[attila]

I watched the video, read the article and the comments and still have a big question mark in my head. Most importantly, just like the testers, I expected better track performance from the Z06. Regardless of the GT-R times. They said in the article that the Z06 was just minimally faster than the GT3?? With way stickier tires. I do not want to speculate, I admit, I do not know what creates this "missing of performance" on track, but I feel disappointed. I was/am considering the Z06 as a replacement for my 997.2 GT3RS but I am not sure anymore. I have a feeling the new RS will be a better track car especially with R-rated tires.

[auf Deutsch]

Originally Posted by attila

. I have a feeling the new RS will be a better track car especially with R-rated tires.

Book it.

[FormulaMMM]

This shouldn’t be seen as a Z06 problem as much as an absurd Nismo triumph, imo.

It’s not the Z06’s manual trans. Auto trans would count for a few tenths on this track. The Nismo DCT advantage was more than negated by the tire advantage of the Z06.

It’s also not heat soak. The indicated speed at the start/finish line was equal start and conclusion of the lap for the Z06.

For one thing, GTR’s have consistently been underrated in power. This Nismo is probably closer to the Vette’s claimed output than its own reported 600 bhp.

With power close to, if not a wash, the Nismo wins due to traction out of corners and perhaps an aero advantage at this high speed track.

The new gen Z06 is 5 seconds faster around this track than the previous gen Z06, about 2.5 seconds faster than the last gen ZR1 and current Z28, and within 3.5 seconds of the 918. That’s pretty impressive I’d say.

That Nismo is just absurd.

(I will say that I expected the Z06 to be more than 1/10 faster than the 991 GT3 non-RS though… Here again, perhaps an aero advantage for the GT3 at a very high speed track. At a glance I’m not totally sold on the Z06’s aero.)

1. Porsche 918 Spyder
1:23.54

2. Nissan GT-R Nismo
1:25.70

3. McLaren 650S Spider
1:25.88

4. Dodge Viper SRT-10 ACR
1:26.00

5. Chevrolet Corvette Stingray Z06
1:27.10

6. Porsche 911 GT3
1:27.22

7. Porsche 911 (991) 50 Years Edition
1:28.93

8. Chevrolet Corvette ZR1
1:29.69

9. Chevrolet Camaro Z/28
1:29.72

10. Nissan GT-R
1:31.23

11. Dodge Viper SRT-10
1:31.28

12. Lamborghini Gallardo LP560-4
1:31.32

13. Chevrolet Corvette Z06
1:32.06

[attila]

Originally Posted by FormulaMMM

This shouldn’t be seen as a Z06 problem as much as an absurd Nismo triumph, imo.

It’s not the Z06’s manual trans. Auto trans would count for a few tenths on this track. The Nismo DCT advantage was more than negated by the tire advantage of the Z06.

It’s also not heat soak. The indicated speed at the start/finish line was equal start and conclusion of the lap for the Z06.

For one thing, GTR’s have consistently been underrated in power. This Nismo is probably closer to the Vette’s claimed output than its own reported 600 bhp.

With power close to, if not a wash, the Nismo wins due to traction out of corners and perhaps an aero advantage at this high speed track.

The new gen Z06 is 5 seconds faster around this track than the previous gen Z06, about 2.5 seconds faster than the last gen ZR1 and current Z28, and within 3.5 seconds of the 918. That’s pretty impressive I’d say.

That Nismo is just absurd.

(I will say that I expected the Z06 to be more than 1/10 faster than the 991 GT3 non-RS though… Here again, perhaps an aero advantage for the GT3 at a very high speed track. At a glance I’m not totally sold on the Z06’s aero.)

1. Porsche 918 Spyder
1:23.54

2. Nissan GT-R Nismo
1:25.70

3. McLaren 650S Spider
1:25.88

4. Dodge Viper SRT-10 ACR
1:26.00

5. Chevrolet Corvette Stingray Z06
1:27.10

6. Porsche 911 GT3
1:27.22

7. Porsche 911 (991) 50 Years Edition
1:28.93

8. Chevrolet Corvette ZR1
1:29.69

9. Chevrolet Camaro Z/28
1:29.72

10. Nissan GT-R
1:31.23

11. Dodge Viper SRT-10
1:31.28

12. Lamborghini Gallardo LP560-4
1:31.32

13. Chevrolet Corvette Z06
1:32.06

I agree with you completely! Still, somehow for some reason I expected/hoped more form the Z06.

