So, GM used a lot of lightweight materials in the C5, and somehow managed to drop weight and maintained the price. And then it happened again with the C6. Are we suggested that 13 years after the intro of the C5, it's somehow impossible to extend the same weight-saving techniques to a lower-cost higher-production platform? This is not what I call progress.

BTW - titanium doesn't necessarily save weight over properly-engineered steel or aluminum structures, or at least not at lower temperatures. That, however, is a discussion for another thread.

 

Aren't you an engineer in the automotive world? How *dare* you go against the grain of your line-toeing colleagues in this thread?

That's exactly where I'm at with it.

And, the focus of "affordable" vs. "cheap" as mentioned is important. What this tells me is that the V6 offerings will likely be limited to HV options only, with no chance for a HF, and definitely not the DI. Not that I'd buy a V6 model anyway, but hey...

 

Yeah, the M3 gets lots of exotic lightweight materials to keep mass down. The carbon fiber roof for example saves 11 pounds according to BMW. Imagine that, going to a CF roof in order to save 11 pounds - probably more of a marketing tool, I'd imagine.

OTOH, every nook and cranny of the M3 is crammed with electronic gee-gaws and high tech features.

Stuff like:
and

Put that (and more), all together and it probably adds up to quite abit of weight.

As far as what would a $32,000 M3 weigh - well, I have no idea. But replacing the M3's 420 hp V8 with a 430 hp LS3 would probably save what?......$10,000?, $15,000?, $20,000?...with no appreciable increase in mass. Subtract another $10,000 worth of electronic wizardry - and we're probably left with a $32K, 3,400 lbs coupe with an LS3 smallblock.

 

^ The torque from that LS3 would turn the M3 into a convertible....say bye bye to CF roof.

 

What about all the aluminum in the chassis and suspension? I figure that whatever mass the electronics give, the cheaper materials would take away. FWIW, I don't see a $32K M3 weighing 3400 pounds. More like 3650-3700. Your guess indicates that you think it's a lot easier to remove weight than I think it is. And that's probably why I consider your desires to be unrealistic. I just find it hard to believe that, for example, Cadillac would be selling a 4000+ pound 2nd generation CTS if it were relatively simple to bring it in at 3700 pounds. Not impossible, just hard.

Speaking of that, do you really really think that adding IRS only adds 25 pounds, with equivalent strength and anti wheelhop and all the other good things that we want?

 

 

I don't know about the E90s, but the E46s were pretty solid structures, and I would imagine the newer structure is even more solid. It could probably deal with the LS3 pretty well.

 

You asked me a hypothetical question and I took a crack at guessing at a hypothetical answer. Nothing more. I have no idea what the M3's V8 costs,(beyond it being very expensive), nor do I have any idea of what the M3's electronics weigh or cost, (beyond the fact that they must weigh something and are also very expensive).

The CTS, BTW, gains about 300 lbs from the 1st gen model. Specifically where that weight came from, I couldn't say.

As far as IRS adding 25 lbs over a modern live axle, that's no guess. As long as it's integrated into the architecture from the beginning. Could creep up to be abit more, but certainly nowhere near some of the numbers I've seen in this thread.

 

Right. I just figured cheaper meant heavier, or perhaps the same, due to less equipment versus less advanced materials. You guessed 3400, or roughly 250 pounds less, by reducing equipment somewhat, while presumably putting in a steel roof instead of carbon fibre, etc. I found your guess far more optimistic than mine.

Of course, the whole discussion makes certain assumptions. I assume that any Camaro I'd buy would have leather and power windows/seats and the same sort of stuff that was in my '98 and '02 models. The '98 also had TC and the Ttops. It's not like it was some lightweight stripper. But maybe you're thinking of stripped out sound deadening, crank windows, no A/C, etc. ??


Extra width, huge moonroof, I guess. Extra sound deadening for the DI engine? Maybe the anti-hop improvements? The C&D says that the moonroof is 100 pounds of the increase. Without that, it's only a 200 pound diff. On the same subject, the later 1st gen CTS's with the 3.6 usually came in the low 3700 range in tested vehicles, whereas the early models with the 3.2 were in the mid 3500 range.

Does that assume using steel in both designs?
Or perhaps a steel solid axle versus AL IRS?

 

Ahhh but REAL progress comes at a cost! I'm sure GM could develop a REAL M3 rival for slightly less money... but not many would buy it!

 

For once we agree.

Dunno about the 3V but I recall reading the 4.6L DOHC 4V is around 250 kg (550 lbs). The LS2 is around 190 kg (420 lbs).

Btw, LS2 is slighter lighter than the LS1.

 

The comment may be true (although I sort of doubt it) but interesting nevertheless.

The comment is most interesting because it seems to me there have been a few posts in this thread that leave the impression that putting a 500HP monster engine into the fifth-generation (or any other car) is no big deal and GM shouldhn't have to "beef-up" components to handle the HP/Tq!

 

Well, when you c onsider that GM's main objective isn't making something to withstand massive horsepower, it's about light weight and fuel economy. The 4th gen had that infamous "delicate" rear end and those "crap-o-matic" power window motors because of weight concerns, so I'm in no way going to shoot myself or spontenously combust if the next Camaro gains weight.

I'd rather have a car that's a bit overbuilt (ie: Shelby Mustang GT500) than to have a car that to keep weight down was built with just barely enough durability to get me through the warranty... and then only if I didn't do anything that the computer recorded that would void my warranty and leave me stuck replacing a barely engineered part.

Doubtful.

The live axle is it's own structural component. IRS needs an entire cradle to support it.

The only way to integrate it into the structure is via semi-trailing arms, much like BMW's 3 series from the 90s and the former GTO-Monero-VT/VZ Holdens.

If we're talking about a system that's used on just about every modern RWD car, 150 pounds may be a bit high, but 25 pounds....


Still waiting to hear what we're willing to sacrafice to get these weight savings (outside of price) or for an example of a modern, RWD, IRS, V8 powered, 400+ horsepower, 4 passenger, $35,000 or below pricetag, federal safety and emissions passing car from any car maker that proves that it can be done so I can stop believing it's just being unrealistic.

I'm never going to get an example, am I?

 

I recall when the VE was introduced, and the Australian press was going on about the increased weight, it was remarked that the more sophisticated IRS on the VE added about 30kg, which is 66 pounds. The hypothesis put forth on this forum was that the VZ IRS actually was lighter than a solid axle would have been.

 

I'm 99% sure that GM went with all those components you described because of cost not weight. GM apparently had all that stuff built by the absolute lowest bidder because it all sucked.

Oh yeah, and go back to Page 14 of the thread and read my reply to your post about what "sacrifices" I'd be willing to make; it seems you missed it.

Lastly, if GM is worth it's salt, you'll have your example in the Camaro.