rotaryPilot

Does this rotational weight affects performance or it is not so important because the large rotors are in the front wheels?

In other words rotational weight in terms of performance is more important in the rear wheels than in front wheels ,,,,,because RX-8 is a rear wheel drive?

Spin9k

I would say any rotational weight removal is a good thing, where ever it is. It directly affects accleration of the wheel, it also affects suspension characterisitcs. The rear rotors are lighter, less braking is needed there, so front reduction is perhaps more helpful, % wise for money spent, as you can get more weight out.

I have 2-piece lightweight front rotors (saved 6 lbs I think) and brake cooling ducts but didn't see my way to spend $500 more for the rears (I think it was 4 lbs saved). Rather I invested in lightweight wheels (15lbs vs 21lbs stock) as a way to reduce RW all around and get wider wheels in the process. Further the lost wheel weight is further from the hub, therefore exerting a stonger amount of inerta against quick accleration than the rotors that are more concentrated closer to the hub.

With unlimited money and interest you could really go crazy with this, but one has to make the best with what they want to spend. That's where the decisions are.

Raptor75

MS Duel can Exhaust
Mid pipe: 6.5 lbs
Muffler: 24 lbs
Total: 30.5 lbs

Race Beat Exhaust
Mid pipe: 7.5 lbs
Muffler: 40 lbs
Total: 47.5 lbs

WarmFreedom

U cant afford removing back seats as they will expose wheel noise and u wont like it 1 bit, besides the cushions are very light anyway,

however Ive been dwelling on thought of removing the entire Bose speaker systems and put in place a set of Altec Lancing PC speakers with its awesome subwoofer. They are lightweight and powerful, in contrast to Boses heavy and suck. A good replacement I think, what do u guys think?

suay

It might hit the wallet first but......



http://www.brailleauto.com/



the ultr light battery weighs 6.5 pounds!

TeamRX8

iTrader: (25)

you might want to search that

and even though it's rwd, the rear wheels still have to make force to rotate the front wheels for the car to move forward

rx8evo

Those cells definitely are extremely light, however, 527 pulse cranking amps & 10 Amp/Hr Reserve isn't very much to rely on to start your car after being parked for the average time one usually spends at work or sleeping (8+ hours), unless the ultra light were to be used for track days only. You could get away with using one on a daily basis, but I wouldn't recommend it for use in colder climates.

Braille's B2015(15lbs) is a more reliable choice for daily use, especially where temperatures average around or below 10C/50F. When the weather starts dropping below 10 degrees Celsius(50 deg. F) batteries rated below 15Amp/hrs will start having trouble starting a car after being left uncharged for an 10 hour period or longer. Better to have a few extra pounds under the hood than to be looking for a jump start in the winter months.

The HC600 kinetik power cell is an alternative to the braille batteries as they weigh just 14lbs and match braille's 20Amp/hr rating and physical size, albeit slightly less cranking amps at 850 vs. 1067; both of which are more than the OEM factory's 525.

Price wise, they retail from 159.95 for the braille, 199.95 for the kinetik, and 239.95 for the carbon fiber version of the B2015. All the cells from Braille and Kinetik rely on Absorbed Glass Mat for it's amazing amperage>size ratio, and are valve regulated, which will easily outperform any of the popular Optima series batteries when it comes to weight and performance, and they don't cost much more vs. a similarly powered Optima.

I've been using the HC800(Weight:26 lbs./Ah:36/Amps:950/Farads:200) for over a year and a half, and recommend this cell for those who are powering avg. sized external audio amplifiers(30-60amps of max current draw) and/or additional lighting that is left on without the car running for longer than 10 minute periods. I've just recently replaced my HC800 with the lighter HC600 to save an additional 12lbs. The HC600 has half(100farads) the electrical stiffening farad equivalent of the HC800, but will still handle double duty for starting as well as providing just enough amp/hrs for electrical aftermarket add-ons. I like the carbon fiber look of the braille, but there doesn't appear to be any weight advantages over it's non-cf clad batteries, but if you're going for appearance, nothing beats having the cf version brailles under the hood.

