Show of hands:

Who thinks the Challenger is not a large car?

 

That's tires. What about wheels?

I have my original 16x8" Z28 wheels with Goodyear Eagle F1 GS-D3 tires mounted, sitting in a stack in my garage. I will try to remember to weigh one of them.

If I'm feeling ambitious, I could also pull off one of my 17x9" WS6 wheels with BFGoodrich g-Force Super Sports mounted and weigh that.

Anybody with a 5th gen want to volunteer to pull a wheel and weigh it?

 

Literally hands down, the Challenger is a BIG car, especially for something with 2 doors. The irony is that there are plenty of people here who just love the Challenger, despite it's size and mass. Maybe it's because it looks bad@$$ and actually has a backseat with room for 2-3 "normal sized" adults.

 

I'm pretty sure that changes in the safety laws have also required additional structural reinforcing which means more steel or aluminum, depending on the price point of the vehicle. That would account for the most significant increases in weight.

 

IMO, Challenger is really big for a coupe, but pales in comparison to truly large cars (Suburban, Excursion, '70 Electra 225, etc).

The new Camaro is just somewhat big for a coupe.

 

So it's easier to engineer a compact and lightweight IRS as a retrofit than it is to design one with a clean sheet of paper?

 

But the Zeta was a clean sheet. The Zeta IRS was heavier than the older VZ IRS, but then it is also more sophisticated.

There are a lot of unstated assumptions in that 25-50 pounds number, such that it's impossible to argue effectively over whether it is or isn't correct.

 

I'd say that's a fair statement. Consider that figure applicable to a truly clean sheet design.

Zeta is not as clean sheet as you may think. It still traces it's roots back to VZ and GM2800 before that. Yes, from GM2800 to V was a major tear up and from VZ to VE/Zeta was an even more extensive re-engineering - but clean sheet to me, means clean sheet.

 

The 3650 is rated at 360. The T5 at 300. The differenced in weight is ~45 lbs. Add the bellhousing to the T5 (integrated into the 3650) and the difference is ~30 lbs.

So.....other IRS systems are more than twice the weight of the Cobra unit? Numbers and sources please. And please....don't get offended for my asking for documentation and not just taking your word for it. This is the internet...

I did both a 99 and a 2004 swap. The difference between the two is less than 10 lbs (85 vs ~95). That's why I used 90 lbs as my original number.

90 lbs is absolutely significant - even huge, if I can be so bold as to use that term these days. But please....I'd rather see numbers and sources than just assumption and conjecture.

Please do, because I ain't buying your numbers (no offense, again). And in fact, I have ALL the A/C stuff out of the 99 in a box in the corner of the shop in Texas. I can weigh it when I am back there, if necessay.

What I am prepared to give up is irrelevant, as there is no way GM would build it. So mute point.

Concur.

No I don't, but if you want to, that's ok with me.

Cool. Don't care, but cool!

Bob

 

It really depends on the width and aspect ratio too.

BFGoodrich g-Force T/A KDW 2

215/40ZR16: 20 pounds
215/40ZR17: 22 pounds
255/40ZR17: 27 pounds
255/35ZR20: 27 pounds
285/30ZR20: 31 pounds
285/55R20: 40 pounds

Then you have to look at wheel weights. I'll bet it's at least 10 pounds and probably more like 15 per corner between the 2010 Camaro SS and 2002 Z/28.

The 245/50s on a 2002 weigh 27 pounds. The front tires of the 2010 are 32 pounds and the rear are 36 pounds. So that's 28 pounds, just for the tires. I looked up wheels for the '02 and found some 16" American Racing Muscle wheels at 22 pounds each. The 20" wheels were "Weight not available". I'm thinking that if you have to ask, it weighs too much.

 

Yes, but is that for an advanced IRS like in Zeta or the simpler, lighter one in VZ? Does it assume steel in the IRS and SRA or aluminum? (Side question: Did anyone ever sell a car with an Al SRA?)

We know that sophistication in IRS can improve its operation at the cost of weight. We also know that spending more on materials can reduce weight at the cost of ... cost . What are you assuming regarding sophistication and materials? How about cost?

As a further example, the "Z-axle" IRS in the E36 3-series was quite a bit more sophisticated and heavier than that in the E30.

My thinking here is that an advanced IRS will have more than a 25-50 pound penalty....

As a further aside, my recollection is a little hazy, but I seem to recall Holden stating that the upgraded IRS in the VE added about 50 pounds (I have an old post on here with that number), which leads me to infer that the old VZ IRS added 30 pounds over an SRA (wheelhop was free). I can guess a number of reasons why that inference may be wrong, but....

 

See also the resurrected "Are we happy with IRS" thread on the 5th gen forum, where it's stated that Mustangs (even the current, but especially the old Fox body) need extra reinforcement when you add power.

Chassis rigidity also adds weight.

 

That's compared to a live axle suspension which itself can be very sophisticated to very rudimentary. Lots of links in a NASCAR live axle suspension for example. Far fewer links and much lighter (with less control) in a '55 Chevy. Both are live axles though. Kind of like your VZ vs Zeta example.

I think the mistake that some people make in comparing the mass of IRS vs solid axle is, that a sophisticated live axle, (like on the Mustang), is more than just a diff and axle housing. It also has a bunch of links, control arms, Panhard bar, etc. All this stuff adds weight of course.

I guess what I'm saying is, that is generally the weight difference when comparing the two equally.

 

Yup, they sure do.

 

Count me in.