Central Valley Corvettes of Fresno - July 2018

2019 CHEVROLET CORVETTE ZR1
FIRST TEST: OUT WITH A BANG!
Did Chevrolet save the best for last? Chris Walton Words, Jade Nelson MT Photo June 30, 2018
This is it. The zenith. The top dog. The 755-horsepower ne plus ultra Chevrolet Corvette C7. The
most powerful and likely the last variant of the front-engine Corvette. While waiting for the arrival of
the mid-engine C8 somewhere in the not-distant future, 2019 model year, there are now 28 iterations
of the seventh-generation Corvette (C7), including coupe/convertible versions of Stingray, Grand
Sport, Z06, and now the ZR1. Is this as good as it gets? Is the ZR1 the greatest Corvette ever?
LT5 VS LT4
Let’s start with what makes the ZR1 the ZR1, namely its mighty LT5 motor. If you like comparisons,
this C7 ZR1’s supercharged V-8 makes more than double the horsepower of the V-8 in the 1990 C4
ZR1 and 117 more horsepower than the C6 ZR1. Based on the venerable LT4 found in the Corvette
Z06, Camaro ZL1, and Cadillac CTS-V, the 6.2-liter LT5 features a new 95mm throttle body, both
port- and direct-injection fuel delivery, an upgraded crankshaft, a new oiling system, and a new Eaton
supercharger. At 2.6 liters, the supercharger is 52 percent larger than the LT4’s, yet cruising at 80
mph, it draws only 1 horsepower while providing virtually no boost. On the other hand, it needs 110
horsepower to spin its roots-type helix rotors up to 15,860 rpm to make peak boost pressure of 13.96
psi near redline. The LT5’s intercooler has roughly double the heat exchange capacity of the LT4’s,
and there are four new heat exchangers (13 “radiators” in total) tucked hither and thither. Combining
all of this with the new “halo” hood, the ZR1 boasts 41 percent more air flow than the Z06, which is
notoriously prone to power-sapping engine-protection mode due to excess heat. Rest assured,
Corvette “Jake” fans, the two ZR1s we had showed no problems with heat during our instrumented
testing (eight consecutive quarter-mile passes followed by a dozen laps of our figure-eight course).
Nor did either lose power with hot laps (two sets of three each) at Willow Springs Raceway, where
we’ve previously documented issues.