Sailfun

http://www.fark.com/vidplayer/8068187

JoesC5

I believe a 505 HP C6 Z06 has a top speed of 198 MPH and I believe a 638 HP C6 ZR1 has a top speed of 205 MPH. Not impressed with 700 HP and only 200.6 MPH.

Blackdevil77

I feel like the car would of passed 200 mph if they kept in it. As soon as it hit 200, they stopped. And the C6 Z06 is just…. special lol. What that car does with 505 horsepower, it takes all other cars at least an additional 100 horsepower.

senah

this guy agrees with you. i don't like most of what he posts, but on this subject, i think there is some truth. in my opinion, the rear spoiler is not very aerodynamic.

http://corvettec7fiasco.blogspot.com...d-is-only.html

post date was feb 5


Corvette C7 Stingray top speed is only 185 MPH!!!

No wonder +Tadge Juechter refuses to disclose it, it is 5 mph lower than LS3 base C6 Corvette and only 3mph faster than the previous generation Grand Sport. Oh and so much for competing with C6 Z06 and its 197 mph top speed.

185 mph top speed makes a lot of sense actually, considering Hennessey needed another 250 hp to cross the 200 mph mark. The inferior aerodynamics, larger frontal area and not enough power are responsible for this humiliation.

Considering the estimated 625 hp rating on the upcoming Z06, it should match the previous Z06 top speed but it will never come close to the last ZR1. Overall, this is pretty embarrassing situation for +General Motors. Oh and yeah Tadge, hush hush, let us not spread the bad news around....

JoesC5

Consider that the C6 Z06 has a Cd of .34 and the C6 ZR1 has a Cd of .35. Compare that to the C7's Cd of .29 and it makes 200 MPH look really weak.

The C6 LS2(400 HP) with a Cd of .287 had a top speed of 186 and the C6 LS3(436 HP) also had a Cd of .287 and had a top speed of 190 MPH.

He had a l-o-n-g run to get up to speed and he came over a rise and was going downhill when he recorded his 200.6 top speed. He was in 5th gear and if he had run it to the 6600 rev limiter setting he would have hit 216 MPH.

he didn't run out of room(he was on a open highway, not a airfield runway) so why would he cut it off before hitting a higher speed? Doesn't 205 or 210 or 215 MPH have more bragging rights than 200.6 MPH if you're trying to get advertising for your company?

Blackdevil77

So basically, the C7 has the best CD out of all of them, yet the slowest top speed? Why would that be? It has more power than a LS3?

Did you see the video of Hennessey's stock standing mile run? The car falls on it's face in the top end.

JoesC5

I believe that is what people are asking. Why? You would think two cars with the same Cd, that the one with the most horsepower(LT1@ 460) would have the higher top speed. But it doesn't appear to be so with the C7.

Reminds me of the C7's announcement last year when Tadge was telling us about all the items on the C7 that weighed less than the same items on the C6. BUT, he wouldn't tell us what the final weight of the car was.

Turns out the C7 actually weighed 90 pounds more than the outgoing C6, after he got through telling us about all the lightweight components. Maybe we aren't hearing all about the C7. Only the points they want us to hear.

Big Dan 427

Senah the new Z may not match the old Z top speed, it will all be based on how aggressive the aero package is. The ACR Viper as a for instance would only run around 180mph but beats everything at the Ring, the GTS would run 200 all day long but was much slower at the ring. Part of the reason the ZR1 was slower at the ring is it didn't have the aero even though its top speed was 25mph greater.

Motohead279

I'm selling my car if it will only do 185!

I'd rather trade a few mph top speed that I will never use for killer looks.

truth.b

My guess is that C7 top speed is lower because the LT1 has a different cam profile probably due to the DOD add-one and the Z51 generates more down-force which inherently takes more HP to overcome at higher speeds.

And I wouldn't say the car falls on its face on the top end; it is just the last decade we've all become spoiled with cars crossing 165+ like its a walk in the park when in reality getting cars to sustain those kinds of velocities is pretty impressive.

robertf97

I think there could be external factors involved like wind, temperature, tire pressure, fuel type, etc. I would tend to believe all other things being equal, the car with the highest power and lowest coefficient of drag should have the higher top speed. Or it could just not be geared optimally for top speed.

