ZR1 = 638 hp and 604 lb-ft

[Sigma Projects]

basically, what i mean is you could take a Z06 and swap all the parts you needed, heck maybe just sleeve the LS7, however. Even if you swap every part from a Z06 or ZR-1 onto a C6 you still don't have the same car, because the CHASSIS is different. The chassis is the base for what the car is. And they're not just modifications to the chassis it's made out of a different material. That's my point. You can't take a C6 and make it into a Z06 even if you swap every nut and bolt over, the chassis aren't the same.

[68_427]

i know comparing 'ring times is pointless... but somewhere in Japan a Nissan engineer just committed suicide

N'ring time: 7:26.4....

Wow.... just, wow.

http://www.autoblog.com/2008/06/27/g...ing-in-7-26-4/

[SVT666]

That's gad damn fast.

[Cookie Monster]

What does the GT-R run again?

[JYODER240]

Does anyone else find all the hype over 'ring times as uninteresting as I do?

[Laconian]

No, I find them a lot more interesting than most other contrived performance metrics, like 0-60 or skidpad grip.

[SVT_Power]

Does anyone else find all the hype over 'ring times as uninteresting as I do?

It's getting old in my view

[Tave]

i know comparing 'ring times is pointless... but somewhere in Japan a Nissan engineer just committed suicide

Actually he's probably too busy putting the finnishing touches on the Spec-V to even care.

[NomisR]

No, I find them a lot more interesting than most other contrived performance metrics, like 0-60 or skidpad grip.

There's a lot more variables to a track lap time than 0-60 and skidpad time.  Just having a different driver in there can mean seconds of difference, not to mention the road and track condition, tires used, etc.  In the end, it doesn't mean anything.  But not to take away from the GTR's achievements, it's still pretty damn good.

[Tave]

But the variables are quantifiable and accounted for. It's not like one guy is going to run 7:29 and the next guy run 27:29.

I don't see how it's any difference than 0-60 and skidpad, which vary by driver, surface condition, tires, etc...

[sportyaccordy]

Does anyone else find all the hype over 'ring times as uninteresting as I do?

Yes I find it quite ridiculous

People say '0-60 times are so pointless'... then in the same breath go crazy over lap times

Really though there's much more to a sports car than numbers... accel times, lap times, whatever. What good is capability you will never be able to fully exploit 99% of the time?

[Tave]

Really though there's much more to a sports car than numbers... accel times, lap times, whatever. What good is capability you will never be able to fully exploit 99% of the time?

Are you asking, "Why aren't people excited by the mundane?"

Do you really need an answer?

[JYODER240]

I just fail to see how a car that can cover a 13mi track a few seconds quicker than another is relevant unless you're talking about some kind of racing competition. There are far more important things to a road car than the difference between 7:30s and 7:34s around a track.

[NomisR]

But the variables are quantifiable and accounted for. It's not like one guy is going to run 7:29 and the next guy run 27:29.

I don't see how it's any difference than 0-60 and skidpad, which vary by driver, surface condition, tires, etc...

Well, I'm just saying there's even bigger difference with a change of driver and condition on a track than it would on a skid pad or 0-60 time.  Either way, magazine racing is stupid anyways.

[sportyaccordy]

Are you asking, "Why aren't people excited by the mundane?"

Do you really need an answer?

No,

Like JYODER said, #'s don't tell the whole story.

I am sure a 400HP or so rally or grand touring car would be faster than any car in production.

But would that be a car I would want to drive on a daily basis?

Is it pleasing beyond how it performs? Specifically, in aesthetics, sound, ride quality...?

A sports car doesn't have to be slow or expensive as hell to look good. And it doesn't have to be the fastest around a track for it to be the most enjoyable to own.

[Soup DeVille]

In other words, an old turbo Thunderbird would likely beat a Miata around almost any track you can choose.

That doesn't make it a better sports car.

[Vinsanity]

i know comparing 'ring times is pointless... but somewhere in Japan a Nissan engineer just committed suicide

N'ring time: 7:26.4....

Wow.... just, wow.

http://www.autoblog.com/2008/06/27/g...ing-in-7-26-4/

lol really? because a $100,000 3300lb 2-seater beat a $70,000 3800lb 4-seater?

The ZR1 is stupid fast, but let's not kid ourselves; noone's committing suicide over it

[Tave]

No,

Like JYODER said, #'s don't tell the whole story.

I am sure a 400HP or so rally or grand touring car would be faster than any car in production.

But would that be a car I would want to drive on a daily basis?

Is it pleasing beyond how it performs? Specifically, in aesthetics, sound, ride quality...?

A sports car doesn't have to be slow or expensive as hell to look good. And it doesn't have to be the fastest around a track for it to be the most enjoyable to own.

I've never seen a full-story review without a large amount qualitative evaluation.

On the other hand, subjective data by itself is just as worthless.

