3,524 lbs is NOT heavy....it's best-in-class.
08-19-2014, 09:50 AM
#201
Team Owner
08-19-2014, 10:02 AM
#202
Le Mans Master
Member Since: Dec 2005
Location: Port Arthur, Texas 77642
Posts: 8,475
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Although it is not set up for E85, this would be a great solution to fighting heat soak and adding power as well. Although fuel mileage with E85 suffers if C7Z were "flex fuel" it wouldn't affect it's rated mpg. Many GTRs are tuned for E85 and all the big power GTRs run E85 without burden of alky injection. If I tracked my C7Z I would look into making the conversion, as of now I do not know the obstacles.
I meant to post as a "reply to quote" from a post above bringing up cooling/lost power issues of forced induction.
I meant to post as a "reply to quote" from a post above bringing up cooling/lost power issues of forced induction.
Last edited by NemesisC5; 08-19-2014 at 10:05 AM. Reason: Clarification of post , ie not weight related
08-19-2014, 10:47 AM
#204
Team Owner
e85 isn't going to solve intake temp issues unless you tune the car to stop pulling timing for higher temps with the added octane.
08-19-2014, 11:07 AM
#205
Melting Slicks
You have made this time claim before and have not been able to produce the video. Even if it is true the time difference you state can be completely accounted for in the tire difference between the Sport cups and the Cup 2. Tadge specifically mentions the new tire for being a reason that the C7Z06 was faster than the ZR1 out of the box at Milford. Did the C7Z06 get better with more development? Sure, but the results have yet to be released.
08-19-2014, 11:23 AM
#206
Melting Slicks
The z06 carbon is faster around a track than the zr1 when on equal tires: http://www.roadandtrack.com/car-revi...t-corvette-zr1
It's better balanced, lighter and power can be used easier. Maybe at nring and monza the zr1 could be faster due to pure power but it's limited. It's why I got a z07 for track work instead of a zr1.
It's better balanced, lighter and power can be used easier. Maybe at nring and monza the zr1 could be faster due to pure power but it's limited. It's why I got a z07 for track work instead of a zr1.
You're getting too hung up on the c7z times not giving enough respect to the sport cup 2 tires which are 1.8seconds a lap faster per michelin. http://www.michelinman.com/tire-sele...2/tire-details
Last edited by racerns; 08-19-2014 at 11:37 AM.
08-19-2014, 12:47 PM
#208
Instructor
You realize that was the only track that the Z07 got a quicker lap time than the ZR1 (when both were tested on sport cups)? That test was on the ultra tight and technical Radical course at Spring Mountain. I agree the Z07 is a little better balanced and lighter and would be my choice for an autocross over the ZR1 but at most other road courses( Laguna seca, Hockenhiem short, and VIR) the ZR1 turns faster lap times. Though, I would not be surprised to see the C6 Z07 turn a faster lap than the C7Z06 on a track like the Radical Loop if on the same tires.
Last edited by sahowley; 08-19-2014 at 01:38 PM.
08-19-2014, 01:16 PM
#209
Melting Slicks
08-19-2014, 01:33 PM
#210
Melting Slicks
You could delete all of that stuff - Sure - But why would you? This car is supposed to be a track car (That is what a Z06 was made for). I could do the same to my other corvettes, but I refrain from that. I do own highly modified corvettes and did not have to take out the radio, AC out, etc. and they are under 3000 pounds (But we are comparing stock to stock here - so why would we take the radio and such out?) If you are talking a strickly track car - I would take the whole interior out.
I own multiple corvettes so I know that some weighted more and less than 3800 pounds with less HP.
If you think that 3524 pounds is light, that is fine. I do not think it is light at all. While it is not as heavy as some other sports cars, it is still not "light".
Weight comes off everycar with less gas.
A lot of guys who tracked a ZR1 and Z06 can tell you the difference on long straights past 120 - 130 MPH. That is where the 638 shines over the 505 HP. Both cars have heat soak, but with more moving parts, a stock C6 ZR1 might have a little faster warm up period than NA - Correct?
I know the C6 Z06 got heavier. Are you saying that we can expect that from a C7 Z06 as well?
I think a lot of the differnce in the track times comes down to the tires. You failed to mention that in your post. Tires make a huge difference in times.
