Z28Wilson

Dan, you make some good points but this is where you start to lose it. Lord knows I feel the Camaro is overweight as well, but the Miata? BRZ? These cars aren't even in the same country code as the Camaro (and Mustang) in terms of performance-cost expectation. It's best to not use those cars as references.

Guy's long-standing challenge has been to name a coupe for sale today that contains IRS, a V8 and costs somewhere near what Camaro costs and weighs significantly less. I always thought that was a "win by default" argument because outside of Challenger, there ISN'T a non-luxury plated coupe for sale that meets all those criteria. And it doesn't mean that it can't be done, the problem has always been that it is far more cost effective to piggyback a sports coupe like Camaro or Challenger off the larger RWD sedan programs. So you get what we have now.

Dan Baldwin

The *POINT* is that those cars were designed with keeping weight down a priority, and IRS was chosen over live axle.

Specific point of comparison: FR-S/BRZ weigh LESS than the 1st gen Scion TC, which is the same size, a small 2+2 coupe, similar market niche, and had LESS power, and is fwd, which should give it a ~50-100 lb. weight ADVANTAGE vs. the FR-S/BRZ. Yet the rwd/IRS-laden FRS-BRZ are 150 - 200 lb. lighter.

That the car doesn't exist doesn't mean it's not possible. The Camaro and Mustang should *be* that car.

EXACTLY.

EXACTLY.

But since the Mustang survived and did well, while the LS is dead, it bodes well for Mustang priorities to drive the next Mustang's chassis development.

And the next Camaro looks to be platform-shared with a smaller/lighter car, too.

So there is some small amount of hope for the future...

I can see how Amero-centric muscle-car enthusiasts would draw the ERRONEOUS conclusion that IRS adds weight, given the Fox-Mustang-Cobra IRS already discussed ad-nauseum, and that the Challenger and 5th gen IRS Camaro came in so absurdly heavy. But those cars INHERITED that weight from the 4200 lb. sedans they were built on.

But those of us who have enjoyed lightweight rwd/irs cars over the years, and actually physically handled the hardware involved, know better.

All else equal, a rwd/IRS on a dedicated IRS platform invokes little to no weight penalty vs. dedicated live-axle design.

Dan Baldwin

It should be pointed out that way back in the 80s, the E28 535i/M5 were ~3200-3400 lb., offering similar performance to 3rd-gen Z28s/IROCs of the day that also weighed ~3200-3400 lb. The 4-door German luxury sedan with IRS had *zero* weight penalty relative to the smaller-on-the-inside 2+2 live-axle coupe.

Since then, BMW has gone further in the wrong direction (as far as weight goes) than the Camaro has, which is a LOT! A real shame...

falchulk

Yes, and how much more expensive is the BRZ then that 1st gen SCION???????

jg95z28

Let's not forget that the smaller/lighter pony cars of the past didn't put out as much horsepower than the current lot.

While a FR-S/BRZ sized ponycar with a V8 and IRS sounds good on paper; assuming today's V8s have north of 400+ hp, you're going to have a hard time getting the tires to hook up with less mass over the wheels.

Perhaps only implied by Guy and others, but not specifically noted, a smaller lighter ponycar doesn't need a 400+hp V8 when today's V6s have 300+hp. Sure, manufacturers could develop smaller V8s that are lighter with less hp, but then would they be as efficient as the current crop of V6s? Probably not.

I love V8s as much as the next guy, but its getting to a point of diminishing returns. Perhaps its time to reinvent the wheel and people's perspectives of what a performance ponycar should be. The Chevrolet Alpha-coupe should begin to answer the question in the next few years, as to whether people are ready to accept non-V8 power in a smaller RWD coupe.

Dan Baldwin

Didn't have *nearly* as much difficulty putting 500-520hp down with my 2825 lb. RX-7 at the track! Not that we were launching it hard...
As a road-course guy, I'm not so concerned about putting it all down in 1st gear anyway, and my car on warmed up tires doesn't have a problem putting it all down in 2nd. Though it can spin up the tires just rolling on the throttle on cold tires when it gets into the meat of the torque curve

I wouldn't necessarily bet against a smallish-displacement OHV V8 vs. DOHC V6s.

No reason they can't give us a MUCH smaller and lighter-weight car *with* a V8.