I only ever went 140 in my C6 so doesn't really bother me either way.

Blackdevil77

I would like to see Motor Trend or Car and Driver test this like they do with other cars, like the 2013 GT500 and C6 Z06. I know many of you are gonna wanna crucify me for this, but I really think the LT1 should of had a bit more power than it does. Not that I'm not impressed, the engines torque is extremely impressive and it's efficiency is absolutely astonishing. I just wish it had that little extra oomph to make a more substantial difference from the LS3. Still plan on getting a 2016 model with hopes that a power bump is in the works.

Groovepusher Sly

Looks like the goal was 200 mph, and they accomplished that. Maybe next time they'll try for more.

Sly

Steve Snake Driver

Specious argument. The C6Z couldn't do 200 mph...so it was an underpowered dump truck?

The double ton is only useful for bragging at cars and coffee meets and the occasional 1/2 mile or Texas Mile style events. Not like you can find one every weekend. And if it is that important, a few more grand will get you supercharged or heads and cam.

As for weight, thank CAFE. The variable cam timing and cylinder deactivation all play a part in increasing the weight as do increasing safety regulations. A straight up V8 would eliminate a lot of weight as would reducing airbag counts. And of course, cars weighed less when there was only one speaker in the dash instead of 10 speakers and amps.

I'll stop with this. I don't doubt that there is some overhead in LT1 future outputs. The package we have was deemed reliable for 5 yrs and 100,000 miles with the development they were able to complete before production lockdowns. I would bet your money that there are LT1's now making more horsepower/torque in GM labratories and two years from now some making even more power/torque. If you care to wait until they do give you 200mph power that's a personal choice. Oh (I lied about stopping) since most dyno numbers are showing ~410 rwp, that equates to roughly 480 hp at the crank with a 15% loss.

JoesC5

410 and 15% are meaningless numbers. GM has had the LT1 certified and it has 455/460 horsepower at the crank. Your 15% driveline loss is an estimate, and there are no rules specifying how horsepower is measured on a chassis dyno like there is with the SAE certification using an engine dyno. How about 5% or 10% or 20%? Why did you chose 15% and not some other percentage, like 10.86956%?

After all, 10.86956% of 460 horsepower is 50 horsepower and 50 horsepower subtracted from 460bhp = 410 whp.

Steve Snake Driver

Actually, I think that SAE rating is for the MINIMUM power rating obtained through testing X number of production engines. If GM got a few more hp after they got that rating and all the advertising material was printed/distributed, I'm not complaining.

Lets see, 505 horse power Z06, -15% = 430. My Z06 dyno'd at 431 SAE RWHP. 15% has been a widely used yardstick estimate for a number of years. Some people insist that its more like 18% but that seems high.

Blackdevil77

The LT1 dyno-ed using SAE numbers dyno's around ~390 rwhp, not 410 rwhp. Most dyno's use STD numbers.

JoesC5

And my Z06 dyno'd higher than your 430whp. Why? How about chassis dyn's not being certified. Different dyno's, different operators, etc. The SAE certification is to eliminate those variables so all the car manufacturers are reporting horsepower using the same standard. The SAE certification is not a MINIMUM horsepower based on the averages of a bunch of engines tested. The standard spells out the qualifications for the witness and requires the manufacturer to test a production or production-intent prototype engine, documenting all input variables and output statistics, and filing the information with the SAE. The certified output must be within one percent of the dynamometer output. Of course, ringer engines could easily be slipped through this process, but by certifying an engine the manufacturer guarantees all production engines will produce within two percent of the rated output

Read more: http://www.motortrend.com/features/e...#ixzz2uMwMkRRk

http://www.teamzr1.com/ubbthreads/ub...at&Number=2481

thespymaster

Call me special, and I might be wrong on my .02 cents, but the Hennessey C7 is not RWHP of 700 HP but rather to the crank?

JoesC5

the 505 HP Z06 and the 638 HP ZR1 are also at the crank. Odd that 195 horsepower at the crank(over the Z06) can only achieve 2 MPH higher top speed(over the Z06).

That's 62 horses at the crank above the ZR1 but 5 MPH under the ZR1's top speed.

And the reported .29 Cd of the C7 is lower than the .34 Cd(Z06) and .35 Cd(ZR1).

Not actually bragging numbers to be proud of.