I am glad you like the C7 Z06. I do too. I just do not like what it weighs as it is heavy. It definitely makes power. I am sure the "bigger" version of this model (when it comes out) will be more my style.
Just as the C6 Z06 and C6 ZR1 are old news, the new Z will be old news this time next year when we see the news of the bigger model that comes out. It is how the car companies make money, right?
I own multiple corvettes so I know that some weighted more and less than 3800 pounds with less HP.
If you think that 3524 pounds is light, that is fine. I do not think it is light at all. While it is not as heavy as some other sports cars, it is still not "light".
Weight comes off everycar with less gas.
A lot of guys who tracked a ZR1 and Z06 can tell you the difference on long straights past 120 - 130 MPH. That is where the 638 shines over the 505 HP. Both cars have heat soak, but with more moving parts, a stock C6 ZR1 might have a little faster warm up period than NA - Correct?
I know the C6 Z06 got heavier. Are you saying that we can expect that from a C7 Z06 as well?
I think a lot of the differnce in the track times comes down to the tires. You failed to mention that in your post. Tires make a huge difference in times.
I am glad you like the C7 Z06. I do too. I just do not like what it weighs as it is heavy. It definitely makes power. I am sure the "bigger" version of this model (when it comes out) will be more my style.
Just as the C6 Z06 and C6 ZR1 are old news, the new Z will be old news this time next year when we see the news of the bigger model that comes out. It is how the car companies make money, right?
You can always do the radio, AC, and power seat deletes yourself, with basic hand tools you know...
You do realize there are corvettes that are on the road that weighed 3800lbs right?
That had less than 1/3 the horsepower no less.
3500lbs is not a heavy car. The average car today weighs 3600+.
A good 70 lbs can come right off the weight of the car by just filling it with half a tank of gas....
Do you think the C6 ZO6 is a faster car?
Do you think the C6 ZO6 is faster than the C6 ZR1? Because all this worrying about the weight of the C7 ZO6? Comes down to this.
The C7 ZO6 is over a second a lap faster at milford proving grounds, without further R&D work done. It's Very First Lap. Spanked the record set by the C6 ZR1. NOT the C6 ZO6. The C6 ZO6 didn't hold that record. the ZR1 did. And the C7 ZO6 bent the ZR1 over, had it's way with it, the very first time it's tires hit the pavement.
the competition hasn't even met the ZR1's laptimes yet around most tracks in the mag comparos. And the C7 ZO6 is faster.
Weight isn't always a bad thing, if the performance gained (more sophisticated engine computers, ELSDs, bigger brakes, Better steering feedback etc, or Stiffer Chassis) by whatever components you have added exceeding the performance hindrance of the weight added.
The C6 ZO6 is old news. The heavier ZR1 spanks it on every track Forever. Furthermore, BOTH the C6 ZO6 and ZR1 got Heavier in every subsequent year of their existence, as GM tried to bring the interior up from Chevette standards, along with crash standards. And yet... we already know the C7 ZO6 is faster than the fastest C6... the ZR1.
Just like the C7 Stingray, is leagues faster than the C6 Z51 and Grandsport both.
You do realize there are corvettes that are on the road that weighed 3800lbs right?
That had less than 1/3 the horsepower no less.
3500lbs is not a heavy car. The average car today weighs 3600+.
A good 70 lbs can come right off the weight of the car by just filling it with half a tank of gas....
Do you think the C6 ZO6 is a faster car?
Do you think the C6 ZO6 is faster than the C6 ZR1? Because all this worrying about the weight of the C7 ZO6? Comes down to this.
The C7 ZO6 is over a second a lap faster at milford proving grounds, without further R&D work done. It's Very First Lap. Spanked the record set by the C6 ZR1. NOT the C6 ZO6. The C6 ZO6 didn't hold that record. the ZR1 did. And the C7 ZO6 bent the ZR1 over, had it's way with it, the very first time it's tires hit the pavement.
the competition hasn't even met the ZR1's laptimes yet around most tracks in the mag comparos. And the C7 ZO6 is faster.
Weight isn't always a bad thing, if the performance gained (more sophisticated engine computers, ELSDs, bigger brakes, Better steering feedback etc, or Stiffer Chassis) by whatever components you have added exceeding the performance hindrance of the weight added.
