Why doesn't the NSX have 4 piston brakes?

[mikec]

I took for granted that the NSX would have the best brakes available to it, and maybe it does, but i was surprised to learn that the calipers are only 2 piston in front and 1 piston in rear. Heck, my 88 RX7 turbo had 4 piston brakes in front. Anyone know why Honda didn't go all the way?

Or, is a two piston floating caliper just as good as a 4 piston fixed caliper?

 

[supergreen125]

i remember reading a magazine article back when the nsx was first introduced. they described the nsx as having "gorilla brakes." i assume "gorilla" means "good." maybe they were good brakes back then??

 

[Dan H]

Yup, my RX7 Turbo has 4 piston brakes too.

 

[MAJOR STONER]

I think that the brakes on the NSX are a weak point and made from cheap materials. Just the other day, I was washing my car when I had a good look at them. My car has been on the road for three years and the calipers are all rusted and flaked, the rotor edges are rusted while the rotor's contact area is heavily grooved (which leads me to believe that the pads are too), I get crazy stiction after washing or rain, and there is that awful ABS pump noise. When I look at many other cars, the brakes look beefier and in much better shape.

 

[Soichiro]

>>I think that the brakes on the NSX are a weak point and made from cheap materials.

Nonsense. When the NSX was introduced it's brakes were among the best (smallest stopping distance) found on any car. Perhaps Honda has not kept up with other cars (as in engine power) but the brakes are not weak and not cheap.

 

[j14nsx]

The brakes are designed becuase of the small distance between rotor and wheel. This is because of the in-wheel double wishbone suspension design. I think the suspension and handling was the design priority, rather than brakes.

A two piston sliding caliper has as much hydraulic effect as a four piston solid body caliper. Only the sliding caliper has more tendancy to flex.

Another factor may be cost, since the pads and caliper design is very similar to other Honda models.

 

[Ponyboy]

Indeed the NSX braking system was up to par with the rest of it's then current competitors. I think the only flaw is the stock systems inability to withstand continued high temperatures from track use with R compounds and aggressive pads. But for a street/occasional track driver, they are more than competent.

But with the marketing appeal of "Brembo brakes" or "4 piston aluminium calipers" currently, I'm sure the next NSX's braking system will fit with today's standards.

FWIW, at the track, I've had good success with wide R compounds, aggressive track brake pads, hi temp fluid, and AeroRotor rotors. If want 4 pot calipers you can always go aftermarket.

 

[MvM]

Mikec,

A 2-piston caliper doesn't have to be less than a 4-piston caliper. More pistons are much smaller per piston, the total area used is about the same. Think about this, the Tarox 6-piston calipers are usually preffered of the 10-piston ones but 10-piston does sound mighty impressive of course.
As for stopping power, I really have to drive hard to get my brakes to fade and can usually lock my (front) wheels quite easy. You cannot expect more from your brakes.
The brake-discs on the NSX are quite small compared to more modern cars but they were originally designed to fit inside 15" and 16" wheels, not the 17", 18" or 19" that are in voque now. Bigger wheels mean you can fit larger discs.

Bigger brakes don't necessarily give you shorter stopping distances. The do have more heat capacity, meaning it will take them longer to reach fading-temperatures, all else being equal.
They do rust. But I think that if you are driving a HP-car the brakes are something that you should check on a regular basis, just like your oil, cooling fluid, tires and tire-presure.

 

[mikec]

Whatever the design, the NSX brakes feel the best of any car i've had including the RX7 and the big Porsche 928.

 

[Eric5273]

Just curious, but are the brakes on the '02 and '03 any different or did they just start painting the calipars gold?

 

[NSXCessive]

I think that the brakes on the NSX are a weak point and made from cheap materials. Just the other day, I was washing my car when I had a good look at them. My car has been on the road for three years and the calipers are all rusted and flaked, the rotor edges are rusted while the rotor's contact area is heavily grooved (which leads me to believe that the pads are too), I get crazy stiction after washing or rain, and there is that awful ABS pump noise. When I look at many other cars, the brakes look beefier and in much better shape.

Nonsense, NSX brake OEM are not a weak point. Brake rotors rust just stitting there doing nothing. Not to mention that if you live in a costal area your prone to rust on the rotors and calipers. Also your brake wear and grooving of the rotor are signs of hard driving, or harness in the pads or rotors. If you are using genuine Honda Pads and rotors you shouldn't have a problem. Now remember this also depends on your driving habits, and enviorment.