Since switching out my OEM battery, I've been recommending to my friends and local car club members to change out their factory battery with either a braille or a kinetik, and due to their minuscule size, RX-8 owners can relocate them up against the firewall where the windshield fluid bottle normally goes, (If you want to keep a reserve of ww fluid, use any quart sized capped plastic bottle in lieu of the factory container - drill a 1/4" hole in the top cap, use a rubber grommet to seal the vacuum hose, and secure against the firewall with 2 C-clamps)

The relocation is better, of course, for weight distribution, and clears the way for that future turbo upgrade that you're just itching to do anyways Swapping out the heavy and weak OEM battery with either of the two lighter maintenance free AGM batteries are an easy upgrade for weight savings and electrical performance increases. Just don't forget after doing so, to run a couple additional ground wires to take full advantage of the extra amperage.

chiketkd

iTrader: (5)

I measured the 27mm Hotchkis MX-5 (3-way) adjustable front swaybar at 8.4lbs.

FWIW, this is a great FSB option for the RX-8. By my calculations, the settings are roughly 13%, 33.7% and 60% stiffer than stock.

renesisjim

iTrader: (3)

What is the weight of a 6spd manual?

TeamRX8

iTrader: (25)

about 90lbs give or take a few for an 04 - 08 Aisin 6 speed

chiketkd

iTrader: (5)

Mark,

I imagine that's the '04-'08 6spd? I've heard the '09+ 6spd is 20-30lbs heavier.

notorque

this may help in determining benefit of wieght lost

corelation between weight,hp and 1/4 mile time with sae correction

http://www.stealth316.com/2-calc-hp-et-mph.htm

the good stuff is half way down the page for more modern calculations

renesisgenesis

washer fluid tank with full level of fluid must weigh more than the listed 1.43 pounds.

it holds 3.5 liters of soapy fluid. if it were water it would weigh 7.7 pounds.
(3.5 liters is 3.5 kg of water, x 2.2 =7.7 pounds)

So, this plus the weight of the actual washer tank itself must be well over 1.43 pounds, even if the fluid is much less dense than water, which it may be, but it isn't made of air.

I would imagine the total weight of the tank full of washer fluid would be around 8 pounds or so. Just a guess, so we need an actual measurement.


just needed to point out this inaccuracy.

thanks

StealthTL

iTrader: (1)

Where did you get 3.5 liters of fluid?
I thought the standard washer held like 1.5, the headlight washer model holds the 3.5?

S

renesisgenesis

Well, yes apparently, after more research, the 3.5 liter tank is for models which also include headlight washers. So perhaps 1.5 liters is correct for U.S. models?

Still, 1.5 liters of water is 3.3 lbs, so even if it is significantly less dense than water, that plus the weight of the actual tank must be more than 1.xx pounds....

ebb

iTrader: (7)

Windshield is 24 lbs
Rear glass is 12 lbs

Zelse

iTrader: (12)

Anyone figure out the collective total of our BOSE sound system yet? Curious how much it would save to take out all the mounting, wiring for the head unit and our 11 speaker system. Must be something decent, right?

What about weight of stock steering wheel? Would be nice to see what I'm saving by switching to a non airbag, removal steering wheel or something.

Removed sound deadening tar all in the trunk, behind rear passenger seats, and only at the feet of rear passengers and got - 15lbs - 20lbs Unfortunately my scale isn't very accurate, but all of it in a paper bag felt closer to a 20lbs weight from the gym than anything lower.

Thanks to Getready2greddy for weights below

Sunroof Assembly (glass, railings, wiring, all one assembly) - 23lbs
A Pillar to C Pillar Airbags - 4lbs each

Hope this helps some people. Thanks to everyone else for the help so far in my quest for dieting..though recently putting in the new rollbar doesn't help me lose weight..lol.

TorqueyPig

Thats quite a list. Im sure lots of people will find this useful

TeamRX8

iTrader: (25)

The front page list needs to be updated with the new info on the last two or three pages

rotorhead335

My back seats were weighed at bottoms = 5 pounds and backs = 6 pounds (each for both) for a total of 22 pounds. I have the Racing Beat dual catback exhaust (wish it didn't weigh so much), and I do not find the sound unbearable. There is more noise from the wheels, the road, and the exhaust, for sure, but it is not so bad to me. Consider: If you enjoy driving with your windows down on nice days, the wind alone swamps the sound from the rear.

BTW, I have cloth seats.

VS8

iTrader: (4)

for the front seat...is it 37.5 per seat of 37.5 total

staticlag

per seat

VS8

iTrader: (4)

wat is weight of both door panels

pcs

iTrader: (2)

anyone happen to know the weight of the stock r3 wheels?

TeamRX8

iTrader: (25)

About 20 lbs is the closest answer Ive seen based on the R3 wheel/tire combo weighing 47 lbs

it should be noted that this thread applies to 2004 - 2008 US models only