C8 Dyno test results

[Extender32]

Looks like Chevy may have underrated the C8 numbers by almost 160 HP!

 

https://www.motortrend.com/news/2020-chevrolet-corvette-c8-power-dyno/

[JohnU]

Interesting how the difference the SAE technique makes!   Quarter mile time rules.

[theChad]

Sounds like there's a lot of shenanigans being called with those results. 

[joe@cpr.com]

Bs. 121 trap speed does not equal that number 

[Desertdawg]

Motor Trend dyno’d a pre-production 2020 Chevrolet Corvette Z51 at 558 horsepower and 515 pound-feet of torque on the wheels. This, the magazine estimated, translates to 656 hp and 606 lb-ft of torque at the crankshaft, well over the number Chevrolet gave of, a SAE-certified, 495 hp and 470 lb-ft of torque.

The problem with the Dyno numbers are #1 the test car performed exactly as the math said it would with 495hp, and #2 the LT2 would have to be the most efficient naturally aspirated motor of all times.

The C8’s 0-60 performance is spectacular, as it’s nearly a second quicker than the old Stingray, which had a similar power-to-weight ratio to the new C8. The new car’s additional thrust comes from two things: gearing and grip. Second gear on the 2020 Corvette’s new eight-speed dual-clutch automatic is only a hair longer than first was on the old seven-speed manual, and the extra mass over the rear wheels gives the C8 the ability to more easily put its extra grunt to the ground. If it truly had 200 more HP than the C7, you would see much better performance numbers.

As for efficiency, this can be measured using something called Brake Mean Effective Pressure (BMEP). This is a measure of torque per unit displacement; also referred as horsepower per liter. BMEP doesn’t change dramatically from one engine to another, at least where computer-optimized modern engines are concerned. The LT2, at 475 lf-ft, produces 13.0 bar (i.e. a Toyota Corolla 12.0 bar, Ferrari 812 Superfast 13.9 bar), but if it were to produce 606 lb-ft, it would need to have a BMEP of 17.7 bar!

As you can see, the C8’s peak BMEP is right in the middle of a small window that ranges between 12.0 for the base Toyota Corolla and 13.9 for the most powerful naturally aspirated engine in the history of the automobile., 

From Corvette Mike, Thundering Thursday email. 
 

 

[joe@cpr.com]

BBBBBBBBBBBBBBBSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS a car weighing that trapping 121 doesn't make anywhere near that. it's still just an lt1 w/ a different intake manifold and exhaust manifolds. guarantee it makes 420-430 rwhp on my dynojet.