[bogdan]

1st impressions count for a lot in the enthusiast car world. I don't think the Z06 quite makes the mark. It's a ridiculous car, with an incredible chassis, but it's falling a little short on expectations when it comes to power. In owners hands, they will get faster, unfortunately, that means it will miss the buzz around the first introductions.

Personally, I still think it's an awesome car, and few are the cars able to stick with it on a track.

[Vigilante375]

Yet GM claims (video proof) that the C7 Z06 is faster at VIR (same course used in the Lightning Lap tests) than the 918. It was a M7 and the guy who did it was a engineer for GM, vehicle dynamics engineer. Same place where '14 GT-R Nismo ran and was considerably slower than the 918 and ~1.5 sec faster than the Z/28.

The ECU nanny crap GM put in the car is very apparent. Tuners have noted it and people doing highway races, one after another, shows the car is getting timing pulled. Maybe Randy thought it was heat soak, thought that those temps were high but the crap tune GM has in it is giving the car poor performance.

It still doesn't make sense for a car that handles better, brakes better, weighs less and has more power to be slower by that much....but, things do happen.....

[FC4]

Originally Posted by bogdan

1st impressions count for a lot in the enthusiast car world. I don't think the Z06 quite makes the mark. It's a ridiculous car, with an incredible chassis, but it's falling a little short on expectations when it comes to power. In owners hands, they will get faster, unfortunately, that means it will miss the buzz around the first introductions.

Personally, I still think it's an awesome car, and few are the cars able to stick with it on a track.

Expectations were very, very high to begin with. Everyone thought it was going to be orders of magnitude greater than the C6 ZR1, but we've seen that's not the case entirely. Still, power is on target. Mine made 579 RWHP stock on a Dynojet with 125 miles on the odometer. The lowest I've seen is 570, and that's still on target. The power is certainly there...it just gets reigned in at elevated temps. On the street, it will be almost impossible to get enough heat into it for it to pull timing like it will on a track.

The biggest disappointment, to me at least, is its 120+ MPH acceleration. I don't have numbers to back it up, and it's been far too long since I drove a stock C6 Z06 or ZR1, but I'm quite certain a ZR1 is faster on the top-end due to aero. Even though the C7Z still traps 130 MPH, it won't hang with other 130 MPH cars on the top-end due to the downforce it produces.

[fcman]

Originally Posted by happos2

Ah, a non-linear scale. Is is parabolic, log based? hehe

Wouldn't using fractions, by definition, make it impossible for it to be non-linear?

[thebishman]

Originally Posted by FC4

Expectations were very, very high to begin with. Everyone thought it was going to be orders of magnitude greater than the C6 ZR1, but we've seen that's not the case entirely. Still, power is on target. Mine made 579 RWHP stock on a Dynojet with 125 miles on the odometer. The lowest I've seen is 570, and that's still on target. The power is certainly there...it just gets reigned in at elevated temps. On the street, it will be almost impossible to get enough heat into it for it to pull timing like it will on a track.

The biggest disappointment, to me at least, is its 120+ MPH acceleration. I don't have numbers to back it up, and it's been far too long since I drove a stock C6 Z06 or ZR1, but I'm quite certain a ZR1 is faster on the top-end due to aero. Even though the C7Z still traps 130 MPH, it won't hang with other 130 MPH cars on the top-end due to the downforce it produces.

Guys, I'm not trying to be a C7 Z06 apologist here as I have a pretty well loaded Z07 version being built with the A8 transmission in about four weeks; (hopefully), but something was very wrong with the car Probst was driving.

Not one review of the car on track, including Probst's own thoughts at VIR when he stated that the car was so planted it could easily handle another 100 hp, have mentioned that the car was 'squirrely' or difficult to drive on a road course. In fact every review until this MT comparison has mentioned how incredibly planted the Z06 feels when driven rapidly on a road course, so something doesn't seem quite right.