The C6 ZO6 is old news. The heavier ZR1 spanks it on every track Forever. Furthermore, BOTH the C6 ZO6 and ZR1 got Heavier in every subsequent year of their existence, as GM tried to bring the interior up from Chevette standards, along with crash standards. And yet... we already know the C7 ZO6 is faster than the fastest C6... the ZR1.
Just like the C7 Stingray, is leagues faster than the C6 Z51 and Grandsport both.
08-19-2014, 02:48 PM
#212
Melting Slicks
You have made this time claim before and have not been able to produce the video. Even if it is true the time difference you state can be completely accounted for in the tire difference between the Sport cups and the Cup 2. Tadge specifically mentions the new tire for being a reason that the C7Z06 was faster than the ZR1 out of the box at Milford. Did the C7Z06 get better with more development? Sure, but the results have yet to be released.
If you don't think any of that makes a HUGE difference on the lap well....
And the point still there, the ZO6>>>> ZR1. Out of the box. Stock to stock a 2013, ZR1 is < to a 2015 ZO6. Before any of that work was even done. We also don't know if any of the aero spats were equipped on the test mule either. Which it likely wasn't to further throw people off as to it being the Z.
I haven't produced the vid, because this forum's search and links to Google both are total garbage. Even finding threads that you KNOW the title to can be a PITA on the forum search engine.
I'll make a claim as ridiculous as the C6 crowd.
My C4 is better than any Corvette released after. Why? Because I say so. Known performance metrics be damned.
This is just the C6 cry club, all over again. "The C7 can't be faster than the C6! it's heavier! omg! I REFUSE TO BELIEVE IT! CAMARO LIGHTS OMG OMG!" Yet the C7 has repeatedly beat the pants off of the outgoing C6, base to base, Z51 to GS, whatever the trim of the base car.
Last edited by MavsAK; 08-19-2014 at 02:51 PM.
08-19-2014, 02:55 PM
#213
You realize that was the only track that the Z07 got a quicker lap time than the ZR1 (when both were tested on sport cups)? That test was on the ultra tight and technical Radical course at Spring Mountain. I agree the Z07 is a little better balanced and lighter and would be my choice for an autocross over the ZR1 but at most other road courses( Laguna seca, Hockenhiem short, and VIR) the ZR1 turns faster lap times. Though, I would not be surprised to see the C6 Z07 turn a faster lap than the C7Z06 on a track like the Radical Loop if on the same tires.
http://fastestlaps.com/tracks/laguna_seca.html
I guess what I'm trying to say is that the Carbon with the same tires, brakes, suspension etc can match a ZR1 with it's additional 130hp due to being lighter and better balanced. Now the C7Z has a little more HP than a Zr1 but a lot more weight.
I'm hopeful someone does a C6Z07 vs C7Z with sport cup 2 on a track. Would not be shocked at all if the time difference is within .5 seconds
Hell, I might even do it myself if I end up owning both for a period of time
The people downplaying the weight would be the same fanboys cheering up and down if the new car was 3200lbs.
08-19-2014, 03:04 PM
#214
Melting Slicks
except most guys who have one will run them on the street, where roll racing and 0-60 are king, so 200lb heavier, 12hp more is not going to "walk" a ZR1, sorry, at least not a manual car....
So it doesn't really matter how fast it is at a track by a pro driver, the real world outcome will be different....I'm sure I'll be given the point by from C7Z06 at my track....just like I give plenty to 1980's 911 driven by pro guys....no worries!
So it doesn't really matter how fast it is at a track by a pro driver, the real world outcome will be different....I'm sure I'll be given the point by from C7Z06 at my track....just like I give plenty to 1980's 911 driven by pro guys....no worries!
Also you're forgetting the torque curve of the LT4 which is what really moves a car. HP is just a seller. Torque and weight is king. The LS9 doesn't produce anything like the torque in the low, mid or high range like the LT4 of the C7.
That's also ignoring the simple fact that anyone street racing their cars, should have their licenses revoked on the spot.
I save my play for the track where it belongs. Doesn't matter if I'm in my C4 which is only a little better than stock, or on my ZX14 which will frankly stomp just about every corvette on this forum, comfortably and that's without the nitrous.
