cks796

I'm looking to lighten up my RX-8 after I get my Exhaust and wheels for my car. However I have no idea where to start. What parts can I remove or replace to lighten up my car enough to allow my car to be able to use the Horsepower to drive itself instead of push all the weight.

Thanks guys

CK

Falken

Flywheel and 5-speed tranny? Start at the drivetrain.

cks796

So, the RX8 has a 5-speed transmission? I didn't know that. Does the power suffer with that setup?

CK

P.S. Forgive the questions, I'm a computer nerd with a nice car which wants to go fast, I know enough about engines and the way things work to figure out what's wrong and take it to get it fixed. >.<

robrecht

Did you get lighter weight wheels? Rotational weight, especially unsprung weight at the 4 corners of the car is the most important weight reduction.

cks796

The RX8 is currently completely stock, nothing has been done to it at all yet.

CK

EDIT: According to the weights page. The stock 18" wheels weigh approx. 88 pounds total. That's quite a bit. Do aftermarket wheel makers usually give you the weights for the wheel so I know what I'm getting?

Falken

There are a few 5-speed transmissions out there for a few grand each. From what I've heard they will net you a lot of power because of closer gear ratios.

EDIT: Oh, and I think that someone sells lightened rotors but I don't know how much difference they make.

I8U

iTrader: (1)

As far as the 5-speed goes, you can always just swap our tranny out for an RX-7 tranny. Bolts right up!

kersh4w

iTrader: (3)

mazsport also has a 5 speed tranny for the rx8, but its meant for turbo 8s because first gear becomes useless.

take out all the seats you dont need. take out the spare tire. get a lighter battery. get lighter rims. get lighter tires. get a lighter exhaust. take any extraneous pieces off your 8 (ie, a spoiler). never put in more then a 1/4 tank of gas. get in shape. get carbon fiber doors, trunk, and spoiler. replace windows with lexan.

thats all i feel like thinking about now. but there are tons of options.

To be named later

After spending $1,000's of dollars to lower the weight a couple of hundred pounds, will you even feel the difference in HP or performance?

Falken

Yeah you'd feel a difference, especially if some of those pounds were lost off the drivetrain.

Intake, exhaust, flywheel and clutch, wheels, tranny, AP...I wouldn't be surprised to see mid 190s on the dyno, and with less weight low 14s 1/4th.

robrecht

Reputable ones do but sometimes you have to dig a little bit and be cafeful about width and offset. Significant reduction makes a subtle but noticable diference, especially in handling, rough surfaces, and braking, less so in acceleration.

mac11

iTrader: (1)

There is a lot of weight to be lost in the RX8. How far you go will depend on the level on comfort and amenities you would like to keep.

The RX8's running in the Koni Challenge and Rolex Grand-Am series are running 2650lb dry weights with a full cage.

TrochoidMagic

removing weight starting from the top uppermost of the car is the wisest choice.

take off hood/trunk liners, and unnessary seat covers, etc.

remove ur seats and rip out all the useless insulation under the carpet. not much... but they add up.

for those sound deadening tar... use heat gun and a scrapper. but i heard using dry ice and freezing it is easier, which i might do once i find where they sell those.

how hardcore you want to be at this is up to you. personally, i rather not remove brake rotor covers due to its functionality...but people who live in rather less sandy or dusty area often take advantage of this as rocks and such hardly get in between the pads and rotors.

and don't be afraid ro be creative. i gutted and vented my hood, which came out to be lighter than a comparable CF hood at 12lb 14oz. and i save $$$ doing it.
of course i gutted the top of the trunk to match the front balance, and threw away the liners and trunk hydraulics.

it takes a lot of work to find where u can take off PERMANENT excess weight. i say permanenet because these are things i'll never regret of think twice about putting it back into the car. thats why its so hard...(see my signature)

but it all adds up. and you sure can easily surpass me in total pounds shaved off... but again, its really up to how comfortable with what you want( or brave enough) to take out.

xsnipersgox

light weight single side exhaust, lighter rims/tires, smaller wheels, take out AC, mazdaspeed side mirrors to be more aerodynamic at high speed, gut/vent the hood, remove the windshield wiper and sun blocking thing. remove both backseat, remove side driver seat, remove all engine covers, drain all washer fluid, remove fog light if so equipped, lose weight (you), remove everything from glove compartment to trunk, run on 1/4 tank gas, remove center console, light weight pullies, remove the glove compartment assembly, remove the center console/radio assembly, it's really a trade off, if you want, i don't doubt we can make the 8 a 2400 lb car, it just wouldn't be a nice car to drive.