A couple of things that might have caused the result:

some conjecture on-line that the rear tyres were either worn badly or heat cycled badly. I can't say as I wasn't there, and neither was GM, so making sure that the car had good rear rubber was left to MT. I doubt they'd spring for new Michelins unless the tyres were at the tread wear bars;

I really wonder if the car had awful alignment geometry. With incorrect camber and especially with the rears having some toe out, it apparently can make the car pretty unstable mid corner which is what RP was mentioning. I would love to see this car on an alignment rack to see what the 'numbers' showed;

Lastly, RP drove the car with all driving aides off. Again he's a pro and probably drives every car that way, but the PTM in track mode is supposedly the fastest way around a track and is designed for the driver to be able to plant their foot to the floor mid corner and be able to drive the car out of the corner in full control; (kind of what the AWD in the GT-R allows you to do).

Anyway, the Z06 got beat this time around on that particular day; it is what it is. As an ex-owner of a '09 GT-R with some decent road course mods on it I can say that any GT-R can be driven extremely rapidly on a track, especially one so hardcore and unidimensional like the Nismo that it is essentially undriveable on the street.

Bish

[Ezio]

Originally Posted by attila

I agree with you completely! Still, somehow for some reason I expected/hoped more form the Z06.

I also expected more from the Z. I thought this car would BLOW away the competition.

[Revcrazy]

Originally Posted by Ezio

I also expected more from the Z. I thought this car would BLOW away the competition.

From the specs you'd certainly expect more performance. Chevy dropped the ball a bit here.

[CirrusSR22]

Where did everyone get these crazy high expectations for the Z06? The chief engineer said the goal was to bring ZR1 performance levels down the the Z06 price level. That's exactly what they did. There's still nothing else under $100,000 that's faster around a track.

Hard to make huge gains on a FR platform. It's exactly why they are designing a mid-engine Corvette right now.

[Vigilante375]

Probably because of the handling and braking ability of the car. It posted the highest cornering of any car in those magazine tests.

[auf Deutsch]

And as far as straight line speed is concerned, has anyone even sniffed GM's claim of 2.95s to 60 and 10.95s through the quarter?

[hellrotm]

C7 Z06 with (headers/intake/E85/DR's) just did 10.08 at 139 mph.

[Vigilante375]

Originally Posted by auf Deutsche

And as far as straight line speed is concerned, has anyone even sniffed GM's claim of 2.95s to 60 and 10.95s through the quarter?

That 0-60 and 1/4 mile time is from the A8, which is still on hold and nobody has been able to test the car to compare....private owners that is But a privately owned stock M7 Z06 with DRs went 10.9x at 128 on a crappy track and another, completely bone stock, went 11.2.

Car and driver did do a test on the A8 and M7. I believe their times were fairly close to GMs claim for the auto.

Yes, I'm keeping up on this car because I'm very interested in it.....same will be said when the GT350/350R comes out too much like I've kept up with the Z/28 and kicking myself for not taking advantage of that 20% off sale GM had going on last month!

[///MCFC]

Originally Posted by thebishman

Guys, I'm not trying to be a C7 Z06 apologist here as I have a pretty well loaded Z07 version being built with the A8 transmission in about four weeks; (hopefully), but something was very wrong with the car Probst was driving.

Not one review of the car on track, including Probst's own thoughts at VIR when he stated that the car was so planted it could easily handle another 100 hp, have mentioned that the car was 'squirrely' or difficult to drive on a road course. In fact every review until this MT comparison has mentioned how incredibly planted the Z06 feels when driven rapidly on a road course, so something doesn't seem quite right.

A couple of things that might have caused the result:

some conjecture on-line that the rear tyres were either worn badly or heat cycled badly. I can't say as I wasn't there, and neither was GM, so making sure that the car had good rear rubber was left to MT. I doubt they'd spring for new Michelins unless the tyres were at the tread wear bars;

I really wonder if the car had awful alignment geometry. With incorrect camber and especially with the rears having some toe out, it apparently can make the car pretty unstable mid corner which is what RP was mentioning. I would love to see this car on an alignment rack to see what the 'numbers' showed;

Lastly, RP drove the car with all driving aides off. Again he's a pro and probably drives every car that way, but the PTM in track mode is supposedly the fastest way around a track and is designed for the driver to be able to plant their foot to the floor mid corner and be able to drive the car out of the corner in full control; (kind of what the AWD in the GT-R allows you to do).