[565]

the C6 is far different from the way the model ranges were for the C5. This time around the Z06 gets an aluminum chassis, the C5 Z06 shared a very similar chassis to the base C5 last I remember. So you can't just swap parts on a C6 and make it a Z06, the Z06 has a different chassis. The engine sits further back than the base C6 also. The ZR-1 I guess you could buy all the parts and put them on a Z06. But buying carbon ceramic big brakes and such aren't cheap and I'm sure there are a ton of other things that it has.

Actually the C5 Z06 is stiffer and lighter than it's C5 coupe counterpart while the C6 Z06 is lighter, but actually less stiff than it's C6 coupe counterpart (only 97% as stiff with the fixed magnesium roof in place compared to the targa with only the nonstructural fiberglass roof in place).

The C6 Z06 aluminum chassis overall not including roof is much less stiff compared to the steel C6 chassis as it is only 97% as stiff when including its fixed magnesium roof.  The problem is that the Z06's aluminum chassis has to fit in the same space and structure as the C6's steel one, and both structures are very related to the C5 structure which was designed to be steel.  This is why the C5 Z06 (24hz) C6 targa (25hz) and C6 Z06 (25hz) are pretty much even in terms of first torsional frequency (a measure of stiffness).  This is in an age when Nissan's FM platform cars exceed 50hz for first torsional frequency. The reason why the C6 Z06 can exceed the C5 Z06 and almost match the C6 in stiffness is because the roof of the C5 Z06 is not wielded or bolted like the C6 is, but rather glued in place, and does not serve as structural a role (the true reason why the C5 Z06 is stiffer than its targa C5 counterpart is the existence of the extra brace from the C5 convertible, and the shorter rear glass opening), and the C6 targa is well... a targa.  Thus if the C6 was equip with a fixed magnesium roof, the resulting car would enjoy a decent boost in rigidity over the regular C6 Z06.

The advantage of the C6 Z06's aluminum frame is the fact that it saves around 150 pounds, at the cost of rigidity.  Personally I'd take the 150 pound weight disadvantage for the extra rigidity as the C6 Z06 is really lacking in it.  A good chunk of the 150 pounds can be reduced by using a notchback body style similar to the C5 Z06.  The FRC C5 was inherently 70 pounds lighter than the C5 targa due to the smaller rear glass.  Another good chunk can be saved by using non-runflat tires in the C6 Z06 in a similar fashion of the C5 Z06.  The non runflat tires of the C5 Z06 saves 21 pounds of unsprung weight compared to the C5.

My perfect Corvette would be a C6 Z06 built upon some of the ideas of the C5 Z06 and some of the current C6 Z06.

Steel chassis instead of aluminum (+ rigidity, +150 pounds, - cost)

Notchback body style with convertible brace (+ rigidity, - 70 pounds)

Non runflat tires (+ performance, - 21 pounds of unsprung weight, - cost)

Wielded magnesium roof( + rigidity)


Overall you'd have a car that's a tad heavier, a bit cheaper, with less unsprung weight, and probably a lot stiffer.

[Submariner]

No, I find them a lot more interesting than most other contrived performance metrics, like 0-60 or skidpad grip.

I agree...but to an average (or even enthusiast) driver...it really shouldn't be as big of a deal.

[Sigma Projects]

565, but the notchback C5 was ugly... I chose a notch back for my year celica over the  liftback since it's stiffer and lighter true, but I really think it ruins the looks of a Corvette.

So... why can't you strengthen the Z06 chassis? You can always make it stiffer, but you can't make a chassis lighter.

But thanks for side stepping the whole point of my post. I was saying that you can't simply take a C6 and put on stuff from a Z06 and call it a Z06, because the chassis are drastically different. The stiffeners used on a the C5 Z06 I'm sure you can supplement very easily, I mean the Mazdaspeed anything usually means they also welded on stiffeners same with Type R, but that doesn't mean "different" chassis, it means modded. But you CAN NEVER mod a chassis of the C6 to make it like a C6 Z06 and that's my point. It was to stress the major difference between the base and the Z06 and the up coming ZR-1.

BTW, where do you get these frequency numbers? I'd like to know your source sounds interesting.

[omicron]

In other words, an old turbo Thunderbird would likely beat a Miata around almost any track you can choose.

That doesn't make it a better sports car.

An even-older '57 supercharged Thunderbird would be a much better choice.

[565]

BTW, where do you get these frequency numbers? I'd like to know your source sounds interesting.

Right, I didn't disagree with you that you couldn't interchange the chassis, I was just pointing out that there was a sacrifice of stiffness involved.  The Z06 frame is made of a different material, but because it was designed off a steel frame, it is lighter, but also weaker.

Here is the source for the C6 Z06 frame not being as stiff as the C6 steel frame

http://forums.corvetteforum.com/showthread.php?t=1075511&highlight=aluminum+SAE+frame&forum_id=100

It's got a TON of information gleaned from various SAE papers published about the Z06 frame.

Here is the part about the 97% as stiff


"The final Z06 frame including the magnesium roof structure
is 97% as stiff (frequencies not force per unit displacement or moment per unit
angular rotation) as the steel C6 frame."

