mrlegoman

With all the hype about Carbon Fiber hoods and saving weight, why don't I see other Carbon Fiber body parts (like the trunk lid)??

spyder

I agree... Why is everyone so worried about taking weight off the front end with a CF hood? FWD cars already have enough problems with traction WITHOUT taking weight off the drive wheels...

If you really want weight reduction, you have to go the way of the Toyota MR2 Spyder. They made every body panel on that car bolt-on. Want a different color? bolt on different panels. want weight reduction? bolt on CF panels. want a body kit? bolt it on!

Would be nice if Honda did that...

clockworks

I agree, I wonder why companies don't see a market for them.

Greg

EK-Cruiser

CF hoods seem to almost be more of a cosmetic thing than anything else. Why do I always see pictures of rides with carbon fiber hoods, and then 6 12" subs in the trunk with some heavy *** enclosure, and weighty amplifiers? These light hoods might be worth it for someone who is looking to shave tenths of a second off their 1/4 mile time by stripping their interior out, cutting out sheet metal, etc. (seriously functional weight reduction). Otherwise I think the carbon-fiber-hood-craze is just another form of ricey expression just like altezza lights, and 4 foot high terminator wings. Just my opinion.

cjb92

they do make carbon fiber trunk lids. They are around 1000 from bodykits nw I believe.

jgale

not everyone is in to drag racing. A lot of weight reduction and carbon fiber comes from ROAD racing(circuit, road course,etc...). FWD cars are very nose heavy, and tend to push(understeer). The more weight you take off of the front of the car, the better the balance(ie: handling). I saved over 15lbs. over the front wheels by installing my CF hood. It also helps to move the battery to the back of the car...

Dusty

yah weight isn't much of an issue in the rear. you sort of want weight in the back of most ff cars. beside that drag racers have put fiberglass and mybar or some shyt that is lighter than glass for years on hond/acs .

prabably the reason carbon fiber hoods are so popular (originally) is because it is so light and so strong.....you got special stuff underneath you wnat to keep safe.

owen_the_soyboy

they will make you whatever you want / will buy.

there is a demand for only a few major body panels, but others can be custom made...

there are CF hatches for EG civics too ya know....

I bet the teg rear hatch is too much of a pain to make a mold for.... the glass probably weighs MORE than the hatch framework itself!

MiraiZ

Trunk lids on some cars (Integra 3dr, Civic Hatch) are support members for the car and must be stron enough to support a certain amount of force.

EVOCELICA

Has anyone ever seen a car that is made of carbon fiber get in a crash and catch on fire, also the cost to mold and make all the body panels would be major expensive and time consuming

TheShad0w

they do actually make trunk hatches in c/f
and any weight reduction is welcome as we all know thats why we have slicks...

jonsteR

I was about to say

JinMTVT

nah u don't want weight nowhere..
in the front nor in the back

weight reduction = less load on tires = faster potential speed in curves
and the more the car is balanced front/VS rear the better handling u will have too


so i say ..

CF HOOF
CF DOORS
CD TRUNK LIDS

ahha

CF sunroof
...
lexan glasses all around

Dusty

less load on tires? help me out here but that would be bad for traction

more the car is ballanced from front to rear the better handling? so do you propose we put a moped engine in the front and make everything out of carbon fiber or composite?

we have to have a larger enough engine in the front to propel the vehicle adequately. right? so that is weight we have to deal with. now your statement about balencing front to back is somewhat accurate. what you really do is balance the weight diagonally from front passenger to rear driver side...ect.

so it is not uncommon for road racing machines to have wieght added in strategic locations in the rear of FF vehicles.

weight is not all bad especially if its near the ground. (lowers teh vehicle's center of mass)

that description given it would be good to lessen weight on top of the vehicle like hatches and trunks. so ok.

you should have seen back in the day BMW used to have weights on tracks with springs so when the car put the brakes on the weights would shift to the front. that was about the time they dropped off the racing scene for a few years since it was just rediculous.

owen_the_soyboy

um, no.
Road racing machines try to stay as light = as nimble as possible.
There are weight restrictions for classing purposes in any racing series and THAT is the reason for adding weight in racecars.
get it? good.