Brakes look 'Beefier' comapred to what? Remember you are talking about an Engineering achievement that has been on the road proven 12+year and going strong. Look at how close the caliper sits between the rotor and the front wheel. Amazing! That is all I have to say... from what you mentioned above... Maybe its time to do your brakes!

From what I've learned over the years...

The floating design (OEM mostly) was designed by the car manufacturers essentially to make the caliper less expensive to produce. It applies the physics principle of "for every action caused an opposite and equal reaction happens." With this in mind they eliminated the piston(s) on one side of the caliper. This floating caliper is not solidly mounted, but slides back and forth on bushings. When braking force is applied, the piston push the brake pad on the primary side and the reaction is the rotor being squeezed from the force of the pad primary side allowing the horseshoe shaped caliper to slide on the bushings so the secondary pads is used to squeeze the rotor.

Non-floating calipers (i.e. 2, 4 or 6 piston) require a fixed mounting bracket. Most race applications use this type of caliper, because they are generally are made of aluminum which displaces the heat faster and requires both less pressure and less volume to operate. The floating design allows all the piston to be applied at the same pressure, because the pressure is equalized when pressure is applied, thereby allowing the rotor to be squeezed by opposing forces (piston on each side). Aluminum will displace heat 1.5 to 3 times faster than the cast iron or steel calipers. This is important when the rotors heat up to 1100 to 1200 degrees in a race car. Don't forget brake fluid has a boiling point of 550 to 700 degrees F. I don't think our street NSX's get this hot!

The NSX kinda falls to OEM floating type caliper. In order for the caliper to squeeze the rotor it has to use a floating design, otherwise it would only apply pressure from one side to the rotor. But at least here you've got 2 pistons instead of one. I could go on, and on with more master cylinder requirements, pressures etc. I'm not an brake engineer so...


The NSX engineers must know a thing or two about build cars, afterall the NSX has stood the test of time. A car designed in 1990 has changed very little to 2003...

 

[lowellhigh79]

More pistons (brakes or valves)means more area covered in a given radius; just look at the 4 or 5 valve designs for heads versus the two valve designs of the pushrods. I'm sure that back in the late 80's when the NSX was born, the two piston sliding model was more than enough. Still is with the lower weight and mid-engine design, far less frontal weight transfer than comparable weight (or less)/ front engine cars. The diameter has increased since 92. I think it was the 96(?)

 

[nsxtasy]

Just curious, but are the brakes on the '02 and '03 any different or did they just start painting the calipars gold?

Just painted.

Originally posted by RudeBoy_baby_NSX
Brake rotors rust just stitting there doing nothing. Not to mention that if you live in a costal area your prone to rust on the rotors and calipers.

Yup. All brake rotors are made of steel, and they all rust. Well, all short of the ceramic rotors on the big-buck Porsche and Ferrari.

Originally posted by RudeBoy_baby_NSX
your brake wear and grooving of the rotor are signs of hard driving, or harness in the pads or rotors.

No, actually, grooves usually form because something (small rock, metal shaving, etc) gets between the brake pad and the rotor. But rotors and pads are considered wear items, that will be replaced from time to time.

Originally posted by lowellhigh79
The diameter has increased since 92. I think it was the 96(?)

Close. '97.

 

[old_S13]

I agree with MVM, brakes come hand in hand with wheel/tire combination. It has not been until recent "trend" that larger wheels have been in demand, and that is not to say larger wheels are better! It all depends on what the suspension was designed to work with. On many cars I've worked on, upgrading to too tall a rim will definately reduce performance. My car came with sliding single piston caliper and 15" wheels. I upgraded to 16x8" wheels and quad-piston, aluminum calipers with 245/45/16" tires. This upgrade didnt give me quicker stopping distances, it just made my brakes more reliable in being able to stop from 100-0, over and over and over again.

Besides, when you increase things like wheel size, brake size, etc.. you also increase unsprung weight. We ALL know the NSX handles very well. Increasing unsprung weight will ONLY reduce the handling characteristics of this vehicle. As you can see, its all a trade-off.

Remember, the BIGGEST factor in stopping your car is NOT the brakes, its the tires. If you can lockup your brakes, that means you are already pushing your braking system to the max. From that point, better tires would be the item to purchase should you want to "upgrade."

- Mike