I've always enjoyed driving sports cars, but my knowledge of what makes them go is lacking. For the C8 to shave almost a full second off the 0-60 time of it's predecessor is an amazing feat, considering the engine is very similar, it gains a measly 35 HP, and gets heavier in the process. Is the secret in better gearing, better tires, the location of the engine providing better traction, small gains in efficiency in various places, or a combination of these things and other improvements I haven't mentioned?
Can someone explain in simple terms how this exceptional gain in speed is achieved?

 

Mid engine

 

Three things:

1) Horsepower

2) Gearing

3) Traction

All far different from the C7...

 

If I had to rank them, the C7 is the most traction limited car I have owned, off the line. So traction, number one, going to a 40/60 from a 49/51 weight distribution. Second would be the gearing and DCT shifting. The horsepower/torque is likely a push given the weight increase.

 

Yep... and traction is many factors including weight distribution under acceleration, the coefficient of friction and surface area of the tires, and electronics in engine management and with the edff.

I would also include increased torque with increased HP.

 

All of the above and you are getting a slight bit more horsepower per pound with the C8,
1 hp to 7.28 pounds on the C7 and 1 hp to 7.18 pounds on the C8, will vary slight as to the amount of extras you add to the car.
Z51 with front lift and 3lt package, ground effects will not be near that , in fact probably worse hp to pounds than the C7. But as the car accelerates the weight become more rear weight biased,
Thus adding to the better traction.I can smoke the tires in my base C7 M7 with ease, requires some skill to launch. The DCT and electronics with the 40/60 weight will make the C8 launch far better than the C7

 

 

College

 

IMHO - The extra HP the C-8 makes is essentially a non-issue. The Issue is Traction !!!! I believe that the C8 designers did their homework, and designed the rear suspension geometry to use the weight transfer generated by acceleration to improve rear grip.

 

Watch the video. The correct answer is physics... nothing to do the geometry. Other than moving the CG back to increase the normal force. Yeah, I’m an engineer. Lol

 

Three things:

1) Horsepower--up by a smidgeon.

2) Gearing--up by quite a bit.

3) Traction--up by quite a bit

With 40%/60% weight distribution a C8 has 1050 pounds on each rear wheel
With 50%/50% weight distribution a C7 has 850 pounds on each rear wheel

The thrust a tire can generate is <roughly> the coefficient of traction of the tire and the weight it holds
Since the tires can be the same kind/brand/size C7/C8 the traction per unit weight is irrelevant.

Thus, the C8 can produce more forward thrust at the contact patch SIMPLY because 10% of the cars weight moved off the front tires onto the rear tires.

It is the weight distribution which enables the fast 0-60 times
Then it is the gearing which puts the motor in the RPM band to deliver.

 

a couple more factors

the new engine has nice bump in torq curve (*with very agreessive gearing to get with the program!)
without the drive shaft and torq tube there is a bit less parasitic drag and more of the HP makes it to the ground

the car has to flat out hook and book to get to 60 under 3

I'm still very impressed with that out of 495 hp so I'll say the low end torq is quite good

 

Impressive to me, is the 0-60, and the leaked 1/4 mile of 11.3. The 11.3 is 7/10ths of a second faster. Thats much more likely to be gearing, and power delivery, than traction.

 

Will this translate into the time they claim at a random stoplight on highway XX any town usa? Probably not.. will it pull low 3 seconds? Most likely.

They claim many things.. have done so forever. Hasn't always worked that way.

When the youtubers start posting up the videos of sub 3 second to 60 runs? I'll believe it. Until then i will remain skeptical that with the production tune for the engine and trans (remember the production cars will have torque management built in to keep the drivetrain together at least through the watranty period) will perform the same way and not just on a prepped surface. In this case All the physics in the world mean little except one.. traction.

My guess will be the cars base and Z51 will be identical to 60 on the street and run in 3.2-3 range unless on a real tire or the strip.

The C7 ZR1 and Z06 have more than enough pwr/wt to pull low 2 seconds to 60mph. Their advertised times on stock tires even cup 2s have never been duplicated outside of a prepped surface. Nor has any video of chevy performing that feat surfaced.. they show clips of the car on track... top speeds.. but no 0-60, 1/4mi etc. There's a reason for it. And it isn't becaise they're lazy or cheap. It's because if they showed you the car doing it, it would be a on a prepped surface and people like me would call them out on it. It's a fun gimmick to say what it "can do" but outside of being AWD, i have yet to see any hi power FE or ME do what has been claimed by the mfr on the stock tire, on the street... doesn't happen.

Been on plenty of rallys with a full gamut of performance vehicles including exotics. They just can't put it down on the stock tire with stock air pressure espeically without warming up the tires and Still not..

So OP. When you take delivery of your C8.. just remember while you're giving yourself fits when it doesn't come close to sub 3 seconds to 60 for you, you're not alone, and you need a tire under there. No matter how good the new pilot from michelin is for the first 6mos to a year before it loses that "bite" it had when they were new and the rubber begins to harden a bit..

For the opposing view please don't post up numbers and physics and what your heard and saw on the internet. There's more than enough performance data equipment out there - v box draggy pdr for it to surface. And without the proof said vehicle is on the stock tire (as in drag times videos at least he tells you and shows you the tires modes etc great channel for accuracy btw) take it with a grain of salt when 99 do it in x.xx and 1 guy is pulling it off in way less. When something doesn't seem on the up and up, it isn't.. there's other factors at play.

Would be a great question for Jim Mero.. where on what surface and what calibration are the factory performance acceleration specs confirmed/performed.. and is it an average or how many or 1 out of 20 that they use? What temps? Altitude? Etc.

Which being NA is another reason anyone above sea level will siffer way worse than say a base 911 which is forced induction and barely effected by altitude.