Dusty

nah your mistaken. its ok though.

Im specifically speaking of GT/Le mans are you familiar with the concept of corner weighting/balancing?

freakin out autocrossing, huh? ever been on a road track? If you haven't tried it i hope you do. many think its much more fun than autocross.

adding weight in racecar for class? maybe for nascar or soemthing not too familiar with that but i could see how it might be

jg

Owen, Dusty is right about the weight ballast idea. I have good friend w/ a CRX that he races in IT. Yes they do have weight restrictions in certain classes, but they do move weight around in the cars for better balance. Why do you think they add that ballast to the rear of front drive racecars? Here's an example: A car weighing 2000 lbs. with a 50/50 front /rear weight bias will handle much better than a similar set-up car(same chassis/model and drivetrain layout) that weighs 1800lbs. and a 65/35 bias. Yes, the 2nd may be faster in a straight line, but the 1st car will be more balanced in the turns. Hope this helps the understanding of this.


[Modified by jg, 4:25 AM 9/12/2001]


[Modified by jg, 4:26 AM 9/12/2001]

MechE00

uh oh.. a lot of oversimplification flying around here boys.. everybody back off, realize that there's something right in just about everything that's been said here so far.. people are just focusing on little bits..

Overall weight reduction = good
Corner weighting = good (slightly different motivation)
Ballasting cars to balance out a class (as in Speedvision's Touring Car series) = true
Lower polar moment of inertia about the vertical axis of the car = good
Ballasting/relocating for traction = true
50/50 weight distribution = good

fsp31

MechE00=correct.

Weight is never good. A balanced car "can" be good... but it's not always possible. If you drive a Honda, you're driving an unbalanced car. If you want a balanced car then you'll need to look at an M3. At an event last year, my Civic weighed in at 740lbs over each front wheel and 385lbs over the rear wheels. The best I can hope for is side to side bias to compensate for my fat ***. So...

Honda = lawn dart

Let's not mistake a balanced car for balanced handling. Those are two completely different things. Fact is, I don't give a rip about "actual" weight balance. All I do care about is balanced handling. And "ballast" is probably the least efficient way I can think of to achieve balanced handling. The art of suspension tuning is at least as sophisticated as engine tuning, and can solve almost any handling problem... eventually, and after great frustration and agony. ;-)

I'm not familiar with one single class of race cars (the kind that turn..) out there that operates without a weight restriction. Depending on class rules, etc., the rule of thumb is take all the weight out you possibly can, *wherever* you can. Then add it back in at optimal locations until you make your weight limit. That is IF you are lucky enough to strip your car below the weight limit and still be within class rules (except for the weight limit of course).

If you are ABOVE the weight limit, then it's plain crazy to go bolting in even more weight just to "balance" the car. If this does actually happen in some class somewhere, it sure isn't in any type of class where you'd find a low displacement, low HP car like a Honda. For us, weight is everything. But the main thing is, suspension setup will take care of the rest. Somebody else can slap 200lbs in the back of their Honda. I'll use spring rates, adj. struts, and sway bars to achieve the balanced handling I want.

Dusty

that makes things clearer for me thanks yall.

Daemione

I think one point that has not been mentioned is the fact that your maximum grip is going to be limited by the heaviest end of the car.

So adjusting spring rates, shocks, and adding roll bars to the rear of a Honda will create a balanced handling car, but it's done by reducing the available grip in the rear, so it breaks away at the same time as the front.

So assuming two vehicles have the same gross weight, and both are tuned to provide neutral handling, the one that has the closest to 50/50 weight distrubution will have higher limits of adhesion. Of course, this is assuming the center of gravity is identical in boths cars.

owen_the_soyboy

wow.... man, when did we start talking lemans cars?
and lets be nice as well, okay?

sorry to generalize then, I just think INTEGRA only sometimes.

yes I took my sedan to Pocono this year and have since bought a EG to roadrace since I had the best time of my life.
I plan to use adj spring perches to corner weight my car, not add lead plates like realtime racing has to -to limit their times to competitive values.

~mech00 - good words.

jg

This was my point. Yes, a generalization, but the theory applies.