Nano

iTrader: (1)

raywheels total is close to 20-21lbs less than 17" cast about 5lbs lighter for the front, 5,5lbs for the rear.

LSD weight atleast an extra 10lbs. (open diff doesn't even have fluid I believe)

base comes with smaller tires too. that may be another 3-5lbs

Honestly, it's no big deal... all Z (except 35th) weight about the same

ANXIOUZ

iTrader: (13)

I don't think the Ray's are as light as people think. My 2 cents anyway.

What about airbags? The side and side curtain bags will add weight. Are they factoring that in expecting Track owners to get that option?

And the air diffusers and spoiler add next to nothing. The spoiler might be a few lbs but the diffusers together can't be more than 2-3lbs...it's plastic for pete's sake.

kcobean

iTrader: (2)

Your data about the brakes weights is invalid. That is a comparison of the stock vs. stoptech rotors. While the stoptechs may be bigger, they may also be thinner. I'll bet the Brembos are heavier by 5 lbs per corner. It's the extra mass that gives them the ability to resist fade, which is the only real benefit to the Brembo's because the stopping distances were nearly identical to the non-brembo setup with cold brakes.

So that right there is good for, say around 20 LBs. Add in the aero-kit....4-5 lbs...the electronics....4-5 pounds (maybe), more tire (less sidewall, but the weight is all in the construction of the tread). That could account for around 25-30 lbs.

Maizzze

The 300hp engine has variable valve timing on the exhaust valves in addition to the VVT on the intake valves which we all get. The cam phaser hardware probably makes up a little of the extra...

350Zenophile

iTrader: (20)

According to this comparison on Nissan's site, the Track weighs 11lbs more than the performance, 40lbs more than the base, and 46lbs less than the Anniv.

NISSAN Z CAR COMPARISON

I don't see any clear reason why unless they were less than scientific and fluid levels were not consistent from car to car...that would easily make up the difference.

sentry65

iTrader: (11)

I just weighed my track rays wheels that I'm getting ready to sell

fronts weigh 17 lbs
rears weigh 18 lbs

they're the lightest wheel Nissan offers on the Z by quite a bit


that is REALLY weird of nissan to list their curb weight in their spec area being different than the curb weight in the car comparison area


So then I guess brembos must weigh a considerable amount more than the stoptech brakes?

Kolia

iTrader: (2)

Where does the 107 lb for the Brembo kit come from ?

The 15 lb could be found in the rev up engine pretty easily !

And 17" tires are also heavier than 18"...

dkmura

iTrader: (64)

I'm late to this party, but have some data to contribute. I purchased some used Brembo rotors off this board and sent them off to be cryo-treated. When it came time to ship both F & R rotors back from Boston to Denver, I was shocked to learn that the shipping weight was over 135#!

Upon closer inspection, the OEM Brembo rotors are both thicker and larger in diameter than the OEM rotors. Yes, it's more unsprung mass (only partially offset by the Rays), but it's capacity as a heat sink is light years ahead of the standard brakes. I too, wish the track model was lighter, but I can say that the Brembos were worth the money and added weight!

sentry65

iTrader: (11)

i'm actually not even talking particularly about the rev up engine - it's always been this way for the 2003 and 2004 track models

I guess the brembos really are much heavier than I originally thought. I figured they'd be roughly the same as stoptechs - maybe a few lbs heavier on each corner


how thick are stoptech rotors?



this is all the braking info I have:


Brembo Front Caliper- 9 lbs
Stoptech 14" Caliper- 8 lbs
stoptech front caliper: 11.5lbs
stock base front caliper: 12.5lbs


Brembo Rear Caliper- 6 lbs
Stoptech Rear Caliper- 6 lbs
stock base rear caliper: 6.5lbs
stoptech rear caliper: 6.5lbs

Brembo Front Rotor- 20 lbs
Stoptech 14" AeroRotor- 18 lbs
stock base front rotor: 16lbs
stoptech front rotor: 17.5lbs

Brembo Rear Rotor- 17 lbs
stock base rear rotor: 12lbs
stoptech rear rotor: 15lbs




total weight of stock base brake system: 94lbs
total weight of brembo brake system:107lbs
total weight of Stoptech brake system:101lbs

Nano

iTrader: (1)

checked on Japanese website for Z weight

in KG

Base (mt/at) 1430/1440
T 1450
S 1440
ST (mt/at) 1450/1460

the S is the track equivalent only 6MT (brembo+clotch+cheapstereo+etc)
the T is the Touring equivalent only 5AT (stock brakes+leather+bose+etc)
the ST is fully loaded (brembo+leather+bose+etc)

difference is even less than american models

spacemn_spiff

iTrader: (3)

I dont understand what you mean by that. Can you explain?

From what I understand more surface area contributes to better heat dissipation (basics of heat transfer) and also higher temp stable materials used in pads and rotors contribute to reduced fade.

