Corvette ZO6 vs Porsche 997 GT3 RS

[565]

I disagree.

Tell anyone with a smidge of automotive experience that given the choice between two performance suspension set-ups, which is preferred soley on its inherent attributes:

1.) Limited wheel travel, fixed rate, same spring works the suspension and controls body sway

2.) More wheel travel, variable rate, spring separate from anti-roll bar.

Taking it any further would necessitate quantitative tests that GM no doubt peformed, but sure as heck isn't going to make public whatever the results owing to IP concerns on testing and design methodologies.

Once again you continue to speculate.

Where's the evidence for limited wheel travel?

Wheres the evidence for fixed rate.

Where's the evidence that the leaf spring isn't more controlled than an antiroll bar?

All you have is a photo and a flawed understanding of how things work.? Don't try to make speculations of "inherit attributes"

Instead of continuing to speculate, why don't you go on the internet and try to find some informed articles written about the Corvette transverse leaf spring that support your opinions.

If your opinions are valid, then certainly others with more knowledge will back them up.

[GoCougs]

Once again you continue to speculate.

Where's the evidence for limited wheel travel?

Wheres the evidence for fixed rate.

Where's the evidence that the leaf spring isn't more controlled than an antiroll bar?

All you have is a photo and a flawed understanding of how things work.? Don't try to make speculations of "inherit attributes"

Instead of continuing to speculate, why don't you go on the internet and try to find some informed articles written about the Corvette transverse leaf spring that support your opinions.

If your opinions are valid, then certainly others with more knowledge will back them up.

First, you have yet to make the case for my supposed flawed understanding.

Second, the onus is on you to seek proof if you're so eager to prove/disprove my assertions.

Lastly, the only quantitative proof I need beyond common knowledge is that no one else uses transverse leaf springs.

[565]

First, you have yet to make the case for my supposed flawed understanding.

Second, the onus is on you to seek proof if you're so eager to prove/disprove my assertions.

Lastly, the only quantitative proof I need beyond common knowledge is that no one else uses transverse leaf springs.

Why is the onus on me to prove your assertions?  They are your unfounded assertions, you prove them.

The flaw in your understanding is that you think you can look at a photo and a description without any real knowledge and come to any reasonable conclusion.
There have been already manly reasons posted why no one else uses transverse leaf springs and all are related to pracitical concerns.  None related to performance.

[Raza]

Wow, this conversation has moved beyond my area of expertise. 

In other news, I saw a picture of the Z06 in the new issue of Evo, and for the first time ever, it looked like a really nice looking car.  I never thought the C6 would grow on me, but the combination of the low angle (I keep telling people that!) and that snarling little snout on it, it makes for a world of better looks than the standard model.  Shame about the roof.

[ChrisV]

I disagree.

Tell anyone with a smidge of automotive experience that given the choice between two performance suspension set-ups, which is preferred soley on its inherent attributes:

1.) Limited wheel travel, fixed rate, same spring works the suspension and controls body sway

Actually, if you look at the picture, the spring does NOT control body sway, the anti-roll bar does. And the anti-roll bar is clearly pictured in the photo YOU posted. the Corvette spring only works as a spring, just like a coil spring. it's variable rate, AND it has a lower CG and less weight.

And yes, you made the assertions, the onus is on you to prove your assertions. Give ACTUAL articles stating that they are inferior with testing proof, not a "talk to any one" statement.

[ChrisV]

Now that that is settled, on to the full statement I made and not an excerpt out of context:
"ChrisV would have us believe that the low 400 HP Porsche GT3 beat the low 500 HP Corvette Z06 strictly because of its tires.  I'm sure neither of you are that brand blind...right? 

The full statement IS in context. The bolded word makes you come across making the statement that we ARE brand blind in making our assertions. And that's total crap. I'm a Porsche fan and have been for decades, and I still know it's the TIRES that were the difference in how the Corvette handled and felt, as far as precision, nervousness at the limit, etc. And those problems would have been mitigated even had the car not been retuned, as rOtor suggests needed doing.

The rest of your commentary, that YOU have never seen tires make the difference at that level shows a distinct lack of experience on your part. We aren't talking adding HORSEPOWER, but adding CORNERING GRIP. And the DOT semi-slicks are worth a good 2 seconds on the same car over the kind of tires the Corvette runs even on a 45 second course.

[SVT666]

The full statement IS in context. The bolded word makes you come across making the statement that we ARE brand blind in making our assertions. And that's total crap. I'm a Porsche fan and have been for decades, and I still know it's the TIRES that were the difference in how the Corvette handled and felt, as far as precision, nervousness at the limit, etc. And those problems would have been mitigated even had the car not been retuned, as rOtor suggests needed doing.

