Noob to the whole brakes thing. Will it be okay to run four pot front and four pot rear. should i just put new four pot front and keep the brembo rear?
-Tim

 

That question cannot be accurately answered w/o knowing the rotor sizes and piston sizes of each.

Assuming you are putting on the exact same 4 pots on each side, then the quick answer is no. Too much rear bias.

 

You could technically shift the bias up front again by using more aggressive pads up front, like run a track pad in the front and street pad in the rear.

These cars have electronically controlled brake bias anyway, and the ABS pump should be able to adjust accordingly. If it's strictly for street use, I don't think it'd be a problem. For moderate track use, you can try the above method to re-shuffle the "bias" up front.

The rear brakes are woefully under-sized and under-padded anyway, even on Brembo equipped cars.

 

IMHO, you can only make MINOR differences in bias using diff pads.

Also IMHO, you want proper bias from the get go and not rely on heavy usage of the ABS systems to constantly bail you out.

The reason why you think the rears are underpowered is under hard braking, all the weight shifts up front where something like 70-80% of the braking force is needed.

 

Werd...

 

No, the reason why I think the rear are underpowered is because I used to go through an entire set of rear pads in 4 20 minute sessions. They're way too small for the weight of the car and the heat sink (rotor) is too small to dissipate heat fast enough. A few people I know who run track trim (Brembos) on the same tracks I usually go to, will boil their rear fluid first, even using trak ready fluid like ATE superblue or Motul RF600.

The rear brakes on the 350z, and G35, were inadequate for moderate track use. Brembo or not.

 

I'm deferring to StopTech's reply.

 

What kit are you looking at?

 

I would defer to StopTECH for most brake technical information too, but my personal experience on the 350Z (again, maybe the G35 is different...Who knows) is that this chassis is woefully under equipped for rear brakes.

None of the cars (BMW E86 MZ4 coupe, BMW E46 323Ci, BMW E30 318is, all bone stock brake systems) I tracked on the local tracks will burn through a set of rear OE pads in a single day's use. I ruined 2 sets of rotors when there's no pad material left after 4 20 minute sessions on the 350Z. And the lack of any usable braking in the rear resulted in rapid heat build-up and fade to the front pads. This chassis can actually use a little bit more rear bias if you ask me.

Not until I upgraded to a RacingBrake kit front and back, did I ever go through an entire weekend without experiencing fade, no matter what brake pad/fluid/rotor combination I tried on the 350Z. Faded at Vegas. Faded at California Speedway. Faded at Buttonwillow. I think the front brakes are asked to do way too much since the rears aren't doing ANYTHING.

 

I agree, even my oem caliper rear RB kit wears out way faster than the fronts. The rear caliper is just not up to the task.

 

Wouldn't that mean the rears are asked to do TOO much but don't have the capacity?

 

Again, I'm not a brake specialist. From looking at the pads and the way the disintegrated, it looks like the sweep area on the rotor is too small to dissipate heat fast enough, heat builds up past the maximum operating temperature, the pads literally melt and disintegrate with each application.

When I mean shifting the bias rearward, I mean having larger sweep area in the rear to facilitate heat dissipation. I also have a feeling that since the rear pads aren't really doing ANYTHING important to slow the car down, the fronts get overwhelmed quickly when the rears stop working past MOT (max. op. temp).

Just my personal experience with the 350Z on the track, that's all. Obviously a good big brake kit will solve the problem, and I'm not advocating putting bigger brakes in the back than front to solve the problem. I think for street use, it's not a big deal to put 4pot fron and 4pot rear, and even for some moderate track work, you need, at the bare minimum, something bigger than what's currently back there anyway. And obviously you can just use a big kit up front to take away even more work from the rear to resolve the problem too.

I'm rambling. Sorry.

 

I think you are confusing shifting brake bias and adding heat capacity. I don't think Jeff is arguing with you that the rear brakes lack the proper heat capacity to stand up to track conditions. Shifting brake bias to the rear would without making other changes would make the problem worse, this could be tested by installing the older, smaller 03-05 non brembo's on the front of a 05-06 with the larger dual piston setup. The rears on both cars use the same rear calipers, but the newer setup uses a larger rotor, which would shift the brake bias to the rear. I would put money on a setup like this fading the rear even faster, as the rear will be asked to do more of the braking.

Properly designed BBK's don't shift brake bias or add additional braking torque, they are meant to add heat capacity to the brakes through the use of larger pads and calipers for better dissipation, and along with larger rotors. Stoptech specifically designs their kits for the same amount of brake torque as the stock calipers(within a few percent), so their 4 pistion front or 6 piston front will have the same initial braking characteristics, with the only performance difference being heat capacity. So you and Jeff are arguing different points because you don't fully understand what you are trying to point out about the weaknesses in the stock system.

 

what will you do with your stock Brembo action?!?!?

 

Actually Hai, a properly designed BBK can increase the braking torque. Using more pistons (if area is increased) and bigger dia rotors do this. But the system must retain an acceptable front/rear brake bias or else brake performance might actually go down.

But you are right about BBKs adding fade resistance. It's one of many things BBKs add.