Kolia

iTrader: (2)

More mass allow to store more heat before it's transmitted to the fluid and everything else. The caliper sheds the heat normally after braking.

Think of it as an electical condensor...

Does it make sense ?

spacemn_spiff

iTrader: (3)

The electrical condenser or capacitor analogy is good if you are braking very infrequently, but if you are on track it will reach a saturation point (everything is as hot as it can get) where heat input is equal to heat output and that heat output is based on cooling of the system and not the mass.

In carbon ceramic composite brakes, the mass of the rotor is much lesser conventional cast iron rotors and they dissipate heat much faster. Its actually desired to have less mass of the braking system for better overall performance.

Nano

iTrader: (1)

brakes temperature spikes are reached during braking.

carbon brake advantage is that they will "brake" way past the heat range of conventional steel rotors. In F1 they reach 1800F in some curves and brake from 200mph to 30mph in less than 3seconds... less mass would mean they would reach even higher temperatures.

Same on conventional steel rotors. More mass means more energy is required to raise the temperature, so they never reach those insane spikes. Obviously, bigger rotors also mean larger vanes and larger surface to cool down the rotors faster.

BTW Braking technique should be "brake as hard as you can for least amount of time possible". Riding the brakes is a mistake

here is 4 consecutive 100mph stops

sotck rotor (296mm x 24mm) 804°F
brembo rotor (324mm x 30mm) 721°F
stoptech 13" (332mm x 32mm) 695°F
stoptech 14" (355mm x 32mm) 594°F

spacemn_spiff

iTrader: (3)

The data you quoted should not include any effect air or convective cooling of the rotor, otherwise that data is not useful in determining if mass is a bigger factor than air cooling. I assume it includes convective cooling.

Carbon ceramic brakes are lighter, and you didnt explain the effect of their mass on their cooling. And the rotors in F1 cars reach 1300C (2400F), a little more than 1800F, they are practically red hot when braked hard. F1 brakes uses vents to direct airflow around the rotors, again showing that mass is not as important as convective cooling is.

I am not ruling out the effect of mass because its basics of specific heat capacity of a body, what I am saying is the effect is minimal compared to convective cooling. So according to your theory if brake designers increase the mass of the rotor and not the surface area, the brakes should perform better. Sorry, I have to disagree.

Also conventional brake rotors are cast iron and not steel, its difficult to machine vents or vanes out of a steel billet in a one piece rotor.

Nano

iTrader: (1)

I don't know, I got the data from Brembo Website. Monza first chicane from 365kmh to 80kmh rotor temperature = 930C (1706F). What corner in the F1 championship do they reach 1300c?

I don't follow why you keep saying mass is irrelvant. Because they use active/convective cooling?

I said Mass IS a factor and I specified the importance of specific heat capacity... you must realize the nonesense of racing on tin foil rotors. You'd need a hell of a convective system, lol. Air does not have an infinite cooling potential

Steel rotors was a lapsus, sorry

sentry65

iTrader: (11)

you can always buy stoptech aerorotors for the brembos and that'll lower the rotor temps considerably too - and be lighter weight. Advantage being you'll have better accelleration, disadvanage being for really long hard road courses, you'll be more likely to overheat them vs the bigger stoptech ones

spacemn_spiff

iTrader: (3)

The reason why most disk brakes at least on the front wheels have vents or vanes is for convection cooling, if mass were as important, some would increase mass and some would have vents. And its cheaper (manufacturability) to increase mass and not have vents. Z non-Brembos have vented rear brakes too, so the reason they went with vents instead of more mass is because of effective cooling.

Heat generated is dependant on the speed of the rotor, the more the speed, higher the speed of air flowing thru the vents because of the impeller based design of the vents, this results in better cooling at higher speeds. So mass seems to be a little disconnected from this effect. And if you think convective air flow is not a good way of cooling things, then radiators should not exist. I am not talking about infinite cooling potential either, I am just talking of keeping the temperature in the operating range, which is not infinite or impossible.

So again, we go to carbon fiber ceramic composite brakes is because of reduced mass and inspite of that better cooling, if you know Porsche and Ferrari use these rotors on their road cars, so the shift towards low mass indicates that mass is less important/effective in cooling the rotors. I have not done any calculations to analyze the heat transfer, but I know that increasing the mass to cool better is a completely wrong direction in my books.

About the 1300C quote, http://news.bbc.co.uk/sport1/hi/moto...de/3518465.stm
Its not the best source, but I cannot disregard it as being unreliable.

DomZ

Carbon fiber ceramic composite brakes weigh less, but do not have less mass.

spacemn_spiff

iTrader: (3)

If they weigh less and assuming that acceleration due to gravity is constant, then mass should be less. This is based on Newtons laws of motions (2nd) if they have not been refuted lately.