The rest of your commentary, that YOU have never seen tires make the difference at that level shows a distinct lack of experience on your part. We aren't talking adding HORSEPOWER, but adding CORNERING GRIP. And the DOT semi-slicks are worth a good 2 seconds on the same car over the kind of tires the Corvette runs even on a 45 second course.

Or maybe the "at-the-limit" handling problems is because of the soft suspension setup that every other review blames for the squirly handling at the limit.  As I stated earlier, this is not a fair fight because the Z06 is not a car that was designed for track use and the GT3 RS was.  The Z06's suspension is setup for road use, not track use.

[ChrisV]

the Z06 is not softly suspended, and it seems to do fine in track work with real tires put on it, as has been proven by Z06 owners nationwide.

I'm also going by two decades+ of direct experience with cars and tires, and how much difference in feel, stability, and grip real tires make over even good performance street tires. I can take you to the track and show you back to back the difference. The Goodyear run-flats are not even slightly as good as even a cheapy DOT legal semi-slick from a Korean tire manufacturer, much less a top brand one. There is that much difference.

A full tread street tire will be squirmy and imprecise due to the tread blocks moving around and being of a harder compound. Not only do semi-slicks have fewer tread blocks to squirm, the tread blocks themselves are not as tall, so deflect less when subjected to side forces, making them react more predictably, and with even less squirming.

[ChrisV]

Hemi, nice sig. Have you ever done this:

http://mywebpages.comcast.net/cvetters3/rex1.MPG

[Nethead]

ChrisV:  When you've got wider tires and an advantage of about 100 horsepower and you're behind about a half-second per lap, it ain't just your tires lettin' you down...that could easily be the driver, but this was the same professional driver in both cars, and I suspect he knows the differences in tires, too--although admittedly he may not be as knowledgeable about tires as ChrisV here (who is?).  He says the fantastic tires on the Porsche are better than the great tires on the Chevrolet, but the translation upstream in this thread  does not show that the professional driver credited the tires with being the sole reason the GT3 was every bit as quick as the Z06.  Don't take it personally, but I'm taking his word over yours...after all, he was actually behind the wheel of the GT3 and the Z06 and you're behind a keyboard.

[SVT666]

Hemi, nice sig. Have you ever done this:

http://mywebpages.comcast.net/cvetters3/rex1.MPG

I'm assuming that's you in your 302 powered RX-7?  Very nice, and no I have not done what you have done in your video, and if this is your way of saying "I know more then you do", then you are even more childish then I originally thought.  "Look what I did, look what I did" is so high school.  Chris, neither you nor I have driven either the new Z06 or the GT3 on a track, and every review I have read about the Z06 blames the soft suspension that is tuned for street use for the squirly behaviour at the limit.  Are you saying that every review is wrong, because you obviously know more then they do.

[GoCougs]

Actually, if you look at the picture, the spring does NOT control body sway, the anti-roll bar does. And the anti-roll bar is clearly pictured in the photo YOU posted. the Corvette spring only works as a spring, just like a coil spring. it's variable rate, AND it has a lower CG and less weight.

And yes, you made the assertions, the onus is on you to prove your assertions. Give ACTUAL articles stating that they are inferior with testing proof, not a "talk to any one" statement.

Actually, yes, that transverse spring will absolutely see forces from (read: control) body sway owing to the 18" or so between its two mounts on the chassis. (If it were single point contact, then no, it wouldn't see forces from body sway.) That's why the roll bar pictured is small for a performance-based vehicle.

I will back-track a bit on the variable rate. Perhaps there are variable rates "bands" sandwiched in the composite lay-up or it is of tapered construction (narrower toward the ends)

[ChrisV]

ChrisV:  When you've got wider tires and an advantage of about 100 horsepower and you're behind about a half-second per lap, it ain't just your tires lettin' you down...

I see you still don't understand that the width doesn't matter as much as the compound does. The stock Corvette tires may be wider, but they are considerably slimier in cornering use.

Don't take it personally, but I'm taking his word over yours...after all, he was actually behind the wheel of the GT3 and the Z06 and you're behind a keyboard.

Don't take this personally either, but you're behind a keyboard now, too. I've been in the SCCA for 20+ years, been an SCCA and BSCC driving instructor, and built road race and slalom race cars, as well as working on the GT3 Porsches for Team Seattle.

