drove my first american car today

[MNBoxster]

Originally Posted by z12358

Excuse my ignorance but aren't the Corvette's body panels made of plastic? I guess, that's how what looks like a large car can only weigh about 3000lbs. Looks almost like cheating.

Seriously, if that's true how come other sports cars haven't picked up this "secret" way of shedding weight? A plastic Boxster would come out sub 2500 lbs.

Z.

Hi,

The car isn't Plastic, it's composite GRP - Glass Reinforced Plastic - a composition of materials which, when brought together under the right conditions, form a tough, lightweight, durable laminate with countless strengths.

GRP doesn't dent, corrode, rot, or support infestation and has a high strength-to-weight ratio being several times stronger than mild steel on a weight for weight basis.

It can be engineered (by layering and Glass Fibre orientation) to provide greater/lesser strength as required throughout the Body structure, unlike mild steel.

Also, because the Car doesn't have the same rigidity as Uni-Body construction, the Frame must be better engineered to provide this strength. So, it has a better Frame, lower Mass, lighter weight, and corrosion resistance (actually corrosion-free).

Lots of other cars have picked-up this secret through the years. In fact, some of the Best Performers such as Lotus, TVR, Marcos, Ferrari, McLaren, Koenigsegg, Pagani, and virtually all F1, Cart, Indy and Champ Cars of the past 40 years have used this technology to great success. Porsche too cheats with it's Urethane Bumpers and Alloy Deck Lids. The single biggest reason it is not more prevelant is cost - it is more costly (on a per unit basis) than stamping Body panels from mild steel.

No, if you're going to criticize the Corvette, Body composition and construction isn't the place to do it. It's really quite brilliant!...

Happy Motoring!... Jim'99

[z12358]

Originally Posted by MNBoxster

Hi,

The car isn't Plastic, it's composite GRP - Glass Reinforced Plastic - a composition of materials which, when brought together under the right conditions, form a tough, lightweight, durable laminate with countless strengths.

GRP doesn't dent, corrode, rot, or support infestation and has a high strength-to-weight ratio being several times stronger than mild steel on a weight for weight basis.

It can be engineered (by layering and Glass Fibre orientation) to provide greater/lesser strength as required throughout the Body structure, unlike mild steel.

Also, because the Car doesn't have the same rigidity as Uni-Body construction, the Frame must be better engineered to provide this strength. So, it has a better Frame, lower Mass, lighter weight, and corrosion resistance (actually corrosion-free).

Lots of other cars have picked-up this secret through the years. In fact, some of the Best Performers such as Lotus, TVR, Marcos, Ferrari, McLaren, Koenigsegg, Pagani, and virtually all F1, Cart, Indy and Champ Cars of the past 40 years have used this technology to great success. Porsche too cheats with it's Urethane Bumpers and Alloy Deck Lids. The single biggest reason it is not more prevelant is cost - it is more costly (on a per unit basis) than stamping Body panels from mild steel.

No, if you're going to criticize the Corvette, Body composition and construction isn't the place to do it. It's really quite brilliant!...

Happy Motoring!... Jim'99

Thx for the explanation. From the 10mins I spent googling GRP, these are the few things I learned:

1. Also called fiberglass.
2. Easy to mold into various shapes, and it is used for low volume car production when building the steel (or aluminum) stamping machines is not cost effective.
3. The most cost-effective kit-car solution.
4. Lighter and stronger than steel. I'm not a mechanical engineer but I know that there are many different strength characteristics defining materials, so the issue is never one-dimensional.
5. Now, carbon-fiber, on the other hand...

You nailed the fiberglass's "rigidity" problem vs unibody right on the head. Drive a Boxster right after driving a Corvette. It feels like it was made of one piece. Drive the Corvette again and the rattles and squeaks become even more obvious -- even in the Coupe (not even talking about the convertible). Fiberglass pieces may have advantages over equivalent steel/aluminum pieces but you cannot weld them to the rest of the car/frame.

Without question, the Corvette is a formidable performance value for $. But free lunches are very rare. Anyway, it was good to learn something about plastic composites today.

Z.

[Brucelee]

As I said before, both great cars and many folks will like both.

No need to drag either of them down to like what you have.

[John V]

Originally Posted by z12358

You nailed the fiberglass's "rigidity" problem vs unibody right on the head. Drive a Boxster right after driving a Corvette. It feels like it was made of one piece. Drive the Corvette again and the rattles and squeaks become even more obvious -- even in the Coupe (not even talking about the convertible). Fiberglass pieces may have advantages over equivalent steel/aluminum pieces but you cannot weld them to the rest of the car/frame.

Without question, the Corvette is a formidable performance value for $. But free lunches are very rare. Anyway, it was good to learn something about plastic composites today.

Z.

The Corvette's FRP skin isn't exactly fiberglass.

The Corvette's chassis is significantly stiffer in torsional rigidity than the Boxster's. The Boxster is at the low end of the spectrum in terms of torsional rigidity for cars of its ilk (Z4, S2000).

[Brucelee]

Originally Posted by John V

The Corvette's FRP skin isn't exactly fiberglass.

The Corvette's chassis is significantly stiffer in torsional rigidity than the Boxster's. The Boxster is at the low end of the spectrum in terms of torsional rigidity for cars of its ilk (Z4, S2000).

Interestingly, a recent issue of C and D had a test where we saw the z06 spank the new GT3 in a straight line AND at the track, and at 40K less in purchase price.

Not bad!

[insite]

Originally Posted by Brucelee

Interestingly, a recent issue of C and D had a test where we saw the z06 spank the new GT3 in a straight line AND at the track, and at 40K less in purchase price.

Not bad!

the new Z06 is absolutely ridiculous. much easier to drive than the old one, too.

[z12358]

Originally Posted by John V

The Corvette's FRP skin isn't exactly fiberglass.

The Corvette's chassis is significantly stiffer in torsional rigidity than the Boxster's. The Boxster is at the low end of the spectrum in terms of torsional rigidity for cars of its ilk (Z4, S2000).

Then, I guess, the rattles and squeaks weren't caused by lack of torsional rigidity.

Z.