kersh4w

iTrader: (3)

2400lbs is.... really light. i dont think thats possible unless you have a full blown race car (without a rollcage). the lightest autocrossers (ulllloose, teamrx8, etc) have their rx8s a few pounds below 2800lbs. and believe me, they spend money.

buy these
http://cgi.ebay.com/ebaymotors/SEIBO...spagenameZWD1V
http://cgi.ebay.com/ebaymotors/SEIBO...spagenameZWD1V
also
http://www.autoblog.com/2006/07/28/c...uner-near-you/

Flashwing

I am assuming the OP isn't looking to turn his RX8 into a full blown racecar. I have been working on weight reduction and there are a few things that you can do to drop weight but the overall effect is only as much as your wallet can handle.

First things are pretty easy which is making sure you're vehicle is empty of contents...no golf clubs in the trunk or crap in the back seat. I keep my car pretty clean at all times so for me that's a given.

I'd look for areas where you can lighten up rotational mass as that will be where you can free up the most power. These areas would be your wheels/tires, brake rotors, pulleys, and your flywheel.

DBA (disc brakes Australia) makes a great two-piece rotor that's superior to the OEM rotors and also is much lighter.

There are various wheels out there which are lighter than stock. The oem wheel is somewhere around 23 to 24 lbs each without tires. Switching to a lighter wheel will help, but beware that increasing width will add weight as well as a heavier tire.

Tires are the same deal. When shopping for tires, check out ones that have a lighter weight than others.

Installing a lightweight flywheel will help reduce the load on the motor allowing more power to be used to move the car. There are also clutch setups where you can reduce rotational mass as well.

You can also do lightweight pulleys and an underdrive pulley but there isn't much rotational mass to be lost there but those pulleys have a nice bling factor.

Otherwise, reducing weight by adding a lighter weight exhaust, replacing the CAT with a mid-pipe, and also going to a lightweight battery of 20 pounds or less would work as well.

xsnipersgox

true, but i mean like, 2400 lbs is probably possible, the car just will not be comfortable to drive (or drive a long distance) some things such as alternator trunk, lights, plastic covers of interior, and unnecessary decorations can all be removed, side mirrors removed, all bumpers removed, fender removed, exhaust removed. i mean, its possible just not.. practical lol

there are rules to autocross so, from a practical stand point i guess 2800 lbs is as good as it gets lol.

Falken

Can you talk about balance on a car loaded with these?

mac11

iTrader: (1)

don't bother with these. I would be willing to bet once you put everything from inside the OEm doors into these doors (like crash protection!!) the OE doors will be just as light, or more so. Just like most c/f hoods are no lighter than the stock hood.

If you want to be a wild man and drop weight like crazy you can simply take all the existing crash bars, electronics, and glass from the OE doors and save yourself ~2500 + shipping. There is ~100lbs to lose if you do all 4 doors. This is what race teams are doing.

Along the same lines there is 50-75lbs to lose behind the dash while keeping the OE outer dash shell in place for aesthetics. Or you can remove the entire thing and put a single aluminum sheet in with holes punched for gauges.

One could also get in the cabin with a wiring diagram and determine which wires are completely necessary (ABS) and remove the rest. It may seem trivial but there are many thousands of feet of wire running through the car. Probably close to 25lbs worth in total that could be removed.

As I sad before, it's all about the level of comfort and amenity you would like to keep.

dillsrotary

carbon fiber trunk, the stock is heavy. Stock hood is aluminum so a carbon fiber hood will only save a pound or two. 17in wheels, light flywheel and clutch. racing brake has a lighter front braking package that includes new front (lighter) calipers. Remove spare tire also.

mac11

iTrader: (1)

stock trunk is also aluminum and very light.

LionZoo

The stock trunk is steel, please check the weight thread.

mac11

iTrader: (1)

I don't need to check the weight thread. Check for yourself with a magnet.

alz0rz

iTrader: (41)

A wise man once said:
"A lighter car is a faster car."

power:weight ratio...

robrecht

Bottom line: it's a 4-seater, concentrate on unsprung weight.