You still don't show that you have ANY experience in road racing or cornering competition events. I posted a vid of my self in a car I prepped, that won a regional championship. I've also built national champions for other drivers. I'll post pictures from home later on. I think in 20+ years of this that I've learned a tad about what it takes to make a car work.

[r0tor]

yipee... I've designed from scratch, built, tuned, and raced a FSAE car in college... does that make me a superior being as well? 

[ChrisV]

yipee... I've designed from scratch, built, tuned, and raced a FSAE car in college... does that make me a superior being as well? 

What does superior being have to do with anything? nethead was discussing tires as adding hp and that tires won't make the different in lap times. 20+ years of direct experience says otherwise. Sorry, that you can express any fucking opinion you want but *I* can't and apparently BASING said opinion on a life spent LEARNING that information is enough for you to be insulting about it. Great. I guess I should have spent that life writing books that you little fucks could reference on the web in order for it to be fucking valid.

Since you'd rather live by conjecture than experience, I'm done helping, and I'll simply lower myself to your standards and ONLY insult people from know on who use personal experience as ANY form of basis for opinion. In fact, I'll be just like you and ONLY insult people at all times. How's that? That what you want? In fact, I don't know why you're upset about me doing to you what you do to everyone else, including me.

[SVT666]

What does superior being have to do with anything? nethead was discussing tires as adding hp and that tires won't make the different in lap times. 20+ years of direct experience says otherwise. Sorry, that you can express any fucking opinion you want but *I* can't and apparently BASING said opinion on a life spent LEARNING that information is enough for you to be insulting about it. Great. I guess I should have spent that life writing books that you little fucks could reference on the web in order for it to be fucking valid.

Since you'd rather live by conjecture than experience, I'm done helping, and I'll simply lower myself to your standards and ONLY insult people from know on who use personal experience as ANY form of basis for opinion. In fact, I'll be just like you and ONLY insult people at all times. How's that? That what you want? In fact, I don't know why you're upset about me doing to you what you do to everyone else, including me.

You keep proving me right with your childish outbursts.

[Nethead]

I see you still don't understand that the width doesn't matter as much as the compound does. The stock Corvette tires may be wider, but they are considerably slimier in cornering use.

Don't take this personally either, but you're behind a keyboard now, too. I've been in the SCCA for 20+ years, been an SCCA and BSCC driving instructor, and built road race and slalom race cars, as well as working on the GT3 Porsches for Team Seattle.

You still don't show that you have ANY experience in road racing or cornering competition events. I posted a vid of my self in a car I prepped, that won a regional championship. I've also built national champions for other drivers. I'll post pictures from home later on. I think in 20+ years of this that I've learned a tad about what it takes to make a car work.

ChrisV:  The first item--the wider tires on the Z06--is to point out that there is a greater contact patch on the wider tires than would be on the Porsche's (likely to be) narrower tires.  So, we have better compound in the Porsche tires but spread over a smaller area.  Tire engineers could tell us the offset one has over the other if we could give them each tire's compound, diameter, width, tread specifics, inflation pressures (the dynamic pressures, since the pressures and the grip change as the tires heat up), and weights borne by each tire (the dynamic weights, since cornering causes more of it to shift to the outside tires and braking causes more of it to shift to the front tires, yada yada yada).  We don't have enough of that information in this article, nor was it likely recorded in the testing.  If the Z06 had stinkin' tires, this would be an issue.  But the Z06 has great tires, so the difference is much less than would be the case if the Z06 had stinkin' tires.  And the Z06's tires presumably have a greater contact patch than the GT3's tires,
which offsets the presumably greater stickiness of the GT3's smaller contact patch tires to some degree--only careful measurements could nail that exact value for us.  I'd say adding up the pros and cons of the tires is pretty much a wash--one has a greater contact area and one makes better use of the smaller contact area it has.  But the Porsche is down about 100 horsepower yet laps the track as fast as the Corvette.  It's actually a few carlengths per lap faster, but I grant that that may truly be the benefits of having better dry-conditions tires--you'll notice in my postings that I've said they lap equally fast, even though the article makes more of that half-second per lap than I think is justified because the conditions at the track favored the dry-conditions design of the Porsche's tires.  But the 400+ HP Porsche kept right there with the 500+ HP Corvette, which shouldn't shock anyone that has raced Porsches as you have.  I've never raced anything but motorcycles, yet I'm not shocked. 
Is ANYONE besides you shocked by these results?

[r0tor]

maybe someone should ask Mallet why they put a coilover system on their Hammer vette? 

[omicron]

The Annual CarSPIN Bitchslap Thread returns!