And also

" The aluminum C6 frame was mandated to drop 56kg
from it's steel C5 cousin. They got 62kgs out of it (down to 124.6kg). For some
reason, they INTENTIONALLY chose to not match the frame deflections of the
C6 steel frame but rather trimmed off 10kg instead. As is, deflections of
the aluminum frame without the magnesium roof structure are within 5% of
those for the steel frame. "

So basically GM engineers sacrificed stiffness for weight.

The rest is a very interesting read for anyone interested in mechanical matters.


The C5 Z06 and C5 resonance frequency numbers come from this source and various others that quote the same numbers.

http://www.idavette.net/hibz06/page2.htm

"Rocket scientists out there will be interested to know the convertible?s first torsional frequency is 20hz. Coupes with the roof out are at 20.5hz and, with the roof on, jump to 22hz. The Z06 is a stout, 24hz."


The 25hz frequency of the C5 Z06 is stated in this 2006 Corvette pamphlet.

http://www.gm.ca/media/vehicles/2006/chevrolet/corvette/chevrolet_corvette_brochure_en_CA.pdf

On page 13/16 at the top paragraph.

"The Z06 body achieves a 25hz torsional bending freqency, indicating excellent rigidity"


The bit about Nissan's FM cars as a stiffness comparison comes from another SAE paper.

http://www.sae.org/automag/techbriefs/06-2005/1-113-6-47.pdf

"Infiniti believes its frequency numbers for the M body are class-leading: a 52-Hz first bending mode and a 58.1-Hz first torsional mode vs. 46.6 Hz bending and 55.6 Hz torsional for the G35 sedan."

[sportyaccordy]

If the FM chassis has a resonant frequency more than double that the C5....

Is it a better basis for a race car?

It will hold suspension geometry truer under loading and not turn into spaghetti with super high spring rates...

Hmmm....

[Vinsanity]

I remember this discussion back in the C/D forums...

Regular cars and SUV's will have a higher frequency of stiffness (or whatever that measure is called) than a Corvette type car because the inherent in the shape of the vehicles. It's easier for a lower, flatter object to bend than it is for a taller, more box-like object.

I can't take credit for that idea, but I forget who it was that originally posted it.

[565]

I remember this discussion back in the C/D forums...

Regular cars and SUV's will have a higher frequency of stiffness (or whatever that measure is called) than a Corvette type car because the inherent in the shape of the vehicles. It's easier for a lower, flatter object to bend than it is for a taller, more box-like object.

I can't take credit for that idea, but I forget who it was that originally posted it.

I did duh. 

Well at least I started the topic and made that speculation, but it's really just speculation

http://forums.caranddriver.com/auto/board/message?board.id=5&message.id=160447&query.id=17191#M160447

"I got bored and I started looking up the first torsional frequency of my Z06 just for kicks. Well I came across an article where GM brags proudly that the C5 almost achieves the torsional rigidity of a good sedan. My mind chewed on this bit of info before having violent information indigestion. What do you mean to tell me my beloved C5 Z06, whose chassis is praised again and again for stiffness, barely matches up to some sedan?

Well I decided to do some digging online, to see just how stiff sports cars are. I always assumed sports cars were the stiffest motor vehicles around. I was wrong. I was so wrong.




BMW Z3 17 Hz
BMWZ4 19.5 Hz
Audi TT roadster 22Hz
C5 coupe(with roof on) 22hz
C5 Z06 24hz.
C6 Z06 25hz.
STS 25hz
Neon 25hz
1996 Ford Taurus 27hz
Lincoln LS 29hz
Crossfire Roadster 29.2 hz
Ford Explorer 30hz
Subaru B9 Tribeca 34.2hz
BMW 5 44.7hz
G35 55.6hz
M35/45 58.1hz






I guess I learned something. I always assumed that sports cars would be the stiffest cars around, but it is just the opposite. If you think about it, it makes sense, it is more difficult to make something as flat as a pancake (aka Corvette) as stiff as the automotive equivalent of a cube (Explorer).



Did everyone know this but me? I feel like this is some huge auto conspiracy. Magazines always talk about how stiff this sports car is, or that sports car is. But they fail to mention that the garden variety Ford Explorer puts them all to shame. "

[NomisR]

Did everyone know this but me? I feel like this is some huge auto conspiracy. Magazines always talk about how stiff this sports car is, or that sports car is. But they fail to mention that the garden variety Ford Explorer puts them all to shame. "

You just need to get a proper "sports car" instead of a GT.

[Sigma Projects]

not to mention that also they have lower CG compared to a tall boxy stiff vehicle. And I think some sports cars don't need to be as stiff as a SUV, since it's not going to be jumping sand dunes or curbs =P

565, I understand the stiffness thing, you mentioned it before in another topic. My post stemmed from someone saying that you could just basically swap on parts and make their own Z06 or ZR-1 and I was putting out that chassis is not something that is similar enough to be able to swap parts and call it a Z06 or ZR-1.

[sportyaccordy]

I wonder what the first torsional frequency is for cars from the 90s. I think my car might be in the single digits

[NomisR]

Where do u find a list of it anyways?  And how does torsion frequency relates to everything else on the car?