Sutitan

Recently ive been considering a bbk for my car. but ive noticed some kits are only for the front. Wouldn't this upset the brake bias? Wouldent you roast your rear brakes under very hard braking.

Ive tried searching allover the forum with no luck. I did find this little bit which ive never heard of. "The TL has Electronic Brake Force Distribution which adjusts the braking front to rear depending on the way the vehicle is loaded."

So is a only front bbk a terrible idea? Am I missing something?

I hate cars

I've written a lot on this subject from my trial and error. Try a search on my username. It was pretty boring and dry, not a lot of people responded but it's out there. I have a 13" 4 pot 1pc Rotora front kit. To be completely honest, the only thing that stopped me from getting the rear kit too was money. I would be single if I spent $3,000 on brakes at once.

Stoptech retains stock bias. Rotora is not known. I've found bits and pieces from their techs that makes it sound like stock bias is retained.

My experience with the Rotora kit is that bias is fairly close to stock. From normal speeds about the same pedal pressure is required for a given deceleration but that's not much of a test.

I was about to pull the ABS fuse to get a better idea of bias under threshold braking but I never got around to it. I may just do it this weekend.

What I originally did was run a pad with a higher friction coefficient in the rear. It will help with bias but you put more heat into the rear rotors. I chose this way because one stop stopping distances take priority since the car sees 90% street duty. FWIW, the stock Acura pads front and rear are rated "EE"

I'm currently running Rotora's H6 race pad in the front and I ran into scary rear rotor temps while trying to bed them in. After 5 back to back 120-10mph stops and driving normal for about a minute the rear rotors were still around 700F when i shot them with a temp gun. Who knows what they were at before the cool down. The other problem with these pads besides the noise is they run a higher .55-.6 friction coefficient so it shifts bias even more forward. Only under extreme conditions that you would be hard pressed to find even at the track will the rears fade. It's a scary feeling because under hard stopping with the rears gone you will feel the ABS pulsing even though the car is not stopping as quickly as it should.

I still have stock brake stopping distances on the same tires recorded for the stock braking system, I need to take it out to the same spot and try again with the BBK.

As for the EBFD it's still an unknown. I purchased some tech papers on it (not Honda's system but EBFDs in general) to try and understand how a BBK could affect bias and it's inconclusive.

Mechanically (if the EBFD fails) the vehicle will have a huge front bias. So when it's functioning it increases pressure to the rears. Supposedly it measures slip in the rear vs front under hard braking and adjusts brake force pre-ABS involvement. If this is the case all it has to do is "learn" your new parameters and you'll have stock like bias.

If you plan on tracking the TL, you'll quickly learn that the ABS really holds the car back. It's just too conservative and if you begin to lock say an inside front tire under trail braking it reduces brake force to all wheels.

The nice thing about the BBK is the braking is so much more confidence building. It brings speed down effortlessly from triple digit speeds. Pedal feel is better as is modulation. This is probably the best single thing I've done to the car. I'm going to get a rear kit one day but for now just the front is ok. Remember the TL has 70% of it's weight over the front tires.

All of the track stuff aside I love driving the car with the BBK. Stopping from freeway speeds is effortless. Pedal effort never changes from repeated stops. Even at the track it's hard to expose any weaknesses.

94eg!

It may upset the bias, but in the opposite manner of what your thinking. Instead of roasting the rear brakes, they would actually do less work than they do now. This is why I hate cars has switched to a more aggressive rear pad. This helps push bias rearward again.

FYI: Even lowering your car alters bias and moves it forward. If your not timing laps, it probably isn't a lot to worry about...

Excelerate

iTrader: (1)

If the Big Brake Kit is designed properly, the brake bias is maintained. In my experience with BBK's I've found ROTORA has a bit more of a frontward bias and STOPTECH has a bit more of a rearward bias. STOPTECH tries to get the vehicle to squat when braking. Many companies on the market, though, will just try to add a 8 piston caliper and a 14" disc because they think bigger is better but overall piston diameter needs to be maintained. With the upgrade to a 4 piston setup you just have more equal distribution of that brake force, rather than 1 large piston pushing on the pads.

And in most cases a front BBK is all that is needed, even when trying to maintain brake bias. The rear kit will obviously improve the situation but it isn't needed.

94eg!

To maintain bias, piston area must be reduced when rotor diameter is increased.

Also, it's physically impossible for a car to Squat when braking. Even if only the rear brakes are applied (ie parking brake), weight still transfers off the rear wheels and onto the fronts.

I hate cars

I've got one of those calculators but I've been to lazy to use it. I found the total piston area of the Rotoras and stock calipers. This uses piston area vs rotor diameter.

I think the car feels a little more stable in a straight line with more rear bias. It's almost as if the rears help pull the car straight. When I lost my rear brakes during the front pad bed in, it felt like the front end wanted to wander more.