witmaRX

hi all,

i test drove a Porsche Cayenne yesterday and the sales person proudly said that the Cayenne has 6 pistons on Front brakes and 4 on back.

i am Just curious to know how many does our RX's have..if anyone knows this info plz post it here.

tcheung87

Honestly I have no clue, my best guess would be 2F/1R? TunedRX300 has a neat BBK for his fronts, I believe he has Rotora 4Pot with some pretty fat cross drilled rotors. Ask him, he might know about the stock calipers also.

-tc

salimshah

From memory, there are 2 pistons behind each front pad and one for each in the rear.

We had a long discussion (where I POed couple of folks) on brakes. # of pistons essentially helps in reduced effort as you apply brakes and to a large degree in heat dissipation .. influence fading ...[which is a factor ONLY when you have to do exessive braking]. Normal driving conditions and emergency braking [stopping distance] the only factors that apply are the momentum, the tire-road contact patch and friction between the tire_rubber and the road.

* the above is based on the premise that the pads are capable of locking the disc. [good working condition and no fading]

Salim

AlexusAnja

What year? I don't know about post '99, but my RX are one piston per caliper all around.

witmaRX

My RX is 2000 AWD

do you know if we have four sensor/four valve ABS? or other?

Tammy

The 2000 RX300 AWD have single piston calipers on all four corners. These are lighter in weight with less points of failure. The front pistons are larger than the rears. They are reasonably simple in design and for most driving applications are quite adequate.

All ABS vehicles have a speed sensor on each rotating wheel. Our design is under license from Bosch of Germany. (so stated on the ABS accumulator pump)

witmaRX

tammy, not all vehicles have sensors on four wheels, some AWD/FourWD have one sensor for rear wheels in the differential(i think i am saying it right- the big round thing in between rear wheels) and so that sensor would activate ABS only if both wheels are slipping and not if one of them slips.
i am sure Lexus won't do that, but was just curious..

TunedRX300

TC,
I am still trying to get Goodyear Eagle ResponsEdge tires, BBK is still waiting to be installed by...me.
Porsche Ceyanne has even better setup than Rotora BBK, the calipers are forged aluminum to reduce unsprung weight and keep fluid pressure high. Caliper clamp on both side on the rotors so force is doubled than clamping on one side.
RX300 has single piston. Second generation ES has dual piston and PM me if anyone is interested to do a mini BBK.

bob2200

My '72 Mercedes-Benz had 2 pistons per wheel all around and braking wasn't anywhere near as good as on my RX300. There's more to braking than just number of pistons. All you need to do is just control braking to a point below skid of tires on a dry surface.

TunedRX300

I agree your MB may have not have better brake due to shortcoming of other components.
Everything else equal (balanced brake bias, rotor diameter, pad friction coefficient) higher piston pressure area = shorter distance. See this excellent white paper on the physics of braking system
http://www.stoptech.com/tech_info/Th...%20Systems.pdf