Hey Guys,
I bought the fastbrakes willwood bbk, in April of this year.

http://fastbrakes.com/shop/product_i...roducts_id=758

As a matter of fact, thats my actual car in the picture. However, since I got the kit, my rotors feel as if they are warped and my car feels like its biased too much towards the rear.

Brian from fastbrakes has already sent me a replacement set of rotors and they have been fine for about a week, after that they started pullsating again during braking.

The other day I did a hi-speed run about 160kph (100mph) and slowed down to a stop. The rears were glowing while the front seemed pretty normal. Is this an effect of a BBK that the rear gets biased too much?

Also, my pads seem to overhang the rotors a bit, like 1-2mm the pad sticks out past the rotors edge, is this normal.

Thanks for any info.
Kam

matko bosko! That's kind of good to know. I was planning on either going with the BBK or just the 4 POT calipers sometime soon, but I guess I'll just go with the new rotors and new pad plan, considering the numerous bad things i've been hearing about these.

With a BBK wouldn't it reduce the braking in the rear...so why would the rears be put under so much pressure that they heat up so much? Cos jest pojebane tutaj

From what I have read last night, our cars have Electronic Brake Distribution (EBD) if the car is weighed down in the rear the rear brakes are biased accordingly. Since I have lowering springs the car probably thinks I'm fully loaded back there and there fore applies break pressure to the rear more.

I just want to figure out how to make the front brake more then the rear cause my rears are melting through pads every 10,000km.

Kamski

wow, that sucks BADLY considering that you auto-cross too. can you somehow hack into and reprogram the EBD?

And while braking hard, wouldn't most of the weight go towards the front, resulting in the EBD to think that the front is getting mroe weight? Or am I thinking of this in a wrong way?

***, im not even sure how that sheet works at this point. Only thing I can think of is to install OEM rear springs to jack up the rear and give that a shot......... or to figure out what sensor detects pitch in the vehicle and remount it so that it thinks it's level and stops applying the rear brakes so much.

Now dont get me wrong, the car stops on a dime, like I seriously mean on a DIME!!! But at the cost of melting the rears every 10k and freakeshly sliding everytime I hit the breakes on a turn is not my idea of fun.

I dunno, to each is own I guess. Also, I would imagine that the proportioning valve is too slow to react to weight moving forward, I guess it must be one of those start the car and set the pressure devices..... maybe..... so even if I do brake hard the weight goes forward but too late non the less.

Thanks,

Kam

My theory: you brake a lot harder now, and since front brakes do most of the job you don't feel that your rears are starting to overheat.

I brake the same, but why are the rears kicking in more often then usual and why does the rear slide out evertime I brake on a turn?

K, does anyone know anything about this automatic brake proportioning valve and how does it work?

Kamski

I hate to ask the stupid/obvious question but:

Are you sure you bled the brakes correctly (i.e. correct order/procedure as specified in the FSM for that electronic brake proportioning)?

If there is air in the front calipers still, that would explain why the rears are grabbing before the fronts.

Yessir, i bled them as per the FSM manual. RR, FL, RL, FR.... now i dont get that bleed order but thats what the service manual said to do.

The front calipers (4POT) I bled the inside bleeder then outside bleeder, then I used a rubber mallet to tap the calipers and disloge the air bubbles and I redid the bleeding again, just to be sure.

I need to figure out what device or mechanism adjusts the brake bias, otherwise I have to go back to stock or I might end up killing my self on a sharp turn.

Kamski

Brake proportioning vavle needs to be added?

Can't you just pull the fuse to the ABS (or the like) to disable the whole system then recheck?... being careful of course...

BTW - your rears will definitely retain more heat than the new fronts.... so it's not too ununusual that the backs get hotter. The total front surface area of the pistons should be greater than the stock calipers so the bias should be more FRONT than back... should be...

This is messed up, I installed my OEM rear springs back in last night and went for a rip down the same roads I tested it on before, also I filled up 10L to even it out at half a tank of gas. Brought her up to 160kph and hit the brakes at the same road sign as last time to stop her.

None the less, during the same 160kph braking maneuver the rears were now significantly less red then then last time and this time the fronts were also slightly glowing red while last time the fronts were not at all. This tells me to believe that raising the rear end set the brake dristribution back to normal because I now had more front braking then last time. Also on my "test" road the right turn I took before while applying brakes, this time my cars rear didnt want to skid out like last time, the rear stayed in place, but the car started plowing as if understeering.

Like is there no nissan techs on this forum? has anyone ever had this problem, im pretty sure I read about a 5th or 5.5 gen memeber with a BBK that went back to normal cause of this, his post was in the Show off your BBK thread.

Kam

If it's a physical sensor at the rear.... find it, reposition it, test it...reposition if necessary until a Nissan tech replies...

I think the difference you are describing is only due to different suspension setups.

OEM suspension transfers much more weight to the front, so rear brakes do not have to work as hard as they had before. Also, this weight transfer decreases overall traction so you put even less pressure on the brakes.

Regarding the oversteer during cornering, OEM suspension is designed to understeer in virtually any situation, while your aftermarket suspension is probably designed closer to overseer. So pressing the brakes in the corner is probably all you need to start rotating with aftermarket suspension.

Thought about that, but this only pertains to braking distribution not general suspension stuff. Peace,
Kam

So should the guys that are lowered but have stock brakes worry about the rear being used more as well?

yes as the BBK has nothing to do with the rear EBD sensor.

Kam

All of this doesn't speak to why your front rotors are warping so soon, especially when your brake distr. is rear biased as of now. Those rotors may look pretty(I've seen your photos) but they may be too thin.

I, too will be in the market for at least rotors and pads, maybe new calipers and I thank you for the heads up.

I have a feeling my rears are got warped and during pulsation they could transfer pressure to front calipers. THe funny thing now is, that with the OEM springs the front brakes dont shimmy as much.

Kamski

Yeah, I read that. Don't know what to say about that. I tried to do some research on the EBD(electronic brake distribution) in the service manual but it didn't say much.

The thing is, was your brakes doing this before the BBK with the aftermarket springs?

Yeah I chewed through rear pads as well, however now that I have SS lines all around its even more noticable. I did warp OE rotors also, I'm wondering if I did warp the OEM rears as well. I have to take the BBK off for winter wheels, so I will re-install all my OE brakes and rotors. I will get the OE rotors machines and see which ones were warped. But 100% my rear brakes and front ones were being used up equally.

Kamski