Anyway, the Z06 got beat this time around on that particular day; it is what it is. As an ex-owner of a '09 GT-R with some decent road course mods on it I can say that any GT-R can be driven extremely rapidly on a track, especially one so hardcore and unidimensional like the Nismo that it is essentially undriveable on the street.

Bish

you are probably right about those worn rear tires, bad alignment, and PTM. also, i think pobst may have used an analog tire gauge resulting in tire pressure being off by as much as 1.5 psi.

[FC4]

Originally Posted by BlackJetE90

C7 Z06 with (headers/intake/E85/DR's) just did 10.08 at 139 mph.

Stock pully/boost, to boot. That also wasn't on straight E85. The car has 150 MPH in it on pure bolt-ons and E85. Unreal.

[Revcrazy]

Originally Posted by CirrusSR22

Where did everyone get these crazy high expectations for the Z06? The chief engineer said the goal was to bring ZR1 performance levels down the the Z06 price level. That's exactly what they did. There's still nothing else under $100,000 that's faster around a track.

Hard to make huge gains on a FR platform. It's exactly why they are designing a mid-engine Corvette right now.

Pretty sure the Viper TA is faster.

[highrevs]

I've done the math for the Z06 guys. It's partially drag induced from the downforce producing parts, but mostly timing cuts. I created a very sophisticated simulation - it was impossible to match real world acceleration times and top speed without removing significant power on the top end.

This is what the car does (top speed = 186 MPH)



This is what it could theoretically do without a big timing cut above 110 MPH (top speed = 199 MPH):



I don't think it's a coincidence that the new CTS-V has hit 199 MPH during testing. Same engine, different tune.

Original post:
http://www.corvetteforum.com/forums/...post1588798873

If you'd like to see all of the hideous math start here and work your way through. The model on the first page was updated with inputs from a small tiger team that formed. Includes a tire radius dependent on heat, changing coefficient of rolling resistance due to tire temperature, traction losses, shift delays, power and torque models based on dynos, drag, downforce, the whole nine yards:
http://www.corvetteforum.com/forums/...odynamics.html

[DocWeatherington]

[pgviper]

Originally Posted by DocWeatherington

Actually, there are a few. With Videos and stats. I wonder if its a minor build issue, only effecting certain cars. I think Motor Trend should get another car and do a retest and include a few other "Exotics" in.

http://www.corvetteforum.com/forums/...ps-repost.html

http://www.corvetteforum.com/forums/...shut-down.html

Originally Posted by Vigilante375

No, those owners are pushing the car near the limits...as the say 8/10s which is pretty damn close to a "Pro" driver. They are doing 30 minute sessions, not a couple laps to get a feel for the car/warm it up then 1 lap to set a time.

I truly believe that this car needs to be broken in properly since GM has nanny'd the ECU.



How did they lose you at the straight line aspect? Its already been confirmed, lots of times, that the aero package on the C7Z inhibits its ability to go fast in a straight line after 120 or 130 mph but it keeps it planted through turns to keep the speed up (as shown in this article).

Also, I know of only 1 "stock" C7Z in the 10s (barely) and he used DRs to achieve it and his MPH was 128. Everything else I see is 11s.....I like to see what you're talking about.

Originally Posted by FC4

It's not a break-in or transmission issue. The car has overly conservative fail-safes programmed to the ECU reigning things in at elevated oil temps. However this is very easily programmed out while still maintaining very safe parameters and many have done so. I haven't had the car on a track yet and unfortunately I won't be able to experience this since I already got tuned and run it on E85, but I never experienced any issues on the street when bone stock.

I said it from the start that there was some funky shit going on with the test car used in that comparison...

http://www.corvetteforum.com/forums/...t-r-nismo.html

Be on the lookout for "updated" results.