with less aggressive nose diving than is present with stock systems. Also having a smaller piston area means less fluid is required to actuate the pistons which results in a firmer brake pedal with less travel. This allows you as a driver to have a better feel of the pedal along with better pedal modulation which is something you will notice everytime you use your brakes whether you are on the track or not.

 

IMHO only. If you were going to that much effort to reduce the front end bias, (to increase the rear bias), I would perfer that you increase the rear bias via a larger rotor kit or similar.

BTW. Thanks for the informative posts and quicky replies. Learning alot about your brakes!

 

We do offer a rear brake kit, but at a higher cost than a front only. Since a front BBK is mainly used to increase heat capacity for track use, a larger rear rotor setup would not help out the front brakes from overheating. The reson all the work is done on the front calipers is because they do the majority of the braking for a vehicle and produce the most heat. Even under heavy track use, the stock rear brakes have enough heat capacity to keep from overheating making a larger rear rotor essentially unecessary.