The C7 according to everyone I know that owns both, who has tracked both cars have repeatedly said the C7 is far easier to drive up near it's limits, and provides much better feedback, making them far faster around the track. So in the hands of the Everyman, the C7 makes the driver more confident which in turn makes them faster and more willing to explore the car's ability. Even if they were completely equal otherwise, that puts quicker times in more people's hands. And yet...they aren't equal at all. So there's MORE limit to explore, than what the C6 had to start with, in addition to being much more approachable as a car.
I have Zero reason to believe the ZO6 will be any different.
My acceptable limit for a car's weight is 3600 in the case of a Corvette. Once it starts getting heavier than that? No amount of physics defying engineering is going to save it.
Last edited by MavsAK; 08-19-2014 at 03:13 PM.
08-19-2014, 03:38 PM
#215
Le Mans Master
08-19-2014, 04:31 PM
#216
Melting Slicks
Up until the Zr1/viper test recently, Randy was actually faster around Laguna in the carbon.
http://fastestlaps.com/tracks/laguna_seca.html
I guess what I'm trying to say is that the Carbon with the same tires, brakes, suspension etc can match a ZR1 with it's additional 130hp due to being lighter and better balanced. Now the C7Z has a little more HP than a Zr1 but a lot more weight.
I'm hopeful someone does a C6Z07 vs C7Z with sport cup 2 on a track. Would not be shocked at all if the time difference is within .5 seconds
Hell, I might even do it myself if I end up owning both for a period of time
The people downplaying the weight would be the same fanboys cheering up and down if the new car was 3200lbs.
http://fastestlaps.com/tracks/laguna_seca.html
I guess what I'm trying to say is that the Carbon with the same tires, brakes, suspension etc can match a ZR1 with it's additional 130hp due to being lighter and better balanced. Now the C7Z has a little more HP than a Zr1 but a lot more weight.
I'm hopeful someone does a C6Z07 vs C7Z with sport cup 2 on a track. Would not be shocked at all if the time difference is within .5 seconds
Hell, I might even do it myself if I end up owning both for a period of time
The people downplaying the weight would be the same fanboys cheering up and down if the new car was 3200lbs.
08-19-2014, 05:23 PM
#217
Burning Brakes
Member Since: Oct 2007
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C&D already talking about the heavy weight of the Z06 ;(
http://blog.caranddriver.com/heavy-h...weight-leaked/
http://blog.caranddriver.com/heavy-h...weight-leaked/
08-19-2014, 05:35 PM
#218
Melting Slicks
I think it's pretty safe to say that majority of C7 Z06s will be heavier than 3600 lbs as very few people are going to buy a stripper version. At that price point they are going to load up the options - not shy away from them. All those fancy leather/interior upgrades, Auto and Aero bits are easily going to add at least another 85 - 100lbs. That's just the coupe - if you fart at the convertible it will be over 3600 lbs.
I think most will probably buy the one that's festooned with all of the extras. If nothing else because that's how they show up on dealer lots :yuck: to get a stripper car these days, it seems like you have to order one built that way on a website, or get lucky and find one that way that someone else ordered.
Is the C7 Convertible heavier than the coupe at all? I've not done much looking at the C7 Verts specs.
Last edited by MavsAK; 08-19-2014 at 05:38 PM.
08-19-2014, 06:38 PM
#219
Le Mans Master
Member Since: Dec 2005
Location: Port Arthur, Texas 77642
Posts: 8,475
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Article in link below about E85 tuned Grand Sport with Edelbrock E-Force supercharger.
http://jerryscorvettes.com/the-world...port-corvette/
Article in link below descibes general characteristics of running E85.
http://www.whiteracing.com/e85.html
08-19-2014, 06:41 PM
#220
Burning Brakes
lol @ the silly 1/ft metric.
i am qualified to call out abuse of math and physics.
foremost, you're fitting shotgun blasts, and most of the R^2 is driven by the ACR and two corvette data points remove those and your R^2 goes to something much less than 0.1 for either metric with the weight/torque (lol) metric having an R^2 of an impressive 0.02 (hp has an impressive 0.05). who knows how else the data is doctored. track conditions, driver, tires, mag suspension vs not, humidity, aerodynamics, flying start or not...
there's a ton more to the time than power/weight or the silly torque/weight metric, as evidenced by the pathetic R^2s.
below is something that is not a misapplication and one deterministic step removed from first principles.