HAZ-Matt

I don't know. If you shrink V8 to near V6 displacement, what sort of bore and valve sizes will you end up with? Will you still flow air efficiently for power production and fuel economy?

I suppose cam phasing could help with this somewhat. But at some point it makes more sense to go with a V6, although I couldn't say where that would be.

Anomaly

I agree with a lot of what you're saying in regards to weight, but it's not just all about stopping as quick. My thirdgen with LS1 brakes stops "about" as fast as my CTS-V with 14 inch rotors and Brembos, due to the thirdgen being a solid 400lbs lighter. The difference is, the cts-v can do it all day long on a track, whereas thirdgen's brakes are fading in no time. Another example, my cts-v (and the new camaro) has a decent oil cooler. (Thirdgen, not so much) That adds weight, but reliability on the track.


And of course I wish the Camaro, Cts-v, etc etc were lighter, but the capability of these cars from the factory is pretty impressive. (Fairly) Track ready, and great daily drivers with a warranty...So You have to compromise somewhere. If GM\Dodge\Ford could easily reduce weight of their sports cars, and get better fuel economy without driving the production costs up they would. All these engineers aren't missing something simple.

WhiteHawk

The reasons they are going back to steel are quality and manufacturing. From a quality standpoint, you have to have tight fit and finish and gaps. Plastic fenders sound like a great idea, but when you have to hold a 4 mm gap to be competetive with Audi, making a fender that will expand 4 mm in the sun doesn't make much sense unless you like high paint warranty. Most of the OEMs have gone here and got burned by it so they have gone back to steel.

So why don't they do it on just some cars? That is part two - manufacturing. Plastic parts (or even fiberglass) take extra space in a paint shop for both painting and repair. They take extra space in assembly since they usually get painted and go on separately. So most OEM's don't want to spend the extra money for all the special equipment required to process non-steel parts. Add in the trouble with gaps and warranty, and that is why it is a no-go.

The real future is in Aluminum. You see it in hoods and decklids now, and I think it is just a matter of time before fenders and doors are aluminum too. It is tougher to process - it doesn't spotweld well - but hems fine and holds with epoxy. Also, the plant can run them down the same paint shop and body shop, so they are much less intrusive.

-Geoff

WhiteHawk

And GM has one plant building one low volume car. Not very cost effective - they would be much better off moving the vette to another plant but they can't because it is so specialized.

Look at the current Equinox, they needed more volume so they started building in Oshawa. They couldn't do that with the Vette, and you couldn't build anything else at BG unless it was Vette-like. Too specialized, no manufacturing flexibility.

-Geoff

jdhommert

Except in a Corvette/Z06.

WhiteHawk

If you don't understand the relationship between my two posts, then go back and re-read them. I was clarifying the manufacturing issues with building plastic and fiberglass panels and trying maintain flexibility in assembly plants to shift models to meet sales demand. I was never trying to start an argument. Most people don't understand the difficulties of processing alternative materials, and I was just trying to point out some of the issues. It is not just a matter of "Making it out of plastic this time".

Obviously I am wasting my time explaining the complexities of the auto industry (that I have been employed in for 20 years as an engineer) because you already know everything. My apologies for wasting your time.

-Geoff

falchulk

Actually, sir...you are ignoring a lot of valid points. The bottom line is if it were as easy and cost effective as you think, why is it not done? If you truly think that its because the car companys are full of lazy idiots then why not go show them how to do it right? There are trade offs and thats why we have what whe have.

Z28Wilson

I have almost no knowledge of the situation, but I would guess that there have always been difficulties. Remember, Saturn switched from plastic to steel panels a few years before shutting down, the die hard Saturn people hated it but there were a myriad of reasons IIRC.

WhiteHawk

I am saying it has always been difficult, and in today's competitive market, you can't put the extra manufacturing costs and quality hits into a vehicle. The mass you save isn't worth it when you consider the extra processing and quality hit.

Saturn struggled with JD Powers and Consumer Reports for years because of the fit and finish problems the plastic panels caused. You can't put out a new model and have the quality ratings in the toilet right out of the gate.

GM is the world leader in forming Aluminum. They actually have invented a proprietary process to form aluminum almost like vacuum molding plastic. I thin kit is just a matter of time before almost every car they make has aluminum hood and decklids, with doors not far behind.

-Geoff