[Nethead]

ChrisV:  What is this shit:
"nethead was discussing tires as adding hp and that tires won't make the different in lap times."
Tires DON'T add horsepower! Tires DO make a difference in lap times.  Are we gonna havta start giving you a breathalyzer test before we let you approach a keyboard?
Now take notes if you can't grasp what I'm saying this time and surely you can find someone at your middle school that can explain it to you:
The tires on the Z06 are great tires, but the tires on the GT3 are fantastic tires for dry-track conditions.  But the difference here between great and fantastic is greatly reduced by the bigger contact patch of the Z06's tires--possibly totally negated, but more likely the narrower tires on the GT3 still have a small grip advantage.  The big reasons the GT3 can lap as quickly, or quicker, than the Z06 despite the Z06's nearly 100 horsepower advantage is that the GT3 has much better handling at speed in the dry, much better braking at speed (wet or dry), much better control at speed in the dry, and a much better engine location for dry-track traction--more weight over the driven wheels.  Pee on the track and that engine location becomes as big a liability as it is an asset on a dry track. 
Once again, and this shouldn't have to be stated a third time in the same topic but in our case it does:  the Porsche used superior handling, braking, and control to lap just as fast as the Z06, which used its 100 horsepower advantage to catch back up to the GT3 on the straights.  Why are you the only one who's in denial about this?  You should be thankful that the Z06 had a hundred horsepower advantage or the Porsche would have been much, much further ahead. 

[565]

maybe someone should ask Mallet why they put a coilover system on their Hammer vette??

Well most tuners add stiffer springs as well as better shocks to make their modified car handle more aggressively than standard.

What would Mallet do if they wanted to put a stiffer leaf spring on the Vette?? Ask GM's supplier to redesign special ones just for their tiny production of cars?

Alot of people put aftermarket stiffer coil springs on the Vette quite simply because there is little aftermarket support for the leaf springs.? They are a specialized piece of engineering and it's not exactly trivial to make them.

I did a quick search and just found a few places that actually make aftermarket leaf springs, and the selection is limited at best.

http://www.lgmotorsports.com/catalog/product_info.php?products_id=1569&osCsid=c39f56f9ebe0b8c50bd4729aacae37a4

and they only offer 1 single stiffness set.? If Mallet wanted a different set of spring rates, they are out of luck.


By comparision that same site offers coil over solutions.

http://www.lgmotorsports.com/catalog/product_info.php?cPath=342_230_337&products_id=272&osCsid=c39f56f9ebe0b8c50bd4729aacae37a4

and on their site, they say you can specify whatever spring rates you choose.


Thus for a tuner, coil overs allow them more choice in their suspension tuning.

[nickdrinkwater]

ChrisV:Are we gonna havta start giving you a breathalyzer test before we let you approach a keyboard?

[Raghavan]

Sig worthy.

[280Z Turbo]

maybe someone should ask Mallet why they put a coilover system on their Hammer vette?

Coilovers are easily adjustable.

[Danish]

Dude, I keep reading stupid comments coming from you. 

[Danish]

Caling me BRAND BLIND? I'm not even a Chevy fan. I'm an Ex PCA member ,and have owned 3 911s, raced 2 of them, and a few other Porsches, as well as worked on many other racing Porches. Jesus CHRIST. I've been racing in SCCA for a couple DECADES. I've SEEN the difference TIRES FUCKING MAKE you SHITHEEL.

God DAMN. That REALLY pissed me off.

ChrisV:  The Nethead here has shit on my heel from stomping you in the head. 

The Annual CarSPIN Bitchslap Thread returns!

Are we gonna havta start giving you a breathalyzer test before we let you approach a keyboard? 

 

[Nethead]

This topic's old.  We don't know why the German publication picked a GT3 and a Z06 for a professional driver to take to a racetrack.  We don't even know what each car would cost in Germany, certainly a strange omission--were the costs given in the article but no one copied & translated them?
Never mind.  We don't own either, so we have to accept what their results showed at that testing session on that day (which was dry).  If I had a Z06's money in Euros or a GT3's money in Euros, I'd put it in the bank until one or the other of my four vehicles need replaced--and then buy something else with just part of that moolah.
Yawn.  Time to move on...

[heelntoe]

time to move on, albeit with some fond memories (check my sig)

[Eye of the Tiger]

Yes, let's move on.


























CHEVY RULES!!!

[r0tor]

Coilovers are easily adjustable.

they are no more adjustable then a corvette with its leaf springs and an adjustable shock... shock dampening and ride height is adjustable on both