T = 1/2 * m*v^2 the (newtonian) defn of kinetic energy.
d(Energy)/dt is the defn of power.
allow me to whip out some super simple freshman level calculus:
power = dT/dt = 1/2*m*2*v*dv/dt = m * v * dv/dt = m * v * a where a = acceleration.
then a deft application of middle school algebra:
power/(m*v) = a.
or acceleration at a given speed is a function of power unless your mass isn't constant. torque is nowhere to be found in the above with good reason. this is why people call your metric silly.
if peak torque is what matters, i can put down about 250 ft*lb of torque at the crank of my bicycle, and the entire bike + me system weight maybe 230 lbs, making for a most excellent 1/ft ratio!
the reason peak torque may fit better than peak power is peak torque is often a useful indicator of area under the power curve in the RPM range used in racing. but DCTs and a fast track will will do away with this in short order. your reasoning is faulty, and your correlations are weak.
i am qualified to call out abuse of math and physics.
foremost, you're fitting shotgun blasts, and most of the R^2 is driven by the ACR and two corvette data points remove those and your R^2 goes to something much less than 0.1 for either metric with the weight/torque (lol) metric having an R^2 of an impressive 0.02 (hp has an impressive 0.05). who knows how else the data is doctored. track conditions, driver, tires, mag suspension vs not, humidity, aerodynamics, flying start or not...
there's a ton more to the time than power/weight or the silly torque/weight metric, as evidenced by the pathetic R^2s.
below is something that is not a misapplication and one deterministic step removed from first principles.
T = 1/2 * m*v^2 the (newtonian) defn of kinetic energy.
d(Energy)/dt is the defn of power.
allow me to whip out some super simple freshman level calculus:
power = dT/dt = 1/2*m*2*v*dv/dt = m * v * dv/dt = m * v * a where a = acceleration.
then a deft application of middle school algebra:
power/(m*v) = a.
or acceleration at a given speed is a function of power unless your mass isn't constant. torque is nowhere to be found in the above with good reason. this is why people call your metric silly.
if peak torque is what matters, i can put down about 250 ft*lb of torque at the crank of my bicycle, and the entire bike + me system weight maybe 230 lbs, making for a most excellent 1/ft ratio!
the reason peak torque may fit better than peak power is peak torque is often a useful indicator of area under the power curve in the RPM range used in racing. but DCTs and a fast track will will do away with this in short order. your reasoning is faulty, and your correlations are weak.
I've been trying to say that you guys are thinking emotionally...you cannot dispute math. Below you'll find a Pearson coefficient correlation test which scientifically proves, without doubt, that torque-weight correlates 49% better than horsepower-weight in setting Nurburgring lap times. Other metrics don't even compare. Please do not dispute cold, hard facts.
Let me state again: the weight to torque ratio is, by a large margin, the single most relevant performance metric because it's the one that correlates closest to real lap times. When it comes purely to racing one car against another around a track to set the best time, objectively & removing all human emotion out of the argument, torque versus weight matters most. Above all else...no other metric even comes close.
But then, car enthusiasts generally don't run mathematical correlation & regression analysis to prove their point so I can understand how all this forum banter can lead you to believe the wrong thing.
Correlation Summary
Weight to torque = 0.55 (55% moderately high correlation)
Weight to horsepower = 0.37 (37% weak correlation)
Weight = 0.19 (very weak correlation on weight alone)
Horsepower alone = -0.33 (high HP alone lowers ring time)
Torque alone = -0.59 (high torque alone lowers ring time)
PART I - Baseline measurements
Tested vehicle (Ring time in seconds, LB/HP, LB/Torque)
2012 Corvette ZR1 (439/5.22/5.52)
2009 Viper ACR (442/5.59/5.99)
2012 Z06 (443/6.29/6.76)
2011 Aventador (445/5.49/7.49)
2008 GTR (446/ 7.86/ 8.79)
2009 458 Italia (448/5.83/8.23)
2010 MP4-12C (448/5.33/7.12)
2012 Ferrari F12 (453/4.54/6.61)
2009 911 Carrera S (454/9.12/11.32)
2013 Camaro Z28 (457/7.72/8.21)
2009 911 Turbo (457/ 7.10/ 7.19)
2009 Gallardo LP 560-4 (458/5.88/8.31)
20109 Audi R8 V10 (459/6.55/8.80)
PART II - Weight to torque correlation = 0.55
X Values
∑ = 5849
Mean = 449.923
∑(X - Mx)2 = SSx = 550.923
Y Values
∑ = 100.34
Mean = 7.718
∑(Y - My)2 = SSy = 26.8
X and Y Combined
N = 13
∑(X - Mx)(Y - My) = 67.038
R Calculation
r = ∑((X - My)(Y - Mx)) / √((SSx)(SSy))
r = 67.038 / √((550.923)(26.8)) = 0.5517
PART III - Weight to horsepower correlation = 0.37
X Values
∑ = 5849
Mean = 449.923
∑(X - Mx)2 = SSx = 550.923
Y Values
∑ = 82.52
Mean = 6.348
∑(Y - My)2 = SSy = 19.838
X and Y Combined
N = 13
∑(X - Mx)(Y - My) = 38.798
R Calculation
r = ∑((X - My)(Y - Mx)) / √((SSx)(SSy))
r = 38.798 / √((550.923)(19.838)) = 0.3711
PART IV - Weight-torque versus weight-HP
Comparing the difference in variance,
(0.55 - 0.37)/0.37 = 49%
Let me state again: the weight to torque ratio is, by a large margin, the single most relevant performance metric because it's the one that correlates closest to real lap times. When it comes purely to racing one car against another around a track to set the best time, objectively & removing all human emotion out of the argument, torque versus weight matters most. Above all else...no other metric even comes close.
But then, car enthusiasts generally don't run mathematical correlation & regression analysis to prove their point so I can understand how all this forum banter can lead you to believe the wrong thing.
Correlation Summary
Weight to torque = 0.55 (55% moderately high correlation)
Weight to horsepower = 0.37 (37% weak correlation)
Weight = 0.19 (very weak correlation on weight alone)
Horsepower alone = -0.33 (high HP alone lowers ring time)
Torque alone = -0.59 (high torque alone lowers ring time)
PART I - Baseline measurements
Tested vehicle (Ring time in seconds, LB/HP, LB/Torque)
2012 Corvette ZR1 (439/5.22/5.52)
2009 Viper ACR (442/5.59/5.99)
2012 Z06 (443/6.29/6.76)
2011 Aventador (445/5.49/7.49)
2008 GTR (446/ 7.86/ 8.79)
2009 458 Italia (448/5.83/8.23)
2010 MP4-12C (448/5.33/7.12)
2012 Ferrari F12 (453/4.54/6.61)
2009 911 Carrera S (454/9.12/11.32)
2013 Camaro Z28 (457/7.72/8.21)
2009 911 Turbo (457/ 7.10/ 7.19)
2009 Gallardo LP 560-4 (458/5.88/8.31)
20109 Audi R8 V10 (459/6.55/8.80)
PART II - Weight to torque correlation = 0.55
X Values
∑ = 5849
Mean = 449.923
∑(X - Mx)2 = SSx = 550.923
Y Values
∑ = 100.34
Mean = 7.718
∑(Y - My)2 = SSy = 26.8
X and Y Combined
N = 13
∑(X - Mx)(Y - My) = 67.038
R Calculation
r = ∑((X - My)(Y - Mx)) / √((SSx)(SSy))
r = 67.038 / √((550.923)(26.8)) = 0.5517
PART III - Weight to horsepower correlation = 0.37
X Values
∑ = 5849
Mean = 449.923
∑(X - Mx)2 = SSx = 550.923
Y Values
∑ = 82.52
Mean = 6.348
∑(Y - My)2 = SSy = 19.838
X and Y Combined
N = 13
∑(X - Mx)(Y - My) = 38.798
R Calculation
r = ∑((X - My)(Y - Mx)) / √((SSx)(SSy))
r = 38.798 / √((550.923)(19.838)) = 0.3711
PART IV - Weight-torque versus weight-HP
Comparing the difference in variance,
(0.55 - 0.37)/0.37 = 49%